چکیده:
Objectives: The role of cognitive process for postural control was shown in dual task studies. However, there was no definite evidence how verbal instructions influence the allocation of attention to postural control. This study determined whether young and elderly adult are able to deliberately control the resource allocation when performing a sensorimotor and cognitive task simultaneously and are there any differences between young and older adults in this regard. Method: Cross-sectional study was performed in 16 young adults aged (23.95 ± 3.31) and 20 older adults (61± 2.21). Participants selected by non-probable sampling method. Parallel standing and tandem standing on hard surface were used as postural tasks. Force plate was used for postural performance. Postural sway was measured and the choice reaction time task was conducted as cognitive task. Dual- task performance was measured under three different instructions including pay attention to cognitive task, postural task, and equal attention to both tasks. Results:for postural performance the main effect of instructions and interactions by difficulty and groups were not significant (P ≥ 0.05) for cognitive performance, the main effect of group was significant (F=5.672, P=0.023), showing that elderly adult have longer reaction time. The interaction of instruction by group effect and also interaction of instruction by postural difficulty on mean reaction time was also significant, (F=3.710, P=0.030), (F=5.242, P=0.008) respectively. Discussion: Because of age related changes in brain, flexibility in older adults are less than young adults.
خلاصه ماشینی:
This study determined whether young and elderly adults are able to deliberately control the resource allocation when performing a sensorimotor and cognitive task simultaneously and if there are any differences between young and older adults in this regard.
Keywords: attention, resource allocation, instruction, flexibility, dual task Submitted: 05 Dec 2011 Accepted: 28 Jul 2012 Introduction Falls are a serious problem in health care (1).
Here is an unanswered question: how do cognitive deficits resulting from the aging process affect the performance of dual tasks in elderly adults?
Two groups of young and elderly adults were matched for gender, weight and height to remove the possible effects of these factors on postural performance.
Results Postural performance Table (1) shows the mean and SD of COP parameters in different conditions of postural task and instructions for both groups.
Cognitive performance The mean and SD of mean reaction times in different conditions of postural difficulty and instructional sets for both groups have been demonstrated in table (3) and (4).
Results from the present study showed that the young group can adopt instruction and reduce reaction time by following cognitive priority instruction, but focus of attention on postural task did not change postural performance.
In their study shifting attention toward a secondary cognitive task was identified by reduction in verbal reaction time and also postural Parallel standing Tandem standing performance was stable under different instructional sets.
Age-related changes of postural control: effect of cognitive tasks.