Effects of Motor Imagery Tasks on Brain Functional Networks Based on EEG Mu/Beta Rhythm

Hongli Yu,Yuxue Guo,Lei Guo,Guizhi Xu,Sidi Ba

doi:10.3390/brainsci12020194

Abstract

Motor imagery (MI) refers to the mental rehearsal of movement in the absence of overt motor action, which can activate or inhibit cortical excitability. EEG mu/beta oscillations recorded over the human motor cortex have been shown to be consistently suppressed during both the imagination and performance of movements, although the specific effect on brain function remains to be confirmed. In this study, Granger causality (GC) was used to construct the brain functional network of subjects during motor imagery and resting state based on EEG in order to explore the effects of motor imagery on brain function. Parameters of the brain functional network were compared and analyzed, including degree, clustering coefficient, characteristic path length and global efficiency of EEG mu/beta rhythm in different states. The results showed that the clustering coefficient and efficiency of EEG mu/beta rhythm decreased significantly during motor imagery (p < 0.05), while degree distribution and characteristic path length increased significantly (p < 0.05), mainly concentrated in the frontal lobe and sensorimotor area. For the resting state after motor imagery, the changes of brain functional characteristics were roughly similar to those of the task state. Therefore, it is concluded that motor imagery plays an important role in activation of cortical excitability.

Highlights

Motor imagery (MI) is carried out as a mental representation of movement in the absence of corresponding muscle activities [1,2]
Cognitive physiology research has shown that the regions used to perform motor tasks might be essentially the same as those activated by motor imagery [4,5]
This paper described the causal relationship between brain functional networks by drawing a directed graph to analyze the different states of brain functional networks during motor imagery

Summary

Introduction

Motor imagery (MI) is carried out as a mental representation of movement in the absence of corresponding muscle activities [1,2]. When you perform a task of consciousness, such as imagination, the cortex is activated, and the local component of the EEG in this area is attenuated [3]. Cognitive physiology research has shown that the regions used to perform motor tasks might be essentially the same as those activated by motor imagery [4,5]. The prefrontal cortex, which is responsible for maintaining and guiding the imaginative motor task, shows selective activation during the task [6]. The influence of motor imagery on brain activity remains to be further explored

Results

Discussion

Conclusion