Brun C, Metral M, Chancel M, Kavounoudias A, Luyat M, Guerraz M
Univ. Savoie, LPNC, F-7300 UMR 5105 Chambéry, CNRS, France.
Univ. Savoie, LPNC, F-7300 UMR 5105 Chambéry, CNRS, France; Univ. Lille 3, Laboratory of Functional Neurosciences and Pathologies, EA 4559, Villeneuve d'Ascq, France.
Neuroscience. 2015 Jan 29;285:343-55. doi: 10.1016/j.neuroscience.2014.11.036. Epub 2014 Nov 27.
Recent studies of both healthy and patient populations have cast doubt on the mirror paradigm's beneficial effect on motor behavior. Indeed, the voluntary arm displacement that accompanies reflection in the mirror may be the determining factor in terms of the motor behavior of the contralateral arm. The objective of the present study was to assess the respective effects of mirror reflection and arm displacement (whether real or simulated) on involuntary motor behavior of the contralateral arm following sustained, isometric contraction (Kohnstamm phenomenon). Our results revealed that (i) passive displacement of one arm (displacement of the left arm via a motorized manipulandum moving at 4°/s) influenced the velocity of the Kohnstamm phenomenon (forearm flexion occurring shortly after the cessation of muscle contraction) in the contralateral arm and (ii) mirror vision had no effect. Indeed, the velocity of the Kohnstamm phenomenon tended to be adjusted to match the velocity of the passive displacement of the other arm. In a second experiment, arm displacement was simulated by vibrating the triceps at 25, 50 or 75 Hz. Results showed that the velocity of the Kohnstamm phenomenon in one arm increased with the vibration frequency applied to the other arm. Our results revealed the occurrence of bimanual coupling because involuntary displacement of one arm was regulated by muscle-related information generated by the actual or simulated displacement of the other arm. In line with the literature data on voluntary motor behavior, our study failed to evidence an additional impact of mirror vision on involuntary motor behavior.
最近针对健康人群和患者群体的研究，对镜像范式对运动行为的有益影响提出了质疑。事实上，在镜子中反射时伴随的自愿性手臂位移，可能是对侧手臂运动行为的决定性因素。本研究的目的是评估镜像反射和手臂位移（无论是真实的还是模拟的）对持续等长收缩后对侧手臂非自愿运动行为（科恩斯塔姆现象）的各自影响。我们的结果表明：（i）一只手臂的被动位移（通过以4°/秒移动的电动操作器使左臂位移）影响了对侧手臂科恩斯塔姆现象（肌肉收缩停止后不久出现的前臂屈曲）的速度，并且（ii）镜像视觉没有影响。实际上，科恩斯塔姆现象的速度倾向于调整以匹配另一只手臂被动位移的速度。在第二个实验中，通过以25、50或75赫兹振动三头肌来模拟手臂位移。结果表明，一只手臂中科恩斯塔姆现象的速度随着施加到另一只手臂上的振动频率而增加。我们的结果揭示了双侧耦合的发生，因为一只手臂的非自愿位移受另一只手臂实际或模拟位移产生的肌肉相关信息调节。与关于自愿运动行为的文献数据一致，我们的研究未能证明镜像视觉对非自愿运动行为有额外影响。
