title: Effect of COMT Val158Met polymorphism on the Continuous Performance Test, Identical Pairs Version: tuning rather than improving performance.
abstract: OBJECTIVE
  It has been suggested that variation in catechol O-methyltransferase (COMT) activity associated with variation in COMT Val158Met genotypes may result in enhanced or reduced cognitive performance, depending on whether the phenotype requires cognitive stability or cognitive flexibility. The authors' goal was to determine whether, in confirmation of this prediction, performance on a measure of cognitive stability would be associated with Met loading.
  
  
  METHODS
  COMT genotyping was investigated in relation to a measure of reaction time variability on the Continuous Performance Test, Identical Pairs Version, in a large and representative sample of 527 young men (mean age=21 years).
  
  
  RESULTS
  Met loading was associated with reduced reaction time variability.
  
  
  CONCLUSIONS
  Met genotype loading may confer enhanced "tuning" or greater stability in performance, possibly by stabilizing active neural representations in the prefrontal cortex during tasks involving working memory.
authors.affiliation: Department of Psychiatry, National and Kapodistrian University of Athens Medical School, Eginition Hospital, 74 Vas. Sofias Ave., Athens 11528, Greece. nistefan@med.uoa.gr
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Stefanis
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Avramopoulos
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Smyrnis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Evdokimidis
authors.forename: Costas N
authors.initials: CN
authors.lastname: Stefanis
mesh_terms: D000328:Adult; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D003071:Cognition / Q000502:physiology*; D005838:Genotype; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008715:Methionine / Q000235:genetics*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011110:Polymorphism, Genetic; D017397:Prefrontal Cortex / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D014633:Valine / Q000235:genetics
chemical_list: D008715:Methionine; D002394:Catechol O-Methyltransferase; D014633:Valine