title: Cognitive abilities in preterm and term-born adolescents.
abstract: OBJECTIVE
  To investigate the influence of a range of prenatal and postnatal factors on cognitive development in preterm and term-born adolescents.
  
  
  METHODS
  Woodcock-Johnson III Tests of Cognitive Abilities were used to assess general intellectual ability and 6 broad cognitive abilities in 145 young adolescents aged approximately 12.5 years and born 25-41 weeks gestational age (GA). To study potential links between neurophysiologic and cognitive outcomes, corticomotor excitability was measured using transcranial magnetic stimulation and surface electromyography. The influence of various prenatal and postnatal factors on cognitive development was investigated using relative importance regression modeling.
  
  
  RESULTS
  Adolescents with greater GA tended to have better cognitive abilities (particularly general intellectual ability, working memory, and cognitive efficiency) and higher corticomotor excitability. Corticomotor excitability explained a higher proportion of the variance in cognitive outcome than GA. But the strongest predictors of cognitive outcome were combinations of prenatal and postnatal factors, particularly degree of social disadvantage at the time of birth, birthweight percentile, and height at assessment.
  
  
  CONCLUSIONS
  In otherwise neurologically healthy adolescents, GA accounts for little interindividual variability in cognitive abilities. The association between corticomotor excitability and cognitive performance suggests that reduced connectivity, potentially associated with brain microstructural abnormalities, may contribute to cognitive deficits in preterm children. It remains to be determined if the effects of low GA on cognitive outcomes attenuate over childhood in favor of a concomitant increase in the relative importance of heritability, or alternatively, if cognitive development is more heavily influenced by the quality of the postnatal environment.
authors.affiliation: Research Center for Early Origins of Health and Disease, Robinson Institute, School of Pediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia.
authors.forename: Luke A
authors.initials: LA
authors.lastname: Schneider
authors.affiliation: School of Psychology, University of Adelaide, Adelaide, Australia.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Burns
authors.affiliation: Discipline of Public Health, University of Adelaide, Adelaide, Australia.
authors.forename: Lynne C
authors.initials: LC
authors.lastname: Giles
authors.affiliation: Research Center for Early Origins of Health and Disease, Robinson Institute, School of Pediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia.
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Higgins
authors.affiliation: School of Psychology, University of Adelaide, Adelaide, Australia.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Nettelbeck
authors.affiliation: Research Center for Early Origins of Health and Disease, Robinson Institute, School of Pediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ridding
authors.affiliation: Research Center for Early Origins of Health and Disease, Robinson Institute, School of Pediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia. Electronic address: julia.pitcher@adelaide.edu.au.
authors.forename: Julia B
authors.initials: JB
authors.lastname: Pitcher
mesh_terms: D000293:Adolescent; D002648:Child; D002657:Child Development / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007234:Infant, Premature / Q000502:physiology*; D007858:Learning; D008297:Male