Library Open Repository

Age-related changes in interlimb coordination

Downloads

Downloads per month over past year

Fujiyama, H (2009) Age-related changes in interlimb coordination. PhD thesis, University of Tasmania.

[img] PDF
Fujiyama_Thesis...pdf | Download (4MB)
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Appendix D)
Appendix D_EXP1...pdf | Download (1MB)
Available under University of Tasmania Standard License.

| Preview
[img]
Preview
PDF (Appendix E)
Appendix E_EXP2...pdf | Download (1MB)
Available under University of Tasmania Standard License.

| Preview
[img]
Preview
PDF (Appendix F)
Appendix F_EXP3...pdf | Download (1MB)
Available under University of Tasmania Standard License.

| Preview
[img] Other (Appendix D)
Appendix D_EXP1...str | Download (98MB)
Available under University of Tasmania Standard License.

[img] Other (Appendix E)
Appendix E_EXP2...str | Download (37MB)
Available under University of Tasmania Standard License.

[img] Other (Appendix F)
Appendix F_EXP3...str | Download (74MB)
Available under University of Tasmania Standard License.

Abstract

Age-related changes in motor performance have often been associated with functional
decline with advancing age such as general motor slowing, degraded attentional capacity,
and declined physiological inhibitory control. The overarching aim of the current series of
empirical studies was to investigate the contribution of these functional alterations to agerelated
changes in motor function.
The first part of the study investigated age-related changes in inter-limb
coordination and the associated attentional cost using a dual-task paradigm. The primary
task involved the coordination of arm and leg movements performed by limbs on the same
(ipsilateral) or opposite (contralateral) sides of the body. Difficulty of the primary task was
manipulated by varying movement direction (isodirectional vs non-isodirectional) and
movement frequency, with attentional cost being reflected in responses to a secondary
probe reaction time task. The results showed that the performance of older adults
selectively deteriorated depending on task difficulty. That is, the age-difference was
pronounced in the most attentionally demanding' condition in which the movement
frequency was highest and the motor task was performed simultaneously with a reaction
time task.
The second part of the study used electroencephalography (EEG) to provide a direct
measure of the eNS activity associated with mental resource allocation in older adults
during the performance of the interlimb coordination task. Attentional resource allocation
was assessed by Event-Related Potentials (ERPs) during concurrent performance of
interlimb coordination tasks and a visual oddball task. The amplitude of the P3b component
of the ERP has been associated with the allocation of attentional resources. For both young
and older adults coordination performance was less stable and visual reaction times (RTs)
were longer during the coordination of ipsilateral limbs than contralateral limbs. Although
older adults showed slower RTs to targets in the visual odd ball task, they exhibited similar
patterns in P3b latency and amplitude to younger adults. Of particular interest was higher a
P3b amplitude at the frontal sites in older adults, suggesting an increased cognitive
monitoring of performance with aging.
In the last part of the research the modulation of cortical activity during interlimb
coordination was examined using transcranial magnetic stimulation (TMS). The length of
the silent period (SP) following a motor evoked potential (MEP) was used as a measure of
corticospinal inhibition during the interlimb coordination task. As expected, older adults
showed less stable coordination performance than younger adults during production of non-isodirectional patterns. SP duration was lengthened, indicating increased inhibition, in the
young group during the performance of the ipsilateral non-isodirectional pattern. In
contrast, the older group showed a consistent level of cortical inhibition across conditions.
These results suggest that deterioration in motor performance with advancing age might be
associated with the declined ability to modulate inhibitory function.

Item Type: Thesis (PhD)
Additional Information:

Copyright 2009 the Author

Date Deposited: 18 Mar 2010 03:53
Last Modified: 11 Mar 2016 05:53
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page