Activity in the visual cortex of a hemianope measured using fMRI

Abstract

Functional magnetic resonance imaging (fMRI) can be used to identify and map visual areas in the cerebral cortex of visually normal humans (Engel et al., in press). Here, we use the methods that have been developed on normal observers to assess the neural responses in subject, G.Y., who has cortical damage that includes left area V1. This subject has reported limited sensation of select stimuli beyond 2.5 deg in his right peripheral visual field (Barbur et al. 1980). Here we report preliminary analyses of the organization of this subject’s visual areas, and we describe some of the cortical signals that occur when stimuli are presented to the subject’s “blind” visual field.