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Age-related cognitive task effects on gait characteristics: do different working memory components make a difference?

Qu X - J Neuroeng Rehabil (2014)

Bottom Line: In addition, we also examined age-related differences in such dual-task effects.In addition, cognitive task effects on step width variability differed between two age groups.In particular, the Brooks' Spatial Memory task led to significantly larger step width variability only among older adults.

View Article: PubMed Central - PubMed

Affiliation: Institute of Human Factors and Ergonomics, College of Mechatronics and Control Engineering, Shenzhen University, 3688 Nanhai Avenue, Shenzhen, Guangdong Province 518060, China. quxd@szu.edu.cn.

ABSTRACT

Background: Though it is well recognized that gait characteristics are affected by concurrent cognitive tasks, how different working memory components contribute to dual task effects on gait is still unknown. The objective of the present study was to investigate dual-task effects on gait characteristics, specifically the application of cognitive tasks involving different working memory components. In addition, we also examined age-related differences in such dual-task effects.

Methods: Three cognitive tasks (i.e. 'Random Digit Generation', 'Brooks' Spatial Memory', and 'Counting Backward') involving different working memory components were examined. Twelve young (6 males and 6 females, 20 ~ 25 years old) and 12 older participants (6 males and 6 females, 60 ~ 72 years old) took part in two phases of experiments. In the first phase, each cognitive task was defined at three difficulty levels, and perceived difficulty was compared across tasks. The cognitive tasks perceived to be equally difficult were selected for the second phase. In the second phase, four testing conditions were defined, corresponding to a baseline and the three equally difficult cognitive tasks. Participants walked on a treadmill at their self-selected comfortable speed in each testing condition. Body kinematics were collected during treadmill walking, and gait characteristics were assessed using spatial-temporal gait parameters.

Results: Application of the concurrent Brooks' Spatial Memory task led to longer step times compared to the baseline condition. Larger step width variability was observed in both the Brooks' Spatial Memory and Counting Backward dual-task conditions than in the baseline condition. In addition, cognitive task effects on step width variability differed between two age groups. In particular, the Brooks' Spatial Memory task led to significantly larger step width variability only among older adults.

Conclusion: These findings revealed that cognitive tasks involving the visuo-spatial sketchpad interfered with gait more severely in older versus young adults. Thus, dual-task training, in which a cognitive task involving the visuo-spatial sketchpad (e.g. the Brooks' Spatial Memory task) is concurrently performed with walking, could be beneficial to mitigate impairments in gait among older adults.

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Related in: MedlinePlus

Marker placement on the human body.
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Fig1: Marker placement on the human body.

Mentions: The second phase was started one month after completing Phase 1, and the same group of participants as in Phase 1 were involved. At the beginning of the experiment, participants changed into tight-fitting suits, and 26 reflective markers were placed bilaterally over selected anatomical landmarks of the body (Figure 1). This marker placement scheme was used to track several body segments, including the head, trunk, upper arms, lower arms, thighs, shanks, and feet. A test was then conducted to determine the participants’ comfortable walking speed. In this test, the participant was asked to walk on a treadmill (Biodex RTM 600, Shirley, NY, USA) at a relatively low initial speed. Then, the treadmill speed was increased by a small amount (i.e. 0.1 mph) on each successive trial until the participants reported that they felt uncomfortable with the speed. The treadmill speed was then increased further and slowly decreased by the same small amount on each successive trial until the speed was reported to be comfortable. The average of the transition speeds was taken as the comfortable treadmill speed. Note that each participant was tested at their comfortable treadmill speed for all trials. There was a significant difference between the two age groups in treadmill speed (Young: 0.73 ± 0.12 meters/second; Old: 0.54/±0.26 meters/second; p = 0.028).Figure 1


Age-related cognitive task effects on gait characteristics: do different working memory components make a difference?

Qu X - J Neuroeng Rehabil (2014)

Marker placement on the human body.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4221663&req=5

Fig1: Marker placement on the human body.
Mentions: The second phase was started one month after completing Phase 1, and the same group of participants as in Phase 1 were involved. At the beginning of the experiment, participants changed into tight-fitting suits, and 26 reflective markers were placed bilaterally over selected anatomical landmarks of the body (Figure 1). This marker placement scheme was used to track several body segments, including the head, trunk, upper arms, lower arms, thighs, shanks, and feet. A test was then conducted to determine the participants’ comfortable walking speed. In this test, the participant was asked to walk on a treadmill (Biodex RTM 600, Shirley, NY, USA) at a relatively low initial speed. Then, the treadmill speed was increased by a small amount (i.e. 0.1 mph) on each successive trial until the participants reported that they felt uncomfortable with the speed. The treadmill speed was then increased further and slowly decreased by the same small amount on each successive trial until the speed was reported to be comfortable. The average of the transition speeds was taken as the comfortable treadmill speed. Note that each participant was tested at their comfortable treadmill speed for all trials. There was a significant difference between the two age groups in treadmill speed (Young: 0.73 ± 0.12 meters/second; Old: 0.54/±0.26 meters/second; p = 0.028).Figure 1

Bottom Line: In addition, we also examined age-related differences in such dual-task effects.In addition, cognitive task effects on step width variability differed between two age groups.In particular, the Brooks' Spatial Memory task led to significantly larger step width variability only among older adults.

View Article: PubMed Central - PubMed

Affiliation: Institute of Human Factors and Ergonomics, College of Mechatronics and Control Engineering, Shenzhen University, 3688 Nanhai Avenue, Shenzhen, Guangdong Province 518060, China. quxd@szu.edu.cn.

ABSTRACT

Background: Though it is well recognized that gait characteristics are affected by concurrent cognitive tasks, how different working memory components contribute to dual task effects on gait is still unknown. The objective of the present study was to investigate dual-task effects on gait characteristics, specifically the application of cognitive tasks involving different working memory components. In addition, we also examined age-related differences in such dual-task effects.

Methods: Three cognitive tasks (i.e. 'Random Digit Generation', 'Brooks' Spatial Memory', and 'Counting Backward') involving different working memory components were examined. Twelve young (6 males and 6 females, 20 ~ 25 years old) and 12 older participants (6 males and 6 females, 60 ~ 72 years old) took part in two phases of experiments. In the first phase, each cognitive task was defined at three difficulty levels, and perceived difficulty was compared across tasks. The cognitive tasks perceived to be equally difficult were selected for the second phase. In the second phase, four testing conditions were defined, corresponding to a baseline and the three equally difficult cognitive tasks. Participants walked on a treadmill at their self-selected comfortable speed in each testing condition. Body kinematics were collected during treadmill walking, and gait characteristics were assessed using spatial-temporal gait parameters.

Results: Application of the concurrent Brooks' Spatial Memory task led to longer step times compared to the baseline condition. Larger step width variability was observed in both the Brooks' Spatial Memory and Counting Backward dual-task conditions than in the baseline condition. In addition, cognitive task effects on step width variability differed between two age groups. In particular, the Brooks' Spatial Memory task led to significantly larger step width variability only among older adults.

Conclusion: These findings revealed that cognitive tasks involving the visuo-spatial sketchpad interfered with gait more severely in older versus young adults. Thus, dual-task training, in which a cognitive task involving the visuo-spatial sketchpad (e.g. the Brooks' Spatial Memory task) is concurrently performed with walking, could be beneficial to mitigate impairments in gait among older adults.

Show MeSH
Related in: MedlinePlus