Visual processing, memory, and lateralization in alcoholism and aging

Abstract

Visual processing, memory, and cerebral lateralization were examined in alcoholic and in normal aging populations. Central field visual thresholds were obtained on five groups of participants (“young” and “older” alcoholics, age‐matched normal controls, and alcoholic Korsakoff patients). Stimuli were presented tachistoscopically and consisted of three‐letter words or dots located at different positions within a square referent border. Pairs of stimuli from each class were then presented simultaneously to the two visual hemifields (and, therefore, to both cerebral hemispheres) to determine laterality differences. A further requirement of successive responding from each visual field enabled additional measures of perception and of memory to be obtained. First reports are presumed to rely upon rapidly decaying perceptual information; second reports rely on information held in memory store. Overall visual thresholds and accuracy of performance were found to be impaired in the Korsakoffs and in the older groups (with or without a history of alcoholism), as was verbal memory. Although type of stimulus material did not distinguish among the groups, there was some evidence of an abnormal visual field difference for words in the non‐Korsakoff alcoholic groups.