title: Regulating task-monitoring systems in response to variable reward contingencies and outcomes in cocaine addicts.
abstract: BACKGROUND
  We investigated anticipatory and consummatory reward processing in cocaine addiction. In addition, we set out to assess whether task-monitoring systems were appropriately recalibrated in light of variable reward schedules. We also examined neural measures of task-monitoring and reward processing as a function of hedonic tone, since anhedonia is a vulnerability marker for addiction that is obviously germane in the context of reward processing.
  
  
  METHODS
  High-density event-related potentials were recorded while participants performed a speeded response task that systematically varied anticipated probabilities of reward receipt. The paradigm dissociated feedback regarding task success (or failure) from feedback regarding the value of reward (or loss), so that task-monitoring and reward processing could be examined in partial isolation. Twenty-three active cocaine abusers and 23 age-matched healthy controls participated.
  
  
  RESULTS
  Cocaine abusers showed amplified anticipatory responses to reward predictive cues, but crucially, these responses were not as strongly modulated by reward probability as in controls. Cocaine users also showed blunted responses to feedback about task success or failure and did not use this information to update predictions about reward. In turn, they showed clearly blunted responses to reward feedback. In controls and users, measures of anhedonia were associated with reward motivation. In cocaine users, anhedonia was also associated with diminished monitoring and reward feedback responses.
  
  
  CONCLUSIONS
  Findings imply that reward anticipation and monitoring deficiencies in addiction are associated with increased responsiveness to reward cues but impaired ability to predict reward in light of task contingencies, compounded by deficits in responding to actual reward outcomes.
authors: The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Department of Pediatrics, Children's Evaluation and Rehabilitation Center (CERC), Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY, 10461, USA.|Program in Cognitive Neuroscience, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA.
authors: Kristen P
authors: KP
authors: Morie
authors: The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Department of Pediatrics, Children's Evaluation and Rehabilitation Center (CERC), Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY, 10461, USA.|Program in Cognitive Neuroscience, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA.
authors: Pierfilippo
authors: P
authors: De Sanctis
authors: Department of Psychiatry, University of Vermont, 1 South Prospect St, Burlington, VT, 05401, USA.
authors: Hugh
authors: H
authors: Garavan
authors: The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Department of Pediatrics, Children's Evaluation and Rehabilitation Center (CERC), Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, NY, 10461, USA. foxe@nki.rfmh.org.|Program in Cognitive Neuroscience, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA. foxe@nki.rfmh.org.|The Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, NY, 10461, USA. foxe@nki.rfmh.org.|The Ernest J. Del Monte Institute for Neuromedicine, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA. foxe@nki.rfmh.org.
authors: John J
authors: JJ
authors: Foxe
mesh_terms: D000328:Adult; D059445:Anhedonia / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D003463:Cues; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012201:Reward
keywords: Addiction; Anhedonia; EEG; ERP; Motivation; Reward; Substance abuse; Task monitoring