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

Distinct cortical activity during face recognition was reported by a number of studies. 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 in α rhythm during cognitive processing.