Neurophysiological correlates of emotional reactions toward a synthetic index of emotional experience: Preliminary findings

The emotional characterization is a crucial application in the field of industrial neurosciences, where the objective is to objectively assess human experience through the employment of neurophysiological signals. In this scenario, the present study developed and validated a physiology-driven indicator of the user’s emotional experience, namely, the emotional index, computed as the synthetic combination of the user’s heart rate and the skin conductance level. The index was validated on a sample of 25 participants looking at a set of emotional videos taken from a previously validated affective database, thereby highlighting a substantial effect of valence and arousal labels in terms of heart rate and skin conductance level modulations. The results pointed out a significant effect of valence on heart rate values, χ2(4) = 31.14, p < .001, and an effect of arousal on the skin conductance level, F(24, 2.35) = 4.95, p = .007. Additionally, an effect of the stimuli emotional content was also found on values of the emotional index, χ2(4) = 29.57, p < .001. At the same time, the index demonstrated its capacity to overcome the limitations affecting a previous version of its definition while maintaining its correlation with it, rs (418) = .81, p < .001. In conclusion, the new computation of the emotional index was validated for the emotion characterization of video stimuli, and it was demonstrated to be more representative of the physiological response.