title: Neuroanatomical correlates of executive functions in children and adolescents: a magnetic resonance imaging (MRI) study of cortical thickness.
abstract: A range of cognitive abilities improves in childhood and adolescence. It has been proposed that the protracted development of executive functions is related to the relatively late maturation of the prefrontal cortex. However, this has rarely been directly investigated. In this cross-sectional study, 98 healthy children and adolescents (8-19 years old) were tested with six tasks considered to index three frequently postulated executive functions; updating (Keep track and Letter memory), inhibition (Antisaccade and Stroop) and shifting (Plus minus and Trail making). Task performance was then related to magnetic resonance imaging (MRI) measures of cortical thickness. The behavioral results did not indicate any clear organization of the executive function measures in the domains updating, inhibition and shifting. Limitations associated with the use of speed-based scores from the tasks considered to index shifting ability were also indicated. Independently of the effects of age, performance on the Keep track task was associated with thinner cortex bilaterally in clusters encompassing parietal and frontal regions, including the left inferior frontal gyrus, while performance on the Antisaccade task was associated with thinner cortex bilaterally in occipital and parietal regions. Further, levels of performance on the Antisaccade and Stroop tasks were related to estimated rates of cortical maturation in posterior brain regions, but not in the prefrontal cortex. The results from the present study add to previous knowledge about the cortical correlates of executive functions by indicating an important role of posterior cerebral areas in executive development.
authors.affiliation: Center for the Study of Human Cognition, Department of Psychology, University of Oslo, and Department of Radiology, Rikshospitalet, Oslo University Hospital, PO Box 1094 Blindern, 0317 Oslo, Norway. c.k.tamnes@psykologi.uio.no
authors.forename: Christian K
authors.initials: CK
authors.lastname: Tamnes
authors.forename: Ylva
authors.initials: Y
authors.lastname: Østby
authors.forename: Kristine B
authors.initials: KB
authors.lastname: Walhovd
authors.forename: Lars T
authors.initials: LT
authors.lastname: Westlye
authors.forename: Paulina
authors.initials: P
authors.lastname: Due-Tønnessen
authors.forename: Anders M
authors.initials: AM
authors.lastname: Fjell
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000254:growth & development*; D002648:Child; D056344:Executive Function / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009483:Neuropsychological Tests; D013223:Statistics as Topic; D055815:Young Adult