Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Sensors (Basel). 2021 Jun 26;21(13):4380. doi: 10.3390/s21134380.
Synchronous correlation brain and muscle oscillations during motor task execution is termed as functional coupling. Functional coupling between two signals appears with a delay time which can be used to infer the directionality of information flow. Functional coupling of brain and muscle depends on the type of muscle contraction and motor task performance. Although there have been many studies of functional coupling with types of muscle contraction and force level, there has been a lack of investigation with various motor task performances. Motor task types play an essential role that can reflect the amount of functional interaction. Thus, we examined functional coupling under four different motor tasks: real movement, intention, motor imagery and movement observation tasks. We explored interaction of two signals with linear and nonlinear information flow. The aim of this study is to investigate the synchronization between brain and muscle signals in terms of functional coupling and delay time. The results proved that brain-muscle functional coupling and delay time change according to motor tasks. Quick synchronization of localized cortical activity and motor unit firing causes good functional coupling and this can lead to short delay time to oscillate between signals. Signals can flow with bidirectionality between efferent and afferent pathways.
在运动任务执行期间，大脑和肌肉的同步相关振荡被称为功能耦合。两个信号之间的功能耦合会出现延迟时间，可以用来推断信息流的方向。大脑和肌肉的功能耦合取决于肌肉收缩的类型和运动任务的表现。尽管已经有许多关于肌肉收缩类型和力水平的功能耦合研究，但对于各种运动任务表现的研究还不够。运动任务类型起着至关重要的作用，可以反映功能交互的程度。因此，我们在四种不同的运动任务下研究了功能耦合：实际运动、意图、运动想象和运动观察任务。我们探索了两种信号的线性和非线性信息流的相互作用。本研究的目的是从功能耦合和延迟时间的角度来研究大脑和肌肉信号之间的同步。结果证明，大脑-肌肉功能耦合和延迟时间会根据运动任务而变化。局部皮质活动和运动单位放电的快速同步会导致良好的功能耦合，这可以导致信号之间的延迟时间缩短。信号可以在传出和传入通路之间双向流动。
