Department of Rehabilitation Medicine, Tokyo Bay Rehabilitation Hospital, Chiba, Japan.
Graduate School of Health Sciences, Aomori University of Health and Welfare, 58-1 Mase, Hamadate, Aomori, 030-8505, Japan.
Exp Brain Res. 2024 May;242(5):1215-1223. doi: 10.1007/s00221-024-06820-z. Epub 2024 Mar 25.
Working memory (WM) can influence selective attention. However, the effect of WM load on postural standing tasks has been poorly understood, even though these tasks require attentional resources. The purpose of this study was to examine whether WM load would impact anticipatory postural adjustments (APAs) during step initiation. Sixteen healthy young adults performed stepping tasks alone or concurrently with a WM task in a dual-task design. The stepping tasks involved volitional stepping movements in response to visual stimuli and comprised of simple and choice reaction time tasks and the Flanker task which consisted of congruent and incongruent (INC) conditions. In the dual-task condition, subjects were required to memorize either one or six digits before each stepping trial. Incorrect weight transfer prior to foot-lift, termed APA errors, reaction time (RT), and foot-lift time were measured from the vertical force data. The results showed that APA error rate was significantly higher when memorizing six-digit than one-digit numerals in the INC condition. In addition, RT and foot-lift time were significantly longer in the INC condition compared to the other stepping conditions, while there was no significant effect of WM load on RT or foot-lift time. These findings suggest that high WM load reduces the cognitive resources needed for selective attention and decision making during step initiation.
工作记忆（WM）可以影响选择性注意。然而，WM 负荷对姿势站立任务的影响仍知之甚少，尽管这些任务需要注意力资源。本研究旨在探讨 WM 负荷是否会影响起始阶段的预期姿势调整（APA）。16 名健康年轻成年人在双任务设计中单独或同时进行踏步任务和 WM 任务。踏步任务涉及根据视觉刺激进行自主踏步运动，包括简单和选择反应时间任务以及 Flanker 任务，包括一致和不一致（INC）条件。在双任务条件下，受试者在每次踏步试验前需要记住一个或六个数字。在 INC 条件下，与记忆一位数字相比，记忆六位数字时的错误转移（称为 APA 错误）、反应时间（RT）和抬脚时间从垂直力数据中进行测量。结果表明，在 INC 条件下，记忆六位数字时的 APA 错误率显著高于记忆一位数字时的 APA 错误率。此外，与其他踏步条件相比，INC 条件下的 RT 和抬脚时间明显更长，而 WM 负荷对 RT 或抬脚时间没有显著影响。这些发现表明，高 WM 负荷会减少起始阶段选择性注意和决策所需的认知资源。
