Posterior cortical lesions and specific crossmodal transfer in the rat

Abstract

The present study investigated the neural substrate of specific crossmodal transfer (CMT) in rats, using a direct vs. reversal transfer paradigm. Animals with posterior cortical ablations or sham operations were first trained to criterion on a visual intensity discrimination. Following completion of visual training, they received an auditory intensity discrimination (transfer). A factorial design was used, involving operated groups, intensity of visual S+, and intensity of auditory S+. Among sham operates, both direct transfer subgroups showed performance superior to their corresponding reversal transfer subgroups early in the auditory modality, indicating the presence of specific CMT. Among cortical operates, no direct-reversal differences were found. The results demonstrate the importance of the functional integrity of posterior neocortex of the rat to specific CMT involving the modalities of vision and audition.