title: Increased fronto-striatal reward prediction errors moderate decision making in obsessive-compulsive disorder.
abstract: BACKGROUND
  Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks.
  
  
  METHODS
  We investigated neural mechanisms of decision making in OCD patients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCD patients with those of healthy matched controls.
  
  
  RESULTS
  Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCD patients also had a significantly lower perseveration parameter than controls.
  
  
  CONCLUSIONS
  Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.
authors.affiliation: Wellcome Trust Centre for Neuroimaging,University College London,London WC1N 3BG,UK.
authors.forename: T U
authors.initials: TU
authors.lastname: Hauser
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Iannaccone
authors.affiliation: Wellcome Trust Centre for Neuroimaging,University College London,London WC1N 3BG,UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Dolan
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Ball
authors.affiliation: Anxiety Disorders and Depression Treatment Center Zurich (ADTCZ),Zurich,Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Hättenschwiler
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Drechsler
authors.affiliation: Department of Psychiatry and Psychotherapy,University Hospital Zurich, University of Zurich,Zurich,Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Rufer
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Brandeis
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Walitza
authors.affiliation: Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Brem
mesh_terms: D000293:Adolescent; D000328:Adult; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011699:Putamen / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012054:Reinforcement, Psychology; D012201:Reward; D055815:Young Adult
keywords: Age of onset; anterior cingulate cortex; obsessive–compulsive disorder; reinforcement learning; reward prediction errors