Successful overshadowing and blocking in hippocampectomized rats.
Overshadowing (Experiment 1) and blocking (Experiment 2) were investigated using a conditioned suppression paradigm in rats. Neither hippocampectomy nor cortical control lesions affected the extent to which a salient stimulus overshadowed a less salient one. Nor did the lesions affect the extent to which a stimulus that was highly correlated with shock overshadow a stimulus that was less well correlated with shock. Finally, the lesions did not alter the extent to which a previously reinforced stimulus blocked conditioning to another stimulus when both were presented as a reinforced compound stimulus. It is thus possible for hippocampectomized rats to show apparently normal overshadowing and blocking, at least under some testing conditions.
D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D003213:Conditioning, Psychological / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains