title: Reward feedback alterations in unmedicated schizophrenia patients: relevance for delusions.
abstract: BACKGROUND
  Increased attribution of incentive salience to neutral or aversive stimuli might be associated with dysfunction of neuronal processing of positive and negative reinforcement and contribute to the formation of delusions in schizophrenia.
  
  
  METHODS
  Fifteen unmedicated patients with schizophrenia (8 drug-naive and 7 drug-free for at least 3 months) and 15 age- and gender-matched healthy control participants underwent functional magnetic resonance imaging to investigate neural responses to feedback of (successful vs. unsuccessful) monetary gain or avoidance of loss. Functional connectivity was assessed between the medial prefrontal cortex (MPFC) and ventral striatum (VS), brain areas known to be activated by feedback of reward and loss.
  
  
  RESULTS
  Responses to negative outcome in reward trials (omission of expected reward) were exaggerated in the MPFC of patients with schizophrenia. In contrast, schizophrenia patients showed reduced neural responses to successful versus unsuccessful avoidance of loss in the VS. Increased severity of delusions in schizophrenia patients was associated with a decrease in MPFC activation elicited by successful versus unsuccessful avoidance of loss. Functional connectivity between the MPFC and the VS was reduced in patients with schizophrenia compared with healthy control subjects.
  
  
  CONCLUSIONS
  These findings demonstrate a differential impairment of-and reduced connectivity between--VS and MPFC during processing of reward and loss-avoidance in drug-free patients with schizophrenia. Moreover, our results provide a link between the formation of delusions and the neural processing of aversive outcomes.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Mitte, Germany. florian.schlagenhauf@charite.de
authors.forename: Florian
authors.initials: F
authors.lastname: Schlagenhauf
authors.forename: Philipp
authors.initials: P
authors.lastname: Sterzer
authors.forename: Katharina
authors.initials: K
authors.lastname: Schmack
authors.forename: Martina
authors.initials: M
authors.lastname: Ballmaier
authors.forename: Michael
authors.initials: M
authors.lastname: Rapp
authors.forename: Jana
authors.initials: J
authors.lastname: Wrase
authors.forename: Georg
authors.initials: G
authors.lastname: Juckel
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.forename: Andreas
authors.initials: A
authors.lastname: Heinz
mesh_terms: D000328:Adult; D003702:Delusions / Q000523:psychology*; D030141:Feedback, Psychological / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009042:Motivation; D017072:Neostriatum / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D012565:Schizophrenic Psychology; D055815:Young Adult