Chronic blindness following lesions of nonvisual cortex in the monkey

Chronic ‘blindness’ was produced in monkeys by a lesion that combined right optic tract section, forebrain commissurotomy, and a large cortical ablation in the left hemisphere that spared most of the modality specific visual cortex. The finding suggests that, contrary to implications from earlier studies, central visual processes can influence behavior only with the participation of nonvisual cortex.