title: Feedback-driven trial-by-trial learning in autism spectrum disorders.
abstract: OBJECTIVE
  Impairments in learning are central to autism spectrum disorders. The authors investigated the cognitive and neural basis of these deficits in young adults with autism spectrum disorders using a well-characterized probabilistic reinforcement learning paradigm.
  
  
  METHODS
  The probabilistic selection task was implemented among matched participants with autism spectrum disorders (N=22) and with typical development (N=25), aged 18-40 years, using rapid event-related functional MRI. Participants were trained to choose the correct stimulus in high-probability (AB), medium-probability (CD), and low-probability (EF) pairs, presented with valid feedback 80%, 70%, and 60% of the time, respectively. Whole-brain voxel-wise and parametric modulator analyses examined early and late learning during the stimulus and feedback epochs of the task.
  
  
  RESULTS
  The groups exhibited comparable performance on medium- and low-probability pairs. Typically developing persons showed higher accuracy on the high-probability pair, better win-stay performance (selection of the previously rewarded stimulus on the next trial of that type), and more robust recruitment of the anterior and medial prefrontal cortex during the stimulus epoch, suggesting development of an intact reward-based working memory for recent stimulus values. Throughout the feedback epoch, individuals with autism spectrum disorders exhibited greater recruitment of the anterior cingulate and orbito-frontal cortices compared with individuals with typical development, indicating continuing trial-by-trial activity related to feedback processing.
  
  
  CONCLUSIONS
  Individuals with autism spectrum disorders exhibit learning deficits reflecting impaired ability to develop an effective reward-based working memory to guide stimulus selection. Instead, they continue to rely on trial-by-trial feedback processing to support learning dependent upon engagement of the anterior cingulate and orbito-frontal cortices.
authors.affiliation: From the Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento Calif.; the University of California, Davis, MIND Institute, Sacramento, Calif.; the University of California, Davis, Imaging Research Center, Sacramento, Calif.; the Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, R.I.; the University of Arizona; and the University of California, Davis, Center for Neuroscience, Sacramento, Calif.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Solomon
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Frank
authors.forename: J Daniel
authors.initials: JD
authors.lastname: Ragland
authors.forename: Anne C
authors.initials: AC
authors.lastname: Smith
authors.forename: Tara A
authors.initials: TA
authors.lastname: Niendam
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Lesh
authors.forename: David S
authors.initials: DS
authors.lastname: Grayson
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Beck
authors.forename: John C
authors.initials: JC
authors.lastname: Matter
authors.forename: Cameron S
authors.initials: CS
authors.lastname: Carter
mesh_terms: D000328:Adult; D002659:Child Development Disorders, Pervasive / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D030141:Feedback, Psychological; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D006801:Humans; D007859:Learning Disabilities / Q000175:diagnosis / Q000209:etiology / Q000523:psychology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D015233:Models, Statistical; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000473:pathology*; D012054:Reinforcement, Psychology; D012107:Research Design; D013647:Task Performance and Analysis