title: Brain white matter structure and information processing speed in healthy older age.
abstract: Cognitive decline, especially the slowing of information processing speed, is associated with normal ageing. This decline may be due to brain cortico-cortical disconnection caused by age-related white matter deterioration. We present results from a large, narrow age range cohort of generally healthy, community-dwelling subjects in their seventies who also had their cognitive ability tested in youth (age 11 years). We investigate associations between older age brain white matter structure, several measures of information processing speed and childhood cognitive ability in 581 subjects. Analysis of diffusion tensor MRI data using Tract-based Spatial Statistics (TBSS) showed that all measures of information processing speed, as well as a general speed factor composed from these tests (g speed), were significantly associated with fractional anisotropy (FA) across the white matter skeleton rather than in specific tracts. Cognitive ability measured at age 11 years was not associated with older age white matter FA, except for the g speed-independent components of several individual processing speed tests. These results indicate that quicker and more efficient information processing requires global connectivity in older age, and that associations between white matter FA and information processing speed (both individual test scores and g speed), unlike some other aspects of later life brain structure, are generally not accounted for by cognitive ability measured in youth.
authors.affiliation: Doctoral Training Centre in Neuroinformatics and Computational Neuroscience, School of Informatics, University of Edinburgh, Edinburgh, UK.|Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, UK.
authors.forename: Ksenia A
authors.initials: KA
authors.lastname: Kuznetsova
authors.affiliation: Brain Research Imaging Centre, Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.|Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK.|Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.
authors.forename: Susana Muñoz
authors.initials: SM
authors.lastname: Maniega
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.|Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Ritchie
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.|Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Cox
authors.affiliation: Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, UK.
authors.forename: Amos J
authors.initials: AJ
authors.lastname: Storkey
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.|Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK.
authors.forename: John M
authors.initials: JM
authors.lastname: Starr
authors.affiliation: Brain Research Imaging Centre, Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK.|Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK.|Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK. I.Deary@ed.ac.uk.|Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK. I.Deary@ed.ac.uk.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.affiliation: Brain Research Imaging Centre, Neuroimaging Sciences, University of Edinburgh, Edinburgh, UK. Mark.Bastin@ed.ac.uk.|Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Edinburgh, UK. Mark.Bastin@ed.ac.uk.|Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), University of Edinburgh, 7 George Square, Edinburgh, EH8 9JZ, UK. Mark.Bastin@ed.ac.uk.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Bastin
mesh_terms: D000368:Aged; D000375:Aging; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology; D008297:Male; D009483:Neuropsychological Tests; D066127:White Matter / Q000033:anatomy & histology* / Q000502:physiology*
keywords: Ageing; Diffusion MRI; Information processing speed; White matter structure