Masumoto Junya, Inui Nobuyuki
Human Services Research Center, Hiroshima Bunka Gakuen University, 3-5-1, Nagatsukanishi, Asaminami-ku, Hiroshima, 731-0136, Japan.
Laboratory of Human Motor Control, Naruto University of Education, Naruto, Japan.
Exp Brain Res. 2017 Jul;235(7):2259-2265. doi: 10.1007/s00221-017-4970-z. Epub 2017 Apr 29.
The present study examined bidirectional learning transfer between joint and individual actions involving discrete isometric force production with the right index finger. To examine the effects of practice of joint action on performance of the individual action, participants performed a pre-test (individual condition), practice blocks (joint condition), and a post-test (individual condition) (IJI task). To examine the effects of practice of the individual action on performance during the joint action, the participants performed a pre-test (joint condition), practice blocks (individual condition), and a post-test (joint condition) (JIJ task). Whereas one participant made pressing movements with a target peak force of 10% maximum voluntary contraction (MVC) in the individual condition, two participants produced the target force of the sum of 10% MVC produced by each of them in the joint condition. In both the IJI and JIJ tasks, absolute errors and standard deviations of peak force were smaller post-test than pre-test, indicating bidirectional transfer between individual and joint conditions for force accuracy and variability. Although the negative correlation between forces produced by two participants (complementary force production) became stronger with practice blocks in the IJI task, there was no difference between the pre- and post-tests for the negative correlation in the JIJ task. In the JIJ task, the decrease in force accuracy and variability during the individual action did not facilitate complementary force production during the joint action. This indicates that practice performed by two people is essential for complementary force production in joint action.
本研究考察了涉及右手食指离散等长力产生的联合动作与个体动作之间的双向学习迁移。为了检验联合动作练习对个体动作表现的影响，参与者进行了一次预测试（个体条件）、练习块（联合条件）和一次后测试（个体条件）（IJI任务）。为了检验个体动作练习对联合动作过程中表现的影响，参与者进行了一次预测试（联合条件）、练习块（个体条件）和一次后测试（联合条件）（JIJ任务）。在个体条件下，一名参与者以最大自主收缩（MVC）的10%为目标峰值力进行按压动作，在联合条件下，两名参与者产生的目标力为他们各自产生的10%MVC之和。在IJI和JIJ任务中，后测试时峰值力的绝对误差和标准差均小于预测试，表明个体和联合条件之间在力的准确性和变异性方面存在双向迁移。虽然在IJI任务中，两名参与者产生的力之间的负相关（互补力产生）随着练习块的进行而增强，但在JIJ任务中，预测试和后测试之间的负相关没有差异。在JIJ任务中，个体动作过程中力的准确性和变异性的降低并没有促进联合动作过程中的互补力产生。这表明两人进行的练习对于联合动作中的互补力产生至关重要。
