title: Childhood cognitive ability accounts for associations between cognitive ability and brain cortical thickness in old age.
abstract: Associations between brain cortical tissue volume and cognitive function in old age are frequently interpreted as suggesting that preservation of cortical tissue is the foundation of successful cognitive aging. However, this association could also, in part, reflect a lifelong association between cognitive ability and cortical tissue. We analyzed data on 588 subjects from the Lothian Birth Cohort 1936 who had intelligence quotient (IQ) scores from the same cognitive test available at both 11 and 70 years of age as well as high-resolution brain magnetic resonance imaging data obtained at approximately 73 years of age. Cortical thickness was estimated at 81 924 sampling points across the cortex for each subject using an automated pipeline. Multiple regression was used to assess associations between cortical thickness and the IQ measures at 11 and 70 years. Childhood IQ accounted for more than two-third of the association between IQ at 70 years and cortical thickness measured at age 73 years. This warns against ascribing a causal interpretation to the association between cognitive ability and cortical tissue in old age based on assumptions about, and exclusive reference to, the aging process and any associated disease. Without early-life measures of cognitive ability, it would have been tempting to conclude that preservation of cortical thickness in old age is a foundation for successful cognitive aging when, instead, it is a lifelong association. This being said, results should not be construed as meaning that all studies on aging require direct measures of childhood IQ, but as suggesting that proxy measures of prior cognitive function can be useful to take into consideration.
authors.affiliation: 1] Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada [2] Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Verdun, QC, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Karama
authors.affiliation: 1] Brain Research Imaging Centre, Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [3] SINAPSE (Scottish Imaging Network, A Platform for Scientific Excellence) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: M E
authors.initials: ME
authors.lastname: Bastin
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: C
authors.initials: C
authors.lastname: Murray
authors.affiliation: 1] Brain Research Imaging Centre, Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [3] SINAPSE (Scottish Imaging Network, A Platform for Scientific Excellence) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: N A
authors.initials: NA
authors.lastname: Royle
authors.affiliation: 1] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] SINAPSE (Scottish Imaging Network, A Platform for Scientific Excellence) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK [3] Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: L
authors.initials: L
authors.lastname: Penke
authors.affiliation: 1] Brain Research Imaging Centre, Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [3] SINAPSE (Scottish Imaging Network, A Platform for Scientific Excellence) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: S
authors.initials: S
authors.lastname: Muñoz Maniega
authors.affiliation: 1] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Gow
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: J
authors.initials: J
authors.lastname: Corley
authors.affiliation: 1] Brain Research Imaging Centre, Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [3] SINAPSE (Scottish Imaging Network, A Platform for Scientific Excellence) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: M del C
authors.initials: Mdel C
authors.lastname: Valdés Hernández
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Lewis
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: M-É
authors.initials: MÉ
authors.lastname: Rousseau
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Lepage
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Fonov
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: D L
authors.initials: DL
authors.lastname: Collins
authors.affiliation: 1] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: T
authors.initials: T
authors.lastname: Booth
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Rioux
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Sherif
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Adalat
authors.affiliation: 1] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Alzheimer Scotland Dementia Research Centre, Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Starr
authors.affiliation: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors.forename: A C
authors.initials: AC
authors.lastname: Evans
authors.affiliation: 1] Brain Research Imaging Centre, Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [3] SINAPSE (Scottish Imaging Network, A Platform for Scientific Excellence) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Wardlaw
authors.affiliation: 1] Department of Psychology, Center for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors.forename: I J
authors.initials: IJ
authors.lastname: Deary
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000523:psychology*; D001921:Brain / Q000473:pathology*; D002648:Child; D003071:Cognition; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012044:Regression Analysis; D012737:Sex Factors; D055815:Young Adult