Emotional responses are organized along two dimensions: (1) valence, varying from negative to positive, and (2) arousal, varying from low to high. Behavioral responses along these dimensions are assumed to be mediated by different brain circuits. In this study, we used functional magnetic resonance imaging to characterize neural activity correlating with ratings of subjective emotional experience elicited by negative socio-emotional stimuli.

Hemodynamic changes were recorded in 40 healthy volunteers using functional magnetic resonance imaging (fMRI) while they viewed a set of socio-emotional pictures. In addition, we took ratings of valence and arousal of emotions arised in response to emotional stimuli after scanning. A block-design paradigm has been used consisting of pairs of negative and neutral periods generated by adding labels to ambiguous socio-emotional pictures.

In ROI analysis, a positive correlation was found between arousal ratings of emotions in response to negative emotion-eliciting stimuli and activation in the insula as well as inferior frontal areas. Our results confirm previous literature pointing out the role of insula in arousal generation through stimulus-driven evaluative processes and possibly the integration of cognitive, emotional and somatic components of emotion. Moreover, inferior frontal areas may modulate arousal to socioemotional cues as a result of considering subjective goals and experiences amongst situational demands.