title: Prefrontal contributions to rule-based and information-integration category learning.
abstract: Previous research revealed that the basal ganglia play a critical role in category learning [Ell, S. W., Marchant, N. L., & Ivry, R. B. (2006). Focal putamen lesions impair learning in rule-based, but not information-integration categorization tasks. Neuropsychologia, 44(10), 1737-1751; Maddox, W. T. & Filoteo, J. V. (2007). Modeling visual attention and category learning in amnesiacs, striatal-damaged patients and normal aging. In Advances in Clinical-cognitive science: formal modeling and assessment of processes and symptoms (pp. 113-146). Washington DC: American Psychological Association] but less is known about the specific role of prefrontal cortical (PFC) regions in category learning. The current study examined rule-based (RB) and information-integration (II) category learning in 13 patients with damage primarily to ventral PFC regions. After 600 learning trials with feedback, patients were significantly less accurate than matched controls on both RB and II learning. Model-based analysis identified subgroups of patients whose impaired performance in each task was due to the use of sub-optimal learning strategies. Those patients impaired at either II or RB learning, performed significantly worse on the Wisconsin Card Sorting Test, a test of abstract rule formation and the ability to shift and maintain rules. Lesion analysis pointed to damage in a fairly circumscribed region of ventral medial prefrontal cortex as common to the impaired group of patients and those patients without ventral PFC damage mostly performed normally. These results provide further evidence that the ventromedial prefrontal cortex is critically important for the ability to monitor and integrate feedback in order to select and maintain optimal learning strategies.
authors: Department of Psychology, Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA. schnyer@psy.utexas.edu
authors: David M
authors: DM
authors: Schnyer
authors: W Todd
authors: WT
authors: Maddox
authors: Shawn
authors: S
authors: Ell
authors: Sarah
authors: S
authors: Davis
authors: Jenni
authors: J
authors: Pacheco
authors: Mieke
authors: M
authors: Verfaellie
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002561:Cerebrovascular Disorders / Q000523:psychology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D017397:Prefrontal Cortex / Q000473:pathology / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology