Number Coding in Association Cortex of the Cat

In electrophysiological investigations of single neurons in cortical association response areas of the cat, cells have been encountered that appear to code the property of number. In a sequence of stimulus presentations, these cells characteristically discharge to a particular numbered stimulus in the series. This effect is independent of stimulus modality, intensity, and interstimulus interval; thus, the cells seem to be responding to the number of stimulus presentations.