One study used a task assessing DR performance in both the visual and auditory sensory modalities in humans (Oscar-Berman et al. 1992). The study found that alcoholic Korsakoff patients showed clear deficits on this task compared with the non-Korsakoff alcoholics and normal control subjects (especially when demands were placed on visual processing time and on short-term memory). Based on these observations, the researchers hypothesized that prefrontal cortical structural change, particularly involving the orbitofrontal system, must be a prominent characteristic of alcoholic Korsakoff’s syndrome. The non-Korsakoff alcoholics showed little evidence of damage to frontal systems by these tests, either because the tests were not sufficiently sensitive to mild deficits or because frontal damage is minimal or absent in alcoholism uncomplicated by Korsakoff’s syndrome.
