STIMULUS-SPECIFIC ADAPTATION IN EXCITED BUT NOT IN INHIBITED CELLS ININFEROTEMPORAL CORTEX OF MACAQUE

Many cells in inferotemporal cortex respond more actively to a novel p resentation than to a subsequent re-presentation of the same image, ex hibiting stimulus specific adaptation (SSA). Previously, analysis of t his adaptation was limited to visually excited cells, excluding visual ly inhibited cells. In the present experiment we studied 654 cells in four macaques performing visual tasks. Strong SSA (P < 0.0001) was obs erved in those cells which were excited by visual stimuli. This adapta tion was also seen in the subset of such cells which, though excited b y visual stimuli, failed to show visual specificity in their responses . Interestingly, no SSA (P > 0.1) was observed in the group of cells i nhibited by visual stimuli. Furthermore, most inhibited cells failed t o show visual specificity. This lack of visual specificity and SSA sug gests that the visually inhibited cells have a limited role in the det ailed information processing of visual perception and memory activated by the tasks used in the present experiments.