Brain dynamics during emotion elicitation in healthy subjects: An EEG study

Emotion regulation involves several brain areas such as prefrontal cortex, amygdala, and insular cortex. However, how such a brain dynamics is further modulated by emotional valence (pleasantness /unpleasantness), considering also different arousing levels, i.e., the intensity of the emotional stimuli, is still unknown. To this extent, we here study Electroencephalographic (EEG) oscillatory dynamics in healthy subjects during emotional visual elicitation. Twenty-two healthy volunteers were elicited through affective pictures gathered from the International Affective Picture System (IAPS). The experimental protocol foresaw 110 images associated to 4 increasing arousing levels, each of which included two valence levels: pleasant and unpleasant. EEG spectral analysis revealed no significant changes, between the two valence levels, during the lower and higher arousing elicitation at all considered bands, 6, a, ft, and 7. On the other hand, valence changes in the intermediate arousing sessions, in the 6, ft and 7 bands, were associated to changes in the prefrontal and parietal regions.