THE ROLE OF EXECUTIVE FUNCTION IN IMAGERY MNEMONICS - EVIDENCE FROM MULTIPLE-SCLEROSIS

The use of imagery in learning and memory involves metacognitive skill s that seem to depend upon executive function as well as motivational mechanisms. This implies that the efficacy of imagery mnemonics should be impaired in neurological patients who show either executive dysfun ction or affective disorders. This hypothesis was tested in patients w ith multiple sclerosis. Imagery instructions led to improved recall in three different tasks, although experimenter-generated imagery proved to be more effective than subject-generated imagery and there was lit tle evidence that patients maintained the use of imagery mnemonics on follow-up testing. Three other tasks defined a unitary trait of execut ive processing efficiency, and this was significantly correlated with the benefit obtained from the use of the Method of Loci in a free-reca ll tasks, but not with the benefit gained from other imagery mnemonics . The patients' scores, on a widely used depression inventory, were no t significantly correlated with the benefit obtained from the use of i magery mnemonics. Nonetheless, it is concluded that executive processi ng capacity determines the benefit that is derived from the use of mor e complex forms of imagery mnemonic in verbal-learning tasks. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.