Mental rotation in Alzheimer's patients and elderly controls

It has been suggested that Alzheimer's disease (AD) produces an amount of cognitive slowing greater than that produced by normal aging (Nebes & Brady, 1992). To evaluate this hypothesis, Alzheimer's patients and elderly controls were tested on a mental rotation task. AD patients produced longer reaction times (RTs) overall, had slower mental rotation rates, and committed more errors than controls. Unexpectedly, direction of rotation affected the performance of patients (RTs and error rates) but not of controls. Mental rotation errors of AD subjects correlated significantly with performance on standardized tests of visuospatial ability, constructional skill, and short term visual memory but not with verbal or verbal memory tasks. These findings suggest that MR may be mediated, at least in part, by the same systems used during these paper and pencil visuospatial tasks.