Retrieval of active and inactive visual discriminations while temporal cortex is suppressed with cold

While local cooling of inferotemporal cortex (IT) impairs new visual learning, it has little effect on recall. However, in visual discriminations, there is typically extensive exposure to the stimuli before cortical inactivation. Perhaps if recall was prevented before suppression, it would fail during suppression. Three animals with cryodes covering a major part of IT were trained on two face discriminations. They were then run on one of these discriminations for 3 days to create the expectation that the task would be continued with the same stimuli, and on the 4th day, they were started with these stimuli, but after cold suppression, they were switched to a discrimination that they should not have anticipated. IT suppression prevented recall of the discrimination that had not been pre-exposed; performance dropped to chance and stayed there for 50 trials. When they were switched back to the initial pair, performance returned nearly to normal. The experiment was repeated with the role of anticipated and unanticipated stimuli reversed. It was suggested that pre-exposure to the discrimination created the expectation that the same stimuli would continue to be used, and induced information about them to be copied from IT into prestriate cortex.