Voluntary and automatic visual spatial shifts of attention in Parkinson's disease: An analysis of costs and benefits

Visual spatial shifts of attention were investigated in 13 patients sufferi ng from Parkinson's disease and 20 control subjects. Attention was directed towards a target location with peripheral or central cues at varying SOAs in two separate experiments. A benefit and cost analysis was conducted on r eaction times. The results of the central cueing task showed that in compar ison with control subjects, costs of invalid cueing were reduced in patient s. Results of the peripheral cueing task revealed that although the cueing effect (valid-invalid) was similar for patients and controls, the effect of valid cueing (neutral-valid) was greater in patients. The effects observed in both tasks were explained as an impaired ability of patients with Parki nson's disease to maintain attention.