EFFECTS OF INTERFERENCE ON DISCRIMINATION-LEARNING AND RECALL BY RATS WITH HIPPOCAMPAL-LESIONS

The performance of rats with hippocampal, cortical, or sham lesions on a visual pattern discrimination task was examined under various interference conditions. In Experiment 1, all groups learned the discrimination within normal limits but the hippocampal group was impaired in a retention test if a high interference task involving similar stimulus material was introduced between original learning and retesting. In Experiment 2, animals with hippocampal lesions were similarly impaired in the initial acquisition of the discrimination habit when the high interference task was introduced prior to the beginning of training. The results were related to similar deficiencies in human amnesics with known or suspected hippocampal damage and were interpreted as reflecting a basic inability to use available cues to dissociate competing experiences. © 1979.