خلاصة:
Objectives: The aim of this study was to identify the role of attentional process in postural control using choice reaction time task while changing the visual and proprioceptive cues under difficult balance task (standing on one-leg). Methods: This cross-sectional study was conducted by participating 20 young people (22.75± 2.29). Each subject performed one-leg standing as balance task for each of the following 2 test conditions: free balance position (single task), and balancing while performing secondary cognitive task (choice reaction time task). Each test was carried out for each of the following 3 sensory conditions: on hard surface with open eyes, on hard surface with closed eyes and on foam surface with closed eyes. One way ANOVA was used for analysis. Results: Analyses of the task conditions didn’t show significant difference between single and dual task under two sensory conditions, in open and in closed eye on hard surface (P > 0.05), but there was significant difference between single and dual tasks on soft foam with closed eyes [t(19) = -2.391, P = 0.027]. Discussion: Findings revealed that significant difference in balance performance of individuals under three different sensory conditions caused by reduction in base of support and this effect can be seen in dual task condition as well. Therefore it can be concluded that the nature of the primary task have the most influence on balance performance and this is not the effect of dual task condition.
ملخص الجهاز:
University of Social Welfare and Rehabilitation Sciences, Tehran, Iran Vahid Nejati, Ph. D Shahid Beheshti University, Tehran, Iran Objectives: The aim of this study was to identify the role of intentional process in postural control using choice reaction time task while changing the visual and proprioceptive cues under a difficult balance task (standing on one-leg).
com> however; the reasons being the types of dual-tasks studies, individual differences, age of participants, nature of cognitive and balance tasks, and the instructions given to participants for performing the experiment.
Results The subjects’ demographic data are shown in Table (1) Table (2) and table (3) present the results of balance and cognitive performance under single and dual tasks in three different sensory conditions.
The Findings of the present study showed that there was no significant difference between single and dual tasks under two different sensory conditions (open eye and closed eye/hard surface) which is consistent with the capacity processing hypothesis.
Whereas, in Lajoie et al (1993) (8) and Yardley et al’s (2001) (26) studies, changes in difficulty of postural task using static and dynamic positions influenced cognitive performance.
In Shumway-Cook et al’s (2000) study, the effect of sensory context on postural stability while performing attentionally-demanding cognitive tasks in youth and older adults was investigated.
Dual- tasking postural control: Aging and the effects of cognitive demand in conjunction with focus of attention: Brain Rese Bulletin, 2006: 69: 294-305.