Light sensitivity in cortical scotomata contralateral to small islands of blindness

Detailed perimetry on two patients with extensive defects in one half of the visual field together with the presence of small scotomata in the opposite visual field suggest that interhemispheric interactions in man are organized with a symmetric topography.

Abstract

Detailed perimetry was performed on two patients with extensive defects in one half of the visual field together with the presence of small scotomata in the opposite visual field. In both cases, visual function can be demonstrated within the major scotoma, but only in a small region that occupies a mirror-symmetric position with the small scotoma in the opposite half of the field. These results are analogous to an earlier finding by Sprague in the cat, and suggest that interhemispheric interactions in man are organized with a symmetric topography.