Academic Medical Organization of

Objective: The aim was to examine the effect of dopaminergic medication on stimulus-response learning versus performing decisions based on learning. Method: To see the effect of dopaminergic therapy on stimulus-response learn-ing and response selection, participants with Parkinson’s disease (PD) were either tested on and/or off their prescribed dose of dopaminergic therapy dur-ing different testing days. Forty participants with PD and 34 healthy controls completed the experiment on consecutive days. On Day 1, participants learned to associate abstract images with spoken, “right ” or “left ” responses via feed-back (Session 1). On Day 2, participants recalled these responses (Session 2) and indicated the location (i.e., right or left of center) of previously studied images intermixed with new images (Session 3). Results: Participants with PD off medication learned stimulus-response associations equally well compared to healthy controls. Learning was impaired by dopaminergic medication. Regard-less of medication status, patients recalled the stimulus-response association