Zheng Ronglin, Wang Zhongmin, He Yan, Zhang Jie
School of Computer Science and Technology, Xi'an University of Posts and Telecommunications, Xi'an, 710121 China.
Shaanxi Key Laboratory of Network Data Analysis and Intelligent Processing, Xi'an University of Posts and Telecommunications, Xi'an, 710121 China.
Cogn Neurodyn. 2022 Apr;16(2):325-336. doi: 10.1007/s11571-021-09714-w. Epub 2021 Sep 13.
It has been shown that brain functional networks constructed from electroencephalographic signals (EEG) continuously change topology as brain fatigue increases, and extracting the topological properties of the network can characterize the degree of brain fatigue. However, the traditional brain function network construction process often selects only the amplitude or phase components of the signal to measure the relationship between brain regions, and the use of a single component of the signal to construct a brain function network for analysis is rather one-sided. Therefore, we propose a method of functional synchronization analysis of brain regions. This method takes the EEG signal based on empirical modal decomposition (EMD) to obtain multiple intrinsic modal components (IMF) and inputs them into the Hilbert transform to obtain the instantaneous amplitude, and then calculates the amplitude locking value (ALV) to measure the synchronization relationship between all pairs of channels. The topological properties of the brain functional network are extracted to classify awake and fatigue states. The brain functional network is constructed based on the adjacency matrix of each waveform obtained from the ALV between all pairs of channels to realize the synchronization analysis between brain regions. Moreover, we achieved a satisfactory classification accuracy (82.84%) using the discriminative connection features in the Alpha band. In this study, we analyzed the functional network of ALV brain in fatigue and awake state, and the results showed that the connections between brain regions in fatigue state were significantly increased, and the connections between brain regions in the awake state were significantly decreased, and the information interaction between brain regions was more orderly and efficient.
研究表明,随着脑疲劳加剧,由脑电图信号(EEG)构建的脑功能网络拓扑结构不断变化,提取该网络的拓扑特性能够表征脑疲劳程度。然而,传统的脑功能网络构建过程通常仅选择信号的幅度或相位分量来衡量脑区之间的关系,使用信号的单一分量构建脑功能网络进行分析较为片面。因此,我们提出一种脑区功能同步分析方法。该方法对基于经验模态分解(EMD)的EEG信号进行处理,得到多个本征模态分量(IMF),将其输入希尔伯特变换获取瞬时幅度,进而计算幅度锁定值(ALV)来衡量所有通道对之间的同步关系。提取脑功能网络的拓扑特性对清醒和疲劳状态进行分类。基于所有通道对之间由ALV得到的各波形邻接矩阵构建脑功能网络,以实现脑区之间的同步分析。此外,利用Alpha波段中的判别性连接特征,我们实现了令人满意的分类准确率(82.84%)。在本研究中,我们分析了疲劳和清醒状态下ALV脑功能网络,结果表明,疲劳状态下脑区之间的连接显著增加,清醒状态下脑区之间的连接显著减少,且脑区之间的信息交互更加有序和高效。