Skin conductance response and habituation to emotional facial expressions and words

Skin conductance response (SCR) serves as a dependable marker of sympathetic activation used to measure emotional arousal. This study investigates the impact of presentation modality (face or word) on the degree of emotional discrimination elicited by SCR. Facial expressions or words associated with six basic emotions—anger, happiness, disgust, fear, sadness, and surprise—were studied among 102 participants. The amplitude of SCR was accurately predicted by subjective arousal ratings of these stimuli, but not by valence ratings. The habituation process to emotional and neutral stimuli across six successive presentations was characterized by an exponential decay function, capturing the rate at which SCR response diminishes in relation to the preceding trial of the same stimulus. Through the subtraction of the response to neutral stimuli from the emotion-evoked SCR, it was demonstrated that the initial presentation of each emotion elicits a substantial response, particularly attributable to the emotional content. Notably, the initial emotional response to faces expressing happiness, disgust, and sadness surpassed that of words conveying the same emotions. The results indicate that different emotional responses can be quantified using a simple electrical instrument.