Memory

views updated Jun 11 2018

MEMORY


autobiographical memory
charles p. thompson

development of
patricia j. bauer rebecca m. starr

graphics, diagrams, and videos
priti shah

implicit memory
henry l. roediger iii lisa geraci

mental models
gabriel a. radvansky
david e. copeland

metamemory
gregory schraw
john nietfeld

myths, mysteries, and realities
elizabeth j. marsh

structures and functions
peter e. morris

AUTOBIOGRAPHICAL MEMORY

In the early twenty-first century there is general agreement among memory researchers that memory consists of a number of distinctly different types of memory rather than one single memory. A brief overview of the major divisions in memory will help put autobiographical memory in context. Philosophers have long made a distinction between knowinghow (e.g., knowing how to ride a bicycle) and knowing what (e.g., knowing what a bicycle is). Modern research has verified the distinction between these two types of memory, and they are currently called procedural or implicit memory (knowing how) and declarative or explicit memory (knowing what). In 1972 Endel Tulving divided declarative memory into semantic and episodic memory. Semantic memory, because it contains general information such as facts, names, and important historical dates, could be described as a person's knowledge of the world. Episodic memory refers to a person's memory of events.

Autobiographical memory is a large and important subset of episodic memory containing those events that constitute the story of one's life. In the words of Katherine Nelson, autobiographical memory is "specific, personal, long-lasting, and (usually) of significance to the self-system. Phenomenally, it forms one's personal life history" (p. 8). If the first meeting with a loved one involves going to a movie, that event stands a good chance of becoming part of autobiographical memory. Other occasions on which movies are attended, however, will be remembered for a short time but probably will not become part of autobiographical memory. Instead, those events will contribute to generic memory. Generic memory contains memory for frequently occurring events such as brushing teeth or going to a movie. When asked about such events, it is unlikely that a specific instance of toothbrushing or going to a movie will be remembered.

The Organization of Autobiographical Memory

Autobiographical memory is organized as nested clusters of events that are all highly interconnected. Take the memory of a lawyer as a hypothetical example. Under the topic of school, that person would find events for elementary school, secondary school, college, and law school. Nested under each of those categories would be the events for each year (e.g., sophomore in college). Under the category of sophomore in college would be the events for each semester, which, in turn, would be grouped in categories such as academic events (e.g., classes), jobs, and friends. All these autobiographical events would be accessible in a number of ways. A particular event might involve a certain year in college, a particular job, and certain friends. That event could be accessed when thinking about school, friends, or jobs.

The topic of school is just one example of the many topics that have many subcategories. Other such topics include marriage, jobs, and military service. Just like the clusters of events nested under topics, the topics also are highly interconnected. The end result is a memory system that has the ability to retrieve the memory of a particular event from a large number of starting points. The most obvious example of the power of autobiographical memory to retrieve events is involuntary memorymemories that just pop into mind. In a 1998 article Dorthe Berntsen described her studies of involuntary memories, which showed that people average six to eight such memories every day.

Memory for Autobiographical Events

Remembering an autobiographical event usually involves both retrieving the content of the event (remembering what) and placing it in time (remembering when). Of course, memory for both fades over time. Autobiographical memory can be either reproductive or reconstructive. When it is reproductive, virtually all the details are retrieved from memory. When it is reconstructive, a few major points are retrieved from memory and the rest is constructed from generic memory. People are very good at reconstructing memory from generic events, and they are usually not aware that they are doing so. One of the consequences is that memory for old events is often wrong. Sometimes the error is minor and sometimes it is not.

Memory researchers have shown that memory for the content of the event gradually changes from being almost entirely reproductive to being, after about a year, almost entirely reconstructive. By contrast, memory for when an event occurred is almost always entirely reconstructive.

There are three additional distinctive characteristics of memory for autobiographical events. First, as time passes, the number of events that can be recalled drops off rapidly at first and then more slowlya negatively decelerating curve. Second, older people show what David C. Rubin and his colleagues called a "reminiscence bump." Older people recall more events for the period when they were in their twenties than predicted by the negatively decelerating memory curve. Typically, many important life events (such as college graduation, marriage, and children) occur when people are in their twenties. Research has shown that the reminiscence bump can be attributed to these important life events. Third, almost all people show infantile amnesia. When people are asked to recall events from their childhood, they usually cannot recall events prior to age three. Not only are they unable to recall memories before age three, but the number of memories retrieved between ages three and six is also markedly below the number available after that period. Infantile amnesia is an intriguing puzzle because researchers have shown that children under age three can report details of isolated specific events and, most important, can remember them for up to two years. There is a growing consensus that the answer to the puzzle may lie in the development of autobiographical memory.

The Development of Autobiographical Memory

By the early twenty-first century there was considerable evidence that children learn how to talk about memories with others. They learn how to tell their life stories as a narrative. This is the social interaction view of autobiographical memory. This view proposes that infantile amnesia is overcome when children learn how to retain their memories in a recoverable form by turning them into narratives.

One strong source of support for the social interaction view has been the investigation of mother-child discussions of past events. These discussions can be classified as narrative or pragmatic. The narrative conversations focused on what happened when, where, and with whom. The pragmatic conversations used memory to retrieve specific information such as "Where did you put your book?" Children of mothers who used the narrative type of discussion remember more about the events than children of mothers who used the pragmatic type of discussion.

Autobiographical Memory as an Expert System: Implications for Learning

Experts learn new material in their field much faster than novices, and they retain that material much better as well. The reason for their outstanding performance in learning and memory is that they have a highly organized and detailed memory for their area of expertise. This allows them to relate new material to one or more pieces of information that they already know. Metaphorically speaking, they have many potential pegs on which they can hang new information. When they have to retrieve the new information, they can follow a well-beaten path to that information.

Autobiographical memory is also a highly organized and detailed memory. When it is possible to relate new information to life events, autobiographical memory functions in the same way as an expert system. The new information will be learned faster and remembered better than information that cannot be related to life events (or to another expert system).

Life Is Pleasantand Autobiographical Memory Makes It Better

In studies of subjective well-being conducted around the world, people generally report that they are happy with their life. In the United States, this positive feeling is found in people with physical disabilities, people with mental illness, low-income people, minoritiesin short, it is found for virtually all categories. Research on autobiographical memory shows two sources for this positive feeling of well-being. First, life events are generally pleasant with positive events occurring roughly twice as often as negative events. This is true for childhood memories, involuntary memories, and adult memories.

Second, the general level of pleasantness typically is enhanced when remembering life events. That occurs because the emotion attached to the events fades over time but the emotion for unpleasant events fades much faster than the emotion for pleasant events. Thus, the overall emotional tone becomes more pleasant for autobiographical memory. The mechanism responsible for this change appears to be the rehearsal (thinking about or talking about) of pleasant events.

For most people, autobiographical memory is a very positive and useful part of memory. It is equivalent to an expert system and therefore can be very helpful in learning new material. Most important, it holds the story of one's life. That story is typically very pleasant and, because negative emotions fade rapidly, becomes more pleasant as time passes. People's lives would be much reduced without their access to autobiographical memory.

See also: Memory, subentries on Development of, Myths, Mysteries, and Realities.

bibliography

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Thompson, Charles P.; Skowronski, John J.; Larsen, Steen; and Betz, Andrew. 1996. Autobiographical Memory: Remembering What and Remembering When. New York: Erlbaum.

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Walker, W. Richard; Vogl, Rodney J.; and Thompson, Charles P. 1997. "Autobiographical Memory: Unpleasantness Fades Faster than Pleasantness over Time." Applied CognitivePsychology 11:399413.

Charles P. Thompson

DEVELOPMENT OF

Traditionally, the construct of memory has been divided into a number of different types, defined largely in terms of the length of time over which information is retained or stored. For example, memory is divided into a very brief (on the order of milliseconds) sensory store for visual or acoustic properties of a stimulus; short-term or working memory, in which information can be stored and manipulated for about twenty seconds; and long-term memory, in which information can be stored virtually permanently. Long-term memory can be further divided into storage of procedures or skills, such as how to tie a shoe, and storage of explicit or declarative memories, such as memories of personal events or of general knowledge about the world. The study of the development of each of these systems can aid in understanding the cognitive abilities of both children and adults. Because working memory has important implications for learning and education, it is the focus of this entry.

Defining and Measuring Working Memory

Whereas short-term memory refers to the storage of information over brief delays, working memory refers to the capacity to store information for brief periods and to manipulate it during storage. A prominent model of working memory suggests that it is a multicomponent resource consisting of a limited-capacity central executive or "work space," where processing takes place, and two storage components, one for verbal information and one for spatial information. Working memory underlies a variety of complex cognitive tasks, including reading comprehension and mental arithmetic. For example, mentally adding the numbers 12 and 49 requires that both numbers be held in mind as the operation of addition is performed. Because conscious manipulation of information depends on working memory, one must examine its development in order to understand the abilities of different aged children to comprehend, learn, and remember the information taught to them.

Unlike the capacity for long-term memory, which is considered to be virtually unlimited, the capacity for working memory is limited to a few items. Indeed, the increase in the number of items that can be stored and manipulated at a time (referred to as the working memory "span") is a major source of age-related change in working memory. Moreover, at any given age, there are differences among individuals in their working memory spans. Measures of working memory span thus are integral to the study of working memory. Methods of assessing working memory include the reading span task, the A-not-B task, and the imitation task.

The reading span task. A classic measure of working memory in adults is the reading span task. Reading span is assessed by having adults read a series of sentences and then recall the final word of each of the sentences in the order that they read them. The reading span task requires both the storage and manipulation of information: The reader must store the last word of each sentence while reading subsequent words and sentences. Measures have also been developed to assess working memory throughout childhood, and these measures reveal systematic increases in working memory capacity across age.

The A-not-B task. In the second half of the first year of life, working memory most frequently is assessed by the A-not-B task. In the A-not-B task, a small toy is hidden in one of two identical wells (Well A) in full view of the infant. After a brief delay, the infant is allowed to reach into Well A to find the toy. Following several "A" trials, the toy is hidden in the second well (Well B). Even though the infants watch as the toy is hidden in Well B, they often reach to Well A again, making the "A-not-B error." Overcoming the A-not-B error, and thus, successfully searching in Well B, requires that infants (1) remember where they saw the toy hidden (requiring storage of information) and (2) inhibit the learned tendency to reach to Well A (requiring processing of information). As working memory ability increases, infants are able to withstand longer delays without making the A-not-B error. The delay that infants are able to tolerate without making the error increases about two seconds per month between the ages of seven to twelve months.

The imitation task. In the second year of life, working memory can be assessed using imitation. In a standard imitation task designed to assess short-term or long-term memory, props are used to produce a sequence of actions (e.g., making a rattle by putting a ball into a nesting cup [step 1], covering it with another cup [step 2], and shaking the cups to make a rattle [step 3]). The child then is allowed to imitate the sequence either immediately (as a measure of short-term memory) or after a delay (as a measure of long-term memory). To assess working memory, the steps of several sequences are presented in interleaved order. That is, rather than the steps of a single event in sequence (A-1, A-2, A-3, with the alphabetic character referring to the sequence and the number referring to a step in the sequence), the child sees, for example, A-1, B-1, C-1, A-2, B-2, C-2, A-3, B-3, C-3. The child is then provided with the materials for each of the sequences in turn (e.g., all of the materials for sequence A) and is encouraged to produce the sequences. The interleaving of the sequences during presentation requires that the child not only store the information for each individual step but also attend to subsequent steps and integrate the steps into their respective sequences. Researchers have used the imitation task with seventeen- and twenty-month-old children, finding increases in performance, and therefore in working memory, with age.

Tasks for assessing older children. Working memory may be assessed in older children with an adaptation of the reading span task and with a similar task using numbers. Both tasks indicate increases in working memory across the age range of seven to thirteen years. In addition, children with reading disabilities perform at lower levels on both tasks than do their normal age-mates, and children with arithmetic disabilities have trouble with the number task. Thus, working memory plays an important role in the development of reading and number skills during middle childhood. Adult levels of performance on working memory tasks are reached by the high school years.

Factors Affecting Developmental Changes in Working Memory

Developmental changes in working memory may be due to several factors, including brain maturation, increases in the speed of information processing, increases in knowledge, better use of strategies, and more effective management of attention. For example, the processes involved in working memory are largely dependent on the prefrontal cortex of the brain. The prefrontal cortex matures late relative to other brain regions, such as those involved in sensory and motor processes, and does not reach full maturity until adolescence or even early adulthood. Thus, the time courses of development of the functions of working memory and of the brain regions thought to support them are closely linked. Brain maturation also involves a process called myelination, in which a fatty substance surrounds the nerve cells and aids in the conduction of brain impulses. Myelination may increase the speed of processing, thereby increasing working memory abilities as children mature: Faster processing allows for the storage of more information before it decays from working memory.

Other factors that may affect the development of working memory include increased knowledge, strategy use, and management of the focus of attention. Breadth of knowledge affects working memory to the extent that new information can be linked to existing knowledge. For example, it is easier to store nine letters that form three words that are already stored in long-term memory (e.g., p-e-n, d-o-g, ha-t) than to store a list of nine random letters in working memory (e.g., p-o-h-e-d-t-n-g-a). The learning of and increased efficiency in the use of strategies also aids working memory. For example, as children reach the late grade-school years, they begin to spontaneously use rehearsal (the strategy of repeating the information mentally) when they attempt to remember something new. Working memory also develops with age as children gain increasing control over the focus of their attention. This permits them to attend to more information, switch the focus of attention as needed, and inhibit attention to irrelevant information. All three of these factorsincreased knowledge, strategy use, and management of attentionlikely play a role in the development of working memory throughout childhood.

Summary

Working memory involves the conscious storage and manipulation of information that is integral to the performance of complex cognitive tasks. It is clear that working memory develops throughout childhood, as children are able to hold increasingly more information "online" even as they perform a greater number of mental manipulations on the information. Because working memory underlies so much of mental functioning, it is important to understand its development, as well as the sources and implications of individual differences in it.

See also: Memory, subentry on Myths, Mysteries, and Realities.

bibliography

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Patricia J. Bauer

Rebecca M. Starr

GRAPHICS, DIAGRAMS, AND VIDEOS

Graphics, diagrams, and videos are frequently used to enhance learning of verbal material. Indeed, as much as half of the space in K12 textbooks is devoted to graphics and diagrams, and videos are frequently presented in classrooms. Furthermore, recent technological advances have made possible the use of additional, primarily visual, materials for instruction, such as animation and hypertext.

Presumably, graphics, diagrams, video, and other visual materials are used to make information accessible and memorable. But how might such visual materials be exploited to facilitate learning and memory? When are such displays actually beneficial for learning, and when are they simply decorative or even distracting? This brief review begins with a discussion of general research on how visual media displays aid comprehension and enhance memory for verbal material, and the circumstances in which visual materials are distracting and perhaps even reduce comprehension memory of verbal material. This discussion incorporates guidelines for the design of visual displays for effectively enhancing memory in the context of specific commonly used displays such as graphic organizers, graphs, diagrams, and videos.

Main Benefits of Graphics, Diagrams, and Videos

Visual displays and videos play a number of important roles in learning. Perhaps the most cited cognitive explanation for the benefits of presenting information both visually and verbally is Allan Paivio's dual-coding theory. In classic memory studies, Paivio and his colleagues demonstrated that people were better at remembering lists of words coded visually and verbally, rather than merely verbally. One explanation for the superiority of dualcoding is that by encoding information to be learned in two modalities rather than a single modality, people have multiple retrieval cues that help them access information, thus enhancing memory.

A second general benefit of visuospatial displays is that they are visually appealing. Viewers' attention is attracted to these displays, and viewers are more likely to study them for longer periods of time. This, in turn, can lead to enhancement of memory for information depicted in them. For example, one study of memory for materials taught in introductory psychology courses found that students recalled ideas and examples presented in videos and in-class demonstrations better than information presented in the text alone.

In addition to directly enhancing memory for information, diagrams, graphics, and videos can also make complex information easier to comprehend. Specifically, visual representation can make complex information "visually obvious" and thus require less cognitive effort to understand than text-based descriptions of the same information. Better comprehension, along with more cognitive resources that can be allocated to learning and memory, will together enhance memory for the information to be learned.

Concepts that Visual Displays Are Most Useful in Communicating

Visual displays are particularly beneficial to the comprehension of some classes of concepts that often involve specialized types of displays. First, visual displays are useful for communicating cause- and-effect information. For example, a diagram can help illustrate how turning a key can unlock a door. When such displays are designed to highlight the cause- and-effect sequence (e.g., by animating one portion at a time or by using a sequence of arrows), viewers' comprehension and memory for the cause- and-effect information is enhanced.

Second, visual displays are frequently useful for representing relationships amongst elements (e.g., a Venn diagram, a text-based graphic organizer, a scientific model). One benefit of such representations is that they can facilitate problem solving. Another benefit is that they provide concrete representation of key concepts or elements and their relationships. Graphic organizers, for example, are often used to represent relationships among the main ideas in a text. For example, information in a text can be summarized in matrix form such that similar concepts are closer together along one or more dimensions. Research has suggested that representations that group relevant concepts, such as matrices, can significantly enhance memory for text compared to representations that simply summarize materials, such as outlines. Indeed a general principle that is relevant for any diagram intended to represent relationship elements, including graphic organizers but also including graphs, flowcharts, and so on, is that information that is closely related be placed close together on a page or related visually (e.g., via Gestalt principles of grouping).

Third, visual displays are useful for communicating information that is intrinsically visuospatial. For example, visual displays of a map of a building or a drawing of how different parts of a car engine fit together communicate information that is difficult to describe verbally. Not all intrinsically visuospatial displays, however, are equally beneficial. One general guideline is to design displays that facilitate integrating relevant information (placing text and graphics together) to reduce working memory load and allow viewers to focus on learning relevant content. A 2001 book by Richard Mayer on multimedia learning includes a number of guidelines for the design of such displays.

Fourth, visual displays provide natural mappings to quantitative information (e.g., more is higher) and thus increase comprehension and memory for quantitative information. One difficulty associated with graphs is that students often make interpretation errors and therefore remember erroneous data. In a 2002 article, Priti Shah and James Hoeffner discuss a set of guidelines for teachers and other graph designers who need to depict data for students. These guidelines include making relevant trends visually salient in the graph and writing text to be compatible with information in the graph.

Additional Benefits of Visual Displays

In addition to making some concepts easier to understand, diagrams, graphics, and videos tend to focus viewers' or readers' attention and thus highlight important information. Displays or videos can guide a viewer's attention from one step to the next in a description of causal information or in instructions. For example, a sequence of arrows might highlight how a mechanical device, such as a bicycle pump or a toilet, works, or a sequence of panels might instruct someone how to bake cookies. Such displays, by highlighting information or key elements in a sequence, help students learn and remember relevant information.

In addition to the cognitive aspects of how they influence memory, visual displays and videos serve a social function beneficial to memory. In particular, visual displays and videos provide a common motivating experience for students. In "anchored instruction," students view movies with built-in problems that serve as a reference point for lessons on a wide variety of topics such as solving mathematical problems, discussing social issues, and understanding physics concepts. The common anchor may provide a social and personal context for information to be learned.

The use of graphics, diagrams, and videos includes not just presenting such visual information to students but also asking them to create them. Creating visual artifacts or inscriptions appears to be motivating to students, especially when they share their products with fellow students. Furthermore, developing them forces students to consider the important elements and relationships and also to identify what information they understand and what they do not. Thus, the creation of graphics, diagrams, and videos can be used to enhance comprehension and memory for to-be-learned information.

Drawbacks of Displays and Videos

Despite the benefits of graphics, diagrams, and videos for helping students comprehend and remember important information, there are some cases in which displays and videos can be harmful. Specifically, because graphics, diagrams, and videos attract attention, it is possible that in many cases such visual presentations serve as seductive details detracting attention from important information and thus impair rather than enhance learning. A concrete example of a display that may serve as a seductive detail is a picture, in a scientific text about how lightning is formed, of someone who was struck by lightning. Although the intention of such a picture might be to interest the students in the content of the text, research has found that, in fact, displays such as these are actually distracting and reduce the quality of readers' understanding of the scientific content of the text. Videos, also, can serve as or include seductive details detracting viewers from the main message of a particular lesson.

In summary, this general discussion of visual displays suggests that diagrams, graphics, and videos can help users comprehend relevant information and enhance memory for that information. The content and format of the information, however, should be consistent with the goals of communication. When the content is not consistent with the goals of communication, students may remember irrelevant or inaccurate information.

See also: Literacy, subentry on Learning from Multimedia Sources; Media and Learning; Reading, subentry on Content Areas.

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Priti Shah

IMPLICIT MEMORY

Implicit memory refers to the expression of past events on current behavior when people are not trying to retrieve these past events and when they are usually not even aware of the events' influence. This process is different from explicit memory, which refers to conscious attempts to retrieve memories of past events; in implicit memory tests there is no conscious effort to retrieve. The customary use of the terms memory or remembering refers to explicit, conscious recollection during which people attempt to travel back in time to mentally relive or reexperience past events. Many behaviors people perform, however, reflect past learning even when they are not consciously attempting to retrieve; therefore, these behaviors reflect the manifestation of implicit memory. Some of these behaviors involve motor skills. When people tie their shoes or ride a bicycle or walk, they need not consciously retrieve their first attempts to learn these skills. The same is true of other types of learning. It is much easier to read a passage of text that one has read before, even if not consciously trying to remember the original time the passage was read. As these examples indicate, implicit learning is sometimes referred to as occurring rather automatically or at least to having an automatic component.

As a Reflection of Conscious Learning

Implicit memory measures are sometimes said to reflect unconscious learning because densely amnesic brain-damaged patients typically show intact uses of implicit memory. The data in Figure 1 are from a 1984 experiment by Peter Graf, Larry Squire, and George Mandler. They compared brain-damaged participants who displayed serious impairments on explicit memory tests such as recall and recognition to age- and education-matched control participants. In one test condition, both groups of participants studied lists of words and attempted to recall them in any order (free recall). As can be noted on the left of the graph in Figure 1, the patients recalled the words much worse than did the controls. This pattern reflects the patients' deficit on an explicit memory test, in which they were asked to consciously retrieve past events.

In the implicit test, both groups studied the lists of words but were tested by being shown three-letter stems of words with the instruction to produce the first word that came to mind in response to each stem clue. So, if the word chair had been in the list, participants would get cha and be asked to say the first word that came to mind (chain, chapter, challenge and so oneach stem had at least ten possible

FIGURE 1

completions). If chair had not been presented in the list, people in both groups produced it about 10 percent of the time (the dashed line on the right side of Figure 1). However, if chai had been presented in the list, both patients and the control participants produced the word about 45 percent of the time. The fact that both groups completed the word so much above the base rate reflects priming, the basic measure of implicit memory tests. Priming is defined as the difference between performance on a test when the relevant information has been presented and performance when the relevant information has not been recently presented. Therefore, the amount of priming reflected in the data in Figure 1 was about 35 percent (45% in the primed condition minus the 10% base rate). Although the participants were told to produce any word that came to mind, the presentation of chair in the list primed them to produce that word rather than another on the test.

This priming effect reflects a use of memory, but not a conscious or intentional use of memory. Because the patients were densely amnesic and probably did not remember even studying the list of words, the priming may be said to be unconscious (in this sense). The amnesic patients produced just as much priming as did control participants. Because the patients had suffered brain damage that impaired their use of explicit memory processes, it appears that the brain mechanisms and processes that underlie explicit and implicit memory tests are quite different. Put another way, the results show that memory is not a unitary entity; people with certain types of brain damage can be severely impaired on one type of memory test and unaffected on other types of tests.

Implicit Memory Tests

The study of implicit memory began in psychology in the early 1980s and in the early twenty-first century there is a large amount of literature on the topic. There seem to be at least two distinct types of implicit memory tests, perceptual and conceptual.

Perceptual memory tests. Perceptual implicit memory tests challenge the perceptual system by presenting impoverished test stimuli to which participants respond. The word stem completion test already described (cha ) is one such test. Others are word identification (presenting words very briefly and having participants guess what they are), and word fragment completion (naming words from fragments such as l_p_a_t. (That fragment is hard if not recently primed [with word elephant ].) If pictures are used as study materials, then the test can involve giving fragmented forms of pictures or having them be gradually clarified through a series of successively fuller fragments until the participant can identify the picture. Again, the measure in all cases is primingas reflected by more accurate or faster completion of the target when it has been studied relative to when it has not been studied.

Factors that greatly affect priming on perceptual implicit memory tests are often quite different from those that affect performance on most explicit memory tests in both patients and in healthy control participants, indicating further that these two types of tests seem to be measuring different processes. For example, modality of presentation of words strongly affects performance on perceptual implicit tests. Visual presentation of words enhances priming on visual tests, whereas auditory presentation enhances priming on auditory implicit tests (e.g., presenting words describing noise with auditory cues for identification). Modality generally matters little in tests of explicit memory. On the other hand, factors that can have a great effect on explicit memory tests can have little or no effect on priming on implicit tests. For example, when participants read pairs of words (hot and cold ) or generate the second word from a clue such as "opposite of cold," they scored better on an explicit test of recognition for the words they generated, but exhibited more priming for the words they just read on an implicit test, in which they had to quickly identify the word. The data are shown in Figure 2.

The results described above can be explained, at a general level, by the theory of transfer appropriate processing. This principle states that performance on memory tests will be enhanced if there is a match between the conditions of study and test, which will permit the study experience to transfer better to the test. For example, if the test involves deciphering a fragmented or briefly presented word given visually (classified as a perceptual test), then performance on this test should benefit from prior visual presentation more than from a prior auditory presentation or from generating the word, as is indeed the case. Practice reading a visual word (versus hearing or generating it) transfers better to a test that also involves reading words.

Conceptually driven tests. Whereas most implicit tests depend on perceptual processing, most explicit memory tests depend heavily on the meaning of the concepts or events that are being remembered. These tests are called conceptually driven tests because, when people are trying to retrieve past events, it is the meaning of the events that is important. Generating a word involves more attention to meaning than simply reading it, and so generating produced greater explicit recognition in results shown in Figure 2. Again, this finding is in accord with the transfer appropriate processing theory. The transfer appropriate processing theory can account for a large body of findings although some problems remain.

Although explicit memory tests are usually driven by meaning or by conceptual information, there is a class of implicit memory tests that is also conceptually driven. These tests are probably the most relevant for education, but they have not yet been studied as much as perceptual implicit tests. One class of conceptual implicit memory tests that has been studied is the general knowledge test. "What animal did Hannibal use to help him cross the Alps in his attack on Rome?" and "What is the name of the ship that carried the pilgrims to America in 1620?" are examples of questions on general knowledge tests. Prior exposure to the words elephant or Mayflower before the questions are asked increases correct answers to these questions, which reflects priming of concepts. Free association tests ("say the first word that you think of to the stimulus word tusk ") and category association tests ("list as many African animals as you can in thirty seconds") are other examples of conceptually driven implicit memory tests. These priming effects again seem to be indicative of implicit retrieval because they also appear in brain-damaged patients with severe difficulties in explicit expressions of memory.

In some sense, much of education is intended to permit people the automatic, unconscious retrieval of facts, routines, and principles when they need them. Education is meant to provide learning experiences that will, at least in some cases, last a lifetime. Of course, not all facts and principles will be remembered for that long. Much information learned in the classroom will be forgotten (at least when explicit tests are given). The hope is that one's general knowledge and skills (writing, thinking logically)

FIGURE 2

will survive. There are no studies of residual, implicit retention of formal education but such studies will surely come in the future.

See also: Memory, subentries on Myths, Mysteries, and Realities, Structures and Functions.

bibliography

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Jacoby, Larry L. 1983. "Remembering the Data: Analyzing Interactive Processes in Reading." Journal of Verbal Learning and Verbal Behavior 22:485508.

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Roediger, Henry L., and McDermott, Kathleen B. 1993. "Implicit Memory in Normal Human Subjects." In Handbook of Neuropsychology, ed. François Boller and Jordan Grafman. Amsterdam: Elsevier.

Schacter, Daniel L. 1987. "Implicit Memory: History And Current Status." Journal of Experimental Psychology: Learning, Memory, and Cognition 13:501518.

Squire, Larry R. 1987. Memory and the Brain. New York: Oxford University Press.

Tulving, Endel. 1985. "How Many Memory Systems Are There?" American Psychologist 40:385398.

Vaidya, Chandan J.; Gabrieli, John D. E.; Keane, Margaret M.; and Monti, Laura A. 1995. "Perceptual and Conceptual Memory Processes in Global Amnesia." Neuropsychology 9:580591.

Henry L. Roediger III

Lisa Geraci

MENTAL MODELS

Mental models, also called situation models, are mental representations of the state of affairs in a real or possible world. They serve as mental simulations of events. For reading, a mental model represents the situation described by the text rather than the text itself. The creation of a coherent mental model is the goal of comprehension.

Mental models are complex representations that contain many different types of information. This includes a spatial-temporal framework about the spatial context in which an event occurred and the time period in which the event transpired (i.e., where and when it occurred). They also contain tokens to represent entities, such as people, animals, objects, and ideas. These tokens might have properties associated with them, such as physical characteristics, emotions, or names. Within a framework there may be structural relations that define the event. This can include spatial relations (e.g., the umpire is behind home plate), ownership relations (e.g., the players are using the shortstop's ball), social relations (e.g., the two teams are bitter rivals), and so forth. Finally, because events are dynamic, several frameworks can be joined by linking relations that contain temporal order and causal information.

The Role of Experience

Mental model creation involves integrating prior knowledge with what has been given. This allows inferences to be drawn for information that has not been provided. Of course, the more knowledge a person has, the more likely it is that an adequate mental model will be constructed. For example, when watching a baseball game, a person with a lot of baseball knowledge will better understand the structure of the game, the causal and goal-related relations among the players, and the sequence of events.

The structure of one's experience influences the creation of mental models. Suppose a person reads a text on a topic that the reader has a fair amount of knowledge of, such as going to a baseball game. In this case, there is a certain sequence in which the events occur (e.g., buying a ticket before finding one's seat). Even if two events are adjacent in the text, reading times increase as the distance between them in the standard sequence increases. So when building mental models, people consult their knowledge systematically. It is as if they are scanning sequentially through their knowledge to assess where the current events fit. The greater the distance, the longer the scanning process and the more that needs to be inferred.

Mental models are essentially an amalgam of the given information that can be acquired through a film, book, lecture, discussion, and so forth, along with prior knowledge that a person has in long-term memory. The use of mental models is found in a wide variety of circumstances, including language comprehension and memory.

Comprehension

Mental models are critical for understanding. When people comprehend language, they create three types of mental representations. The simplest is a verbatim representation of what was heard or read. This is forgotten very quickly unless there is something important about the exact wording, as with a joke. At a more abstract level is the propositional textbase. This is a representation of the idea units that were expressed. For example, the sentences "The ball was hit by the batter" and "The batter hit the ball" would correspond to the same propositional representation. This representation is forgotten less rapidly. Finally, at the most abstract and highest level is the mental model. This is a referential representation of the described events. The mental model is a representation of what the message is about. In contrast, the verbatim and textbase levels are representations of the message itself but may serve as scaffolding from which to build a mental model.

While the goal of comprehension is to construct a mental model, its organization and function can influence comprehension itself. During reading, people keep track of what is going on in the described situation. For example, readers may keep track of the spatial location of a protagonist in a story. When that person moves from one location to another, knowledge about people or objects in the old location become less available. Switching from one spatial framework to another influences what information is readily available during comprehension. Moreover, the further the protagonist moves from the original location, the less available the information becomes. A similar thing occurs for temporal frameworks. Short time periods are more likely to be part of the same time frame, whereas long time periods are more likely to include a shift to a new time frame, and hence a new situation. Information that was relevant to the original situation is less available after a large time shift. Finally, people also monitor a protagonist's goals. Information that is relevant to current, unsatisfied goals is more available than information relating to goals that were successfully completed. The prior goal information is no longer maintained in the current mental model.

When the structure of the situation changes, reading times increase, as if readers are monitoring the described events. This includes changes in space, time, entities, causality, or the goals of the protagonist. When a major change in the described situation occurs, people update their mental models. In addition to monitoring event changes, people may also notice inconsistencies with what has been described before. Such inconsistencies result in increased reading times as the reader tries to resolve what they know of the situation with the current information.

One of the most important dimensions that people monitor is causality. Information varies in the degree of its causal importance. Information that plays an active role in the described situation is causally more important. Such information is typically read more quickly. Presumably, this is because it can be more easily integrated into the current mental model.

Memory

Mental models are also involved in memory. At very long periods of time, this is the representation that will dominate a person's recollections. Many of the influences during comprehension carry over into memory. For example, shifts in a situation during comprehension result in the memory being organized around those shifts. Also, causally important parts of an event are better remembered than less important parts. It should be noted that the ease with which information is integrated into a mental model has an influence on the ability to identify that situation later. Continuous and consistent descriptions are remembered better than discontinuous, inconsistent descriptions.

Mental models include both given information and inferences a person generates. With the passage of time, it becomes difficult to disentangle these two. People often mistakenly identify information as having been encountered before if it is consistent with the previously described situation, even when that information is new.

How information refers to the world is important for how it is represented in mental models. This has important consequences for memory. When given a large set of related information, a person can integrate this information into one mental model if the information can be interpreted as being consistent with a single situation in the world. Otherwise, it may be stored in separate mental models. When a person needs to remember one piece of information, if there are related mental models containing related but irrelevant information, this will produce interference, causing the memory retrieval to be slower and more error prone. If, however, the information is integrated into a single model, there is no such cost to memory.

While these findings suggest that a mental model can influence memory retrieval, it is also possible to remove these influences to a certain degree. As mentioned earlier, people create multiple representations during comprehension, including verbatim, propositional, and mental model representations. The mental model will contain many inferences and will also capture the perspective of the comprehender. If the mental model is discredited in some way, such as asking a person to take a different perspective on the text that was read, then the person will rely less on the mental model and more on the propositional representation. For example, people reading a description of a baseball game might originally be told that the home team was going to make the playoffs. Then when the person is asked to recall the story, they could be told that the story was about a team that ended up in last place. This shift in perspective will cause a decrease in the number of inferences a person reports and also increase memory for those previously unremembered propositions that are consistent with the new perspective. Thus, the person has disregarded their mental model during memory retrieval.

Summary

Mental models are mental representations of specific states of affairs in the world. They are created using the knowledge a person has at hand, along with prior knowledge. The organization and extensiveness of this prior knowledge is of great importance. People use mental models during comprehension as the basis for their understanding. Changes in the described situations cause people to update their mental models, which has a tangible effect on the comprehension process itself. Finally, mental models appear to be the form of mental representation that is stored in memory for long periods of time. The ability of a person to remember information in part reflects the organization and structuring of information into mental model.

See also: Learning, subentry on Knowledge Acquisition, Representation, and Organization; Reading, subentry on Comprehension.

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Zwaan, Rolf A., and Radvansky, Gabriel A. 1998. "Situation Models in Language Comprehension and Memory." Psychological Bulletin 123:162185.

Gabriel A. Radvansky

David E. Copeland

METAMEMORY

Metamemory refers to a person's knowledge about the contents and regulation of memory. The term originally derives from the work of John H. Flavell in the early 1970s. Metamemory enables a person to reflect on and monitor her memory. In addition, metamemorial knowledge plays an important role in planning, allocation of cognitive resources, strategy selection, comprehension monitoring, and evaluation of performance.

This entry begins with a description of the two main structural components of metamemorydeclarative knowledge, which enables a person to evaluate the contents of memory, and procedural knowledge, which enables a person to monitor and regulate memory performance. It next summarizes important developmental trends in metamemory, then discusses several important educational implications of metamemory research, including the relationships among metamemory, strategy instruction, and self-regulation.

Declarative and Procedural Aspects of Metamemory

Most theorists distinguish between declarative and procedural components of metamemory. The declarative component corresponds to statable knowledge about the contents and contexts of memory use and includes knowledge of memory's contents, knowledge of essential intellectual tasks such as reading and problem solving, and conditional knowledge about why and when strategies are most effective. The procedural component includes knowledge about procedural skills necessary to manage memory efficiently, including control processes such as planning and evaluating and monitoring processes such as judgments of learning. Some theorists, but especially those interested in the relationship between metamemory and social cognition, have proposed a third component, usually referred to as a beliefs component, that regulates affect, social cognition, and efficacy judgments of memory performance. The focus here, however, is on the declarative and procedural components.

The declarative component includes at least three distinct subcomponents: knowledge of contents and capacity, knowledge of tasks, and conditional knowledge about optimal memory performance. The content subcomponent enables a person to assess whether he possesses enough knowledge to meet task demands. The task subcomponent allows a person to determine whether he fully understands task demands and possesses adequate resources to perform the task. The conditional knowledge subcomponent, which many view as the most important of the three, helps a person determine why, when, and where to use a particular strategy or under what conditions he is most likely to achieve optimal performance. Conditional knowledge plays an especially important role in self-regulation.

The procedural component includes control and monitoring subcomponents. The control subcomponent includes regulatory processes such as planning, selection of relevant information, resource allocation decisions, selection of relevant strategies, and inferencing. The monitoring subcomponent includes a variety of self-assessment strategies such as ease-of-learning judgments, judgments of learning prior to beginning a task, feeling-of-knowing judgments made during learning, and comprehension-monitoring judgments made during or after a task. Most theories of metamemory assume that control processes directly regulate cognition and performance, whereas monitoring processes inform the precision of control decisions. Thus, control processes are at a higher level than monitoring processes, even though both reciprocally inform one another.

Development of Metamemory

A number of researchers have studied the development of metamemory, and four main conclusions can be drawn from this research. The first conclusion is that metamemory awareness is rather poor in children until the age of ten or older. Younger children frequently find it difficult to monitor the contents of memory, estimate the resources needed to complete a task, select appropriate strategies for a task, and monitor their learning. As a consequence, self-regulation is quite poor among children younger than ten years of age. Even among adults, however, metamemory awareness is poor, sometimes leading to overconfidence and illusions of knowing.

A second conclusion is that metamemory development is incremental and continuous. Development appears to be linear in nature with a steady increase in metamemory awareness, control, and monitoring from preschool through early puberty. Research generally does not reveal significant breaks or jumps in metamemory ability, suggesting continuous development over a ten-year period from early childhood through adolescence. It is less clear whether metamemory awareness continues to develop in adults, although most research indicates that awareness increases within specific domains as expertise develops.

A third conclusion is that metamemorial knowledge is self-constructed in nature through individual and interactive problem solving, as well as explicit strategy instruction and monitoring training. One essential element of the construction process is self-generated and other-generated feedback that increases knowledge of the contents of memory and tasks. A second essential element is modeling, in which an individual has the opportunity to observe and emulate skilled models. Thus far, researchers have failed to detect a strong link between metamemory and either intellectual ability or traditional measures of working memory speed and capacity. This suggests that metamemory awareness develops independent of other individual differences in memory.

The final conclusion is that metamemory facilitates strategy use and performance. For example, correlations between metamemory and memory performance typically range from .30 to .50, even in younger children between the ages of five and ten years. The correlation may be even stronger in adults and experts. Knowledge about the contents of one's memory as well as tasks clearly should affect performance. In addition, declarative knowledge appears to be correlated with regulatory awareness. The more one knows about memory, the better able one is to regulate one's performance.

Metamemory and Learning

Metamemory affects learning in many ways but especially with respect to the efficient use of limited cognitive resources, strategy use, and comprehension monitoring. Children and adults often experience difficulty learning because of cognitive overloadthat is, too much mental work to do and too few cognitive resources at their disposal. Research reveals that declarative and procedural knowledge enables learners to use available resources more efficiently because they are better able to plan, sequence, and monitor learning tasks.

A second way that metamemory improves learning is through the flexible use of cognitive learning strategies. Research indicates that self-regulated learners use a diverse repertoire of strategies that are controlled using conditional knowledge in metamemory. Strategy use is highly correlated with skilled problem solving. Research also suggests that strategy training increases metamemory awareness, provided that conditional knowledge about the strategies is embedded within the instruction. In 1999 Roger Bruning, Gregg Schraw, and Royce Ronning provided a step-by-step summary of cognitive strategy instruction that includes feedback and modeling from peers, tutors, and teachers. Strategy instruction is especially effective for helping students develop conditional knowledge that enables them to select the most appropriate strategy and monitor its usefulness.

A third way that metamemory improves learning is comprehension monitoring. Unfortunately, many children and adults do not monitor with a high degree of accuracy. Monitoring training helps learners monitor more successfully and also improves performance. Strategy instruction also improves monitoring even when monitoring instruction is not included as part of the instruction. Thus, either strategy instruction or monitoring training improve monitoring accuracy. Combining strategy instruction and monitoring training within the same intervention helps learners construct the control and monitoring subcomponents of regulatory knowledge described above.

Classroom Implications

Metamemory research has not had a major impact on classroom instruction. The research suggests, however, that children acquire and construct metamemory knowledge in three distinct ways. One way is hands-on experience that provides declarative knowledge about tasks as well as procedural knowledge about optimal performance. A second way is through skilled models who provide detailed feedbackespecially conditional feedbackthat enables the student to distinguish between effective and less-effective strategies. A third way is through self-reflection and group reflection in which students explicitly discuss the effectiveness of different strategies and ways to improve performance in the future. Thus, there are many ways to improve metamemory awareness through classroom activities.

Several learning interventions have been developed that promote metamemory development and awareness. For example, in 1984 Annemarie S. Palincsar and Ann L. Brown described a program of reciprocal teaching that promotes the self-regulation of metamemory strategies. The program involves the teacher gradually handing over control of reading processes to the student in a small-group format. The teacher first models effective strategies (e.g., finding the main idea of a passage) then provides scaffolding to the students as they attempt to do the same while receiving feedback from their peers regarding the strategies they employ.

Summary

Metamemory is knowledge about memory. Metamemory awareness develops late and incrementally yet has an important impact on memory and cognitive performance. Metamemory is not linked strongly to other cognitive factors such as intelligence and memory capacity. Rather, it develops as a function of experience, guided modeling and feedback, and individual and group reflection.

See also: Learning to Learn and Metacognition; Reading, subentry on Comprehension.

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Butler, Deborah L., and Winne, Philip H. 1995. "Feedback and Self-Regulated Learning: A Theoretical Synthesis." Review of Educational Re-search 65:245282.

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Schraw, Gregg, and Moshman, David. 1995. "Metacognitive Theories." Educational Psychology Review 7:351372.

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Sweller, John; Van Merrienboer, Jeroen J.; and Paas, Fred G. 1998. "Cognitive Architecture and Instructional Design." Educational Psychology Review 10:251296.

Gregory Schraw

John Nietfeld

MYTHS, MYSTERIES, AND REALITIES

Why is it that people remember some things and forget others? How long do people remember things? What kinds of cues are likely to help a person remember a forgotten item? These are just a few of the many questions of interest to memory researchers. This entry reviews some of the important questions in the field of memory research and describes how psychologists use experimental methods to answer these questions. It also describes some of the major findings and rebuts some of the common myths about memory. This discussion is structured around the three stages of memory: encoding, storage, and retrieval.

Encoding refers to the intake of information and creation of a memory trace. In a typical memory experiment, the encoding phase involves presentation of the to-be-remembered stimuli, such as nonsense syllables, words, pictures, stories, films, or staged events. In real life, encoding includes all forms of perception, from watching a movie to having a conversation. Encoding may be intentional in that subjects are forewarned to memorize the items or incidental in that subjects learn the to-beremembered material through performance of another task such as making a category judgment. In educational settings, encoding is intentional when students deliberately study the meanings of vocabulary words, learn facts for a test, or memorize a famous speech. In everyday life, however, most things are learned incidentally. Examples in the education domain include students learning about a historical period by watching films, role-playing, and reading memoirs.

Storage or retention refers to the maintenance of the memory trace over time. In most laboratory experiments, the retention interval is quite short and the subject does an unrelated task during that time. In the education domain, there may be a retention interval of several weeks between learning and testing; students may continue to practice the target information during the retention interval.

Retrieval involves later accessing that memory trace. There are many different ways to test memory. Explicit tests require subjects to consciously remember events from the study phase. Most educational tests are explicit; students know they are being tested and that they should remember facts from class and textbooks. Explicit educational tests include essay, short-answer, multiple-choice, and true-false tests; these roughly correspond to the laboratory tests of free recall, cued recall, forced choice, and old-new recognition. Implicit tests measure the effect of previous experience on a task that does not require the subject to consciously refer back to the study phase. In education, pure implicit tests are rare although many explicit tests may tap a student's implicit knowledge (e.g., essay tests implicitly test a student's knowledge of grammar). In the laboratory, there are many different implicit tests. For example, a subject who had recently seen a list that included the word octopus would complete the word stem "oct" with "octopus" at a higher rate than subjects who had not seen the list.

In the following sections, some of the facts and myths associated with each of the three stages of memory are described.

Encoding

Key questions about encoding include what kinds of things are easily memorized and what study strategies can be employed to ensure later memory.

Not all materials are remembered equally well. Pictures are remembered better than words, and in general memory is better for distinctive items. Likewise, concrete words are better remembered than abstract words. Good teachers often apply this finding by using concrete analogies to explain abstract phenomena or theories, such as when the movement of gas molecules is compared to the movement of billiard balls on a pool table.

Not all study strategies are equal. In general, elaborative encoding yields the best memory. Elaboration involves going beyond the stimulus at hand to create a richer memory trace. For example, rather than simply repeating a to-be-memorized vocabulary word, a student might think of other words similar in sound and meaning, draw a picture that somehow represents the word and its definition, or write sentences using the word in context. In perhaps the most famous laboratory demonstration of this, Fergus I. M. Craik and Endel Tulving looked at subjects' memory for words after perceptual, phonemic, or semantic processing in a 1975 study. For example, if all subjects studied the word EAGLE, one group decided if the word was in uppercase letters (perceptual), the second group decided if it rhymed with legal (phonemic), and the third group decided if it was an animal (semantic). All of these questions would have been answered affirmatively, but memory was best following semantic processing, next best with phonemic processing, and worst after perceptual processing. This is the classic levels of processing effect. The educational implication is that incidental study can be just as effective as intentional memorization. If students are studying via a semantic or other elaborative task, the resulting memory can be just as strong even if they are not forewarned about the upcoming memory test.

Encoding is not like taking pictures with a camera; not everything is recorded. Instead, encoding is selective. The levels of processing effect is an example of this; depending on the instructions, subjects directed their attention to different features of the target word. More generally, what students encode will be a function of what they already know and how well they can understand and link the incoming information to their prior knowledge. A schema is the term for a person's knowledge representation of a concept or domain. Without a schema, the understanding and interpretation of incoming information is difficult. For example, in a 1977 study by D. James Dooling and Robert E. Christiaansen, subjects had poor memories for such passages as "With hocked gems financing him/our hero bravely defied all scornful laughter that tried to defy his scheme/Your eyes deceive, he saidan egg not a table correctly typifies this unexplored planet." Good memory required knowledge that the upcoming passage would be about Christopher Columbus. Schemas also serve to direct a subject's attention to particular schema-relevant details and to allow for inferences. For example, according to a 1977 study conducted by James Pichert and Richard Anderson, students who read a story about two boys playing hooky and spending the day at home remembered different things depending on which of two perspectives had been instantiated at encoding: home buyer or burglar. Subjects who read the story with the perspective of a burglar attended to and remembered better such details as that the house's side door was unlocked, a fact unlikely to be relevant to a home buyer.

Another fact about encoding is that more is not necessarily better; massed study is not a good idea. While many students choose to cram for exams the night before, the data clearly suggest that spaced study opportunities are preferable. The same holds true for rehearsal of to-be-remembered information, which is described in the next section on activities during the retention interval.

Storage

Encoding is a necessary but not sufficient condition for later memory. As time passes, it becomes less and less likely that a person will be able to retrieve the target event. In 1985 Herman Ebbinghaus first documented the now classic forgetting function; he taught himself series of consonant-vowel-consonant trigams and tested his memory after varying time lags. Memory dropped off quickly at first, but eventually forgetting leveled out over time to a fairly stable level. Most laboratory studies involve fairly short retention intervals; in 1984, however, Harry P. Bahrick examined knowledge of Spanish following retention intervals of up to fifty years (participants reported very little use of Spanish during that time). Again, there was a sharp drop in knowledge by three to six years poststudy, but after that initial drop, knowledge was surprisingly stable over the next twenty-five years. Bahrick termed this long-term retention the permastore.

Rehearsal during the retention interval aids memory; not all forms of rehearsal, however, are equal. Simply repeating a to-be-remembered item will not necessarily lead to enhanced memory. A student who writes a fact over and over will not remember that fact as well as a student who takes a more active approach to rehearsal. One of the best strategies is that of expanding rehearsal combined with self-testing. For example, the student who wants to learn a vocabulary word should not simply stare at the word paired with its definition. Rather, she should test herself and produce the definition of the word from memory; after a short delay she should repeat the process, and so on, incrementally increasing the delay until the retention interval is at the desired length.

Memories do not lie dormant during the retention interval but are affected by the new information that continues to enter the system. In one classic demonstration of interference, subjects saw a slide show of a traffic accident involving a car passing a stop sign. In the next phase of the experiment, subjects in the experimental condition read a narrative description of the slide show that included a misleading reference to a yield sign. Control subjects also read a narrative, but it did not contain the misinformation. All subjects were later asked whether they had seen a stop sign or a yield sign. Subjects who had been exposed to the misleading post-event information were more likely to mistakenly say they had seen a yield sign than the control group. Although the exact mechanisms underlying the misinformation effect are still under debate, in at least some circumstances the misinformation works to block or interfere with access to the original memory.

Retrieval

No single test of memory is perfect. No one test yields an absolute measure of what is in memory; rather, one can ascertain what is accessible only under a particular set of test conditions. The failure to recall part of a list is not necessarily synonymous with forgetting those words. Rather, they may be available in memory but not accessible given the current retrieval cues. When asked to write down all the words from a studied list, a subject may not be able to recall studying the word robin. This allegedly forgotten word, however, may be recalled in response to the category cue "birds" or correctly labeled as "old" on a test that re-presents the word robin for an old-new decision. Similarly, a student who is unable to produce an answer on an essay test may recognize it on a multiple-choice test.

Conclusions about memory may vary across tests. Take, for example, the effects of word frequency on memory. Following study of a word list, words that occur with high frequency in the language (e.g., tree ) are recalled with a higher probability than are words that occur with low frequency in the language (e.g., ecru ). The opposite result, however, is obtained on recognition memory tests. When subjects are asked to label words as "old" or "new," they do a better job with low frequency than high frequency words. This paradox is one that continues to interest researchers.

So, how then to get the best performance possible on a memory test? The general rule is that the test should match study as much as possible. Returning to the levels of processing effect described earlier, semantic processing leads to better memory in part because most memory tests are semantic in nature. When subjects are given a phonological test (e.g., did you study a word that rhymes with beagle ?), performance is better when words are encoded as rhymes than when they are categorized. Effects of test expectancy are nicely explained within this framework. Performance on an open-ended (essay or free recall) test suffers if students are incorrectly led to expect a multiple-choice test. Depending on which test is expected, students study differently. Students expecting a multiple-choice test focus less on relations between items and spend less time preparing than do students expecting a more open-ended test. The way students study for multiple-choice tests does not match the demands of the recall test; hence, performance suffers when students are surprised with the unexpected version of the test. A good educator will make clear the test demands early in a course so that students will tailor their study strategies appropriately.

Memory is not like a tape that can be played back perfectly at test. Rather, memory is reconstructive. In one example of this, from the 1977 study of Dooling and Christiansen, subjects read a paragraph that began "Carol Harris was a problem child from birth. She was wild, stubborn and violent." Right before the test phase, some of the subjects were told that Carol Harris was really Helen Keller. These informed subjects were much more likely to incorrectly identify the statement "She was deaf, dumb, and blind" as having been in the original paragraph than subjects who were not informed of Harris's true identity. Subjects made use of their knowledge at test to reconstruct what they read during the first part of the experiment. Schemas are as active during test taking as they are during encoding, and they provide retrieval cues and allow for reconstruction.

Conclusions

There are two very general requirements for effective memory: quality encoding and appropriate retrieval cues. These principles are exemplified in a classic study method, the SQ3R method, which Francis P. Robinson described in 1970. SQ3R stands for: s urvey, q uestion, r ead, ehearse, and eview. Students begin by surveying the textbook chapter before reading it, to become familiar with its organization. As they read the chapter, they form questions that they then answer. Finally, they rehearse and test themselves on what they have just read, and review all the material repeatedly. Each of these activities links to basic memory processes. The initial survey of the chapter leads students to set up a schema for the chapter that guides both encoding and later retrieval. The questions students create serve as retrieval cues later on. Answering these questions, repeated rehearsing, self-testing, and reviewing the material are all forms of retrieval practice that will aid memory. Studying a textbook chapter need not be a mystery to students.

See also: Memory, subentries on Autobiographical Memory, Implicit Memory, Metamemory, Structures and Functions.

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Elizabeth J. Marsh

STRUCTURES AND FUNCTIONS

In the study of memory there have been many metaphors adopted in the search for an explanation of the memory process. The fourth century b.c.e. Greek philosopher Aristotle compared memorizing to making impressions in wax, and the idea that memories are copies of reality that a person stores and later retrieves has been widespread. This is sometimes called the storehouse metaphor, and many of the ways in which people talk about memory (searching for memories, bringing them back from the recesses of one's mind) assume such a metaphor. The computer metaphor that has been popular with psychologists researching memory is a version of the storehouse view. It conceptualizes the stages involved in remembering in terms of encoding, storage, and retrieval in which information is entered into memory, retained, and then found again at a later time. Thinking about remembering in this way can be valuable, but it can lead to the incorrect assumption that what is remembered is a simple copy of what was originally experienced. In reality, much that is remembered captures the gist rather than the details of the original experience, and remembering is often a process of reconstruction. Examples of constructive remembering can be found in research on false memories. Elaborate and detailed false memories of events from an individual's past can be easily created. More mundanely, hearing a list of close associates to a particular word leads to recall of the word itself even though it was not presented. One alternative to the storehouse metaphor is the correspondence metaphor that emphasizes the deviation between the memory and the original experience.

Memory Structure

Researchers who study memory use a number of terms to subdivide the enormous field. One major distinction is that between explicit and implicit memory. Explicit memory refers to the conscious recall of information. Conscious awareness of past experiences involves explicit memories. Often, however, people are influenced by experiences that are not consciously recallable. For example, the ease and speed with which a person solves the anagram rbocoilc depends upon how recently the person has encountered the word broccoli. This facilitation reflects implicit memory. Processing of new information is primed by past experiences without conscious awareness. The distinction between explicit and implicit memory may reflect different underlying memory systems. Quite different timescales and sensitivities have been demonstrated for some explicit and implicit memory tasks. The differences may arise, however, from the processing requirements of the tasks rather than from different memory systems.

A distinction that overlaps with explicit and implicit memory is that between episodic and semantic memory. This distinction, associated with Endel Tulving, is between memory for events and memory for facts. Episodic memory is for events that people can remember happening, whereas semantic memory is for facts that people know about the world without necessarily retaining any recollection of the situation in which they learned the information. One's memory for eating breakfast on a particular morning is an episodic one, whereas one's memory that Coca-Cola is a drink is a semantic one. One area of episodic memory is autobiographical memorymemory for personal events in one's own life. Autobiographical memories from the first two years of life are very rare, while memories from the late teens and early twenties are more frequently held than the average. Certain autobiographical memories seem to be so distinct and full of the apparently irrelevant details from the original event that they have been called flashbulb memories because the nature of the memory is similar to a photograph of the moment. Archetypal examples of flashbulb memories are associated with hearing or seeing particularly dramatic events such as the assassination of a famous person or a major accident.

Submemories. One approach to understanding the structure of memory has been to seek separate submemories that are responsible for retaining information over differing time periods. In 1968 Richard Atkinson and Richard Shiffrin proposed a model with three types of memory: a sensory store, a short-term store, and a long-term memory. Visual information, for example, is believed to be retained for about one second in a sensory store while perceptual processing takes place. Similar sensory memories aid in the processing of acoustic and other inputs. Beyond the perceptually based sensory memories is the short-term memory, which retains information for a few seconds before selected elements of that information are transferred to a long-term memory. Atkinson and Shiffrin recognized that there were control processes in short-term memory that influence what is attended to and processed. The Atkinson and Shiffrin model has been elaborated into the working memory system, which has been particularly investigated by Alan Baddeley and his colleagues. Baddeley has subdivided the working memory into several subcomponents, the most heavily researched of which are the phonological loop, the visuospatial sketchpad, and the central executive. The phonological loop holds a couple of seconds of speech sounds and plays a role in reading. The visuospatial sketchpad is used in the creation of mental images and in the solution of visual and spatial problems. The central executive is a controlling attentional system that supervises and coordinates current cognitive processing.

Formal models of memory. A number of formal models of memory that can be run as computer simulations have been developed. Among the most influential of these are Jerome Raaijmaker's and Richard Shiffrin's 1981 SAM model, James McClelland, David Rumelhart, and Geoffrey Hinton's 1986 PDP model, and John Anderson's 1993 ACT model.

SAM (Search of Associative Memory) is a mathematical model based upon items and the strength of associations between them. It is particularly appropriate to the learning of lists of words. Each word has a memory strength as a result of it being studied, and each word has an associate strength with the other words in the studied list. The memory strength is combined with the association between the word and the context in which it was learned to produce a strength that is the basis of recognition or retrieval. The model can account for many of the memory phenomena associated with the learning of lists, but it shares with the other two formal models described here the difficulty that many of its assumptions are not based on observations and are difficult to test.

The PDP (Parallel Distributed Processing) model is a neural network model inspired by the analogy of neural circuits in the brain. The network consists of units that are connected to form a network. The strengths of the connections (weights) are adjusted as the network is trained to produce correct responses. Activation spreads through the network and the weightings direct that spread. A response is selected when it achieves a sufficient level of activation. One feature of neural network models is that memory is not located in one place but is captured by particular patterns of activation over many units and links. The neural network models are attractive in apparently simulating the structure of the brain. The choice of the particular structure of units and their interconnections, however, turns out to be important for each simulation of human memory. A general representation that is applicable to many types of remembering has yet to be developed.

The ACT framework is a production system theory for both memory of facts and skills. Anderson has developed several versions of ACT including ACT-R (Adaptive Control of Thought-Rational). Production rules are condition-action rules of the form: If this is the condition, then execute that action. Within the system, units of information are linked by associations, with the association strength being increased through use. The ACT models were developed to account for problem solving and skill acquisition as well as memory. As with the other formal models discussed here, there are many assumptions that make a model difficult to evaluate.

Memory Functions

What is remembered of a particular event depends upon the way in which it is processed. Elaborate processing that emphasizes meaning and associations that are familiar leads to good recall. So, for example, the word albatross would be remembered poorly if only the font in which it was printed was noticed and little thought was given to its meaning. It is much more likely to be remembered, however, if at the time the word is read the reader thinks about how albatrosses are white seabirds living in southern oceans. On the other hand, if what is encountered is difficult to understand, then not only will it be poorly remembered but what is remembered may be distorted by an effort to comprehend the meaning.

The processing of new information draws very heavily upon memory of past experience. Schemas have been developed for often-encountered familiar situations such as going to a supermarket or eating at a restaurant. These schemas guide understanding and memory of the new events but may also lead to memory errors by adding expected events that did not actually occur. Information that is organized on the basis of one's existing knowledge is much easier to learn and remember than is disorganized information. So, for example, a list of the names of animals is much easier to memorize if it is categorized according to type of animals (domestic, farm, wild) and if the categories are laid out in a structured way. Experts in an area memorize new information within their area of expertise much more quickly than do novices. So, soccer fans easily learn new soccer scores and chess masters memorize real board configurations easily.

When material is restudied to strengthen the memory of it, the shorter the interval between the first and second study periods, the less the improvement in recall. This spacing effect is large, so that studying in two spaced sessions can produce twice as much recall as a single session of equal length. The rereading of factual material makes only a small contribution to the further learning of it. Testing oneself by retrieving studied material, however, is a particularly effective technique for improving memory.

What is remembered depends upon the information that is available to cue recall when it is retrieved. In 1983 Tulving summarized much research in the encoding specificity principle. This principle asserts that retrieval is successful to the extent that the cues available at retrieval match those that were processed by the learner at the study phase. The retrieval cues may be aspects of the material that was studied, but they also include environmental cues and the mood and mental state of the learner.

The learning of information that is similar creates a problem for retrieval. There is interference from similar material learned earlier (proactive interference) and from material encountered since the original learning (retroactive interference), and these reduce recall. More insidious are misinformation effects. These occur when misleading information is presented, for example, to eyewitnesses during questioning. The misleading information is then frequently recalled, and the original information becomes very difficult to retrieve.

When tested across time, forgetting follows a logarithmic curveinformation loss is rapid initially but then information is lost more slowly. Nevertheless, the fate of information that has been initially very well learned is rather different. Where facts, names, or foreign-language vocabulary have been used repeatedly but are no longer regularly recalled, the pattern of their forgetting is an initial loss over a three-year period, after which recall may be equally good with delays of one or twenty-five years.

See also: Memory, subentry on Myths, Mysteries, and Realities.

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Peter E. Morris

Memory

views updated May 17 2018

MEMORY

Most people recognize that their memories are changing as they grow older. They have a harder time coming up with names; they have a harder time finding things they need; they have to rely more on external memory cues such as notes or calendars. In fact, research results support these perceptions. The bad news from this research is that memory declines are experienced throughout the adult life span and not just in the older ages. Forty-year-olds as a group are worse than twenty-year-olds, and fifty-year-olds are worse than thirty-year-olds. The good news is that research shows that, unlike the serious and ubiquitous memory declines associated with Alzheimer's disease and other dementias, memory changes associated with healthy aging are selective (e.g., Zack et al.). Some memory tasks show large and reliable adult age differences (e.g., working memory, episodic memory), while other memory tasks show little or no effects of age (e.g., semantic memory, implicit memory).

Figure 1 shows the results from study of 345 adults ranging in age from the twenties to the eighties (Park, Lautenschlager, et al.). Different types of memory were tested, including working memory (computation span), episodic memory (free recall of a word list), and semantic memory (defining words in a vocabulary test). The results were plotted in deviation units from the mean for all the participants on any test (z scores). As can be seen in the graph, the memory changes occur across the entire adult life span and are not limited to old age. Second, the graph shows that age has selective effects on memory. Working memory and episodic memory decline significantly across the life span, while semantic memory increases significantly.

Other theories suggest that age differences in memory depend on the extent of deliberate cognitive processing or cognitive resources required to perform the task (e.g., Park). According to this view, the size of age differences in different memory tasks is determined by the amount of cognitive resources needed to adequately remember in those tasks. Other theories suggest that age effects are limited to specific memory structures or types (e.g., Craik). Clearly, the explanation for the differential effects of age with different memory tasks depends on how one conceptualizes memory.

Memory stage theory

Memory stage theory separates memory into the temporal, sequential components that define any act of remembering. Information first has to be perceived or experienced (i.e., encoding). Then the information has to be maintained over a retention interval of some length of time (i.e., storage). Finally, the information has to be produced at the time memory is tested (i.e., retrieval). Early researchers believed that adult age differences in memory were located primarily at retrieval, the final of the three stages. Early laboratory research, for example, demonstrated that age differences were large when the recall of a word list was measured (with instructions such as "Write down all the words you can remember having seen on the list presented earlier."). Age differences, however, were greatly reduced or even eliminated when recognition memory was used to test memory at retrieval (with instructions such as "Select the words on this list that were presented on the list that you saw earlier."). Because the use of a recognition memory task is assumed to reduce the retrieval requirement of the memory task, it was then inferred that the locus of the age effect must be retrieval. Such findings were prevalent in the 1960s and 1970s.

More recent research, however, has clearly demonstrated that recognition memory is not totally insensitive to aging, and the stage theory lost its appeal because of the methodological difficulties in isolating one memory stage from another in different age groups. In order to isolate retrieval, for example, everything must be held constant until the time retrieval is tested. This is difficult to accomplish in aging research, however, because adults of different ages may process information differently at one of the earlier stages, thus violating the requirement that all be held constant until retrieval (Smith).

The major reason, however, for the loss of interest in identifying the stage at which aging had its effects is clear evidence that age has effects on all stages of memory: encoding, storage, and retrieval. For reasons not directly related to memory stage theory, however, memory research in the 1970s and early 1980s focused heavily on the encoding stage of memory. This focus on encoding was due to the development of a conceptual view of memory, the "levels of processing" framework, which proposed that the ability to remember was determined by the extent of semantic processing during the encoding of the to-be-remembered information (Craik and Lockhart). For this reason, much research on memory and aging during this period focused on the nature of encoding processes in different age groups. Even with the magnitude of the research effort, however, the relationship between aging and levels of processing is still unclear. The research did, however, suggest that encoding is especially affected by adult aging. For example, the memory performance of older adults, relative to younger adults, is more detrimentally affected by performing a divided attention task during the encoding stage of a memory task, but not if the divided attention task occurs at retrieval (Park, Smith, et al.).

Memory system theory

Another view of memory that has both behavioral and neurological support considers memory not as a unitary construct but as a collection of component systems. The general view is that memory consists of sensory memory, short-term memory, and long-term memory. Short-term memory is further divided into primary memory and working memory, and long-term memory is divided into episodic memory, semantic memory, and procedural memory. These memory systems differ in the nature of how memories are represented and in how these representations are maintained and retrieved. They also differ considerably in how they are affected by adult aging.

Sensory memory. After an event is experienced, it is first represented very briefly in the sensory system. Here the information is represented as it is processed and analyzed by the attentional and perceptual systems. There has been very little work on this type of memory and aging, but some research does suggest that older adults are less efficient in this early type of processing, especially in the visual system. It should be pointed out, however, that differences in sensory-perceptual processing would be an unlikely explanatory construct for memory differences found in later memory systems because later memory differences vary according to what system is examined (Craik). Adequate perceptual processing of the to-be-remembered stimulus would seem to be a requirement for all types of long-term memory, and the fact that some long-term memory systems are minimally affected by aging while others show large effects would not support an explanation that relied solely on faulty processing at the very early stage of processing.

Primary memory. Primary memory refers to the number of items that can be represented in the mind at one time. Primary memory is typically measured by digit- or word-span tasks. For example, when strings of numbers are presented one at a time at one-second intervals, primary memory would be the number of items that could be repeated back without errors. The digit-span test found on most intelligence tests is a measure of primary memory. When primary memory is tested by digit-span tests with individuals of different ages, no reliable age differences are found (Craik). Another measure of primary memory is recall of the last few items presented on a word list. Again, research finds no age differences in the ability to recall the most recently presented items in a word list.

Working memory. Age differences are found, however, on a measure of short-term memory called working memory, which takes into account both the ability to keep things in mind and, at the same time, the ability to process information. Working memory, unlike primary memory, requires individuals to keep information in mind while engaging in another processing task. One commonly used working memory task is reading span. Individuals read a series of short sentences (e.g., "The girl hit the ball.") and answer questions about the sentence (e.g., "Who hit?"). At the same time, individuals have to remember the last word in each sentence (e.g., "ball") and report the words when told to do so. The number of sentences presented varies, and reading span is the greatest number of words that can be remembered without making an error. Because working memory tasks require simultaneous storage (remembering the words) and processing (reading the sentences and answering the questions), it is a better simulation of everyday information processing.

Working memory is used to understand a conversation or to write an e-mail message on the computer. Other working memory tasks have been developed that involve different kinds of information processing, such as arithmetic calculations (computational span) and spatial manipulations (spatial working memory). Regardless of the type of information involved, however, large, reliable age differences are found on working memory tasks (Zacks et al.). Therefore, while the more passive primary memory tasks, such as simple digit span, do not show age differences, differences are found with working memory measures. As will be discussed later, working memory capacity is considered by many researchers to be a fundamental mechanism for more complex memory processing.

Long-term memories are not kept in conscious awareness, as short-term memories are, but instead have to be retrieved into consciousness when they are needed.

Episodic memory. Episodic memories are recollections that are actively retrieved as previous personal experiences. For this reason, episodic memory is sometimes called autobiographical memory. The memory is a reconstruction of an earlier experience very much like looking something up in an internal cognitive diary. For this reason, contextual information about when and how an event was originally experienced is often used to guide retrieval. "What did I have for dinner last night?" "Where did I park my car?" "Did I take my medicine this morning?" "Did you see Joan at the party last night? To answer each question, one attempts to reconstruct the original event.

Older adults do worse on most episodic memory tasks than do younger adults (see Figure 1). In the laboratory, typically a list of words or some other to-be-remembered information is presented to individuals, and later, after a retention interval, memory is tested. Because the items presented are commonly used words, they are already known to the individuals. The memory task, therefore, is to remember the words in the particular context of the original list. Episodic memory requires one to put what one is trying to remember in a specific context. Even though the magnitude of age differences varies considerably among different memory tasks using different materials and types of tests, older adults tend to have greater problems with episodic remembering than do younger adults.

As will be discussed later, the variable that seems important in determining the magnitude of age differences is the degree to which the memory task involves deliberate processing by the individual. At both encoding and retrieval, the more intentional processing required to perform the task, the larger the age differences that will be found with that task. For example, free recall of a word list requires more deliberate processing than recognition tasks, and age differences are larger on free recall (Craik). Instead of trying to actively recall the items, individuals in a recognition task only have to pick out the words they saw earlier on a longer list of words.

Because episodic memory is so dependent on contextual information, one of the reasons for older adults' poorer performance on these tasks is probably their inability to encode and remember contextual information easily. Older adults, for example, do not do as well as younger adults in identifying the way in which information was presented to them (i.e., source memory). They do worse when asked to remember whether a word was presented in uppercase or lowercase, spoken by a male or a female voice, in one color versus another, or in the upper part of a computer screen or the lower part (Zacks et al.). These tasks require individuals to remember contextual detail. Because older adults encode less contextual detail, they do not do as well on tasks in which contextual detail provides the cues for retrieval. In fact, because older adults encode less context, they have problems distinguishing events they actually experience from those they have only thought about, a phenomenon called "reality monitoring." In a reality-monitoring task, individuals either read words at encoding or generate words in response to some cue. Older individuals have greater problems in determining whether remembered events were the ones read or the ones imagined in response to the cue (Norman and Schacter).

In addition to the problems associated with remembering context itself, older adults have problems with binding the context with the to-be-remembered information. In one study, for example, younger and older adults were presented with pairs of words and asked to generate a sentence that included both words. There were no age differences in the nature of sentences generated, but older adults did have more problems generating sentences, especially for unrelated word pairs that required them to generate the binding sentence through deliberate processing (Smith et al.). Older adults were better able to generate sentences when the two words were related to one other. They were also better able to recall one word from the word pair when given the other word as a cue. By having related word pairs, there was less need to bind the two words together because their relationship provided an existing bond. Again, because less deliberate processing was required in both the encoding and the retrieval conditions when related pairs were used, age differences were smaller. In fact, research has shown that age differences in the ability to recall a target picture when another picture is given as a cue depends on the relationship of the cue to the target. Age differences are large when the two pictures are unrelated, but smaller when the two pictures are either semantically related or presented as perceptually interacting (Park, Smith, et al. 1990).

One interesting type of episodic memory, "prospective memory," does not involve remembering something from the past, but instead involves intending to do something in the future. "Stop by the store when you leave work, and bring home some milk." "When you see Wanda, tell her to look at my new Web page." "Take two of these pills every other day after lunch." These are examples of prospective memory tasks. In the laboratory, prospective memory tasks simulate these real-world examples (e.g., "Press the key when you see a word with an 'R' in it" or "Press the key every ten minutes"). The prospective task is combined with some other cognitive task, such as trying to study a word list for a later memory test. With simple laboratory tasks, however, such as pressing a key when a certain letter is found in a word, age differences in prospective memory are often not found. Again, the determinant of whether age differences are found seems to be the degree of deliberate recollection required to perform the task, either for the prospective task or for the background task. As the difficulty of either task is increased, requiring more deliberate processing, age differences are increased.

Age differences are often larger in time-based tasks (e.g., individuals are asked to press a computer key every ten minutes while performing another computer cognitive task) than in event-based tasks (e.g., individuals are asked to press the key when a certain cue word appears). Because event-based prospective remembering involves less deliberate processing, given the external cue, age differences sometimes were not found. It is also clear that prospective memory errors in older adults increase when the background task they have to perform becomes more demanding in terms of processing resources (Einstein et al.).

Semantic memory. Not all remembering requires one to reconstruct the experience of encoding. There are many examples of remembering without reference to how or when what one is trying to remember was originally learned. There is access to a great deal of knowledge that has lost all connection to the context of its original episodic learning. "What is the capital of North Dakota?" "What bug has eight legs and weaves webs?" "Where were you born?" Answering these questions requires semantic memory. Semantic memories are retrieved conceptually rather than contextually, and represent accumulated knowledge. Instead of using a cognitive diary, semantic memory is like looking something up in an internal cognitive encyclopedia. Of course, the information is not alphabetically organized, but instead organized conceptually or semantically.

As mentioned earlier, tests of semantic memory typically show either no age differences or improvement over the adult life span (see Figure 1). Vocabulary tests and tests of general knowledge (such as found in Trivial Pursuit games) show either no age differences or increases for older adults up until very late in life (eighties or nineties). In Figure 1, vocabulary knowledge increased steadily through the seventies and showed only a slight decline in the eighty-year-old group.

There have also been attempts to examine the architecture of semantic memory (i.e., the way semantic organization is conceptually associated). Free association tests are one way to look at semantic organization. Individuals are given a word and asked to generate another word, the first word that comes to mind when thinking about the word given. A category name is given in another type of test (e.g., vehicle), and individuals are asked to generate the first five vehicles they can think of. If semantic information in memory is organized in different ways by different age groups, then there should be qualitative differences in the nature of the responses given on free association tests or category generation tests. If older adults' semantic memories are organized differently, then the organization should produce differences in the strength of associations between different concepts. Norms of free associations, however, as well as norms of generating instances in categories, show no differences between age groups (Smith and Earles).

One aspect of semantic memory that does seem to decline with aging is the ability to find a word, given its definition. This phenomenon extends to finding proper names and to the "tip-of-the-tongue" phenomenon (Craik). A tip-of-the-tongue state is created when a person knows that he or she knows something but cannot think of it at the moment. Often one can generate information about the answer that is correct but cannot think of the answer itself. Some of this effect (word finding, name finding, tip-of-the-tongue), however, is associated with older adults simply being slower to respond. Some research suggests equivalent word finding in different age groups with difficult words (Craik). Other research suggests that older adults eventually can resolve tip-of-the-tongue states when given enough time (MacKay and Abrams).

Procedural memory. Several times in this entry it has been stated that age differences in memory seem to increase when the degree of deliberate processing required to remember increases. Procedural memories are assumed not to require any deliberate, intentional processing at all. They instead involve only automatic processing and, in fact, do not even require conscious awareness of the effects.

Procedural memory tasks, sometimes called implicit memory tasks, often use repetition priming as a measure. For example, individuals first examine a list of words (stand, chair, . . . radio), not aware that a later memory test is involved. Rather, they are told to make some judgment about the words, such as to rate the pleasantness of each word on a five-point scale. Then several other word tasks are performed. Finally, a series of word stems is presented (fe___, ra___, . . . bl___) and the individuals are asked to complete the stem with the first word that comes to mind. Some of the word stems could be completed with a word presented earlier on the list. Even though they are not aware that the word stem list contains stems for words seen earlier, individuals will use the presented words to complete the stems at a level greater than chance. This increase in "remembering" previously presented items represents implicit or procedural memory.

As might be expected, given the lack of deliberate recollection, age differences are typically not seen on implicit memory tasks (Zacks et al.). If they are found, they are very small, especially when compared with the large effects seen in explicit episodic recall.

In summary, the memory systems approach has been very useful in describing when significant age differences in memory are found. Whether or not memory systems eventually are supported by neuroscientific data, they have provided a useful conceptual framework for organizing memory phenomena and for showing dissociations with age.

Cognitive resources

Another view of memory is more closely based on the observation that age differences in memory tasks seem to be determined by the degree of deliberate processing required to perform the task. Deliberate processing requires processing resources, and if processing resources are diminished in older adults, then the ability to engage in deliberate processing will be reduced. According to this view, age differences in memory are assumed to be caused by an age-related reduction in cognitive resources available to perform memory tasks as well as other cognitive tasks. Support for this theoretical position comes from studies which show that individual differences in measures of cognitive resources can account for age-related differences in memory performance. This research approach is represented in Figure 2. The circles in the figure represent individual differences in age, memory, and cognitive resources. Overlap in the circles represents shared variance among the variables. The age-related variance in memory is reflected by the overlap in the age and memory circles (a + b). The degree to which processing resources mediate the relationship between age and memory is shown by b.

Four mechanisms have been suggested as estimates of cognitive resources: perceptual speed, working memory, inhibitory function, and sensory function (Park).

Perceptual speed. Older adults are slower at performing simple perceptual/motor operations. In one test, for example, individuals are asked to look at two strings of letters (e.g., xpltvg xpltvg) and indicate in the space between them whether the strings are the same or different. The number of letter comparisons that can be completed in ninety seconds declines significantly across the life span. Perceptual speed is assumed to be an estimate of the efficiency of neural functioning, and thus to be a possible mechanism to account for age differences on memory and other cognitive tasks (Salthouse). Timothy Salthouse has produced an impressive amount of evidence that individual differences on simple measures of perceptual speed can account for most of the age-related variance in complex cognitive tasks, even those that do not require completion in a given time (i.e., speeded).

Working memory. Many researchers believe that working memory is a good measure of processing resources. Like perceptual speed, individual differences in working memory can account for much of the age-related differences on long-term memory tasks. Denise Park and her colleagues conducted a study with over 300 adults of different ages that measured perceptual speed, working memory, and different measures of long-term episodic memory. The long-term memory measures included free recall of a word list (looking at a word list and then recalling as many words as possible), cued recall (presenting word pairs at encoding and then presenting one word from each pair as a cue for the other word at retrieval), and spatial recall (remembering what quadrant of the computer screen words had been presented in earlier) (Park, Smith, et al. 1996). This study showed that when perceptual speed as a construct was included in a model of memory performance, it accounted for essentially all of the age-related variance in memory performance. Measures of working memory, however, were also important in the model with the more effortful measures of episodic memory, free and cued recall. Speed alone accounted for the age differences in the less effortful spatial recall task, but both speed and working memory were necessary to account for the age differences in free and cued recall, tasks that are assumed to require more processing resources. These results suggest that no single mechanism may be adequate and that multiple measures may be necessary to account for age differences in memory.

Inhibitory function. Another construct that has been suggested as the mechanism for cognitive resources is inhibition (Hasher and Zacks). Inhibitory function allows the individual to focus on information relevant to the task and suppress information that may be activated but is irrelevant to the task. Lynn Hasher and Rose Zacks suggest that older adults are less able to inhibit irrelevant information, and thus cannot focus as well on the information needed to perform the task. According to this view, it is not working memory capacity that is limited in older adults, but the inability to inhibit irrelevant information from cluttering up the content of working memory. The result of this "mental clutter" is that older adults experience more interference at both encoding and retrieval. There is a great deal of evidence that older adults are in fact deficient in inhibiting irrelevant information when performing memory tasks (Zacks et al.).

Sensory function. Paul Baltes and Ulman Lindenberger, in their large-scale Berlin Aging Study, found that auditory and visual acuity can account for much of the age-related variance on a variety of cognitive tasks, including associative memory. In one study, they found that sensory function accounted for over 90 percent of the age-related variance in cognition. Other research, however, has shown that this relationship is not simply due to the fact that poorer vision and hearing cause a decline in cognition. Instead, Baltes and Lindenberger suggest that the sensory measures are one of a large number of physical and cognitive variables that reflect the efficient functioning of the nervous system. According to their view, there is a "common cause" related to biological aging that affects a variety of abilities, both cognitive and somatic, are affected by aging.

Deliberate processing

In summary, different theoretical mechanisms have been proposed to account for age differences in memory performance. Each mechanism has been shown to be important, and research is needed to better understand the relationship among the different constructs. It is becoming clear that no single mechanism can account for all age-related variance in memory performance, and future research will address the relationship among the mechanisms when predicting performance on different types of memory tasks. All of the theoretical mechanisms, however, assume that older adults have more limited processing resources.

One theme that has emerged from the discussion is that age differences in memory are determined by the degree of deliberate processing. Fergus Craik has suggested that memory performance is determined by an interaction between internal (self-initiated processing) and external (environmental support) factors (Zacks et al.). The amount of deliberate processing required in a task decreases as the task itself becomes more supportive. As mentioned earlier, a great deal more processing resources are needed to remember the words in a free recall task than in a recognition task. In a recognition task, the words themselves serve as retrieval cues and the processing required to recognize is minimal. No explicit cues, however, are provided in a free recall task, and the individual must engage in a great deal of self-initiated processing in order to retrieve the words. Age differences in recall therefore are much greater than age differences in recognition (Craik). As the amount of deliberate processing increases, age differences should increase; as the environmental support provided by the task increases, age differences should decrease.

There have been some research attempts to determine the extent to which a task requires deliberate processing versus the extent to which it relies on automatic processing. One such attempt is known as the "remember-know" procedure. After individuals correctly identify words in a recognition memory experiment, they are asked to estimate whether the word was deliberately recollected ("remember") or whether the recognition was based on familiarity, with no specific recollection of encoding the word ("know"). Several different experiments have found that older adults produce a smaller proportion of "remember" judgments for the words they recognize, and a greater proportion of "know" judgments (Zacks et al.). This finding implies a reduced ability to deliberately recollect the items at the time of test and a greater reliance on familiarity.

Another method for examining deliberate and automatic remembering has been developed by Larry Jacoby and his colleagues. The "process dissociation" procedure actually provides quantitative estimates of the deliberate and automatic processing requirements of different memory tasks. As an example of process dissociation, Jennings and Jacoby looked at age differences in recognition memory. Younger and older participants first looked at a list containing words that they simply read. Then they listened to a second list and were told they would be tested on the second list later. Following the two lists, they were given two different recognition tests. In both tests they were given pairs of words, one of which they saw earlier, either as a word they read in list 1 or as a word they heard in list 2. The second word in the pair was a new word they had not seen or heard previously.

On the first memory test, they were misinformed that one word in each pair had been presented auditorially in list 2, and the other word was either new or one that they read in list 1. They were to pick the word that they had heard in list two (exclusion test). If they picked a word that was presented in list 1, they could do that only through familiarity, because if they had recollected the word, they would have correctly rejected it because it was a list 1 word. In the second memory test, they were told that one word from each pair was a new item, and they were to pick the one they had either seen or heard before. In this case, their judgments could be based on either familiarity or recollection (inclusion test). By subtracting the estimate of recognition due to familiarity derived from the first test (exclusion) from the scores on the second test (inclusion), an estimate of recall based on recollection alone could be derived. The results showed that the age effects were limited to the deliberate recollection component of recognition memory. Estimates of familiarity showed no age effects. This analytical procedure provides further support for the conclusion that age effects are determined by the extent of deliberate processing required in a task.

Dementia: age-related memory pathologies

So far, the discussion has been limited to healthy older adults. For most of this research, good health is a requirement for participation in the research. A small percentage of older adults, however, develop dementias that have a primary symptom of memory loss. There are many types of dementia, the most common one being Alzheimer's disease, which accounts for over two-thirds of all cases.

Because there are memory changes associated with normal, healthy aging, it is very difficult to diagnose Alzheimer's disease and other dementias early. There are many neuropsychological memory tests that can determine the progression of the disease once it has been established, but it is much more difficult to determine the early signs of dementia that distinguish Alzheimer's disease from normal memory change and that could be used as a diagnostic test. Unfortunately, the types of memory that are associated with very early dementia (episodic memory and working memory) are the very ones most affected in normal aging (Hodges). This means that the boundary between healthy memory change and unhealthy memory change is often not clear. One possible early difference is in the ability to remember things after retention intervals (delayed recall). One of the earliest symptom of Alzheimer's disease seems to be the loss of newly learned information after delay intervals (Albert and Killian). Forgetting rates often are the same in healthy adults if information is learned to the same criterion of performance. Alzheimer's patients, on the other hand, show greater delayed recall and more forgetting over the retention interval.

Very accurate cognitive diagnosis, however, remains difficult until the patient reaches the mild to moderate level, when other memory changes occur that are not typically associated with normal aging except for the very old (e.g., semantic memory and visuospatial memory). Category fluency (generating instances of categories) and providing verbal definitions seem to show the greatest sensitivity to early Alzheimer's disease (Hodges).

Anderson D. Smith

See also Alzheimer's Disease; Brain; Dementia; Memory Dysfunction, Drug Treatment; Memory, Everyday; Memory Training; Metamemory; Neuropsychology.

BIBLIOGRAPHY

Albert, M. S. and Killiany, R. J. "Age-Related Cognitive Change and Brain-Behavior Relationships." In Handbook of the Psychology of Aging, 5th ed. Edited by J. E. Birren and K. W. Schaie. San Diego: Academic Press, 2001. Pages 161185.

Baltes, P. B., and L indenberger, U. "Emergence of a Powerful Connection between Sensory and Cognitive Functions across the Adult Life Span: A New Window to the Study of Cognitive Aging?" Psychology and Aging 12 (1997): 1221.

Craik, F. I. M. "Age-Related Changes in Human Memory." In Cognitive Aging: A Primer. Edited by D. C. Park and N. Schwarz. Philadelphia: Psychology Press, 2000. Pages 7592.

Craik, F. I. M., and Lockhart, R. S. "Levels of Processing: A Framework for Memory Research." Journal of Verbal Learning and Verbal Behavior 11 (1972): 671684.

Einstein, G. O.; Smith, R. E.; McDaniel, M. A.; and Shaw, P. "Aging and Prospective Memory: The Influences of Increased Task Demands at Encoding and Retrieval." Psychology and Aging 12 (1997): 479488.

Hasher, L., and Zacks, R. T. "Working Memory, Comprehension, and Aging: A Review and a New View." In The Psychology of Learning and Motivation, vol. 22. Edited by G. H. Bower. San Diego: Academic Press, 1988. Pages 193225.

Hodges, J. R. "Memory in the Dementias." In The Oxford Handbook of Memory. Edited by E. Tulving and F. I. M. Craik. Oxford: Oxford University Press, 2000. Pages 441459.

Jennings, J. M. and Jacoby, L. L. "Automatic Versus Intentional Uses of Memory: Aging, Attention, and Control." Psychology and Aging 8 (1992): 283293.

MacKay, D. G., and Abrams, L. "Language, Memory, and Aging: Distributed Deficits and the Structure of New-Versus-Old Connections." In Handbook on the Psychology of Aging, 4th ed. Edited by J. E. Birren and K. W. Schaie. San Diego: Academic Press, 1996. Pages 251265.

Norman, K. A., and Schacter, D. L. "False Recognition in Younger and Older Adults: Exploring the Characteristics of Illusory Memories." Memory & Cognition 25 (1997): 838848.

Park, D. C. "The Basic Mechanisms Accounting for Age-Related Decline in Cognitive Function." In Cognitive Aging: A Primer. Edited by D. C. Park and N. Schwarz. Philadelphia: Psychology Press, 2000. Pages 321.

Park, D. C.; Lautenschlager, G.; Hedden, T.; Davidson, N.; Smith, A. D.; and Smith, P. K. "Models of Visuospatial and Verbal Memory Across the Adult Life Span." Psychology and Aging 17 (2002).

Park, D. C.; Smith, A. D.; Dudley, W. N.; and Lafronza, V. N. "Effects of Age and a Divided Attention Task Presented during Encoding and Retrieval on Memory." Journal of Experimental Psychology: Learning, Memory, and Cognition 15 (1989): 11851191.

Park, D. C.; Smith, A. D.; Lautenschlager, G.; Earles, J. L. K.; Frieske, D.; Zwahr, M.; and Gaines, C. "Mediators of Long-Term Memory Performance across the Life-Span." Psychology and Aging 11 (1996): 621637.

Park, D. C.; Smith, A. D.; Morrell, R. W.; Puglisi, J. T.; and Dudley, W. N. "Effects of Contextual Integration on Recall of Pictures by Older Adults." Journal of Gerontology: Psychological Science 45 (1990): P52P57.

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Smith, A. D. "Age Differences in Encoding, Storage, and Retrieval." In New Directions in Memory and Aging. Edited by L. Poon, J. Fozard, L. Cermak, D. Arenberg, and Larry Thompson. Hillsdale, N.J.: Lawrence Erlbaum Associates, 1980. Pages 2346.

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Zacks, R. T.; Hasher, L.; and Li, K. Z. H. "Human Memory." In The Handbook of Aging and Cognition, 2d ed. Edited by F. I. M. Craik and T. A. Salthouse. Mahwah, N.J.: Lawrence Erlbaum Associates, 2000. Pages 293358.

Memory

views updated Jun 11 2018

Memory

History

Theories of basic memory processes

Models of memory operation

Three information processing systems

Sensory memory

Short-term memory

Long-term memory

Divisions of long-term memory Procedural memory

Episodic memory

Semantic memory

Mental representations in semantic memory

Relations among memory systems in long-term memory

Research methods

Reminding and forgetting

Memory disorders

Physiological basis

Current research/future developments

Resources

Memory refers to the mental systems and processes involved in storing and recalling information about stimuli that are no longer present, as well as to all of the information that is stored. Memory is essential to healthy human functioning, and it can be said that every mental process involves some aspect of memory. Indeed, the ancient Greek philosopher Cicero once described memory as the treasury and guardian of all things.

The human brain has evolved an enormous capacity for remembering, and in the course of life, people gather and store vast amounts of information. Memories of past experiences are necessary to understand new ones, and to decide how to behave in unfamiliar situations. Without memory every person or situation we encountered would be strange and unfamiliar, and we could never learn from past experience. In fact, we would not be able to learn anything at all, since all learning requires remembering the material learned. Memory is also essential to a sense of self or identity, as memories of our past experiences, thoughts, and feelings inform us as to what we have done, who we have been, and who we are now. Memory can hold information ranging from how to put pants on, to the composition of the stars.

History

People have sought to understand the nature of memory since at least the time of the ancient Greek philosopher Plato, who is usually credited with the earliest serious discussion of it. He believed memory was like a blank slate on which accurate impressions of the world were made and preserved indefinitely. Plato distinguished two aspects of memorythe power to retain or keep information, and the power of recollection, or remembering information that is already present in memory. Platos ideas still influence many contemporary psychological theories of memory contain these same beliefs.

During the Middle Ages, before the invention of the printing press, memory served as the vehicle through which history and knowledge were passed between people and generations. A good memory was greatly prized during the Middle Ages, and the improvement of memory skills was an important topic. A distinction was made between natural and artificial memory where natural memory was the memory abilities we were born with. They could not be trained and were thought to operate in a spontaneous, instinctive manner. On the other hand, artificial memory abilities were held to be trainable, and numerous systems were developed to improve them.

As the printed word spread and the individuals memories became less essential in the transmission of knowledge the importance placed on memory by society apparently diminished. During the 1800s, educators also focused on training and exercising the memory, which was was seen by many as being like a muscle that required exercise to remain fit. Thus memorization was thought to strengthen ones current memory system as well as future memorization skills, and rote memorization (memorizing information for no purpose other than to memorize it) was advocated for students. This view came under great criticism in the twentieth century, and eventually the advocacy of rote memorization within the school system faded. Indeed, more recent research indicates that memorization for memorizations sake does not improve overall memory abilities in any observable way.

During the late 1800s the medical profession became interested in memory disorders such as aphasia (a complete or partial impairment of the ability to understand or use words), and amnesia (generally, a partial or total loss of memory). The medical profession naturally focused on physiological and biological factors, and one of their most important findings was that aphasia was caused by lesions in the brain. This finding was of immense importance as it demonstrated for the first time that physiological and psychological functioning are connected.

Sigmund Freud, an Austrian physician who began his career in the 1890s, focused on psychological disorders that he felt were caused by memory disturbances. Freud felt mental illness occurs when unpleasant childhood memories are repressed, or kept from consciousness. His highly influential theory of psychoanalysis is in fact based on the concept that memories can be repressed, and he developed psychoanalytic therapy to uncover those memories and cure the patient.

The German psychologist Hermann Ebbinghaus carried out the first controlled experiments on memory in 1885, and in so doing developed many methods of studying memory that are still in use today. For example, he developed lists of nonsense syllables (one syllable groups of letters that have no meaning, e.g. treb, fug, or duj), that individuals would be asked to memorize. Ebbinghaus used nonsense syllables in an attempt to avoid the effects of previous learning, and associations the individual might have to meaningful words. Ebbinghaus would vary different aspects of the experiments to test different aspects of memory. For instance, he varied the lists by length to see how the number of syllables affected recall, and he would vary the amount of time between memorization and recall to see how the amount of time lapsed between learning and recall affected the amount of material recalled or forgotten.

Theories of basic memory processes

It is important to note that Ebbinghaus was working within the philosophical/psychological framework of associationism. With roots stretching back to Aristotle, associationism asserts that higher-order mental processes, such as creativity or language, are produced by the combination of simpler mental processes, such as the mental association of objects, ideas, or experiences due to their similarity. Memory is said to be made up of associations between elements based on their similarity, contrast, or occurrence together in time or space. This implies a rather passive or inactive mind and memory, where the individual and their memory receives impressions and basically categorizes them according to their straightforward, objective characteristics. Remembering is simply reproducing these impressions and associations. Within this framework, when asked to remember and describe a rose, a person might search their memory for a specific representation of a rose or a specific experience with a rose, and use this to describe one.

This is in contrast to reconstructive theories of memory as proposed for example by William James in 1890, and by Sir Frederic Charles Bartlett in 1932. Within these theories, memory is seen as an active reconstruction and organization of past experiences that influences how new information is interpreted and organized, as well as how and what information is remembered. In contrast to associative theories, reconstructive theories of memory hold that abstract principles about new experiences and information are what is stored, not exact reproductions of the experiences themselves. During recall, specific memories are often reconstructed according to these general principles, they are not always reproductions of experience. Thus memory processes take an active role in what and how information is remembered. Within this framework, a person asked to remember and describe a rose might first access their general knowledge of plants, then flowers, then their knowledge of roses in general, and using this information, build or construct a description of a rose. In recent years, reconstructive theories of memory have gained favor as many psychologists believe that most mental processes, such as language and perception, are too complex to be explained by the combination of simple associative connections and reproductive memory.

Models of memory operation

Since memory and memory formation cannot be observed directly, various models have been put forth by memory researchers in an effort to clearly and simply describe how memory operates. In the early 1900s, psychologists proposed that memory was like a filing cabinet with everything categorized neatly and logically. To retrieve information, one simply and logically located the correct file folder. Later, as telephone systems were expanded, memory was likened to a telephone operators switchboard with information coming in from many directions to a central source that sorted the information and decided on the appropriate output. With the development of the digital computer in the 1950s, psychologists began describing memory in terms of a computer model and focused on how the mind and memory might process information like computers do. This model has been highly influential, and since the 1950s researchers using this model have focused on the input and sequencing of information processing.

Three information processing systems

Most researchers divide memorys information processing operations into the stages of acquisition, consolidation, storage, and retrieval. Acquisition refers to the process the brain and the sensory organs use to bring information into the memory system. Consolidation is the process of organizing information to facilitate its storage in long-term memory. Storage describes the forming of a potentially permanent representation of information in the brain. Retrieval is the process of bringing stored information to consciousness. These processes are thought to occur within three largely accepted divisions of the memory processing system that are distinguished by the length of time information can be held, the amount of information that can be held, and the different processes that occur in each: sensory memory, short-term memory, and long-term memory. It should be noted that these systems are not presumed to occupy specific physical spaces within the brain. They are, more accurately, hypothesized systems distinguished by their varying characteristics.

Sensory memory

Sensory memory, or sensory register, notes (or registers) sensory stimuli as they are experienced. It consists of representations of the outside world as experienced through the senses such as touch, sight, or smell. It holds information for approximately one to two seconds. If, for instance, you glance at the ocean and turn away, the image of the ocean will be lost in one to two seconds unless the image is quickly transferred into the short-term memory system. The contents of sensory memory are constantly changing as new stimuli are perceived. Information that does not fade from sensory memory enters short-term memory.

Short-term memory

Short-term memory is thought to process information by actively repeating, grouping, and summarizing it to aid its storage in long-term memory. Information is thought to last within short-term memory for only a short period of time before it is either passed into long-term memory or discarded. For information to be transferred into long-term memory, it must be rehearsed or repeated.

Generally, short-term memory can hold five to nine units of information for between twenty seconds to one minute. It holds information for as long as its actively thought about, or until new information basically forces it out. Unless we repeat the information and purposely try to retain it, most, or all of it, will be lost. A good example of this process can be seen when you look up a new phone number, and repeat it to yourself as you dial it. After dialing it, within a few seconds you will usually forget it. Yet if you do this repeatedly (repetition or rehearsal), like for a friend with a new phone number, it will eventually enter long-term memory.

These units of information can represent single pieces of information, such as an individuals name, or the units can be single pieces of information that represent a number of different pieces of information, as in the last name of a family representing all of the familys members. The process of using a single item to represent a number of items is called chunking, and researchers have found that short-term memorys information holding capacity can be greatly enhanced with this process.

It seems there are many factors that determine what information enters long-term memory, two of the strongest being repetition and intense emotion. If something is repeated often enough, such as multiplication tables, it will enter long-term memory. And it is hard to forget intensely emotional experiences such as being involved in a serious car accident or falling in love.

Long-term memory

Long-term memory has been the focus of most research and theory on the memory system. It holds all the information that has managed to pass through the sensory and short-term memory systems. In contrast to both of those systems, long-term memory is thought to be able to hold potentially unlimited amounts of information for an indefinite period of time, possibly for a lifetime. It is thought to hold all of the memories of our life, as well as our knowledge of the world in general. In long-term memory one might find memories as diverse as the first person you ever had a crush on, knowledge of how to ride a bike or cook scrambled eggs, the names of the five great lakes of North America, or a second language. Indeed, long-term memory is often compared to an encyclopedia in terms of the amount and range of information it holds.

Long-term memory then stores and operates on very diverse types of information, and there are many theories as to how the different types of information are represented and organized within it. Research shows that long-term memory operates according to a number of different systems, and researchers disagree as to exactly how it should be divided up. Yet there are some very influential theoretical divisions of long-term memory that are now widely accepted. These are the divisions between procedural memory, episodic memory, and semantic memory.

Divisions of long-term memory Procedural memory

Procedural memory is, as its name implies, knowledge of the steps necessary to perform certain procedures or activities. It is the knowledge of how to ride a bike or swim, how to cook spaghetti and meatballs, and even how to walk and run. Procedural learning is the acquisition of skills, such as learning how to operate a computer. How well something is learned is reflected in improved performance of the skill. It seems well-learned knowledge stored in the procedural memory system can be used without conscious awareness of the steps being performed. For instance, once a behavior is masteredsuch as walking or driving a carone rarely has to stop and think about what step comes next, and attention can be paid to other activities.

Often the information stored in procedural memory is difficult for the individual to articulate even though it is obvious from their smooth performance of the activity that they know it well. Procedural memories seem to last for a very long time, if not for a lifetime, and they are often very hard to change. Thus if one learns how to do something in a certain way, such as swim or play tennis, it can be very hard to change ones technique later.

Episodic memory

Episodic memory is the conscious recollection or remembering of specific experiences from a persons life. These memories often include the time and place of the experience, as well as a representation of the role the individual remembering played in it. An example of an episodic memory would be recalling the first time you operated a computer, including where and with whom, in contrast to how to operate a computer. Episodic memories seem to be more affected by the passage of time than are procedural or semantic memories such that if the event is not recalled and thought of relatively often, details of the event, if not the event itself, seems to fade or be forgotten over time.

Semantic memory

Semantic memory is all the easily articulated stored knowledge you have of the world in general that does not refer to specific events in your life. Examples of semantic memory involve factual knowledge such as knowing a car has four wheels, that a United States senator is elected to a term of six years, that the earth revolves around the sun, or that giving a smile increases the odds of receiving a smile. Where procedural knowledge is knowing how, semantic memory is knowing that. Like procedural memory, semantic memory seems to last for a long time. It differs from procedural memory however, in that the knowledge can usually be articulated quite easily.

Exactly how the immense amount of information we acquire throughout life is stored or organized in semantic memory is still an active area of research. Most experts believe that, in general, information is stored in networks of related concepts. The more similar various concepts are, the more closely associated they will be in memory. Research in semantic memory does in fact indicate that it is organized such that when a certain idea is activated or brought to mind, related or similar items will be identified faster. For instance, if one is discussing roses, knowledge of other flowers and plants will be recalled faster and with more ease.

Mental representations in semantic memory

Two specific types of mental representations hypothesized to be used by the semantic memory system to organize information are schemas and categories. Schemas are ordered frameworks or outlines of world knowledge that help us organize and interpret new information. They are like maps or blueprints into which new related information will be fitted. Knowledge of your home town or city, with its streets, various buildings, and neighborhoods is an example of a schema.

Research shows that new information relating to knowledge one already has will be remembered better than information about a topic of which one has little or no knowledge. Thus, if two people are given directions to a party, the one who knows the layout of the city or town pretty well will tend to remember the directions to the party better than a person who has little or no knowledge of the citys layout. This is presumably because the person with the pre-existing knowledge is able to fit the new information into their older knowledge, and thus form a stronger link in memory.

Schemas also help to reconstruct, or try to remember, information that may have been forgotten. For example, if a friend brings up something that happened one time you both went out to eat dinner a few months ago and you dont remember it clearly, you might ask for more information, and then use your schema for the usual sequence of events in eating out to try to remember or reconstruct what happened. The accuracy of reconstructions is open to question.

Categories are another representational form of thought used by semantic memory to organize information. Categories are sets of objects, experiences, or ideas, that are grouped together because they are similar to one another in some respect. For example, apartments, houses, huts, and igloos, might be grouped under the category of dwellings. Like schemas, categories help us make sense of, and organize, the multitudinous aspects of the world.

Relations among memory systems in long-term memory

While it is thought that the procedural, episodic, and semantic memory systems operate relatively independently, it is obvious that they also interact and work together. For instance, ones procedural knowledge of how to ride a bike or operate a computer will be linked with ones semantic knowledge of how bikes and computers work in general. Moreover, episodic memories of, for instance, ones first date, will add to ones semantic knowledge of dating in general, and possibly ones procedural knowledge of how to best have a good time on a date.

Research methods

Most research on long-term memory is highly specialized, focusing on particular types of information storage and the various retrieval processes associated with them. In the research laboratory memory is most often assessed by recognition, recall, or relearning tasks.

In recognition tasks, research subjects are commonly shown lists of words or groups of visual stimuli, such as pictures of faces. After a period of time subjects are then presented with new lists or groups of visual stimuli in which some of the original material is embedded or mixed in. They are then asked to indicate which items they recognize from the original material. In order to assess different aspects of memory, researchers may vary the amount of material presented, how long they let the subject study it, how much time passes between presentation of the original and altered material, and any number of other variables. Recognition is often quite accurate, especially if the subject is asked only if they have seen an item before. An example of a recognition task in which the subject is asked to choose a correct answer from among incorrect ones is a multiple-choice test.

In recall tasks, subjects are asked to reproduce material that was previously learned. The material may consist of lists of words, stories, or visual stimuli. They may be asked to report the material in exactly the same way it was presented, or to report as much of the material as they can remember in any order at all (this is called free recall). In cued recall the subject is given clues to aid their recall. Giving clues can improve recall greatly. As in recognition tasks, many variables, such as the amount of material, and time between learning and testing, can be manipulated to test different aspects of memory. An essay test is an example of a recall task.

In relearning studies, the time it takes to learn material initially is compared to the time it takes to learn the same material a second time after it is forgotten. Findings consistently show relearning time is much less than original learning time. The difference between the two learning times is called the savings score. The high savings scores found across almost all relearning studies indicates that once something is learned, it is never really forgotten completely. It seems some of the original learning remains, although how much and in what form remains unclear.

Reminding and forgetting

Reminding is an aspect of memory that indicates ideas are organized in long-term memory by similarity, whereby when people think of something, they are often reminded of a similar thing. Remindings are usually of information that is similar in content, or of earlier experiences that are similar to the current situation. The most widely accepted explanation of the reminding process is spreading activation which assumes memory is made up of networks of concepts that are connected due to similarity. When a concept from a network of concepts is used, that concept is presumably energized or activated in some way. This activation, if strong enough, spreads along the associative pathways connecting the activated concept to other related concepts and in turn activates the related concepts.

The spreading or activation process is seen as being largely automatic. It can, however, be controlled to a certain extent. In this way we can concentrate on current goals without being constantly distracted by related but largely irrelevant ideas.

Forgetting is the inability to recognize, recall, or reproduce information that was previously known or learned. Different theories within psychology propose various processes for how forgetting occurs. Traditional, associative learning theories believe forgetting is the decay of associative bonds through disuse, or not thinking of something. Associative theories also believe forgetting is caused by interference. Material will be retained to the extent that it was well-learned, unless previously or newly learned information interferes.

Interference is the confusion or substitution of one item in memory with another. There are two types of interference: retroactive interference, when old information is harder to remember because new information gets in the way; and proactive interference, when new information is harder to learn because it is similar to old information. Interference theory holds that material is rarely lost or forgotten, it is simply unavailable or inaccessible.

Psychoanalytic theory, as discussed earlier, sees forgetting as the result of repression. Freud felt a good deal of forgetting happens because the forgotten material is associated with unpleasant experiences that produce anxiety which automatically evokes the defense mechanism of repression. Memories then are never truly lost, but are irretrievable due to repression.

The contemporary cognitive approach proposes that each of the three stages of information processing forgets or loses information for different reasons. In both the sensory and short-term memory systems, information is lost through decay of their underlying neural connections. Information is never really forgotten in long-term memory. It is assumed to be there but cannot be accessed due to a failure in retrieval.

It should be noted that there is no way to know definitively whether information is retained for life or ever truly lost from memory. This is because even if someone cannot recall something that does not mean it is not present in memory. It may instead be inaccessible due to repression, interference, or retrieval failure. Moreover, it is often impossible to assess the accuracy of someones individual memories as there are no available corroborative witnesses.

Memory disorders

The two main memory disorders are amnesia and aphasia. Amnesia is a partial or total loss of memory caused by emotional trauma, disease, or brain injury (usually due to head trauma, surgical accidents, or chronic alcohol abuse). Memory loss can occur for events just prior to the amnesia-causing incident (retrograde amnesia), or for events occurring after the incident (anterograde amnesia). In severe cases of anterograde amnesia, the person may be unable to form new memories, although recall of material learned before amnesias onset is usually unaffected. Many cases of amnesia (even severe) are temporary, so that the person recovers his or her memory.

Aphasias are a complete or partial impairment of the ability to understand or use words which are caused by lesions in the brain. There are numerous varieties of aphasia, and diagnostic classification systems are constantly being revised.

Physiological basis

In recent decades, research on the physiological basis of human memory in the brain has intensified.

KEY TERMS

Associationism A philosophical/psychological stance holding that mental associations are the building blocks of complex mental processes such as language and memory.

Brain imaging techniques High technology techniques allowing non-intrusive visualization of the brain, these include computed tomography, positron emission tomography, and functional magnetic resonance imaging.

Category A set of objects, experiences, or ideas, grouped together because of their similarity, they aid the organization of information in memory.

Episodic memory Memory system holding conscious recollections of events from a persons life that often include time, place, and a representation of oneself.

Long-term memory Part of memory system capable of holding large amounts of information for an indefinite period of time, possibly for a lifetime.

Memory All of the information retained by an individual, and the mental systems and processes involved in storing and recalling information.

Neuron Nerve cell.

Procedural memory Memory system holding often hard to articulate knowledge of how to perform certain procedures or activities.

Reconstructive memory Type of memory thought to store experiences by abstract principles, which are then used to reconstruct memories during recall.

Schema A structured framework of world knowledge that helps organize and interpret new information, as well as reconstruct information that may have been forgotten.

Semantic memory Memory system holding all the easily articulated knowledge of the world an individual has that does not refer to particular events in their life.

Sensory memory Part of the memory system that registers experience through the senses, holding onto information for one to two seconds before it is lost or transferred to short-term memory.

Short-term memory Part of the memory system that repeats and organizes information to aid its storage in long-term memory, it is able to hold only limited amounts of information for short periods of time before it is either lost, or transferred to long-term memory.

Much has been learned about how information in memory is organized in the brain, and the roles various parts of the brain play in memory from research with those with amnesia or aphasia. In fact, detailed studies of individuals with unusual patterns of brain damage have produced much of our current knowledge about the physiological basis of human memory. It seems that numerous brain structures are involved in memory processing and various subtypes of memory. For instance, the ventromedial frontal region of the brain (an area in the lower front portion) seems to link memory and emotions, and the basal ganglia (a set of neural cell bodies set deep in the base of the cerebral hemispheres) are involved in learning new motor skills. Indeed, some researchers would argue that in a broad sense, one could say the entire brain is involved with some aspect of memory.

Current research/future developments

As in many other fields of psychology, research into underlying biological (physiological, genetic, hormonal) factors in mental phenomena is thriving. Studies concluded in the early and mid-1990s clearly show learning/memory mechanisms occur at synaptic connectionsthe site of information transfer between neurons. Dozens of different mutant learning/memory genes have already been identified that block learning and/or short-term, amnesia-resistant, and long-term memory. Further studies will surely help uncover intricate mechanisms at the cellular and molecular level involved in learning and memory. Continual advances since the 1970s in brain-imaging techniques that allow nonintrusive visualization of the brain at work have contributed immensely to this area of research. Improvement in brain imaging techniques such as computed tomography, positron emission tomography, and functional magnetic resonance imaging (MRI), development of new techniques, and neuro-biological and genetic research will undoubtedly lead to exciting discoveries about the basis of memory and other mental functions in the brain.

Resources

BOOKS

Gregg, V.H. Introduction to Human Memory. New York: Routledge, 1986.

Lutz, J. Introduction to Learning and Memory. Pacific Grove, CA: Brooks-Cole, 1994.

McGaugh, J.L., N.M. Weinberger, and G. Lynch, eds. Brain Organization and Memory: Cells, Systems and Circuits. New York: Oxford University Press, 1992.

Morris, P.E., and M.E. Conway, eds. The Psychology of Memory. Vols. 1-3. New York: New York University Press, 1993.

OTHER

Pittsburgh Supercomputing Center. Understanding the Brain: Watching the Brain in Action <http://www.psc.edu/science/goddard.html> (accessed December 4, 2006).

Science Daily Brain Pet Scan Predicts If Memory Lapses Will Progress into Dementia, Detects Alzheimers Disease at Earliest Stage, UCLA-Led Study Finds <http://www.sciencedaily.com/releases/2001/11/011120054932.htm> (accessed December 2, 2006).

Marie Doorey

Memory

views updated Jun 27 2018

Memory

Sarah Arvio
2002

Sarah Arvio's poem "Memory" is one of forty-nine poems collected in her first book, Visits to the Seventh, published in June 2003 by Alfred A. Knopf in New York. Poems in this collection capture traces of dialogue between a woman and several ethereal presences; they talk about the break-up of the woman's love affair and the death of her mother. In "Memory," which first appeared in Raritan Quarterly, the poet examines remembrances of the lovers' quarrel that lead to the break-up. Visits to the Seventh marks Arvio's literary debut, accomplished by Arvio in her forties after publishing poetry in several literary journals such as Poetry, The Paris Review, and Best American Poetry 1998. The poet's dialogues with these visitors—either ghosts of the dead, the voice of Arvio's inner life or a chorus of her poetic muses—speak to the meaning of life and the sense of longing created by the insufficiency of memory. "Memory," like most of Arvio's poems in this collection, is written in free verse, the term typically used to describe nonmetrical and unrhymed poetry, common among contemporary poets. Metrical verse derives its structure from a set of formal rules for the length and arrangement of each line. Arvio groups her poems in stanzas often linked together by lines that continue a thought, a piece of dialogue or an action into the following stanza.


Author Biography

Sarah Arvio, author of "Memory" and other poems collected in her first volume of poetry, Visits from the Seventh, was born in 1954 in Philadelphia, Pennsylvania, and grew up near New York City among radical Quakers. She was educated at schools abroad and later attended Columbia University, where she studied writing. Arvio could not envision herself as a creative writer, she told Borzoi Reader for its website, until she began undergoing psychoanalysis and studying her dreams. "When I thought about writing my own words, I imagined pressing down so hard on the pen that I broke the nib," Arvio said. "When I looked inward I saw nothing but turmoil and grief. I couldn't realize my thoughts; I had a voice but couldn't use it." Soon after turning forty, Arvio found her poetic voice, the product of an "open, amazed mood" that allowed her to listen to her thoughts. She told Borzoi Reader: "I found my own thoughts intriguing and even beautiful."

It was not until she was in her forties that Arvio was able to publish her first collection of poems, which critics have hailed as a highly original debut. Arvio has supported herself as a translator for the United Nations in New York and Switzerland. Visits from the Seventh was published in June 2002 by Alfred A. Knopf. The first eleven poems in this collection won The Paris Review's Bernard F. Conners Prize and were reprinted in The Best American Poetry 1998. Other poems from her first book won Poetry's Frederick Bock Prize. In 2003, Arvio was awarded the Rome Prize of the American Academy of Arts and Letters. "Memory" was first published in Raritan Quarterly, a humanities journal published by Rutgers University. Arvio has published poetry in literary magazines such as The Paris Review, Poetry, Southwest Review, and Literary Imagination. She also has translated literary works, such as Fray Ramôn Panâe's short story, "How the Men Were Parted from the Women," which appeared in the anthology The Oxford Book of Latin American Short Stories.

Poem Text

"And do we remember our living lives?"
Did I remember the clock or the door,
or the words "I love you" or the word "why";
did he recall the blue vein in my wrist
or only the ice-blue burn in my eye?     5
What remained of the room and of the night,
the kiss or the argument that ensued?
"You see, our memories are much like yours,
here a shadow, a sound, a shred, a wisp …"
"And do we want to remember?" one said.     10
"Never never Oh give me the blurred wish
or the dream or the fact half-forgotten,
the leaf in the book but not the read page,
not what I saw but what I felt I saw,
not what I felt but how I wished to feel
,     15
give me what I can bear to know I felt."
I choose to recall only the blue dusk.
"Do you think you choose? If only you could
determine your secret determinants."
Did I recall the cocktail as it smashed     20
against the wall there, so close to my eye,
did I forget why I left my home, why?
The full events of that terrible time
dissolving into the deep hues of dusk
and leaving essence to the inner eye.     25

Poem Summary

Stanza 1

In "Memory," a woman still suffering from the break-up with her lover is addressed by the invisible "visitors" who inhabit a "seventh" dimension, the "sixth" being sex, which they have explained in poems that precede this one in the collection. The first line begins with their question: "And do we remember our living lives?"—our lives as they were lived without the revision of memory? In the first, five-line stanza, the woman in the poem recalls the details of a daily life in which strife and death are temporarily absent—details such as the clock measuring seemingly endless time or the door in which a lover enters. Near the end of this stanza, however, the reader becomes unable to deny what is coming, tipped off by language escalating in emotion from the almost quotidian though tender "I love you" to an urgent and anguished "why?" What caused the argument, which the poet does not actually discuss in detail in the poem. What was its now elusive trigger? What did the speaker mean to the lover who broke from her?

Stanza 2

In the second stanza, lines 6 through 10, the poet's unseen visitors reveal to her that death does not take the sting out of memory, improve the quality of its ability to record events, or resolve its conundrums. "You see," the visitors say, "our memories are much like yours, / here a shadow, a sound, a shred, a wisp." But they also frame for her the choice that she has, which will allow her to put aside memory's puzzle. "And what do we want to remember?" one said.

Stanzas 3 and 4

The third and fourth stanzas describe the poet's immediate rebellion. She believes she can improve her memories by summoning the courage to relive the terribly painful emotions this catastrophic lover's quarrel provoked. The third stanza begins, in the first three of five lines, as the poet's prayer: "Never never Oh give me the blurred wish / or the dream or the fact half-forgotten, the leaf in the book but not the read page." She asks for even more, not merely the facts but what they meant, what she can bear to know.

Stubbornly, perhaps, the woman in the poem tells her visitors in the next stanza that she has made a choice. "I recall only the blue dusk," the aftermath of dissolution in its sad and non-negotiable finality, and not the climactic pain of her last argument. But her visitors, made wise by the transformation of death and the realities of life in the untouchable seventh dimension, attempt to be instructive about the inevitable nature of memory. "Do you think you choose?" they say. "If only you could determine your secret determinates." The last line of this penultimate stanza reveals the poet's immediate reconsideration of her desire to overrule memory as it leads us to the poem's end. Her anguish is once again poignantly apparent.

Stanza 5

In lines 23 to 25 of the last stanza, the narrator's acknowledgement of "that terrible time" recedes, yielding again to the blue transition of dusk and leaving only the essence of catastrophe to the realm of "the inner eye."

Themes

Longing for Life

"Memory" continues to look at the paradox these invisible visitors present to the woman in the poem—her inability to fully examine and appreciate life while she is in the middle of living it, and the visitors' urge to go back to resolve their own issues now that they have the benefit of a perspective earned through death. Other poems in the collection delicately examine the visitors' state of being and their desire to use the woman in these poems vicariously. In this poem, the visitors serve as psychological mentors attempting to instruct her in how to manage the same things they do, such as the pain of loss, while grasping at the straws of memory to make sense of it all.

The Unreliability of Memory

"Memory" examines the distortion of the memory, making it impossible to reassess or sort out events and how they affected not only self-perception but also perceptions of an important, once-loving relationship. The visitors may identify with the woman in the poem, but they are also critical that she does not understand the futility of what she is doing.

Unresolved Issues

The woman in "Memory" longs to know if the last argument she had with her lover killed not only the relationship but also the attraction they once had for each other. She combs her memories, hunting for clues, but can only relive the emotions—regret, anger and fear—that she felt during the argument.

Style

Contemporary Poem

The internal structure of Arvio's poem "Memory" is, unlike a galloping, faithfully iambic Victorian epic, informal and therefore unobtrusive. This allows the poet to construct lines that sound like conversation to the reader. The flexibility of free verse allows the poet a series of stressed syllables, which give the lines a special poetic weight. For example, in the lines "did he recall the blue vein in my wrist / or only the ice-blue burn in my eye?" the poet uses the pounding cadence of "ice-blue burn" to emphasize the anger the argument elicited. Though the poem is relatively informal, Arvio uses sonic devices to emphasize other elements in the poem. The word "why" is rhymed at the end of a line with the word "eye" in the first stanza and again in the final stanza. The structure of the poem may not be guided by the rules of formal convention, but the poem does have symmetry. The poem is composed of five stanzas of five lines each, a neatness that echoes the suggestion of acceptance at the end. The third, fourth and fifth stanzas are each linked by a line that continues a thought introduced in the stanza above it, which reflects the poet's evolving perspective. A dramatic unity is suggested by the rhyming pattern established in the first stanza and repeated in the last. The poem makes maximum use of the word "blue"—a blue vein, ice-blue anger, blue dusk. The opposite of blue, the warmer shades of yellow that Arvio examines in other poems in this collection, is absent, as is red—the color typically associated with both passion and rage. In this poem, memory has rendered all facets of a lover's quarrel and its aftermath in monochromatic hues.

Topics For Further Study

  • Read the rest of the poems collected in Arvio's first volume of poetry, Visits from the Seventh. Compare Arvio's poems with the poetry of other American women such as Sylvia Plath, Maxine Kumin, Anne Sexton, Denise Levertov and Rita Dove. What makes these poems uniquely feminine?
  • What elements of poetic structure does Arvio employ in "Memory" and other poems in Visits from the Seventh? What might their function be? Compare the structure of this poem with the structure of a poem by a modern formalist poet such as Robert Frost, Richard Wilbur or Anthony Hecht as well as neo-formalists such as Rhina P. Espaillat, Dick Davis and Dana Giola.
  • What might the color blue represent in the poem "Memory?" Compare the use of blue in this poem to the use of pink, yellow, white, green and aqua in other poems in this collection. How does color allow the poet to create not only a picture in the mind's eye, but also a mood?
  • Compare the supernatural voices captured by Ephraim and the others in James Merrill's The Changing Light at Sandover. What relationship do they have with their human medium? How do these supernatural conversations differ from those that spring from the relationship Arvio's unseen visitors have with the woman in Arvio's poetry?

Historical Context

Contemporary Poetry

"Memory" is part of a collection of poems that reflect contemporary life in New York City, a city familiar to many Americans, even those who only know the city through movies or the pages of the New Yorker. These sometimes funny and erotic poems reflect the world view of a highly educated woman, one who laces her lines with French phrases, references to other poets and classic Hitchcock movies. The woman in these poems is the perfect audience for the aristocratic ramblings of the chorus of invisible visitors that people her work. In contemporary, post-feminist poetry, women writers can enjoy the fruits of liberation from the mandatory roles of child-rearing and housewifery. Their bold, witty work shows how able they are to avoid the self-destructive impulses evident in the poetry of some women writing a generation before, such as Sylvia Plath and Anne Sexton. Poet Mark Strand, writing for the back of the book, asserts that these poems are neither sad nor confessional. Simply put, a confessional poem is one in which the poet speaks to the reader.

But Rob Neufeld, writing for the Asheville Citizen-Times and once a friend of Arvio's, disagrees. "The poems are, in good measure, confessional and we'd be cheated if they weren't," Neufeld writes, describing the glimpse of the poet taking a contemplative walk down Park Avenue in one poem. Other admirers of Arvio's work, such as New York poet Richard Howard, find links to Arvio's work to that of earlier women writers, such as Christina Rosetti and Virginia Woolf, because of its attentive interest in internal rather than external voices. "The whole series is an articulation of what we used to call 'the inner life': one woman's passionate questioning of her sources," he said. "Memory" is feminine in its self-conscious reflection on lost love and its ear to internal voices, but it is especially contemporary in its un-self-conscious ownership of anger, eroticism and humor. With this freedom, perhaps, comes the insistent flowering of a strong and compelling poetic voice at an age—past forty—that publishers apparently consider to be rare. Contemporary poetry has further pushed the boundaries of language, image, form and voice. Part of Arvio's cultural contribution might be helping to break through another artistic barrier that has constrained and discouraged writers, male and female alike.

Critical Overview

"Memory" is one of forty-nine poems in an award-winning collection hailed as a highly original debut, admired as "a splendidly odd and compelling first book" by the Washington Post. Post critic Edward Hirsch enjoys Arvio's "nervy, fanciful and unified" poetry and commends her attentiveness to her supernatural guests by calling her a "spiritual apprentice." Roy Olson, writing in Booklist, notes that the "poems sparkle with worldly wise wit." Critics and fellow poets enjoy the uniqueness of Arvio's dialogue with the supernatural visitors, and her ability to be both simultaneously funny and erotic in these contemporary odes to life. "Sarah Arvio's poems engage in an agitated description of the inner life," said poet Mark Strand, quoted on the back of Arvio's book. "The voices drop in and out like a beautiful quixotic chorus." Judy Clarence of the Library Journal commends Arvio's competence as a poet in avoiding the pitfalls of engaging the supernatural, which she calls "dangerous ground." "Writers who venture in the realm of the occult risk banality," Clarence says, adding that "Arvio's prodigious talent saves her."

Criticism

Lisa Trow

Trow is a published poet and writer. In this essay, Trow considers the value of employing super-natural voices as a poetic conceit.

"Memory" and other poems in Sarah Arvio's Visits from the Seventh give scant, if any, evidence of how the poet's upbringing in a strict Quaker household, and her subsequent psychoanalysis, affected her poetic voice. These poems are not unique because of their singular cultural references. The only archaisms in speech are the quirky and affected terms of endearment used by the poet's aristocratic invisible visitors. The anger and eroticism of this and other poems are not overblown in the rebellion of an unusually chaste or strict religious environment. "Memory" is not steeped in the self-conscious or hypercritical assessments of the heavily psychoanalyzed. Instead, this poem is open to any woman who experiences the shock of losing a love that had, before the unexpected catastrophe of argument, become a beloved fixture of life.

The origin of the poetry's wry and New York-worldly sense of humor that critics embrace when discussing this unusual collection of poems is not a surprise. Arvio is an educated, already well-decorated poet of diverse professional skills who knows New York City well. But what is unusual is the conceit on which the entire book is founded, a group of visitors—unseen, even to the poet—and their supernatural origin. They are souls who derive their sense of humor and the influence of their commentary from the vantage point of death. While other poets, such as Nobel Prize winner Wistawa Szymborska, unifies the poems of one collection with observations on the human callousness inherent in acts such as terrorism, Arvio constructs an interactive Greek chorus of dead souls and builds a book around their conversations with her.

The chorus seemingly understands its role before the poet does. She is instructed later in the collection, after having become aware of them through the exercise of a post-sexual seventh sense. "'It might / be best," one said, 'to call us a conceit.'" But what purpose does this conceit serve? The voices move in and out of these poems and sometimes require pointed invitations to appear. When they do appear, they cajole and tease, filling in for missing human equivalents, such as a mother who has died, or a lover who has left. To accentuate their elusiveness, these visitors require, like supernatural beings in any genre, that the woman in these poems keep quiet about them or risk losing contact. In "Memory," which appears more than half way into the collection, their capricious playfulness is absent. It is replaced by a more sober consciousness in possession of a secret that has eluded their human companion, who is now preoccupied with the violent quarrel that ended an important romance.

"Memory" is not a fun poem or one of the more lyrical in the collection. This is a pre-memorial poem, written after the death of love but before it is buried. The distance between the poet and her unseen muses is close, more personal and less transcendent. They sit on her shoulder, looking into her past without enjoying the view, something they take particular pleasure in doing in other poems in the collection, such as "Park Avenue." Here the ghostly visitors seem to want to assuage their host's pain by offering unflinching acceptance—even though they share Arvio's preoccupation with unsettled human relationships and the psychic unrest they have assured her follows lovers to the grave. Longing and regret commingle here with the erotic charge that survives death.

The rift between the lovers in this poem is swift and violent and the memory of love in the face of subsequent loss deteriorates quickly. "What remained of the room and of the night, / the kiss or the argument that ensued." An anguished respect for the danger of uncontrolled emotion remains, too. "Why," the poet asks twice. "Did I forget why I left my home why?" The stylistics of the poem emphasize the question and the role memory plays in the mutability of perception. "Why" is rhymed twice with "eye" in this otherwise informally structured poem. At its first mention, "eye" is literal and specific. It refers to the eye of the narrator and its ice-blue reflection of the cold, hard anger she feels for her lover. At the second mention, the narrator's eye is vulnerable to the violence of a cocktail smashing the wall close by. By the last line, the "eye" becomes realized as a symbol for memory and its abstract function of capturing the time as it passes and before it completely dissolves. This cold anger has frozen memory until it is warmed by the poet's reflection, perhaps making it even more elusive until it is only a stain on the mind's eye.

Looking into her past, the spirits are voyeurs to this anguish and to the narrator's insecurities. "Did he recall the blue veins in my wrist / or only the ice-blue burn in my eye?" The poet wonders, in the end, what she was to her lover. Was she attractive, warm, sensual and beloved? Or will he only remember her as the angry shrew she was when he saw her last? The visitors are consoling, saying she is not different from them, even as they watch her from their supernatural perch. Her memories are inexact, the same as theirs. The narrator remains conflicted, but the voices continue to console, now with condescension. "'And do we want to remember?' one said."

One cannot really chose how to remember one's life, how to set it in the proper context based on externals. The quality of memory does not allow such assurances. "'Do you think you chose?'" the voices say. "'If only you could / determine your secret determinants.'" The narrator's sense of resignation that follows is the product of impasse. With supernatural authority, the voices have contributed to the narrator's understanding of two key points about the nature of memory—its resiliency, invulnerable even to death, and its deeply occult nature, unknowable even to the dead.

For the wisdom of these visitors to resonate, one must accept the use of metaphor with proper respect and recognize its descent from an honorable literary tradition. Critics view Visits from the Seventh and its supernatural conceit variously as the foundation of an odd and fanciful collection, an important advance in the poetics of transcendence, or a dangerous flirtation with banality. Judy Clarence of Library Journal makes almost deprecating note of Arvio's "flair for the supernatural" and credits her "prodigious talent" for rescuing her from the pitfalls of literary gimmick. Ray Olson, writing in Booklist, recognizes Arvio's sagely and sometimes wisecracking visitors as less magic and more the voices of "unuttered thoughts most of us have." Other publications giveVisits from the Seventh a lineage with more gravitas. A critic from the New Yorker, who is quoted in the paperback publication of Arvio's collection writes "This extraordinary first book of poems takes its place in an authentic line of descent from such landmarks as Yeats's A Vision and James Merrill's The Changing Light at Sandover," an epic trilogy based on Merrill's transcriptions of Ouija board conversations with the poet's deceased friends, as well as Jesus, Plato, Nefertiti, Mercury, the nine muses and Michael the Archangel.

New York poet Richard Howard, quoted in the hardcover publication of Arvio's collection, seems to understand Arvio best, admiring the poems as "the most 'convincing' visitations since Merrill's Ouija-board transcriptions," but noting her possession by personal voices. "The whole series is an articulation of what we used to call 'the inner life': one woman's passionate questioning of her sources and their equally passionate (if often derisive) answers," says Howard, writing for the hardcover edition book jacket. "She has forged her own dialogue of the dead…. I love hearing her persuasive voices; they are the woman herself."

Perhaps such a manifestation of Quaker Inner Light and psychoanalysis is a chorus of spiritual advisers, in place to speak to the mysteries of life that can be explained and to identify the ones that cannot. Arvio's invisible visitors are a conceit. The visitors admit as much in "Three Green Stars," which appears in the last few poems of Visits from the Seventh. "We were driving in the Jersey meadows / a gray purple sky, roving orange spots, / white clouds lit miasmic yellow. 'It might / be best,' one said, 'to call us a conceit.'" But their voices spring from Arvio's imagination, tilled by years of self-examination, and a cultivated receptivity to self revelation. Their inspired speech has been hidden until Arvio gave them form, like a costume to put on and take off. "Memory" is a poem about a woman talking to her wiser self.

Source: Lisa Trow, Critical Essay on "Memory," in Poetry for Students, Thomson Gale, 2005.

Pamela Steed Hill

Hill is the author of a poetry collection, has published widely in literary journals, and is an editor for a university publications department. In the following essay, Hill examines Arvio's poem as a mental battleground on which the speaker's desire to remember and desire to forget wage a war that neither can win.

What Do I Read Next?

  • In "Park Avenue," which also appears in Visits from the Seventh (2002), the poet describes a walk along the streets of New York, giving her invisible visitors the "intimate view" of the city they crave, and writing bits of their commentary down on scraps of paper.
  • In her poem, "Motherlessness," also from Visits from the Seventh (2002), Arvio describes "the hole in the skin of her soul" left by the loss of her mother.
  • Ezra Pound uses foreign words in The Cantos (1–109) (1964), a technique employed by Arvio in Visits from the Seventh.
  • "Ode to a Nightingale," by John Keats, from The Complete Poems (1988), offers a vehicle for poetic transcendence in the form of an unreachable bird.
  • Arvio's work has been compared to James Merrill's The Changing Light at Sandover (1982), which is based on extensive transcriptions Merrill and his housemate David Jackson took from a Ouija board. The Changing Light at Sandover reports the messages of Merrill's deceased friends as well as mythic, historical, and literary figures such as Gertrude Stein, William Butler Yeats, Richard Wagner, Homer, Jesus, Mohammed and the angels Michael and Gabriel, as well as the nine muses.

Arvio's "Memory" is one of those poems that is better served by reading it within the context of the collection that includes it. The purpose of the visitors that come to Arvio as she writes is more substantiated when one can hear the full range of the strange little spirits' admonishments, encouragements, playful quips, and philosophizing in a variety of situations. That said, however, there is enough ammunition in this single poem to lay open the age-old struggle between one's inner-self and one's other inner-self, exposing the hapless attempts of an individual to recall the good and forget the bad.

In an interview by poetry editor Deborah Garrison for The Borzoi Reader Online, Arvio calls the poems in Visits from the Seventh "love poems to life; poems of longing for life." Growing up Quaker, she was taught not to "glorify an afterlife" but to "long for this life." Perhaps these revelations help clarify the opening line of "Memory": "'And do we remember our living lives?'" This line is supposedly spoken by one of the ghostly visitors, but the curious phrase "living lives" is the thing to note, no matter who says it.

While the noun "lives" may invoke countless adjectives to describe it, the word "living" is not typically one of them. It seems redundant. Her use of "lives" implies living. The need to define lives as living suggests that there are other types of lives, lives that may be forgotten or repressed. The latter is most poignantly addressed in this poem.

Each stanza presents a back-and-forth, tit-for-tat banter about fond memories and not-so-fond memories. In the first, the question regarding living lives establishes the central inquiry that the remainder of the poem tries to answer. The speaker is not sure whether she can recall the specific tangibles—"the clock or the door—" or intangibles—"the words 'I love you' or the word 'why'"—of a personal event in her life. One must assume that the episode involves a romantic relationship in trouble, since someone is leaving and someone is asking why. Memory is tricky here. The speaker may not remember an important declaration of love, but she does recall a "blue vein" in her wrist. She does not know, however, whether her lover recalls that part of her or "only the ice-blue burn" in her eye.

Each of these snippets of thought is a part of the living life of the speaker, but she cannot fully accept that they reflect her actual past. The implication is that they are factual recollections because there would be no reason to question the memory of a clock, a door, or a conversation if those things never existed. Even the slightest bit of doubt allows one to repress thoughts that are too painful to accept as fact. The battleground is established between what the speaker thinks she remembers and what she would prefer to question.

In the second stanza, the "room" and the "night" appear to be accepted, if not desired, memories, but then there is a quick switch to ambiguity when the speaker tries to decide whether "the kiss or the argument"—or both—occurred next. Kissing and arguing obviously connote two very different events in a relationship, although they may both certainly happen in the same setting. But juxtaposing a pleasant moment with an unpleasant one suggests an unsettling battle between good recollections and bad.

In The Borzoi Reader Online interview, Arvio says this about the imaginary beings that visit her when she writes "Their memory is stronger than mine, and their associative powers are stranger and more vivid." Interestingly, in the poem "Memory," one of her visitors remarks, "'You see, our memories are much like yours, / here a shadow, a sound, a shred, a wisp.'" The point is not so much the contradictory opinions about the speaker's versus the visitors' recall ability, but the fact that the idea of memory is an important presence in the struggle of the inner-selves.

Just as important are the words used to describe the memories of both the human and the spiritual visitors—shadowy, shredded, wispy. The uncertainty and incompleteness of memories make them easier to repress at will. However, as is clear in the poem, even those intentionally stifled have a way of creeping into an individual's mind when least expected or least desired. The italicized lines provide the best defense for the repression side. They answer the question, "'And do we want to remember?'" with a resounding, "'Never never'" and then proceed with an explanatory list: a "blurred wish" is better than a "fact half-forgotten," what people think they see is better than what they actually see, what people wish to feel is better than what they really feel, and so on.

The fourth stanza of "Memory" reveals a rather desperate attempt by the speaker to simplify the battle going on in her head. She confidently uses the phrase, "I choose to recall" only to be immediately admonished by a visitor who asks sarcastically, "'Do you think you choose?'" This is perhaps the most poignant indication that the war on her mental battleground is one that cannot be won. She is not in control of her "secret determinants," and if not she, then who?

The latter part of the poem provides the greatest evidence of why the speaker wages such a frustrating war of emotions within herself. Again, she asks a question that implies an irony—if she does not really "recall the cocktail as it smashed / against the wall there, so close to [her] eye," then why ask the question? The details are too specific to be a total figment of her imagination. On the one hand, she longs to forget that such a violent event ever occurred in her life and on the other hand she cannot help but remember it.

In the final stanza of "Memory," Arvio makes a subtle connection to the first stanza, in which the word "why" is suggestive of something bad about a relationship but not conclusive. It is not clear who is asking why in the first stanza, the speaker or her lover, but in the final one, it is clearly the speaker who ponders the question. Again, the query is rhetorical at best. Is it likely that one who leaves her home, her lover, and life as she knows it would actually forget why? No, but the implication is that her mind would like to forget. In reality, she cannot, and so the struggle continues in its back-and-forth cycle.

In spite of the confusion, the speaker cannot be blamed for wanting to forget the "full events" of what she calls "that terrible time." Attempting to repress the memory of unfortunate or tragic moments in one's life is a fairly common human endeavor. With the passage of time, the speaker believes her memory of the events surrounding the break-up of her relationship is "dissolving into the deep hues of dusk," but dissolving does not necessarily mean going away. It may mean simply changing form. In this case, the "essence" of past events are now left to the "inner eye," but is the inner eye still not a part of the person who is trying to forget?

Arvio ends the poem here, without fully disclosing what the speaker's "inner eye" really is. Most likely, it is that part of the human psyche that accepts the truth no matter how painful it may be. Think of it as a kind of receptor that keeps its feelers out for the true "essence" of all the events that happen in a human's lifetime. The inner eye never turns away sad or bitter memories of the worst events in spite of attempts by the rest of the mind to do just that. This inescapable dichotomy is the main fuel for the battle of emotions that rages within the speaker. She may placate one side for a while, but the other side always chimes in with thoughts she would prefer not to entertain.

Perhaps this is the reason for the visitors. They not only act as little alter egos of the speaker but also allow her to carry on mental conversations with herself when plain, simple thinking is not enough or when it provides undesirable results. Thoughts or memories of certain events in her "living" life lead only to despondency, so handing that chore off to imaginary friends alleviates the pain of a direct confrontation. In "Memory," the visitors admit that they "never" really want to remember, that they much prefer wishes to facts or what they long to see instead of what they really see. Yet they are able at least to address the painful truth when they must. This is not always the case for the speaker.

The speaker tends to use the visitors to keep a foothold in reality even though it is not a pleasant thing to do. While it is arguable that she may feel less emotional turmoil with a few less voices pop-ping in and out of her head, the questions, proclamations, and quirky suggestions made by the visitors prod her into staying focused. If she gave in wholly to her desire to forget, allowing this side of the inner-self war to win, one would have to consider what has really been won. Repression and avoidance will take their toll somewhere down the line. Let the battle continue, however, and the speaker herself endures.

Source: Pamela Steed Hill, Critical Essay on "Memory," in Poetry for Students, Thomson Gale, 2005.

Ray Olson

In the following review, Olson praises Arvio's edgy sophistication.

Arvio's debut collection extrapolates entirely on a single conceit—that voices from a seventh sensual dimension counsel the poet in the wake of a long love affair. Like the unuttered thoughts most of us have, the voices remonstrate, sagely advise, philosophically expatiate, pooh-pooh, and wisecrack, but seemingly with greater objectivity than one's own thoughts could achieve. Perhaps the distress of falling out of love has clouded the poet's self-consciousness. Certainly, the first poem's first stanza bespeaks confusion about identity: "'but we're your one design,'" the voices say, "or 'you're our one design'—which was it?" As the poet recalls scenes from the affair and adjusts to her new reality, the poems sparkle with worldly-wise wit, including droll observations about sex, defensive rationalizing about abortion, recriminations against Mom for not comforting her lovelorn daughter, and considerations of the many ways that love relates to death. If Arvio's book lacks the brutal impact of Margaret Atwood's cycle of poems on a love affair, Power Politics (1971), it compensates gratifyingly with edgy sophistication.

Source: Ray Olson, Review of "Visits from the Seventh," in Booklist, Vol. 98, No. 11, February 1, 2002, p. 917.

Rob Neufeld

In the following review, Neufeld recalls being in high school with Arvio and calls the poems in "Visits from the Seventh" masterful.

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Source: Rob Neufeld, "A Glimpse into the Making of a Poet," in Asheville Citizen-Times, March 22, 2002.

Sources

"Arvio, Sarah," in Contemporary Authors Online, Gale, September 11, 2003.

Arvio, Sarah, Visits from the Seventh: Poems, Alfred A. Knopf, 2003.

Clarence, Judy, Review of Visits from the Seventh, in Library Journal, Vol. 127, No. 5, March 15, 2002, p. 85.

Garrison, Deborah, Interview with Sarah Arvio, in The Borzoi Reader Online, at www.randomhouse.com (last accessed March 18, 2004).

Hirsch, Edward, "Poet's Choice," Review of Visits from the Seventh, in Washington Post Book World, June 9, 2002, p. 12.

Howard, Richard, in Visits from the Seventh, Alfred A. Knopf, 2002.

Nadel, Alan, "Replacing the Waste Land—James Merrill's Quest for Transcendent Authority," in Modern American Poetry, at http://www.english.uiuc.edu/maps/poets/m_r/merrill/nadel.htm, (last accessed May 17, 2004).

Neufeld, Rob, "A Glimpse into the Making of a Poet," in the Asheville Citizen-Times, March 22, 2002, at cgi.citizen-times.com/cgi-bin/story/arts/9595 (last accessed May 18, 2004).

Olson, Ray, Review of Visits from the Seventh, in Booklist, Vol. 98, No. 11, February 1, 2002, p. 917.

Review of Visits from the Seventh, in Random House On-line Catalog, at http://www.randomhouse.com/catalog/display.pperl?0375709789 (last accessed May 17, 2004).

Strand, Mark, in Visits from the Seventh, Alfred A. Knopf, 2002, back cover.

Further Reading

Graham, David, and Kate Sontag, eds., After Confession: Poetry as Autobiography, Graywolf Press, 2001.

After Confession: Poetry as Autobiography is a compilation of twenty-eight essays by poets Billy Collins, Yusef Komunyakaa, Louise Glück, and others examining the persistent influence of confessional poetry on contemporary verse.

Komunyakaa, Yusef, and David Lehman, eds., Best American Poetry 2003, Charles Scribner's Sons, 2003.

Best American Poetry 2003 is one in a series of eagerly-awaited annual collections of contemporary poetry. This issue, by decorated Vietnam veteran Komunyakaa—an African American poet from the South, includes the work of well-established poets such as Rita Dove and Billy Collins as well as emerging talent such as Natasha Trethewey.

Schmidt, Elizabeth, ed., Poems of New York, Alfred A. Knopf, 2002.

Poems of New York is an anthology of poetry by poets who have made New York City their subject, beginning with Walt Whitman. Schmidt began collecting poems to celebrate New York City's unique character and vitality after the September 11, 2001 terrorist attacks.

Strand, Mark, ed., The Contemporary American Poets, Signet Classics, 2000.

The Contemporary American Poets is an anthology for the poetry beginner. It includes seminal poetry from the contemporary movement in the United States, written by poets such as A. R. Ammons, Sylvia Plath, Richard Howard, Charles Simic, and James Merrill.

Memory

views updated May 14 2018

MEMORY

Remembering is one of the most characteristic and most puzzling of human activities. In particular, personal memorythe ability mentally to travel back into the past, as leading psychologist Endel Tulving puts itoften has intense emotional or moral significance: It is perhaps the most striking manifestation of the peculiar way human beings are embedded in time, and of humans' limited but genuine freedom from their present environment and immediate needs. Memory has been significant in the history of philosophy as much in relation to ethics and to epistemology as in theories of psyche, mind, and self.

The philosophy of memory is a fascinating, diverse, and underdeveloped area of study, which offers difficult but rewarding connections not only with psychology and the cognitive sciences, but also with the social sciences and political theory, and with literature and the arts. Outside philosophy, interest in memory increased massively and disproportionately in the late twentieth century in both the neurocognitive sciences and the humanities, driven both by internal developments within disparate disciplines and by wider social and cultural concerns about trauma and recovered memories, about the politics of forgetting and collective responsibility, about memory loss in an aging population, and about the manipulation, control, ownership, and protection of individual memory. The widespread and troubled fascination in Western culture with this last set of concerns in particular, and with challenging associated questions about moral psychology and personal identity, is suggested by the success of films like Bladerunner (1982), Memento (2000), and Eternal Sunshine of the Spotless Mind (2004).

As a result, just as in other areas of the philosophy of mind, it has become increasingly difficult to cordon off a set of questions about memory, or methods for its study, which are uniquely or primarily philosophical. Some philosophers treat memory as a case study in philosophy of science, asking for example whether the psychology of memory might be reducible to the neuroscience of memory. Others begin with the phenomenology of memory, the ordinary experiences and practices of remembering; others still inquire into cross-cultural or historical differences in these practices. It seems likely, further, that psychopharmacological influences on memory, and their potential misuse, will make memory a central topic in the emerging fields of neuroethics and philosophy of psychiatry. This entry covers more traditional philosophical issues about the nature of memory, but includes some consideration of the need for a broader framework that can encompass the neural, embodied, psychological, and social aspects of remembering.

Forms of Remembering

When a person is remembering, there are many different activities he or she may be engaged in, and the expression of the individual's memory can take many different forms. One reminisces with old allies about shared experiences; one finally calls to mind that obscure fact; one mindlessly cycles off down the lane, despite not having been on a bike for years; one sits alone and ruminates on one joyful or agonizing moment long ago; one gathers with others to commemorate a significant occasion; one writes or fashions something in memory of a person or an event; a photo, an odd memento, or a long-forgotten melody suddenly immerses a person in the emotions of another time.

It is not easy to pinpoint just what is common across this range of activities, and some philosophers have argued that not all of them involve true memory. But the present-day consensus in both philosophy and psychology is that there are at least three distinct forms of remembering that can helpfully be detected in the variety of ordinary experience.

First, in remembering specific events or episodes from an individual's personal past he or she draws on personal memory (also known as experiential or event memory ): For example, one remembers walking down by the river with a friend that spring afternoon. Psychologists often call this episodic memory, or sometimes autobiographical memory.

A different form of memory is naturally expressed with a "that" complement: One remembers that Aristotle was Alexander's tutor. This factual or semantic memory is akin to simple belief, and the remembered facts can be about events in the remote past, or indeed the future, as well as personally experienced events. One can factually remember details one has been told about one's early life, for example, for which one has no personal memory, no sense at all of what the past experiences were like.

In English, and many other languages, people sometimes contrast things that they "just know" from what they genuinely (personally) remember, thus treating personal memory as the basic or essential kind of memory. But in other contexts people are happy to talk also of remembering facts, and to attribute their general beliefs about the world to "memory" in a broader sense.

Personal/episodic remembering and factual/semantic remembering are both forms of declarative memory, in which individuals seek to hook up to reality, to represent the world or the past. Although remembering activities often have quite different functions as well, under normal circumstances such memories aim at truth. This is so even though, as both scientific and common-sense psychology increasingly suggest, people do not always get there. The point is not that memory necessarily or even reliably achieves this aim, but that one's ordinary practices include a general commitment to its reliability in doing so. For example, an individual may or may not in fact have walked by the river with a friend that spring afternoon, and Aristotle may or may not actually have been Alexander's tutor. But if one is sincerely expressing that personal memory, or that factual memory, one is (among other things) making a claim about what happened.

In these declarative forms of memory, the content of one's memory can in principle at least in central casesbe articulated. But when a person wonders if a friend remembers how to play the flute, or how to drive a car, the person is asking not about the friend's personal or factual memories, but about his or her skills or embodied memories. Philosophers have often talked here of habit memory, while psychologists identify these cases as types of procedural memory, where this category is also taken to include more basic/primitive forms of conditioning and associative learning.

Procedural memory has been sharply divided from declarative memory for a number of reasons: Perhaps most important is the case of H.M., an epileptic patient who suffered terrible amnesia after brain surgery in the 1950s. H.M., who had lost his hippocampus and other brain structures now known to be central to declarative memory, was no longer able to lay down event memories, so that he would forget everything minutes after its occurrence, and lose any clear sense of time passing. Yet H.M. was still able to learn new games, and to improve his performance at new perceptual-motor skills, despite having no idea each time that he had ever tried them before.

Procedural memory is philosophically important for a number of reasons, although habits and skilled activities have been little studied. For example, neither philosophers nor psychologists have a clear grip on the various ways that personal memory and other high-level cognitive processes interact with remembered embodied skills. Competition and coordination between the different memory systems can both occur. On the one hand, skilled performers in dance or sport know that their motor habits often run best in a groove, when not consciously or verbally controlled: yet the skills involved are robust and flexible, unlike more primitive forms of procedural memory, and can sometimes be directly shaped by mood, context, verbal instruction, and conscious decision.

These conceptual, grammatical, and experiential distinctions between personal, factual, and habit memory have in contemporary cognitive psychology been developed into theories of distinct memory systems. There is considerable disagreement about the psychological status of these systems, and about whether the distinction between episodic and semantic memory, in particular, should be characterized by reference merely to the kind of information in question, or by an essential phenomenological difference. Since there is little agreement more generally about what a psychological system or module is, or about the nature of any putative natural kinds in psychology, these debates about memory systems are likely to be resolved only in conjunction with progress on broader questions in philosophy of psychology.

Personal Memory

An individual's capacity to conjure up experiences, emotions, and events from long in the past involves the same kind of memory as the mundane ability to keep track of just what he or she has been doing, feeling, and thinking in the last day or week. Personal remembering does not seem to be distinguished from other related activitiesimagining, dreaming, factual remembering, for exampleby the level of sensory detail or vividness which it involves: some memories, after all, are both faint and fragmentary, while some scenes of fantasy can be richly imagined. Memory capacities, even in their normal and reliable functioning, are both fallible and selective: human beings don't need either total or precise recall to maintain sufficient coherence and continuity of self over time, for personal memory works in part through an ongoing condensing, editing, and summarizing of life experiences, on which people draw in specific autobiographical narratives. One's narratives or other memory expressions can be public or private, and they can be more or less under one's control, either smoothly tailored to specific audiences or emerging in involuntary fragments.

Personal remembering is a context-sensitive activity from the start. As young children build on their earlier abilities to understand typical sequences of events, their capacity to remember particular past experiences is supported and shaped by adults. Joint attention to the shared past emerges in an interactive social environment, as children come to see that there can be different perspectives on the same past time. Spontaneous self-conscious thought about the personal past is a gradual development out of these memory-sharing practices, which can vary considerably in nature, frequency, and significance across contexts and cultures. One condition for the full emergence of such self-conscious thought about his or her own past experiences, which may be surprisingly late, is that the child picks up the causal connections between events in time, and within the child's own history. Some grasp of the temporal asymmetry of experience is needed to understand that, in principle at least, remembered events can be integrated on a connected temporal dimension. Children's personal memory, then, is a highly sophisticated achievement closely linked not only to their emerging self-awareness and understanding of other minds, but also to their recognition that they cannot change the past, and that their current and future actions are unique and irrevocable.

Because early personal remembering is socially situated in this way, it is also tightly meshed with emotional and social/moral development. Key social practices, such as promising and forgiving, and some central complex emotions, such as grief, love, and regret, depend essentially on personal memory and on one's grasp of temporal relations. The point here is not just that the fallible but more-or-less reliable operation of memory in two or more people is needed to give those people current informational access to the past times at which their paths have crossed. Memory's affective tone and influence means that, in addition to its role in retaining the past, it also has a forward-looking function, as Richard Wollheim argued in his Thread of Life (1984): Remembering can keep what happened in the past alive, giving it significance for one's ongoing relationships and projects. According to this view, memory is not just a means for checking on the continuity of the self over time, but also itself partly produces or creates personal identity: As Wollheim puts it, the past affects people in such a way that they become creatures with a past.

The particular ways in which, through memory, individuals deal with events and experiences that are no longer present varies according to context and aim. Most dramatically, for example, legal contexts impose demands and standards on the memory narratives witnesses must produce that differ greatly from the norms operating in other remembering activities. But questions about the reliability of memory and about its mechanisms arise in many different circumstances just because memory, with its orientation to truth, is in these ways intimately involved in both personal identity and significant social practices. Two connected lines of thought have raised the most serious concerns about people's access to the past in remembering: philosophical views about representations and memory traces, and psychological accounts of the constructive nature of remembering.

Theories of Memory

People can, sometimes, remember past events and experiences in the absence of immediate external cues or prompts to memory. It is natural, then, to think that somehow individuals carry around with them what they will need in order to remember when circumstances are right. Even one's ordinary conception of memory, C. B. Martin and Max Deutscher argued in their influential causal analysis Remembering (1966), requires the existence of an appropriate causal link between one's past experience and one's present remembering. Although the notion of the "memory trace" has appeared in many strange metaphors and theories in the history of philosophy and the history of science, it need be no richer than this idea of a state that causally connects experience and remembering in a certain way. This causal analysis embeds the theory of memory in the broader representational theory of mind which has come to characterize mainstream philosophy of cognitive science; however the bare invocation of memory traces is compatible with many quite different views about their nature and operation.

However, even this basic view about memory traces, in the eyes of its critics, engenders serious problems about the nature of a person's access to the past. If the past is thus truly lost, so that a person can only make contact with it by examining certain representations in the present, critics complain, there is a real danger of scepticism, to be countered by affirming that the person is in fact aware of the past directly in memory. The ensuing, long-running debate between representative realists or indirect realists, who accept memory representations, and direct realists or phenomenologists who reject them, is exactly parallel to that found in theories of perception. Although the dichotomous nature of this debate no longer fits the range of positions available, and many quite different views are often condensed by critics into a monolithic target, there is some common ground.

Contemporary trace theorists tend to work in a broadly materialist framework, and do not in general think of traces as direct objects of awareness from which the nature of the past is consciously inferred at the personal level of psychological analysis. If complex nonconscious processes, operating subpersonally on representations which may themselves be partial and context-sensitive, are involved in the shaping and constructing of the contents of memory, this does not mean that the experience of remembering is indirect. On this point, the positive direct realist contribution is convincing: Remembering, under normal circumstances, is a kind of immersion in which one has a pre-reflective confidence.

But this idea that an individual typically inhabits the memory, rather than judging and assessing it for plausibility and coherence, is in fact entirely compatible with the existence and involvement of subpersonal mechanisms operating on enduring but modifiable traces. Such mechanisms can be typically reliable even if they are fallible in particular instances. To raise a general skeptical worry again at this point against the invocation of memory representations would be unrealistically to demand incorrigible access to the past, to seek a blanket guarantee of accuracy in memory. Such blunt certainty about memory was expressed, for example, by the eighteenth-century Scots philosopher Thomas Reid, the most ardent critic of philosophies of "ideas" or "traces," who wrote that "those things really did happen which I distinctly remember" (Reid, Essays, 1849, p. 444). But this renders the indisputable evidenceboth everyday and scientificof errors in memory quite mysterious, and thereby threatens to erode commonsense realism about the past.

Theorists who posit memory traces are also criticized for adherence to what is seen as an arbitrary metaphor of "storage," unfortunately entrenched in the philosophy of memory since Plato's Theaetetus. The bare retention of capacities or dispositions to act or respond in certain ways, the critics complain, implies nothing about the means by which such capacities are retained: Storage is a mistakenly concrete way of thinking, as if each memory had to be stashed away separately, like sacks of grain in a storehouse or fixed entries in an archive. Ludwig Wittgenstein, for example, mocked the static but inaccessible inner records he identified in the psychological theories of his time: In notes of 19351936, he wondered "whether the things stored up may not constantly change their nature" (Stern 1991, p. 204).

In some invocations of memory representations, each trace has indeed been treated as distinct, with each single remembered item mapped on to one storage element. Such atomist or localist representational schemes make control over the contents of memory easier to imagine or achieve: The remembered items are passive, and must be manipulated or altered by an external executive. In this separation of data from process, ordinary digital computers exemplify the localist memory scheme: But what is "stored" in human memory displays more intrinsic dynamics than this, tending in some contexts naturally to interfere, blend, and generalize without deliberate or voluntary control. But just as such computers do not exhaust possible computational devices, so localist representational schemes are not essential to the general framework of memory traces. Both historical theories of memories as patterned flows of "animal spirits" through the pores of the brain, and contemporary connectionist models in cognitive science employ distributed (rather than localist) representation: What can be distinctly remembered need not be held distinctly or independently, since each item is spread or "superposed" across many elements in a system or network. This entry examines the implications of these distributed models of memory after setting them in the context of recent developments in cognitive psychology and the cognitive sciences.

Remembering and the Cognitive Sciences

The recent history of the sciences of memory offers a sharp contrast and corrective to the stereotyped image of cognitive science as a scientistic quest to reduce the human mind to the dull mechanism of digital computers. Memory research was one of the first areas to be taken out of the lab in the 1980s and 1990s, as psychologists sought to address the kinds of memory that matter in everyday life (such as autobiographical memory), and to find ecologically valid methods of studying such memories outside artificial isolated situations. The difficulty facing philosophers or scientists with an urge toward synthesis is not that psychological results are irrelevant to wider concerns about memory, but that the daunting diversity of methods and traditions even within cognitive psychology makes it hard to see how different levels of explanation might relate to one another. There are issues of considerable interest for the philosophy of science in understanding the connections between neuroscientific and cognitive-psychological descriptions and methods; and, equally, robust and philosophically intriguing research traditions on autobiographical memory in developmental, personality, and social psychology. This entry briefly examines ideas about the constructive nature of remembering that seem to have direct relevance to concerns about truth in memory.

Remembering is a multifaceted activity that takes place in the present, and so the best explanatory frameworks for understanding it will attend closely to the context of recall, rather than simply investigating the nature of encoded traces. Memories are often compiled or constructed for particular purposes when needed, not held fully formed. There is room for considerable internal plasticity in memory traces, which are (on the connectionist model) always composites shaped by the entire history of their network. The most dramatic work on construction in memory has come not from connectionist modeling, however, but from the research on suggestibility and false memory by Elizabeth Loftus and her colleagues (2003). Misleading information from external sources can be incorporated into personal recollection. Confident, entrenched childhood "memories" of spilling a bowl of punch at a wedding, for example, or of gazing long at an exceptionally colorful mobile in the days after birth, can be elicited artificially in certain circumstances. This work is partly motivated by a wish to confirm the possibility of false confessions, in which individuals may come sincerely and passionately to believe that they have committed horrible crimes in the past; but the mechanisms in play are just the ordinary and normally robust processes of shaping and generalizing memories to make them fit. Although Loftus has adopted the high moral tone of a crusade, ongoing careful investigation of individual differences and integration of these results with social and personality psychology promises a much richer picture of the conditions which make different kinds of distortion more likely.

Again, the point of this research is not to show, implausibly, that reliability in memory is impossible or unlikely. Psychologists assume that understanding the mechanisms of distortion will also throw light on the processes involved in veridical remembering. Reliability and accuracy are not transparent notions here. Pre-reflective confidence in personal memories can, and in certain contexts should, coexist with attention to the other evidence about the past which is often available, and care for the defeasible but subtle and robust capacities to winnow evidence that individuals have developed in the rich and complex social context of early memory-sharing and memory-using practices.

Social Memory and Shared Memory

The general constructive picture of remembering can be accepted while acknowledging that external influencesparticularly social influenceson memory need not inevitably lead to error. As Sue Campbell argued in her powerful philosophical responses to the "memory wars," there are vital features of relational interaction with others that contribute positively to practices of good remembering, both in development and in adult social life: To treat the true unit of memory as the isolated individual, free from the distorting influence of other people, is to miss the value we often appropriately place on negotiating the pastboth the personal past and the shared pastin company.

Indeed a need for attention to shared remembering and social remembering in both psychology and philosophy can be motivated from within the broadly constructivist framework itself. It is because one's internal memory is partial and context-sensitive, and does not naturally retain information in distinct and unchanging form between experience and recollection, that one relies so pervasively andin the mainsuccessfully on external social and technological scaffolding. A challenge for psychologists is to find ways to study shared memories that do not focus solely on the conformity induced or sought by powerful external authorities; and a challenge for philosophers is to construct a social ontology of memory by which to understand the diverse ways in which people manage to hook their incomplete inner systems of traces with the vast social and cultural resources in which cognition is situated.

Mark Rowlands (1999) and Rob Wilson (2004), for example, have suggested specific ways in which external symbol systemsin their many distinct historical and cultural formsallow individuals to leave information and skills out in the world, saving on the resources and capacity required for biological memory. Drawing on the more precise invocations of terms like social memory and collective memory in the contemporary social sciences, this distributed cognition framework suggests that researchers can study the transmission of particular representations across different individuals and media, and the specific forms of interplay between group dynamics and individual recall. It also promises to throw better light on the influential work on memory by the French sociologist Maurice Halbwachs (1980).

Halbwachs's notion of the collective memory is often cited by contemporary social scientists and historians as deeply anti-psychological, or as sociologically determinist: but in fact his work focuses on the incomplete or shrouded nature of the individual's memory, which (outside of dreams) must be sculpted and completed within a social framework, which provides the context and the means for the construction of a specific recollection. Philosophical analysis can potentially be of immense service to empirical disciplines like cognitive anthropology and historical theory in the study of memory by showing how case studies of remembering activities in particular times and places might be embedded in robust broader theories of memory. So in addition to the long-standing philosophical concerns about truth and the self previously outlined, it is likely that philosophical attention will increasingly engage, through topics like memory, with the urgent challenge of connecting the cognitive sciences and the social sciences.

See also Cognitive Science; Computing Machines; Moral Psychology; Personal Identity; Philosophy of Mind; Plato; Reid, Thomas; Time, Consciousness of; Wittgenstein, Ludwig Josef Johann.

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John Sutton (2005)

Memory

views updated Jun 11 2018

MEMORY.

The history of the idea of memory is associated with the cultural uses of two kinds of memory, episodic and semantic. Episodic memory concerns the conscious recall of particular events. Interest in its nature dates from antiquity, and mnemonic techniques for strengthening memory's resources, known as the "art of memory," were developed as rhetorical skills. Semantic memory deals in tacit understandingshabits of mind and implicit knowledge on the boundary between the conscious and the unconscious. In modern times, scholars have treated it as a realm apart from episodic memory in light of a newly discovered awareness of the significance of the social contexts of collective memory.

The Ancient Art of Memory

In ancient Greek mythology, Mnemosyne, the goddess of memory, was revered as mother of the Muses of the arts and sciences. Ever since, students of memory have acknowledged memory's creative power to evoke the imaginative forms through which humankind represents the reality of its experience. The ancient idea of memory was grounded in the concept of mimesis, according to which memory and imagination are reverse sides of the creative act of "imitating nature." In the primarily oral culture of ancient Greece, the rhapsodes were renowned for their prodigious powers of memory, which allowed them to sing the Homeric epics, the repositories of the Greek heritage and the foundation of Greek cultural identity. But the use of memory in oral tradition was uncritical, and scholars have made much of the differences between the intuitive poetic storytelling of rhapsodes and the studied analytical use of memory among the literate rhetoricians of an incipient manuscript culture.

A changing conception of memory, therefore, is coeval with the passage from primary orality to manuscript literacy (beginning about the seventh century b.c.e.), which permitted a newfound critical perspective on memory's nature. By late antiquity, the idea of memory as remembered episode had come to be closely associated with the art of memory, a rhetorical technique of displacement for accurately recalling facts and stories worthy of remembrance. The art located data difficult to remember within easily remembered imaginary structures of places and images. The discovery of this method for associating the unfamiliar with the familiar is attributed to the Greek poet Simonides of Ceos (556468 b.c.e.) and was developed especially by Roman rhetoricians. The Rhetorica ad Herennium (82 b.c.e.), attributed by some to Cicero, is the oldest such manual to have survived from antiquity. Throughout the Middle Ages and Renaissance, the art found expression in ever more complex mnemonic schemes, until it was marginalized by new encyclopedic reference books for storing knowledge in the emerging print culture of the Enlightenment.

The English historian Frances A. Yates (18991981) was the first modern scholar to analyze the history of the intellectual uses of mnemonic technique. She grounds this critical perspective in two seminal conceptions of memory derived from ancient Greek philosophy, one formulated by Plato (c. 428348 or 347 b.c.e.), the other by Aristotle (384322 b.c.e.). Plato emphasized the power of memory to open pathways to the archetypes of transcendental knowledge. Aristotle presented a down-to-earth analysis of memory's powers of recognition and recall and described mnemonics as a guarantor of the capacity of a well-ordered mind to hold fast to its learning. Yates was especially interested in the ambition the Neoplatonist rhetoricians of the Renaissance had to construct imaginary memory palaces whose architectural structures were purported to mirror those of an ideal universe and so to provide hermetic keys to correspondences between earthly and transcendental realities. But the rise of empirical science in the seventeenth century undercut the art of memory's idealist presuppositions, and while the art remained an elegant technique for the rhetorical display of erudition, it was soon acknowledged that its methods led only to a philosophical dead end.

Modern Memory and Personal Identity

The spread of print literacy by the eighteenth century transformed the cultural understanding of episodic memory. In print culture, collective knowledge could be easily preserved in readily accessible, alphabetically indexed reference books, rendering obsolete the practical applications of the art of memory in information retrieval. The psychological effect was to free memory for personal reflection on formative life experience, particularly that of childhood. The idea of memory thenceforth came to be closely allied with autobiographical soul-searching. The prototypes for this genre of self-analysis were the Confessions (1762) by the French philosopher Jean-Jacques Rousseau (17121778) and the Prelude (1805) by the English poet William Wordsworth (17701850). But for early twentieth-century readers, the most poignant introspective evocation of the past was that of the French writer Marcel Proust (18711922), who, in his multivolume novel In Search of Lost Time (19131927), marveled at the way an impromptu experience of sensory recall could spontaneously awaken the brilliant immediacy of an entirely forgotten cultural world. For the literati of the modern age, recovered memory was perceived to be the surest route to the discovery of the deep sources of personal identity.

Memory reconceived as the search for self was given a scientific foundation by the Austrian physician Sigmund Freud (18561939). Just as Plato had recourse to memory as a means for lifting the soul to an awareness of an ideal world, so Freud aspired to employ memory to open passageways leading to truths hidden in the unconscious. He invented psychoanalysis as a therapeutic technique for helping his patients cope with their neuroses, which he attributed to repressed memories of trauma earlier in their lives. Freud thought of the unconscious psyche as a subterranean archive where forgotten memories of unresolved issues pressed their unanswered claims on the conscious mind in ways that impaired its capacity to deal with present realities. In recovering repressed memories, patients would come to recognize the sources of their inner conflicts and so gain self-knowledge that would enable them to act more effectively in their present endeavors. Like the art of memory, Freud's psychoanalytic technique used the principle of displacement. Seemingly innocuous dreams, "screen memories," and slips of the tongue were often place markers for trauma in an individual's life history, providing clues to more troubling memories buried in the unconscious. The skilled psychoanalyst could help patients recover them.

The Social Frameworks of Collective Memory

In the early twentieth century, near the time when Freud's findings were being popularized, sociologists began to inquire into the nature of semantic memory as a realm of remembrance of a different ordersocially conditioned memory, often tacitly understood. Here the memory was considered in its social context, as subject to social and cultural influences. The French philosopher Henri Bergson (18591941) prepared the way at the turn of the twentieth century by pointing out the difference between the memory of specific events and the memory of enduring attitudes, a distinction he correlated with that between the moment and duration. The French sociologist Maurice Halbwachs (18771945) elaborated a more complete theory of collective memory during the 1920s. For him, collective memory is a function of social power, and its expression varies with the social settings in which we find ourselves. We localize images of the past within imaginary frameworks that conform to our social understanding. For that reason, collective memory is provisional until it is evoked within specific social contexts, and its form and strength is relative to the social forces that impinge on our present circumstances. Without such social props, collective memory cannot survive. Halbwachs was especially insightful about how commemorative practices assimilate specific images of episodic memory into the idealized structures of semantic memory. As for its place in the history of ideas, Halbwachs's theory draws on the method of the art of memory to demonstrate how the strategic mobilization of commemorative monuments in mnemonic landscapes reinforces officially sanctioned collective memory.

The Fragility of Memory in a Postmodern Age

In the twenty-first century, we know more about memory than ever before, but trust its resources less. The idea of memory, conceived as the keystone of identity for the nineteenth century, has been reconceived as the debris of lost identities, the free-stones of aging memory palaces that have fallen into ruins. Since the last quarter of the twentieth century, the topic has inspired intense interest among historians, literary critics, folklorists, sociologists, anthropologists, psychologists, and neurobiologists. Across the curriculum, scholars are as one in noting that memory is easily and often remodeled, almost always distorted, and hence unreliable as a guide to the realities of the past. The idea of memory, therefore, is noteworthy for its fragility, vulnerable as it is not only to the vagaries of the mind but also to social, political, and cultural forces that would alter or obliterate it.

On the edge of fragile memory lies nostalgia, the most elusive of memory's protean forms and one beginning to receive critical attention. An admixture of sweetness and sorrow, it expresses a longing for a vanishing past often more imaginary than real in its idealized remembrance. Nostalgia exercised a powerful appeal in the Romantic sentiments of the nineteenth century, tied as it was to regret over the passing of ways of life eroded by economic and social change, a generalized popular enthusiasm for innovation, and rising expectations about what the future might hold. Nostalgia was the shadow side of progress. Chastened by the disappointments of the twentieth century, however, the idea of progress has fallen on hard times, and nostalgia presents itself as an even more diffuse longing for a fantasy world that never existed (for example, the classless society in Communist propaganda). So reconceived, nostalgia has come to be criticized as a dangerous surrender to anarchistic illusion that contributes to memory's vulnerability to exploitation and misuse.

Situated at an interdisciplinary crossroads, the idea of memory has yet to promote an exchange between humanists and scientists, though they make their way along converging avenues of research. Scientists have moved away from Freud's claim about the integrity of memory's images. Steady research in psychology over the course of the twentieth century exposed the intricacies of the mental process of remembering, which involves complex transactions among various regions of the brain. For psychologists, remembering is conceived as a dynamic act of remodeling the brachial pathways along which neurons travel as they respond to sensory stimuli. The images of memory are encoded in neural networks, some in short-term and some in long-term configurations, and so are mobilized as conscious memories in multifold and continually changing ways. Memory resides in these ephemeral expressions, and its images are constantly subject to revision in the interplay of well-established patterns and chance circumstances that governs recall.

Some neuroscientists propose that memory is an adaptive strategy in the biological life process. Drawing on Charles Darwin's theory of natural selection, the American neuroscientist Gerald Edelman (1929) argues that there is a selective process by which memory cells cluster in the neuronal groups that map neural pathways. He identifies two repertoires of such clusters in the gestation of the brain, one, primarily genetic, in embryo, and the other, primarily adaptive, after birth. They establish the categories of recognition through which the brain thenceforth processes external stimuli, though these categories are continually modified as the brain adapts to new life experience. In this sense, each act of recollection is a creative process that entails a reconfiguration of synaptic connections. There is an intriguing analogy between Edelman's two stages of memory cell formation and the mnemonist's two-step reinforcement of memory in repertoires of places and images. There is a resonance as well between Edelman's notion of the brain's mapping of neural pathways and Halbwachs's conception of the topographical localization of social memory. Both affirm the constructive nature of the act of memory in the interplay of recognition and context.

Cultural Contexts of Memory in the
Twenty-First Century

Among contexts contributing to the idea of memory's fragility in the twenty-first century, one might highlight the following:

The one-way transit to amnesia in the pathologies of dementia.

The degree to which the workings of memory elude research in the biological sciences is dramatized by the difficulties of understanding the perplexing diseases that lead to the deterioration of memory in old age. Freud's faith in the prospect of memory retrieval is difficult to reconcile with the insurmountable barriers erected by the ravages of dementia. An unfortunate by-product of longevity in the affluent Western world has been an increasing susceptibility to the maladies of memory impairment with advancing years. Alzheimer's disease is the most dreaded among an array of forms of dementia that rob victims of their memories and by consequence of their identities. Here there can be no recall of the past from the oblivion imposed by neurological degeneration. Alzheimer's disease has come to serve as a cultural metaphor for twenty-first century fears of trends that promote not only personal but also social amnesia.

Media and the eclipse of tradition in mass culture.

The twenty-first century is characterized by its present-mindedness, but ironically has little regard for the presence of the past. We live in a consumer society whose interest lies in using and then discarding the resources of the present, not conserving them for future generations. Tradition, once valued as the bequest of the wisdom of past generations to the present one, is dismissed as trivial to the manufactured pursuit of immediate gratification in which the hallmarks of tradition are redeployed as the kitsch of consumerism, divested of the social and cultural frameworks that once defined social identity.

The media work their pervasive influence thanks to a revolution in the technologies of communication in the late twentieth century. The invention of new forms of electronic communicationnotably the personal computer, linked by the Internet to a worldwide web of memory banks in cyberspaceso vastly expanded the capacity and facilitated the ease of information retrieval that it reshaped both perception and learning in ways analogous to those that accompanied the transition from orality to literacy (during which the art of memory was invented), and then from manuscript to print culture (when the interconnection of memory and personal identity was established). In this respect, the organization of knowledge on computer screens and Internet Web pages departs from its linear organization in print culture, to be reconfigured spatially on Web sites and in icons reminiscent of the places and images of the art of memory. Temporal models (timelines) are replaced by spatial ones (hyperlinks among Web sites).

The revolution in media communication accelerated the fraying of older forms of social and cultural identity. The media mold images in pervasive and homogeneous ways by virtue of their expanded control of the networks of communication, and favor tendentious publicity over deliberation. The media deepen present-mindedness, since their imperative is to publicize images of recent events as quickly as possible before moving on to others even more recent and enticing in their prurient interest. They evoke a sense of immediacy in which the past is glossed over and the future reduced to idle speculation. The mnemonic power of forms of publicity to incite interest prevails over the force of ideas, undermining the value of cultural traditions that once provided sure reference points of collective identity.

A reluctance to mourn.

In the late twentieth century, historians too turned avidly to research on memory, more specifically to the relationship between memory and the dissolving cultural identities of the postmodern age. Whereas scholars of the nineteenth century had looked to formative beginnings, those of the late twentieth century were more interested in irresolute endings. During the 1970s, social historians such as Philippe Ariès, Pierre Chaunu, and Michel Vovelle launched studies of changing attitudes toward death and mourning across several centuries, in some sense as a response to the denial of death and the difficulties of mourning common in the late twentieth century. For comparison, Ariès portrayed the nineteenth century as a golden age of mourning. He noted newly intense expressions of personal mourning, made manifest in lavish funeral rituals and ornate commemorative monuments in cemeteries reconceived as gardens for meditation. Mourning in the nineteenth century confirmed personal identity by integrating the rituals of private mourning into well-established public traditions. The twentieth century, he claimed, was conspicuous for its reluctance to face death's realities and its diminished capacity to devote time and intensity to the process of coming to terms with the loss of loved ones.

The politics of memory.

Historians soon extended their inquiry to encompass public commemorationwhat the U.S. psychologist Peter Homans has characterized as the mourning of symbolic loss. During the 1980s, historical scholarship addressed the politics of memory, especially as it was displayed in the nineteenth-century commemorative practices that solemnized the building of nation-states in their use of icons of sacred moments (for example, national holidays) and avatars of patriotism (such as "founding fathers"). Given the challenges facing the nation-state in an age more acutely aware of the need for global perspectives on humankind, the historians' perspective on the making of national memory tended to dwell on its present-minded politics and geographical parochialism. Such research drew heavily on Halbwachs's theory of collective memory, as historians sought to rein in memory's claims on the past. In parallel with the efforts of philosophers and literary critics to deconstruct the forms of cultural discourse, historians sought to expose the building blocks from which practices of public commemoration had been constructed. They juxtaposed and to some degree reduced the reverential task of commemoration to its efficacious use in consolidating political allegiances.

Eric Hobsbawm and Terence Ranger's The Invention of Tradition (1983) and Pierre Nora's Les lieux de mémoire (19841992) stand out as pioneering studies in this field. Both seek to expose memory's role in the making of political identities that have become suspect in their biases and whose appeal at the turn of the twenty-first century began to wane. Nora's book on the making of the French national memory provided a method for digging through the accumulating layers of mementos that contributed to the making of political identity over long periods of time. It inspired a host of studies dealing with like political uses of memory in countries around the world.

Traumatic memories of atrocities.

The twentieth century witnessed episodes of genocide and mass destruction on a scale that traumatized entire populations into collective repression. Reckoning with these unhappy memories demanded a new approach. Concerned that the worst atrocities might be glossed over and forgotten, historians undertook an inquiry into a relationship of a different order between memory and history. These investigations reiterated Freud's thesis about the necessity of "working through" the trauma of repressed memory to uncover harsh and painful truths about crimes against humanity. They concluded that some memories cannot be easily tamed by history, and that they maintain their singularity at the limits of history's powers of representation. Memories of the Holocaust of European Jewry are the most studied among them.

The problems involved in historicizing the memory of the Holocaust was the subject of the much-publicized "historians' controversy" in Germany during the 1980s. One group of historians contended that it was time to place the Holocaust in historical context. Another countered that no extant conceptual framework is adequate for doing so. It argued for the importance of the preliminary task of gathering testimony from Holocaust survivors still struggling to come to terms with their painful memories. Meditating on the differences between memory and history, the Israeli historian Saul Friedländer (b. 1932) wondered whether history could ever do justice to the existential meaning the Holocaust held for its victims. His question is whether the immediacy of memory can ever be reduced to the selective perspectives and conceptual abstractions of historical interpretation. He suggests that traumatic memory may be a realm of human understanding whose meaning is to some degree incommensurable with historical explanation. The conversation among historians about the limits of history's claims on traumatic memory lingered into the 1990s, and the European Holocaust served as a point of departure for studies of other instances of genocide in the late twentieth century, the memory of which presented obstacles to adequate historical interpretation.

History's Claims on Memory: A Remedy or a Poison?

The dispute about the relationship between memory and history was put in philosophical perspective by the French phenomenologist Paul Ricoeur (b. 1913). After reviewing the many routes of scholarly inquiry into the idea of memory at the turn of the twenty-first century, he closes his analysis with a meditation on the concerns of the historians of the Holocaust about history's premature claims on memory. In considering why history must first beg pardon of memory, he guides our attention to Plato's philosophical dialogue Phaedrus, an evocation of the debate among the ancients about differences between the remembered and the written word that provides an analogy with the current debate about memory's relationship to history. In this dialogue, Plato's teacher Socrates ruminates on whether efforts to tame memory to the critical perspectives of writing have merit. He poses the question: Is writing as an aid to memory a remedy or a poison? The written word can be a remedy in the sense that it secures knowledge in an enduring form. But it does so by setting limits on the depiction of the past and so discards with a certain finality alternate ways of evoking its presence. Memory, by contrast, may at any moment rescue the past from oblivion. Its uses reside not only in its resources for preservation but also in those for creation. Its virtue lies in its ontological claim to body forth the imaginative forms that make conscious knowledge of human experience possible. History at its best deepens human understanding in its accurate reporting and intelligent interpretation of the past, and it strives to be conclusive. But memory's fidelity to the experience of the past is the basis of its openness toward the future, and it resists closure. Memory stands "as a little miracle" in its distinctive capacity to trigger the creative imagination in a way no other faculty of mind can.

The U.S. intellectual historian David Gross (b. 1940) adapts that insight to consider the status of memory in the twenty-first century. He notes the readiness of society to consign to oblivion all that stands in the way of present-minded expectations. He sorts out the intellectuals of late modernity into those who would discard and those who would value the past remembered. He highlights modern "rememberers" who have argued persuasively for the importance of the past to their present concernsamong them Proust and Freud, but also the nineteenth-century German philosopher Friedrich Nietzsche (18441900) and the twentieth-century German literary critic Walter Benjamin (18921940).

Benjamin in particular fascinated scholars because of his aphoristic insight into memory's remedy for the deficiencies of the timeworn claims of the modern vision of history on the contemporary age. Especially provocative is his interpretation of the painting Angelus Novus (1920) by the surrealist artist Paul Klee, a tableau of the angel of history looking back sadly on the events of the modern age, not as milestones of civilization's advance but rather as remnants of its failed projects and endless disappointments. A disillusioned socialist nostalgic for the heroics of the nineteenth-century revolutionary tradition, Benjamin longed for memory's spark to jump-start an alternative future. Neglected memories, he maintained, respond to our imaginative gaze like heliotropes opening to the sun.

Although assailed by all the pressures of present-minded perspectives that deny the importance of recollecting the past, the rememberers appeal to the present age by calling to mind the striking diversity and rich complexity of past human experience, and so deepen understanding of the timefulness of the human condition in its manifold meanings. Memory's claim on the past, they argue, lies in its creative capacity to resurrect lost worlds worthy of our consideration. Their insight recalls the ancients' reverence for the goddess Mnemosyne, who out of the eons of humankind's lost primordial past brought into consciousness the imaginative forms from which all the arts and sciences would spring.

See also Autobiography ; Death ; Ritual: Public Ritual ; Tradition .

bibliography

Ariès, Philippe. The Hour of Our Death. Translated by Helen Weaver. Oxford: Oxford University Press, 1991.

Boym, Svetlana. The Future of Nostalgia. New York: Basic Books, 2001.

Edelman, Gerald M. Neural Darwinism: The Theory of Neuronal Group Selection. New York: Basic Books, 1987.

Gillis, John R., ed. Commemorations: The Politics of National Identity. Princeton, N.J.: Princeton University Press, 1994.

Gross, David. Lost Time: On Remembering and Forgetting in Late Modern Culture. Amherst: University of Massachusetts Press, 2000.

Havelock, Eric. Preface to Plato. Cambridge, Mass.: Harvard University Press, 1963.

Hobsbawm, Eric, and Terence Ranger, eds. The Invention of Tradition. Cambridge, U.K.: Cambridge University Press, 1983.

Homans, Peter, ed. Symbolic Loss: The Ambiguity of Mourning and Memory at Century's End. Charlottesville: University Press of Virginia, 2000.

Hutton, Patrick H. History as an Art of Memory. Hanover, N.H.: University Press of New England, 1993.

Matsuda, Matt K. The Memory of the Modern. New York: Oxford University Press, 1996.

Nora, Pierre, ed. Les lieux de mémoire. 3 vols. Paris: Gallimard, 19841992.

Olney, James. Memory and Narrative: The Weave of Life-Writing. Chicago: University of Chicago Press, 1998.

Ricoeur, Paul. La mémoire, l'histoire, l'oubli. Paris: Editions du Seuil, 2000.

Rosenfield, Israel. The Invention of Memory: A New View of the Brain. New York: Basic Books, 1988.

Roth, Michael, and Charles Salas, eds. Disturbing Remains: Memory, History, and Crisis in the Twentieth Century. Los Angeles: Getty Research Institute, 2001.

Schacter, Daniel L. Searching for Memory: The Brain, the Mind, and the Past. New York: Basic Books, 1996.

Yates, Frances A. The Art of Memory. Chicago: University of Chicago Press, 1966.

Patrick H. Hutton

Memory

views updated May 18 2018

Memory

Memory refers to the mental systems and processes involved in storing and recalling information about stimuli that are no longer present, as well as to all of the information that is stored. Memory is essential to healthy human functioning, and it can be said that every mental process involves some aspect of memory. Indeed, the ancient Greek philosopher Cicero once described memory as "the treasury and guardian of all things." The human brain has evolved an enormous capacity for remembering, and in the course of life, people gather and store vast amounts of information. Memories of past experiences are necessary to understand new experiences, and to decide how to behave in unfamiliar situations. Without memory every person or situation we encountered would be strange and unfamiliar, and we could never learn from past experience. In fact, we would not be able to learn anything at all, since all learning requires remembering the material learned. Memory is also essential to a sense of self or identity, as memories of our past experiences, thoughts, and feelings inform us as to what we have done, who we have been, and who we are now. Memory can hold information ranging from how to put pants on, to the composition of the stars.


History

People have sought to understand the nature of memory since at least the time of the ancient Greek philosopher Plato, who is usually credited with the earliest serious discussion of it. He believed memory was like a blank slate on which accurate impressions of the world were made and preserved indefinitely. Plato distinguished two aspects of memory—the power to retain or keep information, and the power of recollection, or remembering information that is already present in memory. Plato's ideas still influence many contemporary psychological theories of memory contain these same beliefs.

During the Middle Ages, before the printing press, memory served as the vehicle through which history and knowledge were passed between people and generations. It seems having a good memory was greatly prized during the Middle Ages, and the improvement of memory skills was an important topic. A distinction was made between natural and artificial memory where natural memory was the memory abilities we were born with. They could not be trained and were thought to operate in a spontaneous, instinctive manner. On the other hand, artificial memory abilities were held to be trainable, and numerous systems were developed to improve them. As the printed word spread and the individual's memories became less essential in the transmission of knowledge the importance placed on memory by society apparently diminished. During the 1800s, educators also focused on training and exercising the memory. Memory was seen by many as being like a muscle that required exercise to remain fit. Thus memorization was thought to strengthen one's current memory system as well as future memorization skills, and rote memorization (memorizing information for no purpose other than to memorize it) was advocated for students. This view came under great criticism as the 1800s ended, and eventually the advocacy of rote memorization within the school system faded. Indeed, more recent research indicates that memorization for memorization's sake does not improve overall memory abilities in any observable way.

During the late 1800s the medical profession became interested in disorders of memory such as aphasia (a complete or partial impairment of the ability to understand or use words), and amnesia (generally, a partial or total loss of memory). The medical profession naturally focused on physiological and biological factors, and one of their most important findings was that aphasia was caused by lesions in the brain. This finding was of immense importance as it demonstrated for the first time that physiological and psychological functioning are connected.

Sigmund Freud, an Austrian physician who began his career in the 1890s, focused on psychological disorders that he felt were caused by memory disturbances. Freud felt mental illness occurs when unpleasant childhood memories are repressed, or kept from consciousness. His highly influential theory of psychoanalysis is in fact based on the concept that memories can be repressed, and he developed psychoanalytic therapy to uncover those memories and cure the patient.

The German psychologist, Hermann Ebbinghaus, carried out the first controlled experiments on memory in 1885, and in so doing set a pattern for modern experimental research on memory. Ebbinghaus developed many methods of studying memory that are still in use today. For example, he developed lists of nonsense syllables (one syllable groups of letters that have no meaning, e.g. "treb," "fug," or "duj"), that individuals would be asked to memorize. Ebbinghaus used nonsense syllables in an attempt to avoid the effects of previous learning, and associations the individual might have to meaningful words. Ebbinghaus would vary different aspects of the experiments to test different aspects of memory. For instance, he varied the lists by length to see how the number of syllables affected recall, and he would vary the amount of time between memorization and recall to see how the amount of time lapsed between learning and recall affected the amount of material recalled or forgotten.

Theories of basic memory processes

It is important to note that Ebbinghaus was working within the philosophical/psychological framework of associationism. With roots stretching back to Aristotle, associationism asserts that higher order mental processes, such as creativity or language, are produced by the combination of simpler mental processes, such as the mental association of objects, ideas, or experiences due to their similarity. Memory is said to be made up of associations between elements based on their similarity, contrast, or occurrence together in time or space. This implies a rather passive or inactive mind and memory, where the individual and their memory receives impressions and basically categorizes them according to their straightforward, objective characteristics. Remembering is simply reproducing these impressions and associations. Within this framework, when asked to remember and describe a rose, a person might "search" their memory for a specific representation of a rose or a specific experience with a rose, and use this to describe one.

This is in contrast to reconstructive theories of memory as proposed for example by William James in 1890, and by Sir Frederic Charles Bartlett in 1932. Within these theories, memory is seen as an active reconstruction and organization of past experiences that influences how new information is interpreted and organized, as well as how and what information is remembered. In contrast to associative theories, reconstructive theories of memory hold that abstract principles about new experiences and information are what is stored, not exact reproductions of the experiences themselves. During recall, specific memories are often reconstructed according to these general principles, they are not always reproductions of experience. Thus memory processes take an active role in what and how information is remembered. Within this framework, a person asked to remember and describe a rose might first access their general knowledge of plants, then flowers, then their knowledge of roses in general, and using this information, build or construct a description of a rose. In recent years, reconstructive theories of memory have gained favor as many psychologists believe that most mental processes, such as language and perception , are too complex to be explained by the combination of simple associative connections and reproductive memory.


Models of memory operation

Since memory and memory formation cannot be observed directly, various models have been put forth by memory researchers in an effort to clearly and simply describe how memory operates. In the early 1900s, psychologists proposed that memory was like a filing cabinet in that everything was categorized neatly and logically. In order to retrieve information, one simply and logically located the correct file folder. Later, as telephone systems were expanded, memory was likened to a telephone operator's switchboard with information coming in from many directions to a central source that sorted the information and decided on the appropriate output. With the development of the digital computer in the 1950s, psychologists began describing memory in terms of a computer model and focused on how the mind and memory might process information like computers do. This model has been highly influential, and since the 1950s researchers using this model have focused on the input and sequencing of information processing.

Three information processing systems

Most researchers divide memory's information processing operations into the stages of acquisition, consolidation, storage, and retrieval. Acquisition refers to the process the brain and the sensory organs use to bring information into the memory system. Consolidation is the process of organizing information to facilitate its storage in long-term memory. Storage describes the forming of a potentially permanent representation of information in the brain. Retrieval is the process of bringing stored information to consciousness. These processes are thought to occur within three largely accepted divisions of the memory processing system that are distinguished by the length of time information can be held, the amount of information that can be held, and the different processes that occur in each. The three stages are called sensory memory, short-term memory, and long-term memory. It should be noted that these systems are not presumed to occupy specific physical spaces within the brain. They are, more accurately, hypothesized systems distinguished by their varying characteristics.


Sensory memory

Sensory memory, or sensory register, notes or registers sensory stimuli as they are experienced. It consists of representations of the outside world as experienced through the senses such as touch , sight, or smell . It holds information for approximately one to two seconds. If, for instance, you glance at the ocean and turn away, the image of the ocean will be lost in one to two seconds unless the image is quickly transferred into the short-term memory system. The contents of sensory memory are constantly changing as new stimuli are perceived. Information that does not fade from sensory memory enters short-term memory.

Short-term memory

Short-term memory is thought to process information by actively repeating, grouping, and summarizing it to aid its storage in long-term memory. Information is thought to last within short-term memory for only a short period of time before it is either passed into long-term memory or discarded. For information to be transferred into long-term memory, it must be rehearsed or repeated.

Generally, short-term memory can hold five to nine units of information for between twenty seconds to one minute in length. It holds information for as long as its actively thought about, or until new information basically forces it out. Unless we repeat the information and purposely try to retain it, most, or all of it, will be lost. A good example of this process can be seen when you look up a new phone number, and repeat it to yourself as you dial it. After dialing it, within a few seconds you will usually forget it. Yet if you do this repeatedly (repetition or rehearsal), like for a friend with a new phone number, it will eventually enter long-term memory.

These "units" of information can represent single pieces of information, such as an individual's name, or the units can be single pieces of information that represent a number of different pieces of information, as in the last name of a family representing all of the family's members. The process of using a single item to represent a number of items is called chunking, and researchers have found that short-term memory's information holding capacity can be greatly enhanced with this process.

It seems there are many factors that determine what information enters long-term memory, two of the strongest being repetition and intense emotion. If something is repeated often enough, such as multiplication tables, it will enter long-term memory. And it is hard to forget intensely emotional experiences such as being involved in a serious car accident or falling in love.


Long-term memory

Long-term memory has been the focus of most research and theory on the memory system. It holds all the information that has managed to pass through the sensory and short-term memory systems. In contrast to both of those systems, long-term memory is thought to be able to hold potentially unlimited amounts of information for an indefinite period of time, possibly for a lifetime. It is thought to hold all of the memories of our life, as well as our knowledge of the world in general. In long-term memory one might find memories as diverse as the first person you ever had a crush on, knowledge of how to ride a bike or cook scrambled eggs, the names of the five great lakes of North America , or a second language. Indeed, long-term memory is often compared to an encyclopedia in terms of the amount and range of information it holds.

Long-term memory then stores and operates on very diverse types of information, and there are many theories as to how the different types of information are represented and organized within it. Research shows that long-term memory operates according to a number of different systems, and researchers disagree as to exactly how it should be divided up. Yet there are some very influential theoretical divisions of long-term memory that are now widely accepted. These are the divisions between procedural memory, episodic memory, and semantic memory.


Divisions of long-yerm memory

Procedural memory

Procedural memory is, as its name implies, knowledge of the steps necessary to perform certain procedures or activities. It is the knowledge of how to ride a bike or swim, how to cook spaghetti and meatballs, and even how to walk and run. Procedural learning is the acquisition of skills, such as learning how to operate a computer. How well something is learned is reflected in improved performance of the skill. It seems well-learned knowledge stored in the procedural memory system can be used without conscious awareness of the steps being performed. For instance, once a behavior is mastered—such as walking or driving a car—one rarely has to stop and think about what step comes next, and attention can be paid to other activities.

Often the information stored in procedural memory is difficult for the individual to articulate even though it is obvious from their smooth performance of the activity that they know it well. Procedural memories seem to last for a very long time, if not for a lifetime, and they are often very hard to change. Thus if one learns how to do something in a certain way, such as swim or play tennis, it can be very hard to change one's technique later.


Episodic memory

Episodic memory is the conscious recollection or remembering of specific experiences from a person's life. These memories often include the time and place of the experience, as well as a representation of the role the individual remembering played in it. An example of an episodic memory would be recalling the first time you operated a computer, including where and with whom, in contrast to how to operate a computer. Episodic memories seem to be more affected by the passage of time than are procedural or semantic memories such that if the event is not recalled and thought of relatively often, details of the event, if not the event itself, seems to fade or be forgotten over time.


Semantic memory

Semantic memory is all the easily articulated stored knowledge you have of the world in general that does not refer to specific events in your life. Examples of semantic memory involve factual knowledge such as knowing a car has four wheels, that a United States senator is elected to a term of four years, that Earth revolves around the Sun , or that giving a smile increases the odds of receiving a smile. Where procedural knowledge is knowing "how," semantic memory is knowing "that." Like procedural memory, semantic memory seems to last for a long time. It differs from procedural memory however, in that the knowledge can usually be articulated quite easily.

Exactly how the immense amount of information we acquire throughout life is stored or organized in semantic memory is still an active area of research. Most experts believe that, in general, information is stored in networks of related concepts. The more similar various concepts are, the more closely associated they will be in memory. Research in semantic memory does in fact indicate that it is organized such that when a certain idea is activated or brought to mind, related or similar items will be identified faster. For instance, if one is discussing roses, knowledge of other flowers and plants will be recalled faster and with more ease.


Mental representations in semantic memory

Two specific types of mental representations hypothesized to be used by the semantic memory system to organize information are schemas and categories. Schemas are ordered frameworks or outlines of world knowledge that help us organize and interpret new information. They are like maps or blueprints into which new related information will be fitted. Knowledge of your home town or city, with its streets, various buildings, and neighborhoods is an example of a schema.

Research shows that new information relating to knowledge one already has will be remembered better than information about a topic one has little or no knowledge of. Thus, if two people are given directions to a party, the individual who knows the layout of their city or town pretty well will tend to remember the directions to the party better than a person who has little or no knowledge of the city's layout. This is presumably because the person with the pre-existing knowledge is able to fit the new information into their older knowledge, and thus form a stronger link in memory.

Schemas also help to reconstruct, or try to remember, information that may have been forgotten. For example, if a friend brings up something that happened one time you both went out to eat dinner a few months ago and you don't remember it clearly, you might ask for more information, and then use your schema for the usual sequence of events in eating out to try to remember or reconstruct what happened. The accuracy of reconstructions is open to question.

Categories are another representational form of thought used by semantic memory to organize information. Categories are sets of objects, experiences, or ideas, that are grouped together because they are similar to one another in some respect. For example, apartments, houses, huts, and igloos, might be grouped under the category of dwellings. Like schemas, categories help us make sense of, and organize, the multitudinous aspects of the world.


Relations among memory systems in long-term memory

While it is thought that the procedural, episodic, and semantic memory systems operate relatively independently, it is obvious that they also interact and work together. For instance, one's procedural knowledge of how to ride a bike or operate a computer will be linked with one's semantic knowledge of how bikes and computers work in general. Moreover, episodic memories of, for instance, one's first date, will add to one's semantic knowledge of dating in general, and possibly one's procedural knowledge of how to best have a good time on a date.


Research methods

Most research on long-term memory is highly specialized, focusing on particular types of information storage and the various retrieval processes associated with them. In the research laboratory memory is most often assessed by recognition, recall, or relearning tasks.

In recognition tasks, research subjects are commonly shown lists of words or groups of visual stimuli, such as pictures of faces. After a period of time subjects are then presented with new lists or groups of visual stimuli in which some of the original material is embedded or mixed in. They are then asked to indicate which items they recognize from the original material. In order to assess different aspects of memory, researchers may vary the amount of material presented, how long they let the subject study it, how much time passes between presentation of the original and altered material, and any number of other variables. Recognition is often quite accurate, especially if the subject is asked only if they have seen an item before. An example of a recognition task in which the subject is asked to choose a correct answer from among incorrect ones is a multiple-choice test.

In recall tasks, subjects are asked to reproduce material that was previously learned. The material may consist of lists of words, stories, or visual stimuli. They may be asked to report the material in exactly the same way it was presented, or to report as much of the material as they can remember in any order at all (this is called "free recall"). In "cued recall" the subject is given clues to aid their recall. Giving clues can improve recall greatly. As in recognition tasks, many variables, such as the amount of material, and time between learning and testing, can be manipulated to test different aspects of memory. An essay test is an example of a recall task.

In relearning studies, the time it takes to learn material initially is compared to the time it takes to learn the same material a second time after it is forgotten. Findings consistently show relearning time is much less than original learning time. The difference between the two learning times is called the "savings score." The high savings scores found across almost all relearning studies indicates that once something is learned, it is never really forgotten completely. It seems some of the original learning remains, although how much and in what form remains unclear.


Reminding and forgetting

Reminding is an aspect of memory that indicates ideas are organized in long-term memory by similarity, whereby when people think of something, they are often reminded of a similar thing. Remindings are usually of information that is similar in content, or of earlier experiences that are similar to the current situation. The most widely accepted explanation of the reminding process is spreading activation which assumes memory is made up of networks of concepts that are connected due to similarity. When a concept from a network of concepts is used, that concept is presumably energized or activated in some way. This activation, if strong enough, spreads along the associative pathways connecting the activated concept to other related concepts and in turn activates the related concepts.

The spreading or activation process is seen as being largely automatic. It can, however, be controlled to a certain extent. In this way we can concentrate on current goals without being constantly distracted by related but largely irrelevant ideas.

Forgetting is the inability to recognize, recall, or reproduce information which was previously known or learned. Different theories within psychology propose various processes for how forgetting occurs. Traditional, associative learning theories believe forgetting is the decay of associative bonds through disuse, or not thinking of something. Associative theories also believe forgetting is caused by interference . Material will be retained to the extent that it was well-learned, unless previously or newly learned information interferes. Interference is the confusion or substitution of one item in memory with another. There are two types of interference: retroactive interference, when old information is harder to remember because new information gets in the way; and proactive interference, when new information is harder to learn because it is similar to old information. Interference theory holds that material is rarely lost or forgotten, it is simply unavailable or inaccessible.

Psychoanalytic theory, as discussed earlier, sees forgetting as the result of repression. Freud felt a good deal of forgetting happens because the forgotten material is associated with unpleasant experiences that produce anxiety which automatically evokes the defense mechanism of repression. Memories then are never truly lost, but are irretrievable due to repression.

The contemporary cognitive approach proposes that each of the three stages of information processing forgets or loses information for different reasons. In both the sensory and short-term memory systems, information is lost through decay of their underlying neural connections. Information is never really forgotten in long-term memory. It is assumed to be there but cannot be accessed due to a failure in retrieval.

It should be noted that there is no way to definitively discover whether information is retained for life or ever truly lost from memory. This is because even if someone cannot recall something that does not mean it is not present in memory. It may instead be inaccessible due to repression, interference, or retrieval failure. Moreover, it is often impossible to assess the accuracy of someone's individual memories as there are no available corroborative witnesses.


Memory disorders

The two main memory disorders are amnesia and aphasia. Amnesia is a partial or total loss of memory caused by emotional trauma, disease , or brain injury (usually due to head trauma, surgical accidents, or chronic alcohol abuse). Memory loss can occur for events just prior to the amnesia-causing incident (retrograde amnesia), or for events occurring after the incident (anterograde amnesia). In severe cases of anterograde amnesia, the person may be unable to form new memories, although recall of material learned before amnesia's onset is usually unaffected. Many cases of amnesia (even severe) are temporary, so that the person recovers his or her memory.

Aphasias are a complete or partial impairment of the ability to understand or use words which are caused by lesions in the brain. There are numerous varieties of aphasia, and diagnostic classification systems are constantly being revised.


Physiological basis

In recent decades, research on the physiological basis of human memory in the brain has intensified. Much has been learned about how information in memory is organized in the brain, and the roles various parts of the brain play in memory from research with those with amnesia or aphasia. In fact, detailed studies of individuals with unusual patterns of brain damage have produced much of our current knowledge about the physiological basis of human memory. It seems that numerous brain structures are involved in memory processing and various subtypes of memory. For instance, the ventromedial frontal region of the brain (an area in the lower front portion) seems to link memory and emotions, and the basal ganglia (a set of neural cell bodies set deep in the base of the cerebral hemispheres) are involved in learning new motor skills. Indeed, some researchers would argue that in a broad sense, one could say the entire brain is involved with some aspect of memory.

Current research/future developments

As in many other fields of psychology, research into underlying biological (physiological, genetic, hormonal) factors in mental phenomena is thriving. Studies concluded in the early and mid-1990s clearly show learning/memory mechanisms occur at synaptic connections—the site of information transfer between neurons. Dozens of different mutant learning/memory genes have already been identified which specifically block learning and/or short-term, amnesia-resistant, and long-term memory. Further studies will surely help uncover intricate mechanisms at the cellular and molecular level involved in learning and memory. Continual advances since the 1970s in brain-imaging techniques that allow non-intrusive visualization of the brain at work have contributed immensely to this area of research. Improvement in brain imaging techniques such as computed tomography, positron emission tomography, and functional magnetic resonance imaging (MRI) , development of new techniques, and neurobiological and genetic research will undoubtedly lead to exciting discoveries about the basis of memory and other mental functions in the brain.

Resources

books

Gregg, V.H. Introduction to Human Memory. New York: Routledge, 1986.

Lutz, J. Introduction to Learning and Memory. Pacific Grove, CA: Brooks-Cole, 1994.

McGaugh, J.L., N.M. Weinberger, and G. Lynch, eds. Brain Organization and Memory: Cells, Systems and Circuits. New York: Oxford University Press, 1992.

Morris, P.E., and M.E. Conway, eds. The Psychology of Memory. Vols. 1-3. New York: New York University Press, 1993.


Marie Doorey

KEY TERMS


Associationism

—A philosophical/psychological stance holding that mental associations are the building blocks of complex mental processes such as language and memory.

Brain imaging techniques

—High technology techniques allowing non-intrusive visualization of the brain, these include computed tomography, positron emission tomography, and functional magnetic resonance imaging.

Category

—A set of objects, experiences, or ideas, grouped together because of their similarity, they aid the organization of information in memory.

Episodic memory

—Memory system holding conscious recollections of events from a person's life that often include time, place, and a representation of oneself.

Long-term memory

—Part of memory system capable of holding large amounts of information for an indefinite period of time, possibly for a lifetime.

Memory

—All of the information retained by an individual, and the mental systems and processes involved in storing and recalling information.

Neuron

—Nerve cell.

Procedural memory

—Memory system holding often hard to articulate knowledge of how to perform certain procedures or activities.

Reconstructive memory

—Type of memory thought to store experiences by abstract principles, which are then used to reconstruct memories during recall.

Schema

—A structured framework of world knowledge that helps organize and interpret new information, as well as reconstruct information that may have been forgotten.

Semantic memory

—Memory system holding all the easily articulated knowledge of the world an individual has that does not refer to particular events in their life.

Sensory memory

—Part of the memory system that registers experience through the senses, holding onto information for one to two seconds before it is lost or transferred to short-term memory.

Short-term memory

—Part of the memory system that repeats and organizes information to aid its storage in long-term memory, it is able to hold only limited amounts of information for short periods of time before it is either lost, or transferred to long-term memory.

Memory

views updated May 29 2018

Memory

THE POLITICS OF COMMEMORATION

THE USES OF MEMORY IN CHANGING TECHNOLOGIES OF COMMUNICATION

TRAUMA AND MEMORY

MEMORY AND HISTORY

BIBLIOGRAPHY

Since the 1980s, collective memory has become an intensely studied topic across the social sciences. This sudden remarkable interest may be attributed to a rising preoccupation with dissolving collective identities in the face of new historical realitiesglobalizing economic and cultural trends, the reconfiguration of gender relations, and a media revolution with far-reaching implications for the organization of knowledge. The scholarly discourse about collective memory parallels another about the distinguishing traits of a postmodernism temper.

Serious efforts in the social sciences to understand the dynamics of collective memory, however, date from the early twentieth century in the research of the French sociologist Maurice Halbwachs (18771945). He contended that memory must be investigated within its social settings. The present attitudes, beliefs, and traditions of social groups determine the way memories are evoked, and these are continually remodeled as the interests and fortunes of such groups change. The strength of a collective memory is a function of the relative power of such social forces.

By placing his accent on collective memory, Halbwachs took issue with the Viennese neurologist Sigmund Freud (18561939), who a generation before had addressed the issue of memory as a task of exploring the workings of the individual mind. Freud believed in the autonomy of personal memory, and developed an analytical technique for recovering repressed memories from the unconscious psyches of his patients. His critics claim that he never worked out a plausible theory of collective memory. For Halbwachs, by contrast, all memory is socially conditioned in that personal memories are always evoked within specific social settings. Without these social props, personal memories tend to fade away.

In explaining the malleability of memory in the face of social forces, Halbwachs proposed that social groups families, religious cults, political organizations, and other communitiesdevelop strategies to hold fast to their images of the past through places, monuments, and rituals of commemoration. His La topographie légendaire des évangiles en terre sainte (The Legendary Topography of the Gospels in the Holy Land, 1941) was a pioneering case study of the way an imagined past is localized, conflated, and idealized over time in a commemorative landscape. In his theory, the ancient art of memory as a technique of mnemonic displacement was reinvented as a political strategy for anchoring cultural traditions.

For several decades, Halbwachss theory of collective memory was largely ignored. But it was rediscovered during the 1970s, to become a working model for burgeoning scholarship in this field. The newfound interest in collective memory has had three principal venues of research: the politics of memory; the changing uses of memory that followed from the invention of new technologies of communication; and a deepening meditation on the memory of the Holocaust.

THE POLITICS OF COMMEMORATION

This interest reflected an emerging critical perspective on modern traditions once naively honored as the remembered heritage of a commonly imagined past. In France, for example, a lively debate emerged during the 1980s about how, and even whether, to celebrate the bicentenary of the French Revolution (17891799), hitherto conceived as the enduring moral touchstone of modern French national identity. Many of these studies investigated the making of the identity of the modern state. The most influential was The Invention of Tradition (1983), an anthology edited by English scholars Eric Hobsbawm and Terence Ranger that explored the political uses of tradition in the construction of collective identity. They challenged the long-standing interpretation of tradition as a heritage that impinges on the present through its inertial power and argued that traditions are conceptions of the past invented in the present and periodically refashioned to serve reformulated political goals. Collective memory, they argued, is inspired by present circumstances, and calls into being a serviceable past. In like manner, the anthropologist Benedict Anderson wrote an influential study of the way imagined communities are constructed as public memories to give concrete affirmation to otherwise abstract ideals. From a somewhat different perspective, the sociologist Mary Douglas examined the workings of institutional memory, in which bureaucratic solutions to organizational problems are rapidly forgotten only to be invented anew.

By the turn of the twenty-first century, a vast scholarly literature had been produced on the politics of memory, extending investigations beyond commemoration into a wide range of institutional and cultural practices. Noteworthy among these are studies of the making of national identity by Pierre Nora, Les lieux de mémoire (Places of Memory, 19841992) for France; Michael Kammen, Mystic Chords of Memory (1991) for the United States; Yael Zerubavel, Recovered Roots (1995) for Israel; and Wulf Kansteiner, In Pursuit of German Memory (2006). All display intellectual sophistication in moving beyond commemorative rites to the many cultural forms in which collective memory is embedded. Over time, the study of collective memory has become an impressive strategy for interpreting cultural history.

THE USES OF MEMORY IN CHANGING TECHNOLOGIES OF COMMUNICATION

A parallel but independent line of scholarly inquiry has explored the cultural consequences of advances in the technologies of communication. This research was inspired by the media revolution of the late twentieth century, which stimulated curiosity about earlier thresholds in the processnotably from orality to manuscript literacy in antiquity, and the democratization of print culture during the eighteenth century. Contributors to this scholarship have been variedclassicists interested in Homer as a collective name for epic storytellers, anthropologists in the living oral traditions of Africa, intellectual historians in the emergence of the republic of letters during the Enlightenment, literary critics in the reflective autobiographical soul searching that print culture for the first time made possible. Less has been written to date on the effects of media on cultural memory, but J. David Bolter has pointed out the way electronic memory localized in the icons and Web sites of the computer screen mimics the organizational technique of the ancient art of memory in its images and places. Though contributions to this field were made by specialists, the cumulative effect has been to produce a sweeping new perspective on cultural history from antiquity to the present.

TRAUMA AND MEMORY

Somewhat apart are scholarly reflections on the painful process through which Holocaust survivors sought to deal with the trauma they had suffered. This topic reintroduced Freuds psychoanalytic approach in that it exposed the need for survivors to work through repressed memories of their ordeal before the historical meaning of the Holocaust could be adequately addressed. Beyond inventorying such living testimony, scholars raised the question of how these recovered memories might be historicized within the narratives of modern history. This scholarship provoked the historians controversy of the mid-1980s in Germany about whether such an atrocity could be conveyed within the limits of historical representation. The Holocaust, initially viewed as one among the many horrors of World War II (19391945), came toward centurys end to be reconceived as a singular experience whose memory needed to be processed collectively before an account of its nature could be integrated into any acceptable historical narrative.

MEMORY AND HISTORY

The debate about the limits of historical representation shows how the study of collective memory has unsettled the established conventions of historical narration. During the 1970s, the American scholar Hayden White launched an inquiry into the strategies through which historians compose their interpretations, and so shifted historiographical interest from the evidentiary content of historical research to the rhetorical forms of historical writing. One consequence was to reveal the mnemonic character of historical narrative as a technique for selecting and ordering judgments about what is worth remembering out of the past. Challenging the noble dream of historical objectivity, historiographers such as Peter Novick turned to the task of exposing the bias, distortions, and omissions of the master narratives of modern history. Novick points out how American historians once naively presented a past they wanted to remember. From the founding of the American Historical Association in 1884 until well into the twentieth century, eminent historians tended to favor a patriotic view of American identity that denied the divisive realities of class conflict, racial and ethnic discrimination, and the diverse viewpoints of an expanding immigrant population.

As this historiography of patriotic consensus fragmented from the mid-twentieth century, a new generation of practicing historians sought to reclaim the forgotten past of women, African Americans, and other marginalized groups, while those with a theoretical bent proposed new categories of conceptualization to frame a more complex historical memory, notably through models for gender studies, the history of collective mentalities, and global history. In the process, they subverted the political identities previously highlighted by modern historiography. The conventional model of a directional modern history, originally conceived as a story of ongoing progress, became an uncertain guide to historical writing. This loss of direction coupled with a sense of accelerating time promoted by larger contemporary trendsadvertising that incites the fads of consumerism, the ongoing technological innovations through which global communication approaches the instantaneousled to the collapse of the future-oriented conception of historical time in favor of one that stresses the urgency of present-day problems. The French historiographer François Hartog has characterized this rethinking of the mnemonics of historical time as a new regime of historicity, one that privileges present concerns over past intentions as a point of departure for historical inquiry.

Memorys subversion of the grand narrative of modern history has legitimized some novel approaches to historical interpretationan encounter model in global history, a shift from historys story to historys topics in historical exposition, the genealogical reading of the past to point out its discontinuities vis-à-vis the present, and efforts to recapture sublime moments of historical experience through historical reenactment.

The scholarly discourse about memory across the curriculum in the late twentieth century reveals its essential paradoxthe fragility of its representations of the past in relation to the durability of its resources to imagine that past anew.

SEE ALSO Collective Memory; Freud, Sigmund; History, Social; Holocaust, The; Psychoanalytic Theory

BIBLIOGRAPHY

Anderson, Benedict. 2006. Imagined Communities: Reflections on the Origin and Spread of Nationalism. Rev. ed. London: Verso.

Confino, Alon, and Peter Fritzsche, eds. 2002. The Work of Memory: New Directions in the Study of German Society and Culture. Urbana: University of Illinois Press.

Douglas, Mary. 1986. How Institutions Think. Syracuse, NY: Syracuse University Press.

Friedlander, Saul, ed. 1992. Probing the Limits of Representation: Nazism and the Final Solution. Cambridge, MA: Harvard University Press.

Hartog, François. 2003. Régimes dhistoricité: Présentisme et expériences du temps. Paris: Seuil.

Hobsbawm, Eric, and Terence Ranger, eds. 1983. The Invention of Tradition. Cambridge, U.K.: Cambridge University Press.

Hutton, Patrick. 1993. History as an Art of Memory. Hanover, NH: University Press of New England.

Matsuda, Matt. 1996. The Memory of the Modern. New York: Oxford University Press.

Nora, Pierre, ed. 19841992. Les lieux de mémoire. 3 vols. Paris: Gallimard.

Novick, Peter. 1988. That Noble Dream: The Objectivity Question and the American Historical Profession. Cambridge, U.K: Cambridge University Press.

Ong, Walter. 1982. Orality and Literacy: The Technologizing of the Word. London: Methuen.

Schacter, Daniel. 2001. The Seven Sins of Memory: How the Mind Forgets and Remembers. Boston: Houghton Mifflin.

Patrick H. Hutton

Memory

views updated May 09 2018

MEMORY

Memory is involved in almost every aspect of children's behavior, from everyday occurrences such as finding a misplaced toy, through the routine demands of learning formulas for a math test, to emotionally charged experiences such as explaining why a particular punishment was unfair. In this overview of memory development, the structure of the memory system will be examined, different types of memory processes will be defined, and age-related changes in memory capabilities from infancy through middle childhood will be described.

Overview of the Memory System

The multi-store model of memory developed by Richard Atkinson and Richard Shiffrin has guided research in memory and its development. The model is supported by extensive experimental evidence and is applied productively in work with individuals who have suffered brain injuries and students with typical learning characteristics as well as learning difficulties. In this information-processing model, illustrated in Figure 1, human memory is seen as operating in a manner analogous to that of a computer. The model depicts three separate memory stores that function as the hardware of the memory system: long-term memory, the sensory register, and working memory. Long-term memory, which is what people typically mean when they refer to memory, is a relatively permanent memory store with an apparently limitless capacity. It includes both semantic memory, a mental reference book that contains facts about the world, and episodic memory, a repository of stored traces of experienced events. It should be noted, however, that representations of learned material or personal experiences do not enter long-term memory directly. Information is moved through earlier stores to long-term memory.

Sights and sounds from the world enter the memory system through the sensory register. This store holds the icon of a visual display or the echo of a sound for a very brief period of time. Within only one second, information that an individual has not extracted from the icon or echo is lost. Hence, much of what enters the senses never becomes part of long-term memory. Information that is identified by individuals is often maintained in working memory while the individual interprets it, transforms it, or uses it to solve problems. Applying the computer metaphor, the contents of working memory correspond to open files and running programs. Information moves from working memory into long-term storage when it is processed in a way that makes it meaningful to the individual.

The long-term memory store is often incorrectly described as containing complete and actual representations of past events. In contrast, long-term memory is understood by psychologists to be a reconstructive process. Memories can be altered when individuals encounter new material that interferes with stored information or make inferences that are added to a representation. A well-documented way in which inference occurs is through the operation of schemas, which are organized sets of facts (for example, beliefs about what happens during a visit to the doctor). In a classic study conducted in 1932, Frederick Bartlett read English research participants a story that described events that were inconsistent with their own life experiences and hence seemed bizarre. When they were later asked to recall the story, the participants distorted the actions that took place in a manner that made them consistent with their own culture.

In addition to the memory stores described above, mental strategies are an important component of the information processing system. Strategies correspond to the software of the computer. They are learned procedures that individuals use to direct attention, move information from working to long-term memory, or apply techniques for solving problems. A second grader who repeats a telephone number before dialing it is using verbal rehearsal, a simple memory strategy; a ninth grader who learns a new vocabulary word by using it to describe a principle he has previously learned is using elaboration, an especially effective strategy. Strategies make it possible for memory to be intentional, the term applied when information is deliberately learned or purposefully retrieved. In contrast, memory is described as incidental when information is acquired in the process of performing another activity.

It should be apparent from even this brief introduction that the components of information processing are constantly interacting as a system. The contents of the long-term store are important in encoding, the process of taking information from the world into the memory system. Information stored in long-term memory makes it possible to identify the stimuli in the sensory register so that it can be moved to another store. Knowledge from long-term memory enables the application of strategies or problem-solving procedures in working memory. The contents of permanent memory also determine to a large extent how meaningful new material is, and hence how it can be organized and accessed from the long-term store.

The information-processing model is particularly useful in understanding explicit memory, the type of memory of greatest interest to parents and teachers. Explicit memories are potentially conscious and can be described verbally or pictured in images. A child uses explicit memory when she describes a class field trip or edits a report by applying grammatical rules she has learned. In contrast, some information may affect task performance without entering the individual's conscious awareness. In this case, it is described as implicit memory. Implicit memory is assessed by indirect measurements, such as determining how much quicker individuals can add letters to complete a word when they have previously been presented with a target word, or by physiological indicators, such as changes in galvanic skin response.

Understanding children's memory requires identifying the age-related changes that occur in the components of the information processing system. The first significant advance, of course, is the emergence of memory in development. In the next section, the point in life at which the memory system can be considered to be "up and running" will be discussed. The following sections will examine the changes that occur during childhood in the memory stores and in the use of strategies. The importance of these transitions in children's everyday lives will be explored in each section.

The Developmental Onset of Memory

The memory stores described above are assumed to be universal and present throughout life. Indeed, there is evidence that the capacity to store information in long-term memory begins even before birth. In a well-controlled investigation conducted by Anthony DeCasper and Melanie Spence, the researchers asked pregnant women to read aloud a Dr. Seuss story during the last six weeks of their pregnancies, a point in prenatal development at which fetuses can hear. Shortly after birth, the newborns' recognition memory was tested by comparing their reactions to the familiar passages versus similar but new story excerpts, both of which were read by the babies' mothers. The assessment built on the knowledge that babies can learn to modify the time between bursts of sucking when a change in sucking is followed by the presentation of a stimulus that serves as a reinforcer. The newborns wore headphones and were given a pacifier that recorded their sucking bursts. They indeed modified the way they sucked when the change in sucking was followed by the familiar passage, but they did not do so with the unfamiliar passage. The fact that the old, but not the new, passages served as reinforcers demonstrated that the babies could recognize the stimuli to which they were exposed before birth.

Although even very young infants can recognize sights, sounds, and smells they have previously encountered, the ability to recall an object or an experience develops later. Recall differs from recognition in that it requires coming up with a response as well as determining that it is correct. Some simple recall is present in the second half of the first year. As every babysitter knows, very young infants remain calm when their parents go out; by around seven months of age, however, separation protest is apparent. By about nine months of age, babies can imitate an action after a twenty-four-hour delay. Note that early recall is heavily dependent on cues and is limited to relatively brief time intervals. Recall continues to develop over the second year of life, corresponding to the development of the prefrontal cortex and other brain structures associated with explicit memory. Between age two and two and a half, toddlers can be expected to remember to stay away from common hazards, provide their first and last names when asked, repeat parts of nursery rhymes, and possess simple event schemas (also called scripts) for everyday events.

By age two and a half, as is well documented in the work of Robyn Fivush and her colleagues, children describe specific past experiences such as a trip to an amusement park. Such early memories, however, do not generally become a permanent part of autobiographical memory, the subset of episodic memory that represents individuals' own life histories. Most people do not recall anything that happened before they were three years of age. This phenomenon is described as infantile amnesia. Although the reasons for infantile amnesia are not completely understood, several factors appear to be important in explaining the developmental emergence of autobiographical memory. One of these is the maturation of the frontal lobes of the brain, which continues throughout early childhood. A second factor appears to be the emergence of the self-concept, which serves as a conceptual framework for the organization of memories. Another is the role of social interactions in maintaining early memories. Katherine Nelson has emphasized the importance of the child's participation in family discussions about past events for keeping early memories alive, a process described as reinstatement. Children are about three years old before they can actively participate in conversations about past events. Finally, some early memories may not be retrieved at later points in development because they are not effectively cued. Because the typical everyday environments of older individuals differ greatly from those of very young children, some potential memories may not be accessed.

Developmental Changes in Information Processing Capacity

Does the absolute capacity of the memory stores change with development? The answer to this question is unknown and, according to some experts, may be unknowable. It is clear, however, that memory span, a measure of working memory, improves reliably with age. Memory span is defined as the number of single words or digits individuals can report in order immediately after hearing them. It increases from about two items at age two to five items at age seven to seven items in adulthood. The amount of information that individuals can hold in memory at any one time determines at least in part what they can learn.

It appears that age-related improvements in the memory span are attributable to two factors: changes in the resources that are available in the information processing system and differences in the efficiency with which older children and adults apply these resources. One of the most important developmental changes in the information processing system is in the speed of processing. Robert Kail asked individuals from ages six to twenty-one to perform a variety of cognitive tasks ranging from mental addition to memory search. He found a remarkably similar pattern of age-related increases in reaction time in the performance of all of the tasks. It should be noted that speed of processing is important in executing many cognitive functions, from moving information from the sensory register to working memory to applying strategies. Hence, developmental differences in speed of processing can influence children's capabilities to perform a variety of academic and everyday tasks.

Processing capacity increases if more resources are available; it can also be enhanced if the resources necessary to perform the task can be decreased. Simply providing extra time for study or problem solving improves children's performance in some but not all tasks. Perhaps the most important determinant of task demands is the learner's relevant knowledge. Familiarity with the to-be-remembered material affects the memory process at every step of information processing. Imagine how difficult it would be, for example, for someone who speaks only English to remember a string of digits presented in another language.

Michelene Chi provided a classic demonstration of the importance of prior knowledge. In this investigation, children who were chess experts had better memories for chess positions than did nonexpert adults, even though the adults demonstrated the expected advantage in remembering digits. Here, prior knowledge of chess eliminated age differences in memory. Because children's knowledge bases increase as they get older simply through their experiences in the world, age differences in memory may be explained to a great extent by differences in task-relevant knowledge.

Changes in the knowledge base also affect the organization of information in long-term memory and hence partially determine whether or not material can be reported. As depicted in the semantic network model of memory, items are represented as nodes and the nodes for associated items are linked. Knowledge about a particular content domain (such as dinosaurs or soccer) creates semantic associations between previously unconnected items, resulting in the formation of connections between nodes. When one item is recalled, the activation spreads to associated items as well, increasing the likelihood that they will also be reported. Items that are represented as part of an extensive network of information within a content area are also less likely to be lost over time. Moreover, age differences in children's long-term event recall are minimized when younger and older children have high levels of prior knowledge about the to-be-remembered components of the experience.

Knowledge also enhances memory by making it easy to apply strategies for encoding and retrieving information. As discussed in the next section, the development of memory strategies is another important reason for age-related increases in children's ability to remember, especially in academic settings.

The Acquisition of Memory Strategies

A child's intentional memory shows dramatic improvement when he can effectively use memory strategies. These deliberate tactics for remembering develop over a lengthy period that spans the elementary and middle school years. Preschool children use very simple tactics for remembering in some special task settings; for example, a four-year-old can be expected to use a marker to denote an object's hiding place in preparation for subsequently finding it. Pre-schoolers do not, however, use mental strategies and indeed do not typically differentiate memory and perception. By age seven, most children spontaneously use rehearsal to enhance short-term memory performance. Retrieval strategies (such as going sequentially through the alphabet) begin to be spontaneously used around third grade. Children's self-directed use of organization, the ability to impose a semantic structure on the to-be-remembered items to guide memory performance, emerges later in the elementary school years. For example, a fifth grader could be expected to remember what to take on a school field trip by reviewing the activities involved and packing accordingly (e.g., "things to do on the bus," "what I need for the nature walk," "things I'll need at lunch") by herself. It is unlikely, however, that a third grader would use organization as a guide without the direction of an adult. Elaboration, a highly effective strategy that involves actively creating a representation integrating new information with existing information, may not be used spontaneously by children until early adolescence. An eighth grader may remember the definition of the word "fruition" by creating an image of a ripe pear on a bough, but it is unlikely that most sixth graders would do so.

Most students do not acquire optimally effective study skills, which can be considered forms of memory strategies, until adolescence. By the later elementary school years, children allocate more study time to test items that they have previously missed on practice tests; in contrast, younger elementary school children devote comparable amounts of attention to items that they have previously gotten correct and incorrect. By high school good students can be expected to take spontaneous and effective notes and to emphasize key information in studying.

Regardless of the strategy under consideration, its use emerges initially in highly supportive task settings. At early points in the acquisition of memory strategies, children use a strategy when adults instruct them to use the strategy but they do not generate the strategies spontaneously, a limitation described as a production deficiency. Additional preparation time, the use of familiar materials, and cues that may reduce memory demands are other factors that increase the likelihood that strategies will be used. When they are fully acquired, strategies are applied spontaneously in a wide array of task settings. Metamemory, or knowledge about the operation of the memory system, contributes to the development of strategies. Metamemory involves understanding the demands of the task and the relevant characteristics of the rememberer, as well as identifying and using effective task approaches and monitoring their effectiveness. In general, the development of metamemory increases with age, corresponding to changes in actual memory performance.

Fostering Children's Memory Development

Memory develops largely through social interaction, and consequently parents and teachers play a critical role in assisting children in developing good memories. During early childhood, everyday adult-child interactions provide the basis for memory development by fostering language development and helping children acquire scripts for common events. Conversations that include reminiscing about the recent past are significant in helping children understand what memory is and what should be remembered. Developing family traditions and participating in rituals encourage reminiscing.

When a child begins formal schooling, adults can contribute to the child's acquisition of metamemory and memory strategies by modeling their own approaches to tasks involving memory and discussing their memory failures. It is important that teachers and parents recognize that strategies develop over an extended period. Children's use of effective memory strategies in studying should be monitored, and adults should help children simplify tasks by providing external memory aids and other supports as needed. Informal instruction in the use of memory strategies should be incorporated into class presentations and assignments.

It is also important to keep in mind that memory is facilitated by advances in other domains of development. As examples, narrative skills increase children's abilities to provide reports of their personal experience; problem-solving techniques increase functional working memory capacity. The development of the knowledge base plays a vital role in memory performance. Hence, providing children with opportunities to learn about the world contributes significantly to their capacity to remember effectively.

See also:COGNITIVE DEVELOPMENT; LEARNING

Bibliography

Atkinson, Richard C., and Richard M. Shriffrin. "Human Memory:A Proposed System and Its Control Processes." In K. W. Spence and J. T. Spence eds., The Psychology of Learning and Motivation: Advances in Research and Theory. New York: Academic Press, 1968.

Chi, Michelene. "Knowledge Structures and Memory Development." In R. S. Siegler ed., Children's Thinking: What Develops? Hillsdale, NJ: Lawrence Erlbaum, 1978.

DeCasper, Anthony J., and Melanie J. Spence. "Prenatal Maternal Speech Influences Newborns' Perception of Speech Sounds. Infant Behavior and Development 9 (1986):133-150.

Fivush, Robyn, and Judith A. Hudson, eds. Knowing and Remembering in Young Children. Cambridge, Eng.: Cambridge University Press, 1990.

Howe, Mark. The Fate of Early Memories: Developmental Science and the Retention of Childhood Experiences. Washington, DC: American Psychological Association, 2000.

Kail, Robert. "Development of Processing Speed in Childhood and Adolescence." In H. W. Reese ed., Advances in Child Development and Behavior. San Diego: Academic Press, 1991.

Nelson, Katherine. "The Psychological and Social Origins of Autobiographical Memory." Psychological Science 1 (1993):1-8.

Molly CarterImhoff

Lynne E.Baker-Ward

Memory

views updated May 23 2018

Memory

The Strange Case of H.M.

What Are the Main Types of Memory?

The Anatomy of Explicit Memory

What Else Affects Explicit Memory?

Lessons from a Sea Slug

Resources

Memory is the ability to remember and to recall previous sensations, ideas, experiences, or information that has been consciously learned.

KEYWORDS

for searching the Internet and other reference sources

Amnesia

Alzheimer disease

The Strange Case of H.M.

It is hard to imagine what it would be like to live without memory. What if the things that people had just seen, learned, or heard simply passed out of their minds after just a few minutes? So many of the activities of daily life, such as reading a book, watching a movie, doing homework, holding a conversation, making friends, and going to the store, would be totally impossible. People, places, and events would always seem brand-new, even if they had been experienced before. Living without memory would mean always having to exist in the present moment with no awareness of the past.

This may sound like a science fiction movie, but it actually happened. In 1953, a 27-year-old man, now known by the initials H.M., underwent brain surgery for his severe epilepsy*, a nervous system disorder that caused him to have daily seizures. The surgeons removed his hippocampi*, which are two parts of the lower brain, and portions of his temporal lobes*, which are the side parts of the cortex*. Doctors believed that these areas were diseased and causing H.M.s severe symptoms. (Today, most cases of epilepsy can be controlled with medication, although sometimes surgery still is required.)

* epilepsy
(EP-i-lep-see) is a disorder of the nervous system characterized by repeated seizures that temporarily affect a persons awareness, movements, or sensations.
* hippocampi
(HIP-o-KAM-pie) are two parts of the lower brain that together look like a small pair of rams horns.
* temporal (TEM-por-al) lobes
are the side portions of the cortex. They contain the sensory center for hearing and are centers for language function.
* cortex
(KOR-teks) is the top outer layer of the brain. It controls the brains higher functions, such as thinking, learning, and personality.

H.M. was cured, but with tragic results: He could no longer remember anything for more than a few minutes. He could remember events that happened more than 2 years before the operation, but new experiences or facts were quickly forgotten. In the more than 40 years that psychologists worked with H.M., his situation did not improve. He could remember a set of numbers or a new fact for a short while, but he would forget it as soon as he was distracted or new information was added. In fact, researchers had to reintroduce themselves every time they met with H.M., constantly reminding him where he was and why he was there. H.M. once said, Every day is alone by itself, meaning that he could never make sense of today in terms of yesterday. He experienced time in separate chunks that were quickly erased from his mind.

However, H.M. could still learn parts of new motor skills or routines and repeat them at a later time, even though he did not remember that he had learned them. For example, he gradually learned how to draw an image in a mirror, solve puzzles, and mount cigarette lighters on a cardboard display. H.M.s remarkable case illustrates the fact that there are different types of memory that involve different parts of the brain.

What Are the Main Types of Memory?

Memory is generally divided into two broad categories: short-term and long-term.

Short-term memory

Short-term memory is what a person uses for an activity such as remembering a new phone number after calling directory assistance. The person may repeat the number silently until dialing it, then promptly forget it. If distracted before dialing, the person may have to call directory assistance again. That is because short-term memory is fairly easily disrupted. Think about how students have to study new material in order to learn it, rather than just see it one time. Basically, they are converting the information from unstable short-term memory into more stable long-term memory by attending to it and rehearsing it.

Research has linked memory to the amygdala and to the hippocampus, two structures deep inside the brain. When surgeons removed the hippocampus from a patient known by the initials H.M., hoping to treat his epilepsy, they discovered that H.M.s epilepsy improved but his short-term memory disappeared. H.M. could remember events that happened many years before, but not events of the previous day or the previous hour. H.M.s doctors had to reintroduce themselves to him every single day.

People who experience severe head injury demonstrate how easily the process of short-term memory can be interrupted. For example, a car accident victim may not recall what happened just before impact or even during the accident itself. Some athletes who are knocked unconscious during an especially physical play may not remember what happened minutes before they were hit. This is because there was not enough time for experiences to be converted from short-term to long-term memory.

Long-term memory

Long-term memory, which is much more permanent and stable, can be further subdivided into two types: implicit and explicit. Implicit memory, or procedural memory, is the ability to repeat automatic tasks or procedures, such as riding a bike, driving a car, typing, or swinging a tennis racket. Of course, these tasks are not automatic at first; just ask any sixteen-year-old who is learning to drive. Over time, though, a person can perform the skill without giving it much thought. Explicit memory is recall for facts or events. This is what comes into play when taking a test, for example, or remembering someones name. The patient known as H.M. lost the ability to turn new experiences into explicit memory but retained much of his procedural or implicit memory. Implicit memory appears to be controlled not by the hippocampus but by other parts of the brain.

The Anatomy of Explicit Memory

Thanks to H.M. and other patients who have had diseases affecting the hippocampus, scientists who study the brain now know that this structure and the nearby temporal lobes play a crucial role in turning what people hear, see, and experience into long-term memories. A Canadian neurosurgeon named Wilder Penfield also had a key part in identifying the importance of the temporal lobes in long-term memory. In the 1930s, while performing brain surgery on patients with epilepsy, Dr. Penfield used an electrical probe to stimulate different parts of the brain. Because the brain itself does not feel pain, the patients could remain awake during surgery. Dr. Penfield found that some patients experienced vivid events or scenes from their lives when he stimulated the temporal lobes. The memories were so vivid, in fact, that the patients thought they were actually reliving the experiences. Thus, 20 years before H.M. came on the scene, Dr. Penfield concluded that this part of the brain had a critical role in long-term memory.

Unable to Forget

Writing things down is an important part of the learning process for most people, whether it is to remember phone numbers and addresses, homework assignments, directions, or the teachers lecture in class. But what if you had a memory so powerful that, when you encountered new information, you couldnt make yourself forget it? Such was the case with S., a man with a memory like a trap: whatever he came across, he could remember for life and without writing down a thing.

S.s unusual ability was discovered during his days working as a newspaper reporter, when he never took any notes at news briefings. When his boss became concerned, S recited back to him the briefing, word for word. S went on to work with a psychologist intrigued by his ability, and also became a mnemonist, or a person who demonstrates his extraordinary memory to an audience.

S. had a unique way of remembering that allowed him to experience information through several sensations, such as sound, touch, or taste. He envisioned numbers as forms, for example the number 6 as a man with a swollen foot, and the number 7 as a man with a mustache. Numbers also had textures and colors: the number 2 was a gray-white, and the number 8 a milky blue-green. These personal visualizations are what enabled him to absorb and store data with such extraordinary speed and permanence. After years of memorizing lists, tables, and other tests, S. could always recall anything he had ever learned. It seemed his ability was limitless.

In fact S. tried to invent ways to forget what he learned. It seemed that S. did not really have a short term memory, so he did not experience the usual memory decay. Everything he learned was put into long term memory which is a relatively limitless and permanent storage capacity. Did S. even remember how to forget?

Today scientists know that other parts of the brain are important to the memory process as well. The thalamus (THAL-a-mus), a structure in the middle of the brain, relays incoming information from our senses to the cortex. These structures together with the hippocampus coordinate facts with their appropriate time and space context to ensure that an event is remembered as a unique happening. In other words, todays breakfast is remembered as distinct from other breakfasts in the past.

What Else Affects Explicit Memory?

A persons emotions affect the process of memory, too. Experiences that make people feel happiness, sadness, or some other strong emotion are more likely to be remembered. For example, most people over the age of 50 can remember exactly where they were and what they were doing when President John F. Kennedy was shot in 1963. Scientists believe that the function of the hippocampus is somehow linked to that of the nearby structures that are involved in controlling a persons emotional responses.

Where do long-term memories go once formed, and how does a person retrieve them? Scientists believe that the entire cortex is involved in long-term memory, but exactly what happens to make or keep these memories is unclear. What is clear is that memories are not exact videotapes of an experience. Rather, memories are constructions that are filtered through a persons individual mental abilities and past experiences. Thus, two people seeing the same crime, for example, might remember the events somewhat differently. As a result, when people swear to tell the truth in court, it is only the truth that they have constructed from their memory, not literally the whole truth and nothing but the truth.

Lessons from a Sea Slug

Many researchers believe that short-term memories are the result of ongoing activity by brain cells, while long-term memories actually reflect structural changes in the brain. Basically, long-term memories are thought to be the formation of new connections from cell to cell in the cortex. Eric Kandel, who won the Nobel Prize in Physiology or Medicine in 2000, has found evidence to support this theory in what might seem like the strangest of places: the sea slug.

Neuroscientist Eric Kandel received the Nobel Prize for Medicine in 2000. His research showed that learning and memory affect organisms on a cellular level, permanently changing individual neurons. This may help explain why counseling and therapy, even without medication, can help people change mentally, emotionally, and even physically. AFP/Corbis

Because the sea slug has a very simple nervous system, with large nerve cells distributed up and down its body, it is much easier to study than a human. If the slug is touched, it reacts in self-defense by withdrawing its gill. Dr. Kandel found that, if he repeatedly pricked the slugs head or tail for a few days, it would withdraw the gill more quickly and sharply. This heightened reaction would occur even when the slug was touched again at a later date. It was almost as if the slug remembered what had happened to it before and reacted accordingly. Dr. Kandel was able to show that there were actually chemical and structural changes in the synapses (SIN-ap-siz), or connections, between the nerve cells that sense touch and the nerve cells that control motion. More neurotransmitters (noor-o-TRANS-mit-erz), or message-carrying chemicals, were released between these nerve cells, and the connections between them were chemically strengthened.

This is a very simple explanation of just one part of Dr. Kandels research, but it is enough to show why this work is so important. Now that scientists understand how nerve cells communicate in sea slugs to form memories, they may be able to use this information to better understand how the human brain forms memories.

See also

Alzheimer Disease

Amnesia

Dementia

Resources

Books

Dowling, John E. Creating Mind: How the Brain Works. New York: W. W. Norton, 1998. Professor Dowling teaches a popular general education course on the brain at Harvard University.

Greenfield, Susan A. The Human Brain: A Guided Tour. New York: Basic Books, 1997. Dr. Greenfield, a professor who lives in Oxford, England, is well-known for her ability to explain scientific concepts in ways that most people can understand.

Kandel, Eric, and Larry Squire. Memory: From Mind to Molecules. New York: Scientific American Library, 2000. The authors are two of the scientists at the forefront of memory research. Their book explains some of the most important concepts of how memory works and what can go wrong.

Organizations

Memory Disorders Project at Rutgers UniversityNewark. This project involves neuroscientists, psychologists, and other researchers at Rutgers University in New Jersey who are studying how the human brain creates and stores memories. The website features easy-to-understand information about memory and memory disorders. http://www.memory.rutgers.edu

Exploratorium, The Museum of Science, Art, and Perception: Memory Exhibition. From 1998 to 1999, this famous museum in San Francisco, California, hosted an exhibition devoted to the subject of memory. An interactive web version includes games and activities that encourage users to test their memory and even improve it. http://www.exploratorium.edu/memory

Neuroscience for Kids. This website by a professor at the University of Washington features kid-friendly information about the brain and nervous system, including the functions of learning and memory. http://faculty.washington.edu/chudler/neurok.html

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