The role of rehearsal in the short-term memory performance of patients with Korsakoff's and Huntington's disease

Abstract

Alcoholic Korsakoff patients, patients with Huntington's disease and a notmal control group were given a Peterson short-term memory task. All three groups were required to recall three word trigrams after a 0 sec retention interval, a 20 sec retention interval filled with counting backwards in ones or twos and a 20 sec unfilled retention interval with no distractor task. It was found that all groups were able to rehearse information over the unfilled retention interval but all groups showed a drop in recall performance with a distraction task, counting in twos causing more forgetting than counting in ones and both patient groups were inferior to the control group. Analysis of the error data showed that while Korsakoffs made more prior item intrusion errors than omissions, the converse was the case for the Huntington group. It is argued the results indicate a storage deficit and/or encoding deficit for the Huntington patients.