基于精细化频带的脑磁信号跨频耦合特性分析

摘要

脑信号跨频耦合现象与人的意识活动密切相关。本文将精细化的频带划分方法和多种跨频耦合的度量方法相结合，研究不同类型手腕运动的脑磁信号跨频耦合特征。首先对四类手运动脑磁信号进行精细化的频带分解，采用了三种具有主次关系的耦合度量方法（相干、虚部相干、调制指数），在高频耦合低频、低频耦合高频两种耦合形式下对某一运动方向类型信号显著区别于其它运动方向类型信号的频带数、通道对、频带对进行了统计分析，可以区分出不同方向手腕运动的 MEG 信号；进一步利用通道间的频带耦合关系以及源频带及其激励通道与响应通道等概念，采用相干耦合度量方法对上述两种耦合形式下的统计结果进行分析，获得相应的源频带、激励通道、响应通道，从而可以更加有效地区分不同方向手腕运动的 MEG 信号。%The phenomenon of cross frequency coupling in brain signal is closely related to human conscious activity.We investigate the effect of different hand movement on the cross frequency coupling characteristic in MEG,combining refined frequency bands with various cross frequency coupling measurements.Firstly,we consider a refined frequency bands scheme for MEG signals and three cross frequency coupling methods with the primary and secondary relationship,and com-pare the statistical results with two kind of frequency band coupling modes,i.e.high frequency versus low frequency,or conversely.Furthermore,we take advantage of the frequency band coupling connection in different channels and the con-cept of stimulation and response of the source frequency bands,and use the coherence measurement to investigate the statis-tical results of the above two coupling modes,in order to obtain the appropriate source frequency bands,the stimulation channels and the response channels.The results show we can more effectively distinguish between different MEG signals of various wrist movement.