Visual span of apprehension in patients with unilateral cerebral lesions

The visual span of apprehension for random letter and digit sequences, approximations to English sequences and non-symbolic line stimuli was measured in patients with unilateral cerebral lesions. The left hemisphere group was significantly impaired relative to the right hemisphere group and a control group on all three types of visual span task. The deficit was most marked in patients with left posterior lesions. The visual span deficits were not related to other language deficits. The findings are discussed in terms of a modality-specific defect of visual short-term memory.