6 - Depth of Encoding and Visuoperceptive Deficits

Abstract

The alcoholic Korsakoff patient has significant visuoperceptive difficulties in addiion to his severe amnesia. This chapter discusses the depth of encoding and visuoperceptive deficits. Studies shows that the alcoholic Korsakoff patients' difficulties on digit-symbol substitution and embedded figures tasks. The interest in these perceptual disorders has been twofold: (a) to determine the perceptual processes contributing to the visuoperceptual defects of these patients and (b) to investigate whether the same types of information-processing deficits that contribute to their memory impairments might also play a role in their perceptual problems. The chapter presents the analyses of the alcoholic Korsakoff patient's deficits on the digit-symbol test and discusses limited encoding and the alcoholic Korsakoff patient's deficits in face perception. Glosser, Butters, and Kaplan have questioned whether the alcoholic Korsakoff patients' deficits observed on digit-symbol tasks represent visuoperceptive deficits or simply a motor retardation due to chronic alcoholism. They administered a modified version of the WAIS digit-symbol test to 12 alcoholic Korsakoff patients, 12 chronic alcoholics, 12 nonalcoholic individuals, and 11 patients with right-hemispheric brain damage . The Glosser et al investigation demonstrated that the alcoholic Korsakoff patients' impairment on digit-symbol substitution tasks involved some higher order perceptual capacity, the exact nature of this visuoperceptive deficit was not determined.