RANDOM GENERATION DEFICIT IN ALCOHOLIC KORSAKOFF PATIENTS

Korsakoff's syndrome often affects ''executive'' functions [Baddeley, A. Human Memory, Theory acid Practice, 1990], which in anatomical term s are associated with the frontal lobes. However, in a previous study, Wiegersma, S. and de Jong, E. [J. clin. exp. Neuropsychol. 13, 847-85 3, 1991] failed to observe a diminished performance on the random gene ration task, although this task is thought to be sensitive to ''execut ive'' deficits. In the present study, we sought to replicate and clari fy these earlier findings of Wiegersma and de Jong with a group of Kor sakoff patients in whom frontal lobe dysfunction was indicated by a re duced performance on fluency tasks. Patients and controls were present ed with three tasks. Digit span was used as an index of short term mem ory capacity; memory search and comparison processes were measured wit h the missing item scan; and the randomisation task was used to assess the ability to produce non-routine, random sequences. The results sho wed that the performance of Korsakoff patients declined on the randomi sation task while short-term retention and scanning were intact. Analy sis of the responses indicated that the Korsakoff patients are able to suppress the dominant response, but have problems in generating and c arrying out alternative strategies in novel problem situations.