Effects of inferior temporal lesions on visual discrimination performance in monkeys with complete and incomplete striate cortex ablations.

In order to determine whether inferior temporal cortex participates in the relearning of visual discriminations following striatectomy, monkeys were retrained to perform two preoperatively acquired discriminations (brightness-flux and brightness-area) after receiving bilateral striate cortex lesions and then retested in the same tasks after bilateral inferior temporal surgery. After inferior temporal surgery, the monkeys with histologically verified total ablation of striate cortex showed little or no impairment in relearning the discriminations, whereas the monkeys with remnants of intact striate cortex were severely impaired. These findings suggest that inferior temporal cortex is, at most, of minor importance in relearning brightness-flux and brightness-area discriminations in the absence of striate cortex. This interpretation is consistent with the view that the contribution of inferior temporal cortex to visual discrimination performance depends on input from striate cortex.