VISUOSPATIAL IMAGERY IN ALZHEIMER DISEASE

The purpose of the present study was to investigate the imagery ability of 8 “probable” Alzheimer disease patients using a standard task sensitive to the disruption of the imagery system. These patients were selected based on their good performance on a prerequisite clock-setting task, and with 8 matched control subjects were then required to compare the angles made by the hands on clock faces using only imagined stimuli. There were no significant differences between patients and controls in performance on the clock-imagery task. These data are consistent with models of information processing which postulate the relationships between visual imagery and a short-term memory store and include a central executive system for allocation of cognitive resources.