Ke Weijie, Luo Zhizeng
Institute of Intelligent Control and Robotics, Hangzhou Dianzi University, Hangzhou 310018, China.
Brain Sci. 2024 Jan 13;14(1):81. doi: 10.3390/brainsci14010081.
Maintaining standing balance is essential for people to engage in productive activities in daily life. However, the process of interaction between the cortex and the muscles during balance regulation is understudied. Four balance paradigms of different difficulty were designed by closing eyes and laying sponge pad under feet. Ten healthy subjects were recruited to stand for ten 15 s trials in each paradigm. This study used simultaneously acquired electroencephalography (EEG) and electromyography (EMG) to investigate changes in the human cortico-muscular coupling relationship and functional brain network characteristics during balance control. The coherence and causality of EEG and EMG signals were calculated by magnitude-squared coherence (MSC) and transfer entropy (TE). It was found that changes in balance strategies may lead to a shift in cortico-muscular coherence (CMC) from the beta band to the gamma band when the difficulty of balance increased. As subjects performed the four standing balance paradigms, the causality of the beta band and the gamma band was stronger in the descending neural pathway than that in the ascending neural pathway. A multi-rhythmic functional brain network with 19 EEG channels was constructed and analyzed based on graph theory, showing that its topology also changed with changes in balance difficulty. These results show an active adjustment of the sensorimotor system under different balance paradigms and provide new insights into the endogenous physiological mechanisms underlying the control of standing balance.
保持站立平衡对于人们在日常生活中进行有效的活动至关重要。然而，在平衡调节过程中，皮层与肌肉之间的相互作用过程尚未得到充分研究。通过闭眼和在脚下放置海绵垫设计了四种不同难度的平衡范式。招募了10名健康受试者，在每种范式下进行十次15秒的站立试验。本研究同时采集脑电图（EEG）和肌电图（EMG），以研究平衡控制过程中人类皮质-肌肉耦合关系和功能性脑网络特征的变化。通过均方相干（MSC）和转移熵（TE）计算EEG和EMG信号的相干性和因果关系。研究发现，当平衡难度增加时，平衡策略的变化可能导致皮质-肌肉相干性（CMC）从β波段转移到γ波段。当受试者执行四种站立平衡范式时，β波段和γ波段在下行神经通路中的因果关系比在上行神经通路中更强。基于图论构建并分析了一个具有19个EEG通道的多节律功能性脑网络，结果表明其拓扑结构也随着平衡难度的变化而改变。这些结果显示了在不同平衡范式下感觉运动系统的主动调整，并为站立平衡控制的内源性生理机制提供了新的见解。
