EEG-fNIRS approach in emotions and empathic behaviour

Emotional empathy is crucial to understand how we react to interpersonal situations. In the present study we aim to identify the neural networks underlying the human ability to perceive and empathize with others' emotions during the observation of cooperative or uncooperative interactions. In addition, for the first time a multimethodological approach was adopted. Indeed the indubitable vantage of acquiring both the autonomic (arousal-related) and the central (cortical-related) activities stands in the possibility to better elucidate the reciprocal interplay of the two compartments in empathy behavior. Electroencephalography (EEG, frequency band analysis; source generators analysis, sLORETA), systemic skin conductance response (SCR) and heart rate (HR) were all recorded simultaneously with hemodynamic (fNIRS, functional Near-Infrared Spectroscopy) measurements as potential biological markers of emotional empathy, related to both central and peripheral systems. Subjects were required to empathize with observed interpersonal interaction. As shown by fNIRS and EEG measures, uncooperative situations elicited an increased brain activity within the right prefrontal cortex (dorsolateral prefrontal cortex), whereas cooperative situations showed an increased response within the left prefrontal cortex. Therefore a relevant lateralization effect was induced by the specific valence (mainly for negative conditions) of the emotional interactions. Also the autonomic response (SCR modulation) was modulated by cooperative/uncooperative conditions. Finally EEG activity (mainly low-frequency theta and delta bands) was intrinsically correlated with the cortical hemodynamic responsiveness, and they both predicted the autonomic activity. The integrated central and autonomic measures better elucidated the significance of empathic behavior in interpersonal interactions.