The comparative effects of frontal, parietal, occipitotemporal, and limbic forebrain lesions in weanling rats on learning.

Young rats prepared with discrete bilateral lesions to the cerebral cortex, cingulate cortex, or dorsal hippocampus were required to learn a white-black discrimination, a 3-cul maze, and a nonvisual inclined plane discrimination. Only those rats with parietal lesions were impaired in acquiring all three habits. Those with occipitotemporal, frontocingulate, or posterior cingulate lesions were impaired on two habits, those with dorsal hippocampal lesions were impaired on one habit, and those with frontal (motor) cortical lesions failed to show any impairment. These results coupled with others suggest that the parietal cortex is unsurpassed in the wide range of learning and retention deficits which follows restricted neopallial lesions.