Analysis of Electroencephalogram and Pulse Waves during Music Listening

A tentative study is performed on the psychological effects of music based on the analysis of physiological indexes. We measured simultaneously the scalp electroencephalograms (EEG) and fingertip pulse waves for six healthy subjects before, during and after listening to music. The values of their low frequency (LF) and high frequency (HF) components of heart rate variability are obtained. By the method from chaos analysis, we calculated the largest Lyapunov exponents (LLE) of both scalp EEG and finger plethysmogram. Comparing the data of the resting condition and the music-listening condition, we observed significant tendencies over all subjects. We found that both values of LF and HF decreased, and so did the mean value taken over 14 EEG channels which were used for computation of LLE, whereas the distribution of the values tends to become average. Furthermore, it is notable that this averaging degree of LLE of scalp EEG generally accords with the decreasing rate of HF which reflects the activity of parasympathetic nerves.