Functional modification of agonist-antagonist electromyographic activity for rapid movement inhibition
Functional modification of agonist-antagonist electromyographic activity for rapid movement inhibition
复制标题
DOI：
10.1007/s002210050487
复制
发表时间：
1998-09-01
影响因子：
2
通讯作者：
Ohtsuki, T
中科院分区：
文献类型：
--
作者：
Kudo, K;Ohtsuki, T
受试者在听到go信号后迅速向指定目标伸肘。在45%的试验中，停止信号出现在开始信号之后，受试者被要求尽可能快地停止运动。刺激间隔（ISI），或去和停止信号之间的时间间隔，随机变化0和200毫秒之间。肌电图（EMG）活动记录从肱二头肌和肱三头肌。受试者有时可以完全抑制发起的动作时，ISI为0毫秒，但很少能做到这一点时，ISI超过100毫秒。对于响应，但停止的方式，运动的幅度线性下降的时间间隔（=修改时间）从停止信号到EMG发作增加。峰值速度随运动幅度的增加而线性增加。这种趋势与先前报道的具有不同幅度的步跟踪运动中的趋势相似。尽管在运动学的相似性，肌电图模式是不同的步跟踪运动。而初始激动剂爆发（AGI）线性下降后，修改时间超过100 ms，拮抗剂爆发（ANT）增加相比，从0到200 ms的修改时间和修改时间超过300 ms后减少。这种激活的变化类似于功能修改中潜伏期反射肌电响应负荷，或皮肤扰动。总之，它表明，自适应机制，这将在功能上修改的反射反应，也不断工作在自愿运动，以应对环境信息的突然变化。
Subjects made a fast elbow extension movement to designated target in response to a go signal. In 45% of trials a stop signal was presented after the go signal, to which subjects were asked to stop the movement as rapidly as possible. The interstimulus interval (ISI), or time interval between the go and stop signals, was randomly varied between 0 and 200 ms. Electromyographic (EMG) activity was recorded from biceps brachii and triceps brachii. Subjects could sometimes completely inhibit initiation of the movements when the ISI was 0 ms, but could rarely do so when the ISI exceeded 100 ms. For responses that were initiated but stopped on the way, the amplitude of the movement decreased linearly as the time interval (=modification time) from the stop signal to EMG onset increased. The peak velocity increased linearly as the movement amplitude increased. This tendency was similar to those previously reported in step-tracking movements with various amplitudes. In spite of the similarity in the kinematics of the movement, the EMG pattern was different from that of step-tracking movement. While the initial agonist burst (AGI) decreased linearly after the modification time exceeded 100 ms, the antagonist burst (ANT) increased compared with the go trial for the modification time from 0 to 200 ms and decreased after the modification time exceeded 300 ms. This change of activation is analogous to functional modification of middle-latency reflex EMG response to load, or cutaneous perturbation. In conclusion, it is suggested that adaptive mechanisms, which would functionally modify the reflex responses, are also continuously working during voluntary movements in response to sudden changes in environmental information.