title: Separating the effect of reward from corrective feedback during learning in patients with Parkinson's disease.
abstract: Parkinson's disease (PD) is associated with procedural learning deficits. Nonetheless, studies have demonstrated that reward-related learning is comparable between patients with PD and controls (Bódi et al., Brain, 132(9), 2385-2395, 2009; Frank, Seeberger, & O'Reilly, Science, 306(5703), 1940-1943, 2004; Palminteri et al., Proceedings of the National Academy of Sciences of the United States of America, 106(45), 19179-19184, 2009). However, because these studies do not separate the effect of reward from the effect of practice, it is difficult to determine whether the effect of reward on learning is distinct from the effect of corrective feedback on learning. Thus, it is unknown whether these group differences in learning are due to reward processing or learning in general. Here, we compared the performance of medicated PD patients to demographically matched healthy controls (HCs) on a task where the effect of reward can be examined separately from the effect of practice. We found that patients with PD showed significantly less reward-related learning improvements compared to HCs. In addition, stronger learning of rewarded associations over unrewarded associations was significantly correlated with smaller skin-conductance responses for HCs but not PD patients. These results demonstrate that when separating the effect of reward from the effect of corrective feedback, PD patients do not benefit from reward.
authors.affiliation: Department of Psychological and Brain Sciences, University of Iowa, E11 Seashore Hall E, Iowa City, IA, 52242-1407, USA. michael.freedberg@nih.gov.|Henry M. Jackson Foundation for the Advancement of Military Medicine, 9000 Rockville Pike, 10 Center Drive, Rm 7D49A, Bethesda, MD, 20814, USA. michael.freedberg@nih.gov.
authors.forename: Michael
authors.identifier: 0000-0003-3738-8259
authors.initials: M
authors.lastname: Freedberg
authors.affiliation: Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Schacherer
authors.affiliation: Department of Neurology, University of Iowa, Iowa City, IA, 52242, USA.|Institute of Personality and Social Research, University of California, Berkeley, CA, 94720, USA.
authors.forename: Kuan-Hua
authors.initials: KH
authors.lastname: Chen
authors.affiliation: Department of Neurology, University of Iowa, Iowa City, IA, 52242, USA.|Neurology Service, Veterans Affairs Medical Center, Iowa City, IA, 52242, USA.
authors.forename: Ergun Y
authors.initials: EY
authors.lastname: Uc
authors.affiliation: Department of Neurology, University of Iowa, Iowa City, IA, 52242, USA.|Aging Mind, Brain Initiative, Carver College of Medicine, Iowa City, 52242, IA, USA.
authors.forename: Nandakumar S
authors.initials: NS
authors.lastname: Narayanan
authors.affiliation: Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA.
authors.forename: Eliot
authors.initials: E
authors.lastname: Hazeltine
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D030141:Feedback, Psychological / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D012201:Reward; D055815:Young Adult
keywords: Feedback; Incidental learning; Parkinson’s disease; Reward