title: Associations between reaction time measures and white matter hyperintensities in very old age.
abstract: In old age, a relationship has been reported between intraindividual variability (IIV) in reaction time and white matter integrity as evidenced by white matter hyperintensities (WMH). However, it is unclear how far such associations are due to incipient neurodegenerative pathology in the samples investigated. The present study examined the relationship between IIV and WMH in older individuals (N=526) drawn from the Sydney Memory and Ageing Study. Using a complex reaction time (RT) task, greater IIV and mean-RT were related to a higher WMH burden in the frontal lobe. Critically, significant associations remained having taken future dementia into account suggesting that they were not explained by incipient dementia. Additionally, independent measures of executive function accounted for the association between RT metrics and WHM. The results are consistent with the view that frontally-supported cognitive processes are involved in IIV-WMH relations, and that RT measures are sensitive to compromise in white matter structures in non-demented older individuals.
authors.affiliation: School of Psychology, Faculty of Medicine and Health, University of Leeds, Leeds, UK.
authors.forename: Becky I
authors.initials: BI
authors.lastname: Haynes
authors.affiliation: School of Psychology, Faculty of Medicine and Health, University of Leeds, Leeds, UK; Centre for Health Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia. Electronic address: d.bunce@leeds.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Bunce
authors.affiliation: Centre for Health Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Barker Street, Randwick, NSW 2031, Australia.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Kochan
authors.affiliation: Centre for Health Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Barker Street, Randwick, NSW 2031, Australia.
authors.forename: Wei
authors.initials: W
authors.lastname: Wen
authors.affiliation: Centre for Health Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Dementia Collaborative Research Centre, School of Psychiatry, UNSW Medicine, The University of New South Wales, Sydney, NSW 2052, Australia; Academic Department for Old Age Psychiatry, Prince of Wales Hospital, Avoca Street, Randwick, NSW 2031, Australia.
authors.forename: Henry
authors.initials: H
authors.lastname: Brodaty
authors.affiliation: Centre for Health Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Barker Street, Randwick, NSW 2031, Australia.
authors.forename: Perminder S
authors.initials: PS
authors.lastname: Sachdev
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D001244:Association; D003704:Dementia / Q000000981:diagnostic imaging / Q000503:physiopathology; D056344:Executive Function; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007206:Individuality; D056784:Leukoencephalopathies / Q000150:complications* / Q000000981:diagnostic imaging; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*
keywords: Cognition; Executive function; Intraindividual variability; Reaction time; White matter hyperintensities