title: Category learning deficits in Parkinson's disease.
abstract: Sixteen patients with Parkinson's disease (PD), 15 older controls (OCs), and 109 younger controls (YCs) were compared in 2 category-learning tasks. Participants attempted to assign colored geometric figures to 1 of 2 categories. In rule-based tasks, category membership was defined by an explicit rule that was easy to verbalize, whereas in information-integration tasks, there was no salient verbal rule and accuracy was maximized only if information from 3 stimulus components was integrated at some predecisional stage. The YCs performed the best on both tasks. The PD patients were highly impaired compared with the OCs, in the rule-based categorization task but were not different from the OCs in the information-integration task. These results support the hypothesis that learning in these 2 tasks is mediated by functionally separate systems.
authors.affiliation: Department of Psychology, University of California, Santa Barbara, 93106, USA. ashby@psych.ucsb.edu
authors.forename: F Gregory
authors.initials: FG
authors.lastname: Ashby
authors.forename: Sharon
authors.initials: S
authors.lastname: Noble
authors.forename: J Vincent
authors.initials: JV
authors.lastname: Filoteo
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Waldron
authors.forename: Shawn W
authors.initials: SW
authors.lastname: Ell
mesh_terms: D000368:Aged; D003118:Color Perception / Q000502:physiology*; D003210:Concept Formation / Q000502:physiology*; D003657:Decision Making / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D004298:Dopamine / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D017397:Prefrontal Cortex / Q000503:physiopathology; D011340:Problem Solving / Q000502:physiology; D013378:Substantia Nigra / Q000503:physiopathology; D017557:Ventral Tegmental Area / Q000503:physiopathology
chemical_list: D004298:Dopamine