Department of Sports, Health and Welfare, Faculty of Human Health, Hiroshima Bunka Gakuen University, 3-3-20 Heiseigahama, Saka-cho, Aki-gun, Hiroshima, 731-4312, Japan.
Laboratory of Human Motor Control, Naruto University of Education, Naruto, 772-8502, Japan.
Exp Brain Res. 2019 Jul;237(7):1833-1839. doi: 10.1007/s00221-019-05555-6. Epub 2019 May 11.
The present study aimed to determine the effects of force asymmetry on interpersonal force production. This study consisted of an individual task executed by one participant at a time in a pair, and three joint tasks executed by two participants simultaneously under conditions of 1:1, 1:0.75, and 1:0.5. Two individuals produced discrete forces at the same time so that the sum of forces they produced was the target force in the joint task. Under the 1:1 condition, the target force was the sum of the maximum voluntary contraction (MVC) produced by the index finger of each participant × 0.1 (10% MVC). Under the 1:0.75 condition, the investigators manipulated the force produced by only one of the pair, for example, B, but not A. The feedback was also scaled as a result. The target force was the MVC of participant A + the MVC of participant B × 0.75 × 0.1. Similarly, the target force under the 1:0.5 condition was the MVC of participant A + the MVC of participant B × 0.5 × 0.1. The present study found that forces produced by pairs were negatively correlated and the correlation value was higher under the 1:1 condition than the 1:0.75 and 1:0.5 conditions. The absolute error was smaller under the 1:1 condition than the 1:0.5 condition. Complementary force production was attenuated and the error increased as differences between forces produced by two participants increased. Thus, asymmetry of forces produced by pairs deteriorated complementary force production and interpersonal performance.
本研究旨在确定力不对称对人际力产生的影响。本研究包括一项个体任务，每次由一名参与者在一对搭档中完成，以及三项联合任务，由两名参与者同时在 1:1、1:0.75 和 1:0.5 的条件下完成。两个人同时产生离散力，以便他们产生的力的总和是联合任务中的目标力。在 1:1 条件下，目标力是每个参与者食指最大自主收缩 (MVC) 的总和 × 0.1 (10% MVC)。在 1:0.75 条件下，研究人员仅操纵其中一个搭档（例如 B）产生的力，但不操纵另一个搭档（例如 A）产生的力。结果也进行了缩放。目标力是参与者 A 的 MVC + 参与者 B 的 MVC × 0.75 × 0.1。同样，在 1:0.5 条件下，目标力是参与者 A 的 MVC + 参与者 B 的 MVC × 0.5 × 0.1。本研究发现，搭档产生的力呈负相关，且在 1:1 条件下的相关值高于 1:0.75 和 1:0.5 条件。在 1:1 条件下，绝对误差小于 1:0.5 条件。随着两个参与者产生的力之间的差异增加，互补力的产生被削弱，误差增加。因此，搭档产生的力的不对称性会降低互补力的产生和人际表现。
