Frontal alpha asymmetry and hart rate synchronized during emotional experience when people show facial expression
Motoyuki Sanada1, Masanori Kobayashi1, Keiko Otake1, Jun'ichi Katayama1; 1Kwansei Gakuin University
The purpose of the current study was to unveil temporal dynamics of physiological state during emotional experience. It has been widely accepted that emotion arise from interaction between cerebral processing and bodily response (e.g., Seth, 2013). Therefore, we measured indices of both the activities; frontal alpha asymmetry for cerebral processing and heart rate for bodily response. Frontal alpha asymmetry of EEG reflects emotional state; negative emotion induces larger alpha power in left frontal site than right, and positive emotion evokes the opposite pattern (Davidson et al., 1990). Emotional state also changes heart rate; this modulation reflects valance of autonomic nerves system (Kreibig, 2010). Twenty participants watched six video clips (two for each negative, neutral, and positive), during which EEG and electrocardiogram (ECG) were recorded. In order to track the time course of frontal alpha asymmetry, we extracted alpha wave (8-13 Hz) from their EEG by FIR filter, and then, calculated the power value per one second. Heart rate per one second was computed from ECG as well. These analyses showed that time course of frontal alpha asymmetry synchronized with heart rate fluctuation when they watched one of the positive video clips. Post-hoc observation of participant’s face during the experiment unfolded that the video clip most often induced their facial expression. These results submitted a possibility that cerebral area which has responsibility for frontal alpha asymmetry and the center for controlling autonomic nerves system are connected, and their activity synchronize when expression is exposed.
Topic Area: EMOTION & SOCIAL: Other