title: Impairments in learning by monetary rewards and alcohol-associated rewards in detoxified alcoholic patients.
abstract: BACKGROUND
  Excessive alcohol consumption has been linked to structural and functional brain changes associated with cognitive, emotional, and behavioral impairments. It has been suggested that neural processing in the reward system is also affected by alcoholism. The present study aimed at further investigating reward-based associative learning and reversal learning in detoxified alcohol-dependent patients.
  
  
  METHODS
  Twenty-one detoxified alcohol-dependent patients and 26 healthy control subjects participated in a probabilistic learning task using monetary and alcohol-associated rewards as feedback stimuli indicating correct responses. Performance during acquisition and reversal learning in the different feedback conditions was analyzed.
  
  
  RESULTS
  Alcohol-dependent patients and healthy control subjects showed an increase in learning performance over learning blocks during acquisition, with learning performance being significantly lower in alcohol-dependent patients. After changing the contingencies, alcohol-dependent patients exhibited impaired reversal learning and showed, in contrast to healthy controls, different learning curves for different types of rewards with no increase in performance for high monetary and alcohol-associated feedback.
  
  
  CONCLUSIONS
  The present findings provide evidence that dysfunctional processing in the reward system in alcohol-dependent patients leads to alterations in reward-based learning resulting in a generally reduced performance. In addition, the results suggest that alcohol-dependent patients are, in particular, more impaired in changing an established behavior originally reinforced by high rewards.
authors.affiliation: Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Jokisch
authors.forename: Patrik
authors.initials: P
authors.lastname: Roser
authors.forename: Georg
authors.initials: G
authors.lastname: Juckel
authors.forename: Irene
authors.initials: I
authors.lastname: Daum
authors.forename: Christian
authors.initials: C
authors.lastname: Bellebaum
mesh_terms: D057229:Alcoholics / Q000523:psychology*; D001245:Association Learning / Q000187:drug effects; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007859:Learning Disabilities / Q000139:chemically induced* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D012193:Reversal Learning / Q000187:drug effects; D012201:Reward
keywords: Alcoholism; Basal Ganglia; Detoxification; Reversal Learning; Reward System