Cell assemblies versus single cells

Publisher Summary A fair comparison between psychophysical performance and that of single neurons can be done using a task for which the neuron is adapted, and comparing it with psychophysical performance at the identical task. Comparisons between behavioral and single unit performance are made for tactile discriminations in monkey cortex. The fact that the number of combinations of cells is much greater than the number of cells is an imaginary virtue of cell assemblies. The idea is that if important external objects or events are represented by the joint activity of the N neurons, rather than by a single one, it is possible to represent a much larger number of such events. One of the merits of representing meaningful and useful objects and events by single neurons is that it improves the efficiency of learning. There must be similar cooperative interactions involved in generating directional selectivity and other forms of pattern selectivity in sensory pathways. Understanding how a group of half-a-dozen, or perhaps several hundred cells cooperate to perform some task would constitute an enormous step on the path of explaining how the 1010 cells of the cerebral cortex control behavior.