EVENT-RELATED POTENTIALS IN PARKINSONIAN-PATIENTS UNDER AUDITORY-DISCRIMINATION TASKS

Seventeen non-demented idiopathic medicated Parkinsonian patients and 17 age- and education-matched controls participated in auditory discri mination tasks. The study aimed at revealing the differences in their ability for auditory information processing. Series comprising 1000 Hz and 800 Hz tones were used as stimuli. The accuracy in the tones' dis crimination was determined by means of counting the high tone or recor ding a binary sensomotor reaction. The results based on the mean group values of event-related potential components show that the Parkinsoni an patients had lower amplitude for the exogenous N-1 and endogenous P -3 components of the evoked responses. In the sensomotor task series t he patients had longer N-2 latency than controls.:In the counting seri es the-patients recognized the tones well and gave an exact count but during the sensomotor task they had longer reaction time, more erroneo us answers and depressed P-3. The data show differences in the informa tion processing between the two groups and reveal cognitive impairment in the Parkinsonian patients. (C) Elsevier Science B.V.