title: Genetic sources of covariation among P3(00) and online performance variables in a delayed-response working memory task.
abstract: Genetic and environmental sources of covariation among the P3(00) and online performance elicited in a delayed-response working memory task, and psychometric IQ assessed by the multidimensional aptitude battery, were examined in an adolescent twin sample. An association between frontal P3 latency and task performance (phenotypic r=-0.33; genotypic r=-0.49) was indicated, with genes (i.e. twin status) accounting for a large part of the covariation (>70%). In contrast, genes influencing P3 amplitude mediated only a small part (2%) of the total genetic variation in task performance. While task performance mediated 15% of the total genetic variation in IQ (phenotypic r=0.22; genotypic r=0.39) there was no association between P3 latency and IQ or P3 amplitude with IQ. The findings provide some insight into the inter-relationships among psychophysiological, performance and psychometric measures of cognitive ability, and provide support for a levels-of-processing genetic model of cognition where genes act on specific sub-components of cognitive processes.
authors.affiliation: Genetic Epidemiology Laboratory, Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Queensland 4029, Australia. margiew@qimr.edu.au
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Wright
authors.forename: Michelle
authors.initials: M
authors.lastname: Luciano
authors.forename: Narelle K
authors.initials: NK
authors.lastname: Hansell
authors.forename: Gina M
authors.initials: GM
authors.lastname: Geffen
authors.forename: Laurie B
authors.initials: LB
authors.lastname: Geffen
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001077:Aptitude Tests; D001143:Arousal / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D018913:Event-Related Potentials, P300 / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D007206:Individuality; D007360:Intelligence / Q000235:genetics*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D010641:Phenotype; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000235:genetics*; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*