Visuospatial ability of parkinsonians and elderly adults in location memory tasks

Two experiments addressed the question of the spatial deficits of Parkinson disease (PD) patients, using a spatial location task which varied the characteristics of the task along an effortful continuum. In the more effortful task, 11 PD patients, 10 elderly control subjects, and 13 young control subjects were given 3 min to learn the layout of 12 places labeled on a map and then reproduce it. In the less effortful task, 9 new PD patients, 9 new elderly control subjects, and 10 new young control subjects were given 3 min to learn the layout of 12 black dots and then asked to reproduce it. In both cases the task was repeated twice. The results showed that PD patients were less accurate than young and elderly control subjects in the less effortful task. In contrast, the performance of PD patients and elderly control subjects were equivalent in the more effortful task. These results support the idea of a specific visuospatial deficit in Parkinson's disease. Moreover, the deficit in effortful tasks seems to be due to normal aging.