Inhibition, excitation and bilateral transfer following a unilateral complex finger‐tapping task in young and older adults
Abstract
Neuroplasticity underpins motor learning, with abnormal neuroplasticity related to age‐associated motor declines. Bilateral transfer of motor learning, through rehabilitation, may mitigate these declines; however, the magnitude of transfer may be reduced in older populations. This study investigated excitatory and inhibitory pathways in the trained and untrained hemispheres following unilateral training of a complex finger‐tapping task across ageing. Fifteen young (26.2 ± 3.8 years) and 11 older adults (63.7 ± 15.4 years) received transcranial magnetic stimulation, although surface electromyography was recorded from the extensor digitorum communis (EDC) and abductor pollicis brevis (APB), before and after practicing a complex finger‐tapping task with the dominant hand. Excitability, inhibition (expressed as percent change scores from pre‐ to post‐training), motor task performance and bilateral transfer were assessed between groups. Investigation of hemispheric differences within each group was completed for measures that significantly differed between groups. There were no between‐group differences in task performance or bilateral transfer, with task performance improving post‐training irrespective of group for both hands (p p = 0.034) in older compared with younger adults, indicating reduced inhibition in older adults. Inhibition change scores significantly differed between hemispheres for the young group only (p = 0.037). Only the younger group presented with hemispheric lateralisation, providing some support for the Hemispheric Asymmetry Reduction in OLDer adults (HAROLD) hypothesis. Whether this reduction is evidence of de‐differentiation or compensation will need to be confirmed with additional measures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 27, 2021
- Source ID
- 10.1111/ejn.15467
Entities
People
- Amy Loughman
- Ashlee M Hendy
- Ewa Szymlek-Gay
- Helen Macpherson
- Nathan D Nuzum
- Wei-Peng Teo
Organizations
- Deakin University
- Intelligence Community Postdoctoral Research Fellowship Program
- National Institute of Education