Jayakody, O and Breslin, M and Beare, R and Siejka, TP and Gujjari, S and Srikanth, VK and Blumen, HM and Callisaya, ML, The association between simple reaction time variability and gait variability: The Tasmanian Study of Cognition and Gait, Gait and Posture, 89 pp. 206-210. ISSN 0966-6362 (2021) [Refereed Article]
© 2021 Elsevier B.V. All rights reserved.
Introduction: Greater double support time (DST) variability is associated with falls and memory decline. The underlying neurophysiological mechanisms of DST variability are poorly understood. Simple reaction time (SRT) variability, a measure of attention-processing speed is associated with falls and dementia and, may underlie greater DST variability. The aims of this study were to examine the association between SRT and DST variability and if SRT variability mediates the associations between poorer cognition/brain structure and DST variability.
Methods: Participants (n = 408) were community-dwelling older people without dementia (mean age 72.0 ± 7.0). DST variability was the standard deviation (SD) of DST, assessed with a walkway and averaged across steps of 6 walks. SRT variability was the SD of a button pressing task in response to a visual stimulus. Executive function and processing speed were assessed with neuropsychological tests. Magnetic Resonance Imaging was used to obtain cortical thickness (total and in frontal regions) and cerebral small vessel disease (cSVD). Multivariable linear regression models were used to examine the association between SRT and DST variability and if SRT variability mediated any associations of cognition/brain structure with DST variability.
Results: Greater SRT variability was associated with greater DST variability (p = 0.002). SRT variability partially mediated the association between poorer executive function and greater DST variability. Smaller mean thickness in orbitofrontal regions and greater cSVD burden were only associated with DST variability (p < 0.05), not with SRT variability (p > 0.05).
Conclusions: Greater SRT variability, which may occur due to inefficient executive functioning, could be an underlying neurophysiological mechanism of greater DST variability.
|Item Type:||Refereed Article|
|Keywords:||gait, double support time variability, reaction time, variability, cognition, brain structure|
|Research Division:||Health Sciences|
|Research Group:||Allied health and rehabilitation science|
|Objective Group:||Public health (excl. specific population health)|
|Objective Field:||Behaviour and health|
|UTAS Author:||Jayakody, O (Ms Shanika Jayakody Arachchige Dona)|
|UTAS Author:||Breslin, M (Dr Monique Breslin)|
|UTAS Author:||Srikanth, VK (Dr Velandai Srikanth)|
|UTAS Author:||Callisaya, ML (Dr Michele Callisaya)|
|Funding Support:||National Health and Medical Research Council (1135761)|
|Deposited By:||Menzies Institute for Medical Research|
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