Franco Lepore

Visual discrimination in hemispherectomized patients

Abstract Four hemispherectomized patients and two control subjects (Ss), matched in age and IQ, participated in a pattern (2D) and an object (3D) discrimination task. Ss had to indicate whether pairs of stimuli, presented simultaneously in both hemifields, were the same or different. The control Ss performed well on all tasks. Although the experimental Ss remained at chance level in the 2D task, two of them showed significant above chance performances on both 3D conditions. It was concluded that interfield comparisons are possible and that alternate visual structures (e.g. the superior colliculi), in conjunction with the remaining cerebral hemisphere, are responsible for these residual visual capacities.