The preselection effect on the recall facilitation of motor movements in Alzheimer-type dementia

Two experiments examined the coding and retention of psychomotor information in patients with mild to moderate dementia of the Alzheimer-type (DAT), healthy elderly controls, and young adults. Experiment 1 compared recall accuracy for preselected (subject-defined) and constrained (experimenter-defined) movements under three different retention conditions. Not surprisingly, the DAT patients showed significantly larger reproduction errors than did the controls. In all three groups, however, preselected movements were recalled more accurately than constrained movements. This preselection advantage was replicated in Experiment 2 using a new group of DAT patients with recall being performed under both same- and switch-limb conditions. While the results suggested that DAT patients suffer from both an encoding deficiency and a rapid loss of information from short-term memory, they also indicate that patients are capable of coding meaningful aspects of motor movements. Most importantly, the results suggest that in the motor domain, efforts to enhance encoding can facilitate the recall of DAT patients.