Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, 68182, USA.
Department of Gerontology, University of Nebraska at Omaha, Omaha, NE, 68182, USA.
Aging Clin Exp Res. 2021 Mar;33(3):581-587. doi: 10.1007/s40520-020-01575-3. Epub 2020 May 6.
Task prioritization is an important factor determines the magnitude and direction of dual-task interference in older adults. Greater dual-task cost during walking may lead to falling, sometimes causing lasting effects on mobility.
We investigated dual-task interference for walking and cognitive performance.
Twenty healthy, older adults (71 ± 5 years) completed three cognitive tasks: letter fluency, category fluency, and serial subtraction during seated and walking conditions on a self-paced treadmill for 3 min each, in addition to walking only condition. Walking speed, step length and width were measured during walking and each dual-task condition.
Comparing the percentage of correct answers in cognitive tasks across single and dual-task conditions, there was a main effect of cognitive task (p = 0.021), showing higher scores during letter fluency compared to serial subtraction (p = 0.011). Step width was significantly wider during dual-task letter fluency compared to walking alone (p = 0.003), category fluency (p = 0.001), and serial subtraction (p = 0.007).
During both fluency tasks, there was a cost for gait and cognition, with category showing a slightly higher cognitive cost compared to letter fluency. During letter fluency, to maintain cognitive performance, gait was sacrificed by increasing step width. During serial subtraction, there was a cost for gait, yet a benefit for cognitive performance.
Differential effect of cognitive task on dual-task performance is critical to be understood in designing future research or interventions to improve dual-task performance of most activities of daily living.
任务优先级是决定老年人双任务干扰程度和方向的重要因素。行走时双任务成本增加可能导致跌倒，有时会对行动能力造成持久影响。
我们研究了行走和认知表现的双任务干扰。
20 名健康的老年人（71±5 岁）在自我调节跑步机上完成了 3 分钟的三种认知任务：字母流畅性、类别流畅性和连续减法，同时还进行了仅行走条件下的测试。在行走和每种双任务条件下测量行走速度、步长和步宽。
比较单任务和双任务条件下认知任务的正确答案百分比，认知任务有主要影响（p=0.021），字母流畅性的得分高于连续减法（p=0.011）。与单独行走相比，双任务字母流畅性时步宽明显更宽（p=0.003），类别流畅性（p=0.001）和连续减法（p=0.007）时也是如此。
在两种流畅性任务中，步态和认知都有成本，类别流畅性比字母流畅性的认知成本略高。在字母流畅性任务中，为了保持认知表现，通过增加步宽牺牲了步态。在连续减法任务中，步态成本增加，但认知表现受益。
认知任务对双任务表现的影响差异对于设计未来的研究或干预措施以提高大多数日常生活活动的双任务表现至关重要。
