title: Lower baseline performance but greater plasticity of working memory for carriers of the val allele of the COMT Val¹⁵⁸Met polymorphism.
abstract: OBJECTIVE
  Little is known about genetic contributions to individual differences in cognitive plasticity. Given that the neurotransmitter dopamine is critical for cognition and associated with cognitive plasticity, we investigated the effects of 3 polymorphisms of dopamine-related genes (LMX1A, DRD2, COMT) on baseline performance and plasticity of working memory (WM), perceptual speed, and reasoning.
  
  
  METHODS
  One hundred one younger and 103 older adults underwent approximately 100 days of cognitive training, and extensive testing before and after training. We analyzed the baseline and posttest data using latent change score models.
  
  
  RESULTS
  For working memory, carriers of the val allele of the COMT polymorphism had lower baseline performance and larger performance gains from training than carriers of the met allele. There was no significant effect of the other genes or on other cognitive domains.
  
  
  CONCLUSIONS
  We relate this result to available evidence indicating that met carriers perform better than val carriers in WM tasks taxing maintenance, whereas val carriers perform better at updating tasks. We suggest that val carriers may show larger training gains because updating operations carry greater potential for plasticity than maintenance operations.
authors.affiliation: Aging Research Center, Karolinska Institutet.
authors.forename: Martin
authors.initials: M
authors.lastname: Bellander
authors.affiliation: Aging Research Center, Karolinska Institutet.
authors.forename: Lars
authors.initials: L
authors.lastname: Bäckman
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Tian
authors.initials: T
authors.lastname: Liu
authors.affiliation: Max Planck Institute for Molecular Genetics.
authors.forename: Brit-Maren M
authors.initials: BM
authors.lastname: Schjeide
authors.affiliation: Max Planck Institute for Molecular Genetics.
authors.forename: Lars
authors.initials: L
authors.lastname: Bertram
authors.affiliation: Center for Research on Education and Human Development, German Institute for International Educational Research (DIPF).
authors.forename: Florian
authors.initials: F
authors.lastname: Schmiedek
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Ulman
authors.initials: U
authors.lastname: Lindenberger
authors.affiliation: Aging Research Center, Karolinska Institutet.
authors.forename: Martin
authors.initials: M
authors.lastname: Lövdén
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D003071:Cognition; D005260:Female; D056726:Genetic Association Studies; D006579:Heterozygote; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult
chemical_list: D002394:Catechol O-Methyltransferase