基于Harmonic小波时变相干的人脸识别脑电特征提取

Analysis of Time-varying Coherence of EEG during Face Recognition Based on Harmonic Transform

经典的相干分析是建立在信号平稳的假设基础上,反映两个随机过程在某一频率成分上的同步关系。在脑电研究领域,相干分析主要用于分析大脑不同区域活动的相关程度及驱动-响应关系。经典的相干分析可以刻画脑电不同区域活动在节律上的一致性,但不能提取大脑活动的瞬时特性。为了提取认知过程中脑电活动的空间-时间模式特征,本文引入脑电信号的时变相干性分析。被测者为10名健康的学生,脑电数据是从一个人脸照片认识或不认识的辨识认知过程中采集的,实验结果表明,在α频带两种辩识过程颞区与其他脑区的信息交流模式呈现明显的差异。

Classical coherence analysis reflects the synchronization between two random processes in certain frequency under the assumption that the signals are stationary. In EEG study, the coherence analysis is mainly used to analyze the coupling and drive-response relation about the brain activities in different regions. Classical coherence analysis can extract the rhythmic consistency of the EEG activities in different regains. However, classical coherence can not extract the transient synchrony characteristics of brain activities. In order to track the spatial-temporal characteristics of EEG activities during cognitive conception, the time-varying coherence analysis is proposed. The EEG of 10 participants was recorded during recognition of familiar and unfamiliar faces, experiment results show that there is obvious difference about the model of information communication between temporal region and other brain regions iná rhythm during cognitive processing.