Disclosing the relationship between electrophysiological responses to emotional stimuli and subjective valence, arousal and empathy evaluations

Past research on behavioral measures concerning electrophysiological emotional processing has mainly focused on valence and arousal, or empathy, but not much attention has been given to delta waves (0-4 Hz), often associated with sleep. Some evidence has suggested that delta rhythms might be implicated in engaging with stimuli. This poses a question of how these different measures might relate to delta electrophysiological responses to emotional stimuli. The behavioral measures were collected using self-report methods (PANAS, IRI). An electroencephalography (EEG) study allowed the observation of the electrophysiological responses elicited upon the presentation of Neutral, Erotic, and Mutilation stimuli in 40 participants. The results showed that pleasant stimuli elicited a higher delta power than Neutral stimuli which deviates from previous findings. Moreover, high transitory anxiety appears to hamper the experience of pleasant stimuli, and heighten the experienced intensity of negative stimuli, likely due to appraisal and attentional bias respectively. In addition, more arousing stimuli, regardless of valence are correlated with higher empathy scores (Personal Distress and Fantasy Scale). Certain dimensions of empathy (IRI and FS-IRI) are localized to particular regions of the brain, particularly the anterior regions for pleasant stimuli, and the posterior left for unpleasant stimuli. Finally, Perspective Taking is dominant in the anterior regions regardless of stimuli, but negative stimuli are lateralized to the right hemisphere, consistent with the literature.