Article

Many daily activities require appropriate allocation of attention between
postural and cognitive tasks (i.e. dual-tasking) to be carried out effectively.
Processing multiple streams of spatial information is important for everyday
tasks such as road crossing. Fifteen community-dwelling healthy older (mean
age=78.3, male=1) and twenty younger adults (mean age=25.3, male=6) completed a
novel bimodal spatial multi-task test providing contextually similar spatial
information via separate sensory modalities to investigate effects on postural
prioritization. Two tasks, a temporally random visually coded spatial step
navigation task (VS) and a regular auditory-coded spatial congruency task (AS)
were performed independently (single task) and in combination (multi-task).
Response time, accuracy and dual-task costs (% change in multi-task condition)
were determined. Results showed a significant 3-way interaction between task type
(VS vs. AS), complexity (single vs. multi) and age group for both response time
(p </= 0.01) and response accuracy (p </= 0.05) with older adults performing
significantly worse than younger adults. Dual-task costs were significantly
greater for older compared to younger adults in the VS step task for both
response time (p </= 0.01) and accuracy (p </= 0.05) indicating prioritization of
the AS over the VS stepping task in older adults. Younger adults display greater
AS task response time dual task costs compared to older adults (p </= 0.05)
indicating VS task prioritization in agreement with the posture first strategy.
Findings suggest that novel dual modality spatial testing may lead to adoption of
postural strategies that deviate from posture first, particularly in older
people. Adoption of previously unreported postural prioritization strategies may
influence balance control in older people.
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Langue : ANGLAIS