sum·ma·tion / səˈmāshən/ • n. 1. the process of adding things together: the summation of numbers of small pieces of evidence. ∎  a sum total of things added together.2. the process of summing something up: these will need summation in a single document. ∎  a summary. ∎  Law an attorney's closing speech at the conclusion of the giving of evidence.DERIVATIVES: sum·ma·tion·al / -shənl/ adj.sum·ma·tive / ˈsəmətiv/ adj.

summation
1. (in neurophysiology) The combined effect of the changes in electric potential elicited in one or more postsynaptic membranes by the transmission of impulses at synapses that is sufficient to trigger an action potential in the postsynaptic neuron. Summation occurs when one or a few postsynaptic potentials alone are insufficient to elicit a response in the postsynaptic neuron; it may consist of the effect of two or more potentials evoked simultaneously at different synapses on the same neuron (spatial summation) or in rapid succession at the same synapse (temporal summation).

2. See synergism.

summation The addition of stimuli of different kinds, which may be perceived at more than one time (temporal summation) and in more than one place (spatial summation), to produce a co-ordinated response in an animal. Summation is one of the integrating properties of the central nervous system.

summation The addition of stimuli of different kinds, which may be perceived at more than one time (temporal summation) and in more than one place (spatial summation), to produce a co-ordinated response in an animal. Summation is one of the integrating properties of the central nervous system.