Recovery of function after brain damage: the extrinsic stimulus specificity of spared neural traces

Previous research has demonstrated that while primary visual cortex lesions in rats will disrupt performance of a learned brightness discrimination, the neural traces associated with this discrimination are spared. Moreover, the spared neural traces may, in certain instances, influence the postoperative reinstatement of a brightness discrimination. The present research was designed to determine the generality of this postoperative influence. The results indicate that while the normal rat and the visual decorticate rat may readily transfer learning between discriminations involving different discriminative cues, a visual lesion between two discriminations prevents this transfer. These data are interpreted as indicating that the postoperative influence of a spared neural trace is dependent upon the reoccurrence of specific extrinsic stimulus cues.