Phase-coupling of EEG Rhythms Evoked by Emotional Audio-Visual Stimuli Based on Bicoherence

In order to explore the nonlinear phase-coupling between different EEG rhythms, this paper designed an experimental paradigm for audio-visual stimuli based on six basic emotions (happiness, anger, sadness, surprise, disgust, and fear). By using Neuroscan40 lead event related brain potentials instrument, EEG signal was recorded. AR model and the coherent averaging method were used to remove baseline drift and the spontaneous EEG interference. The Bicoherence Spectrum was used to analyze the phase-coupling of different EEG rhythms. The result shows that under the audio-visual emotional stimuli, compared with the quiet state, phase-coupling of delta, theta, and alpha rhythms were reduced, but phase-coupling between theta rhythm and gamma rhythm was increased. Emotion cognition activity is not only related to phase-coupling between theta-gamma rhythms but also related to gamma rhythm. Phase-coupling of beta rhythm was increased only when the stimulus was the positive emotion. This research can be applied to the emotion recognition and brain cognitive science.