%A Nicholas K Humphrey %J Perception %T Vision in a monkey without striate cortex: a case study %X A rhesus monkey, Helen, from whom the striate cortex was almost totally removed, was studied intensively over a period of 8 years. During this time she regained an effective, though limited, degree of visually guided behaviour. The evidence suggests that while Helen suffered a permanent loss of 'focal vision' she retained (initially unexpressed) the capacity for 'ambient vision'. %K striate cortex, blindsight, two visual systems, monkey %P 241-255 %V 3 %D 1974 %L cogprints1757