Discrimination learning in animals with lesions of hippocampus

Abstract

Rats with either bilateral aspiration lesions or unilateral aspiration lesions combined with contralateral irritative lesions of the hippocampus or overlying neocortex were trained on an operant visual discrimination. Only animals with bilateral aspiration lesions of the hippocampus were impaired in the acquisition of brightness discrimination. All animals were also trained in a two-way shuttle-box avoidance task. Animals with bilateral hippocampal aspiration showed an improved acquisition rate, while animals with ventral hippocampal penicillin placements were retarded in the acquisition of this task.