Effects on visual discrimination of crosshatching and undercutting the inferotemporal cortex of monkeys.

Abstract

Original learning and postoperative retention of 12 rhesus monkeys, trained on a visual pattern discrimination before or after bilateral crosshatching or undercutting of their inferotemporal cortices, were compared with that of 4 normal Ss [subjects]. Cross-hatching produced no deficit in learning or retention even on a difficult 5-alternative discrimination, while undercutting led to a deficit in both. The results reopen the issue as to whether the various sectors of the posterior intrinsic "association" cortex contribute to discrimination performance by acting on information received through transcortical fibers from the respective primary sensory areas, or whether these intrinsic areas act corticofugally to modify activity in the primary sensory pathways.