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.
- Reduced SMA‐M1 connectivity in older than younger adults measured using dual‐site TMS
- B.K. Rurak (Author/Creator) - Murdoch UniversityJ.P. Rodrigues (Author/Creator) - Hollywood Private HospitalB.D. Power (Author/Creator) - Hollywood Private HospitalP.D. Drummond (Author/Creator) - Murdoch UniversityA.M. Vallence (Author/Creator) - Murdoch University
- European Journal of Neuroscience, Vol.54(7), pp.6533-6552
- Wiley
- 991005543620607891
- © 2021 Federation of European Neuroscience Societies and John Wiley & Sons Ltd
- School of Psychology; Centre for Healthy Ageing; Health Futures Institute; School of Allied Health; Centre for Molecular Medicine and Innovative Therapeutics
- English
- Journal article