Mori Hirotaka, Yamamoto Shinji, Aihara Tsuyoshi, Uehara Shintaro
Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
School of Health and Sport Sciences, Osaka University of Health and Sport Sciences, 1-1 Asashirodai, Kumatori-cho, Sennan-gun, Osaka 590-0496, Japan.
Neurosci Lett. 2015 Jan 1;584:119-22. doi: 10.1016/j.neulet.2014.10.012. Epub 2014 Oct 23.
In daily life, we often try to learn motor actions by imitating others' actions. Motor imitation requires us to simultaneously map an observed action onto a motor program used to perform that action. This sensorimotor associative experience can plastically modulate the mirror property of the human mirror system, which has a role in matching observed actions directly with the observer's motor programs, to enhance the association between observed and performed actions. In the present study, we investigated the effects of handedness on the mirror property. Healthy left- and right-handed individuals performed a motor imitation task. They were required to imitate hand actions with their dominant hand as quickly and accurately as possible in response to pictures of a left and right hand. Reaction times (RTs) for imitating the hand actions were evaluated. Under the condition where the hand pictures were presented as if facing the participant, we found that, in left-handed participants, RTs for imitating right-handed actions were significantly shorter than those for imitating left-handed actions. Under the same conditions in right-handers, similar differences in RTs when presented left- and right-handed actions were not observed. These findings demonstrate that the imitative responses for left- and right-handed actions are differently facilitated depending on the handedness of the observer, indicating an effect of handedness on the development of mirror systems. The mirror property in left- and right-handers is likely modulated in a different manner by different sensorimotor associative experiences throughout their daily lives.
在日常生活中，我们常常试图通过模仿他人的动作来学习运动行为。运动模仿要求我们同时将观察到的动作映射到用于执行该动作的运动程序上。这种感觉运动关联体验可以可塑性地调节人类镜像系统的镜像属性，该系统在将观察到的动作直接与观察者的运动程序进行匹配方面发挥作用，以增强观察到的动作与执行的动作之间的关联。在本研究中，我们调查了利手对镜像属性的影响。健康的左利手和右利手个体执行了一项运动模仿任务。他们被要求用优势手尽可能快速准确地模仿手部动作，以回应左手和右手的图片。评估了模仿手部动作的反应时间（RTs）。在手部图片呈现为好像面向参与者的条件下，我们发现，在左利手参与者中，模仿右手动作的反应时间显著短于模仿左手动作的反应时间。在右利手个体的相同条件下，未观察到呈现左手和右手动作时反应时间的类似差异。这些发现表明，根据观察者的利手情况，对左手和右手动作的模仿反应受到不同程度的促进，这表明利手对镜像系统的发育有影响。左利手和右利手的镜像属性可能在他们的日常生活中受到不同感觉运动关联体验的不同方式的调节。
