Preservation of cognitive procedural memory in a case of Korsakoff's syndrome: Methodological and theoretical insights

Using the Tower of Hanoi puzzle, Butters, et al. in 1985 illustrated the difficulties in learning the procedure and questioned the suitability of this task for the assessment of the cognitive procedural memory in Korsakoff's syndrome. Our objective, in the light of these criticisms, was to show preservation of cognitive procedural capacities with the Tower of Hanoi for a man (P.F.) who was suffering from alcoholic Korsakoffs syndrome. For this procedural task, some aids helped to compensate in part for the difficulties with declarative memory and with working memory. In this condition, P.F. was able to learn the cognitive procedure. This study suggests that cognitive procedural memory may be preserved in some patients suffering from Korsakoffs syndrome and that this may be shown when a suitable task is used. The result makes ii possible to discuss the interaction between declarative and procedural knowledge in the solving of the Tower of Hanoi.