COVERT VISUOSPATIAL ATTENTIONAL MECHANISMS IN PARKINSONS-DISEASE

Orienting and focusing of attention were assessed in 32 Parkinson's di sease and 32 control subjects. No differences were found in the covert orienting of attention, suggesting that the Parkinson's disease subje cts of the current study were not impaired in the ability to orient at tention towards an expected source of stimulation. However, with the p rocess of modulating the attentional focus or of managing more than on e attentional task, dysfunction in Parkinson's disease subjects became apparent. The observed results are explained in terms of deficits in the relationship between task-related distribution of attentional reso urces and time efficiency of processing.