EVENT-RELATED POTENTIALS ASSOCIATED WITH COVERT ORIENTATION OF VISUAL-ATTENTION IN PARKINSONS-DISEASE

Event-related potentials (ERPs) were measured in a group of patients w ith idiopathic Parkinson's disease and compared with a matched control group during a task involving covert orientation of visual attention. Central warning cues directed attention to the probable location of a lateralized signal that required a button-press response. Parkinson p atients had enhanced post-cue P1 (at Oz) and P2 (at Cz) amplitudes, de layed N1 (at Oz) latencies, and diminished CNV amplitudes. Post-target amplitudes were similar to controls, except for an enhanced P1 to inv alidly cued targets, and delayed N1 and P3 target latencies. These res ults indicate that Parkinson patients, in addition to their motor defi cits, process spatial cues more effortfully and slowly, have impaired response preparation, and process imperative stimuli more slowly.