Studies on relaxation and inhibitory control mechanism during voluntary human muscle contraction

本文报道了用放松任务研究人类随意运动的抑制控制。本研究主要有两个主题，第一个主题是研究力量输出的大小和肌肉收缩的方式（张力逐渐增加或恒定张力）的影响。运动的抑制控制。另一个主题是环绕抑制和半球间抑制。在这种情况下，对对侧同源肌肉的抑制作用进行了研究，以比较单侧松弛与同时双侧松弛。由于每个研究由两个实验组成，因此本研究共进行了4个实验。实验结果如下：1.松弛的响应模式根据力输出的大小而变化。放松潜伏期与力输出的大小有明显的相关性.张力开始衰减的时间不受输出力大小的影响.抑制命令是在一个恒定的时间从介绍的刺激，然而，由于命令不能完全抑制肌肉活动时，肌肉收缩是非常激烈的，反应时间的放松延长。5.当肌肉力量逐渐增加以追求斜坡波目标时，反应时间随着斜坡波频率的增加而延长。双侧同时收缩的握力小于单侧同时收缩的握力.当双侧握力时仅放松一侧力量时，对侧握力略有升高。这一现象似乎是由于大脑半球间抑制的消除。

Studies on inhibitory control in human voluntary movements were reported by mean of the task of relaxation. There are two main themes in the present research ; the first theme is to investigate the influences of the magnitude of force output and mode of muscle contraction (gradual increment for tension or constant tension. exertion) on inhibitory control of movement. The other theme is surround inhibition and interhemispheric inhibition. In this case inhibitory effects to the contralateral homologous muscle are investigated to compare unilateral relaxation with the simultaneous bilateral one. As each research is consisted of two experiments, total 4 experiments were conducted in the present studies. The results are derived from these experiments as follows :1. Response patterns of relaxation are varied according to the magnitude of force output.2. The latency of relaxation is clearly related with the magnitude of force output.3. The time for the initiation of decrement of tension is not affected by the magnitude of force output.4. The inhibition command is issued at a constant time from the presentation of the stimulus, However, since the command cannot completely inhibit the muscle activity when the muscle contraction is very intense, reaction times for relaxation are prolonged.5. When the muscle strength is gradually increased in pursuit of the ramp wave target, reaction times are prolonged as the frequency of the ramp wave heightened.6. Both grip strength of simultaneous bilateral contraction is smaller than those of the unilateral.7. When only unilateral strength is relaxed during bilateral grip strength exertion, the contralateral grip tension is slightly rised. It seems that this phenomenon is due to the removal of the interhemispheric inhibition.