Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Reduced SMA‐M1 connectivity in older than younger adults measured using dual‐site TMS

Rurak, B.K., Rodrigues, J.P., Power, B.D., Drummond, P.D.ORCID: 0000-0002-3711-8737 and Vallence, A.M.ORCID: 0000-0001-9190-6366 (2021) Reduced SMA‐M1 connectivity in older than younger adults measured using dual‐site TMS. European Journal of Neuroscience . Early View.

Link to Published Version:
*Subscription may be required


With advancing age comes a decline in voluntary movement control. Growing evidence suggests that an age-related decline in effective connectivity between the supplementary motor area and primary motor cortex (SMA-M1) might play a role in an age-related decline of bilateral motor control. Dual-site transcranial magnetic stimulation (TMS) can be used to measure SMA-M1 effective connectivity. In the current study, we aimed to (1) replicate previous dual-site TMS research showing reduced SMA-M1 connectivity in older than younger adults and (2) examine whether SMA-M1 connectivity is associated with bilateral motor control in independent samples of younger (n = 30) and older adults (n = 30). SMA-M1 connectivity was measured using dual-site TMS with interstimulus intervals of 6, 7 and 8 ms, and bilateral motor control was measured using the Purdue Pegboard, Four Square Step Test and the Timed Up and Go task. Findings from this study showed that SMA-M1 connectivity was reduced in older than in younger adults, suggesting that the direct excitatory connections between SMA and M1 had reduced efficacy in older than younger adults. Furthermore, greater SMA-M1 connectivity was associated with better bimanual motor control in older adults. Thus, SMA-M1 connectivity in older adults might underpin, in part, the age-related decline in bilateral motor control. These findings contribute to our understanding of age-related declines in motor control and provide a physiological basis for the development of interventions to improve bimanual and bilateral motor control.

Item Type: Journal Article
Murdoch Affiliation(s): Psychology, Counselling, Exercise Science and Chiropractic
Centre for Healthy Ageing
Centre for Molecular Medicine and Innovative Therapeutics (CMMIT)
Health Futures Institute
Publisher: Wiley
Copyright: © 2021 Federation of European Neuroscience Societies and John Wiley & Sons Ltd
Item Control Page Item Control Page