Hippocampal lesion syndrome: Switching to and from a place hypothesis

Spatial discrimination learning (Experiment I) and strategy shifts (Experiment II) were examined in experimentally lesioned rats. Sixty adult male rats were in one of five lesion groups (N = 12/group): operated controls, fornical, entorhinal, fornicoentorhinal and dorsal-ventral hippocampal. All animals reached criterion on the discrimination learning test. In the strategy shift experiment, however, animals with hippocampal lesions had more difficulty than animals without hippocampal lesions. The findings suggest that the hippocampus may not be involved in learning strategies, but in switching a strategy.