Frontal alpha asymmetry during the audio emotional experiment revealed by event-related spectral perturbation

Due to the recent development of brain computer interfaces (BCI), there has been certain relationship between emotion and brain electrical activities. Brain asymmetry could be used for enhanced electroencephalogram (EEG)-based emotional recognition as a prominent feature. Prefrontal hemispheric asymmetries have been proposed in twenty years ago. It is measured by the power of EEG signal in alpha band (8-13Hz), which is related to electrical power response to different emotional stimuli. In this paper, we designed an auditory evoked emotional experiment in order to explore EEG frontal alpha asymmetry by comparing event-related spectral perturbation (ERSP) maps of left and right frontal regions. Thirty healthy male students are employed to stimulate emotion by affective sound clips. All of auditory evoked stimuli come from the standard International Affective Digitized Sounds (IADS) dataset. ERSP maps exhibited that there are the strongest responses of positive sounds overspread the frontal lobe. To be specific, the right prefrontal and whole medial frontal EEG activation are elicited the stronger responses by emotional sounds of high pleasure-arousal, whereas the left prefrontal and whole medial frontal EEG activation are elicited the stronger responses by emotional sounds of middle pleasure-low arousal. Additionally, the stronger responses of high-arousal level sound clips have been found out over the whole right frontal region, while the low-arousal level sound clips can elicit greater relative electrical power over the whole left frontal region.