Age-related differences in inhibitory processes during interlimb coordination.
The study examined the neurophysiological correlates of age-related changes in the coordination of hand and foot movements. Young and older adults (N=30) performed cyclical isodirectional and non-isodirectional hand-foot movements with contralateral and ipsilateral limb combinations. Motor evoked potentials (MEPs) and silent period durations following transcranial magnetic stimulation (TMS) were measured from the right extensor carpi radialis (ECR) muscle during the interlimb coordination tasks. Older adults demonstrated lower coordination stability than younger adults, particularly when performing non-isodirectional movements with ipsilateral limbs. For all coordination tasks, MEP amplitude was lower in older compared with young participants. Young adults showed significantly longer silent period durations when the coordination pattern involved ipsilateral limbs than during contralateral limb coordination. In contrast, silent period durations did not differ between contralateral and ipsilateral limb coordination in older adults. These results suggest that deterioration in motor performance with advancing age may be associated with a decreased ability to modulate inhibitory function.
Human Motor Control Laboratory, School of Psychology, University of Tasmania, Hobart, Tasmania 7001, Australia.
Hakuei
H
Fujiyama
Mike I
MI
Garry
Oron
O
Levin
Stephan P
SP
Swinnen
Jeffrey J
JJ
Summers
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005528:Foot / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult