Memory of object identity

Neuronal activities were recorded from the superior temporal sulcus (STS), the temporal pole (POLE) and the amygdala (AMY) of rhesus monkeys during the performance of a visual discrimination and memory task. Five hundred and fifty-nine (174 STS, 225 POLE and 160 AMY) neurons were analyzed in detail. a) All Visual responses in the STS and the POLE, and about 91% of visual responses in the AMY were stimulus-selective. b) In many cases, neuronal responses were not dependent on simple physical features of the stimulus, such as the color, its brightness or the shape of its part. c) Stimulus-selective delay activities were recorded in these areas (STS; 11%, POLE; 30%, AMY; 4%). d) All stimulus-selective delay neurons showed responses during the presentation of the same stimulus and had higher stimulus-selectivity compared to the remaining nondelay neurons. e) Stimulus-selective delay activity stopped when the memory process was terminated. The data suggested that neurons in these areas are involved in the recognition and memory of the object identity rather than the physical properties of those objects.