Hemispheric lateralization of spatial contrast sensitivity

Abstract

Visuospatial contrast sensitivity was determined by the Arden grating chart in 23 patients with cerebral infarctions involving the primary visual cortex or visual association cortex. Subjects were classified into three groups according to their lesions: I, 6 patients with unilateral medical occipital or occipitotemporal lesions; II, 6 patients with left lateral parieto-occipital lesions; and III, 11 patients with right lateral parieto-occipital lesions. Contrast sensitivity was markedly reduced in Group III, especially in patients having hemispatial agnosia. Group I patients with hemispatial agnosia showed almost normal contrast sensitivity. Spatial contrast sensitivity appears to be more affected when the lesions has an influence on the nondominant lateral parieto-occipital cortex.