Kotani Shuntaro, Furuya Shinichi
Musical Skill and Injury Center (MuSIC), Sophia University , Tokyo , Japan.
Sony Computer Science Laboratories, Inc. , Tokyo , Japan.
J Neurophysiol. 2018 Aug 1;120(2):439-451. doi: 10.1152/jn.00813.2017. Epub 2018 Apr 11.
Skilled performance, in many situations, exposes an individual to psychological stress and fear, thus triggering state anxiety and compromising motor dexterity. Suboptimal skill execution in people under pressure affects the future career prospects of trained individuals, such as athletes, clinicians, and musicians. However, it has not been elucidated in what manner state anxiety affects multijoint movements and thereby degrades fine motor control. Using principal component analysis of hand kinematics recorded by a data glove during piano performances, we tested whether state anxiety affects the organization of movements of multiple joints or merely constrains the amplitude of the individual joints without affecting joint movement coordination. The result demonstrated changes in the coordination of movements across joints in piano performances by experts under psychological stress. Overall, the change was characterized by reduction of synergistic movements between the finger responsible for the keypress and its adjacent fingers. A regression analysis further identified that the attenuation of the movement covariation between the fingers was associated with an increase in temporal error during performance under pressure. In contrast, neither the maximum nor minimum angles of the individual joints of the hand were susceptible to induced anxiety. These results suggest that degradation of fine motor control under pressure is mediated by incoordination of movements between the fingers in skilled piano performances. NEW & NOTEWORTHY A key issue in neuromuscular control of coordinated movements is how the nervous system organizes multiple degrees of freedom for production of skillful motor behaviors. We found that state anxiety disorchestrates the organization of finger movements so as to decrease synergistic motions between the fingers in musical performance, which degrades fine motor control. The findings are important to shed light on mechanisms underlying loss of motor dexterity under pressure.
在许多情况下，熟练的表现会使个体面临心理压力和恐惧，从而引发状态焦虑并损害运动灵活性。处于压力下的人技能执行欠佳会影响受过训练的个体（如运动员、临床医生和音乐家）未来的职业前景。然而，状态焦虑是以何种方式影响多关节运动并进而降低精细运动控制，目前尚未阐明。通过对钢琴演奏期间数据手套记录的手部运动学进行主成分分析，我们测试了状态焦虑是影响多个关节运动的组织方式，还是仅仅限制单个关节的幅度而不影响关节运动协调性。结果表明，在心理压力下，专家在钢琴演奏中关节间运动的协调性发生了变化。总体而言，这种变化的特征是负责按键的手指与其相邻手指之间的协同运动减少。回归分析进一步确定，手指间运动协变的减弱与压力下演奏期间时间误差的增加有关。相比之下，手部单个关节的最大和最小角度均不易受诱发焦虑的影响。这些结果表明，在熟练的钢琴演奏中，压力下精细运动控制的退化是由手指间运动不协调介导的。新发现与值得注意之处：协调运动的神经肌肉控制中的一个关键问题是神经系统如何组织多个自由度以产生熟练的运动行为。我们发现，状态焦虑会扰乱手指运动的组织，从而减少音乐表演中手指间的协同运动，进而降低精细运动控制。这些发现对于阐明压力下运动灵活性丧失的潜在机制具有重要意义。
