Effects of Dopamine on Reward Learning in Parkinson’s Patients with Impulse Control Disorders
Qualls, Lydia
:
2013
Abstract
This study investigated how dopamine agonist medication differentially affects reward learning in Parkinson’s patients with and without Impulse Control Disorders (ICDs). We tested 16 patients (8 female, 5 with ICDs, mean age = 62.1) on and off of their dopamine agonist medication using a dynamic foraging task with probability reversals. We hypothesized that patients with ICDs, but not patients without ICDs, would have worse task performance on medication than off medication. Paired samples t-tests confirmed our hypothesis – that task performance was significantly worse on medication than off for ICD patients [t(4) = 2.86, p = .046], but not for non-ICD patients [t(10) = 1.67, p = .126]. This suggests that ICD patients are more vulnerable to medication effects that cause aberrant reward learning, which could be the basis of their impulse control behaviors.