The Effects of Divided Attention on the Ability to Rapidly Change Movement Direction in Young Adults

分割注意力對年輕人快速轉換方向能力之效果

卓瓊鈺(Chiung-Yu Cho) ； Louise Gilchrist ； Scott White

《物理治療》 32卷5期 (2007/10) Pp. 255-260

摘要

Background and Purposes: Dual task methodology is a technique that has been used to assess the attention demands of primary motor tasks including balance activities. Researchers have reported that measures of task performance and balance deteriorate with divided attention. The purpose of this study was to investigate the changes of the kinetics of a rapid side-step in nor-mal walking when faced with the challenge of performing a secondary task. Methods: Seven young subjects who were asked to walk along a 10 meter walkway were required to make a sudden sidestep (primary motor task) while performing an arithmetic task (secondary task). For the single task trials, subjects were required to perform the primary task only. Walking velocity, performance speed, correct responses for the arithmetic task, and ground reaction forces were recorded. Paired T-tests were used to compare data obtained from the single and dual task conditions. Pearson correlation coefficients were calculated to evaluate the relationship between walking speed and cognitive task speed as well as walking speed and cognitive task accuracy. Results: Subjects tended to slow down their forward velocity as they made the side-steps under the dual task condition but not for the single task condition (p＜0.05). Those subjects who walked faster tended to make more calculation errors compared to those subjects who walked slower (r=-0.59). Subjects tended to maintain the same amount of vertical peak forces when shifting directions; however, they increased the mid-stance minimum of the vertical force for the dual task condition (p＜0.05). Conclusions: Findings from this study suggest that adding a cognitive task during sidestep gait significantly increased the mid-stance vertical force. The association between walking speed and cognitive task accuracy was moderate. Young participants would sacrifice cognitive task accuracy rather than performance speed for the dual task trials. These changes may reflect the effects of divided attention on the central nervous system adaptation for the side-step gait.

關鍵字

雙重作業 ； 分割注意力 ； 力學

並列摘要

Background and Purposes: Dual task methodology is a technique that has been used to assess the attention demands of primary motor tasks including balance activities. Researchers have reported that measures of task performance and balance deteriorate with divided attention. The purpose of this study was to investigate the changes of the kinetics of a rapid side-step in nor-mal walking when faced with the challenge of performing a secondary task. Methods: Seven young subjects who were asked to walk along a 10 meter walkway were required to make a sudden sidestep (primary motor task) while performing an arithmetic task (secondary task). For the single task trials, subjects were required to perform the primary task only. Walking velocity, performance speed, correct responses for the arithmetic task, and ground reaction forces were recorded. Paired T-tests were used to compare data obtained from the single and dual task conditions. Pearson correlation coefficients were calculated to evaluate the relationship between walking speed and cognitive task speed as well as walking speed and cognitive task accuracy. Results: Subjects tended to slow down their forward velocity as they made the side-steps under the dual task condition but not for the single task condition (p＜0.05). Those subjects who walked faster tended to make more calculation errors compared to those subjects who walked slower (r=-0.59). Subjects tended to maintain the same amount of vertical peak forces when shifting directions; however, they increased the mid-stance minimum of the vertical force for the dual task condition (p＜0.05). Conclusions: Findings from this study suggest that adding a cognitive task during sidestep gait significantly increased the mid-stance vertical force. The association between walking speed and cognitive task accuracy was moderate. Young participants would sacrifice cognitive task accuracy rather than performance speed for the dual task trials. These changes may reflect the effects of divided attention on the central nervous system adaptation for the side-step gait.

並列關鍵字

Dual task ； Divided attention ； Kinetics