Spectator to a Meeting of Minds: Vicarious Eye Contact Elicits Psychophysiological Responses in the Observer

Research has shown that dyadic eye contact elicits psychophysiological responses related to affect and attention. In daily life, we also frequently notice eye contact occurring between other people, even when we are not directly involved. This study investigated whether such vicarious eye contact elicits affect- and attention-related psychophysiological responses in observers. In two experiments, we measured participants' skin conductance (affective arousal), facial muscle activity (affective valence/affiliation), and heart rate deceleration (attention orienting) responses while they viewed gaze interactions between two agents. In Experiment 1, participants observed eye contact between two humans, whereas in Experiment 2, participants saw a human and a humanoid robot NAO. We found novel evidence for a vicarious eye contact effect: viewing eye contact between two humans elicited greater affective arousal in observers compared to non-eye contact conditions. Somewhat surprisingly, facial muscle responses indicated increased zygomaticus activity and decreased corrugator activity during vicarious eye contact relative to non-eye contact conditions when participants viewed eye contact between a human and a humanoid robot, but not when viewing eye contact between two humans. In both experiments, vicarious eye contact failed to elicit a greater heart rate deceleration response, suggesting that it lacks the attention-capturing characteristics of dyadic eye contact. We discuss these findings in the context of mind attribution in gaze interactions and argue that using artificial agents as social stimuli can offer valuable insights into the role of mind attribution in social cognition.