title: Enhanced striatal responses during expectancy coding in alcohol dependence.
abstract: BACKGROUND
  Individuals with alcohol dependence are known to make disadvantageous decisions, possibly caused by alterations in either reward or punishment sensitivity, which lead to persistent alcohol use despite its adverse consequences. Previous studies in alcohol dependence have mainly focused on reward anticipation processing and results from these studies are mixed. To clarify the nature of the motivational deficit that underlies disadvantageous choice in alcohol dependence, the current study sought to characterize the neural representation of expected value in individuals with alcohol dependence, separating expectancy-related processing of gains and losses, as a function of outcome magnitude and outcome probability.
  
  
  METHODS
  Functional MRI was used to examine brain responses during the expectation of gains and losses in patients with alcohol dependence (n=19) and healthy controls (n=19). The task manipulated outcome magnitude (€1 and €5) and outcome probability (30% and 70%).
  
  
  RESULTS
  Compared to healthy controls, patients with alcohol dependence were more responsive to the expectancy of large wins, in the caudate and putamen. This effect was driven by a higher caudate activity in the contrast comparing €5 vs. €1 trials in patients with alcohol dependence. There were no group differences in the responses to the expectancy for loss. The patient group reported lower expectancies of winning in the trial-by-trial ratings.
  
  
  CONCLUSIONS
  Patients with alcohol dependence showed caudate hyperactivity when expecting wins. The result contrasts with past work using the monetary incentive delay task, showing caudate hypoactivity; the passive nature of our task contrasts with an active response requirement in the MIDT studies.
authors.affiliation: Donders Institute for Cognition, Brain and Behaviour, Radboud University, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands. Electronic address: mail@ruthvanholst.nl.
authors.forename: Ruth J
authors.initials: RJ
authors.lastname: van Holst
authors.affiliation: Department of Psychology, University of Cambridge, Downing Street, CB2 3EB Cambridge, United Kingdom.
authors.forename: Luke
authors.initials: L
authors.lastname: Clark
authors.affiliation: Department of Psychiatry, VU University Medical Center, AJ Ernststraat 1187, 1081 HL Amsterdam, The Netherlands.
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.affiliation: Department of Psychiatry, Amsterdam Institute for Addiction Research, Academic Medical Center, Meibergdreef 5, 1100 DD Amsterdam, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
authors.affiliation: Department of Psychiatry, Amsterdam Institute for Addiction Research, Academic Medical Center, Meibergdreef 5, 1100 DD Amsterdam, The Netherlands; Arkin Mental Health Institute, Klaprozenweg 111, 1033 NN Amsterdam, The Netherlands.
authors.forename: Anna E
authors.initials: AE
authors.lastname: Goudriaan
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000503:physiopathology* / Q000523:psychology; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D003342:Corpus Striatum / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011336:Probability; D012201:Reward
keywords: Alcohol dependence; Expectancy; Habit learning; Reward processing; Striatum; fMRI