title: Processing of facial affect in social drinkers: a dose-response study of alcohol using dynamic emotion expressions.
abstract: BACKGROUND
  Studies of affect recognition can inform our understanding of the interpersonal effects of alcohol and help develop a more complete neuropsychological profile of this drug.
  
  
  OBJECTIVE
  The objective of the study was to examine affect recognition in social drinkers using a novel dynamic affect-recognition task, sampling performance across a range of evolutionarily significant target emotions and neutral expressions.
  
  
  METHODS
  Participants received 0, 0.4 or 0.8 g/kg alcohol in a double-blind, independent groups design. Relatively naturalistic changes in facial expression-from neutral (mouth open) to increasing intensities of target emotions, as well as neutral (mouth closed)-were simulated using computer-generated dynamic morphs. Accuracy and reaction time were measured and a two-high-threshold model applied to hits and false-alarm data to determine sensitivity and response bias.
  
  
  RESULTS
  While there was no effect on the principal emotion expressions (happiness, sadness, fear, anger and disgust), compared to those receiving 0.8 g/kg of alcohol and placebo, participants administered with 0.4 g/kg alcohol tended to show an enhanced response bias to neutral expressions. Exploration of this effect suggested an accompanying tendency to misattribute neutrality to sad expressions following the 0.4-g/kg dose.
  
  
  CONCLUSIONS
  The 0.4-g/kg alcohol-but not 0.8 g/kg-produced a limited and specific modification in affect recognition evidenced by a neutral response bias and possibly an accompanying tendency to misclassify sad expressions as neutral. In light of previous findings on involuntary negative memory following the 0.4-g/kg dose, we suggest that moderate-but not high-doses of alcohol have a special relevance to emotional processing in social drinkers.
authors.affiliation: Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, Gower Street, London, WC1E 6BT, UK. sunjeev.kamboj@ucl.ac.uk
authors.forename: Sunjeev K
authors.initials: SK
authors.lastname: Kamboj
authors.forename: Alyssa
authors.initials: A
authors.lastname: Joye
authors.forename: James A
authors.initials: JA
authors.lastname: Bisby
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Das
authors.forename: Bradley
authors.initials: B
authors.lastname: Platt
authors.forename: H Valerie
authors.initials: HV
authors.lastname: Curran
mesh_terms: D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000523:psychology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects* / Q000502:physiology*; D000431:Ethanol / Q000008:administration & dosage*; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
chemical_list: D000431:Ethanol