Effects of single-task and dual-task demands on force control during bimanual coordination in healthy young adults
Date
2024
Authors
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Publisher
University of Delaware
Abstract
Background: People often use both hands simultaneously to accomplish everyday tasks, and occasionally they do so while also attending to a cognitive task. While there's been a significant rise in studies exploring cognitive-motor interactions during walking across various groups, research investigating the effects of dual-tasking on hand coordination remains limited. ☐ Objective: The main goal of this study was to assess changes in force control during a bimanual coordination task in young adults, while participants were engaged in either single- or dual-task scenarios. Bimanual force control has been tested while producing low-to-moderate forces, with and without visual feedback. The study sought to lay the groundwork for future clinical research by first investigating cognitive-motor dynamics in a healthy population. ☐ Methods: Participants included 25 young adults (9 males and 16 females) with an average age of 21.28 ± 2.15 who performed an isometric bimanual coordination modified pinch-grip task, both independently and while concurrently attending to a cognitive task. The bimanual coordination task required participants to sustain low-to-moderate force levels for 20- second periods at 10%, 20%, and 30 % MVC, with and without visual feedback on task performance. For the dual-task paradigm, we used a number-letter task that required counting the number of letters in pre-recorded audio sequences of shuffled numbers and letters while producing force with both hands. We also conducted a standalone version of this attention task, and administered several cognitive tests to assess overall cognitive function. ☐ Results: Results demonstrated a significant decline in performance on the attention task when performed concurrently with the bimanual coordination task. Regarding the force data, participants exhibited increases in force amplitude, variability, and error across all force levels during both the single- and dual-task conditions, irrespective of visual feedback availability. As expected, removing visual feedback resulted in reduced force amplitude, increased variability, and error, particularly at intermediate and high forces. Task effects were observed only in the condition providing visual feedback, indicating reduced force amplitude, increased variability, and error during the dual-task compared to the single-task, effects that tended to be greater at higher forces. Finally, participants generally maintained symmetrical force output across force levels and visual conditions, with no impact from the dual-task on force asymmetry. Importantly, no fatigue effects were present as evidenced by the lack of a significant difference between bimanual MVC pre- and post-experiment. ☐ Conclusions: Results confirm changes in bimanual force control with increased forces and highlight the importance of visual feedback in accurately guiding force output. They also expand the literature by showing that cognitive-motor interference impacted both force regulation during a bimanual coordination task and cognitive performance. The cognitive- motor interference was present only when participants had to visually monitor their performance on the bimanual coordination task and tended to be greater at higher forces. This suggest that the degree of interference may be related to the complexity of the cognitive load and force demands. Such studies in healthy individuals provide an opportunity to establish a baseline that can advance our understanding of conditions that often lead to a deterioration in both motor and cognitive abilities.
Description
Keywords
Bimanual coordination, Dual-task, Cognitive performance, Visual feedback