International audienceWhat processes or mechanisms mediate interpersonal matching of facial expressions remains a debated issue. As theoretical approaches to underlying processes (i.e., automatic motor mimicry, communicative intent, and emotional appraisal) make different predictions about whether facial responses to others' facial expressions are influenced by perceived gaze behavior, we examined the impact of gaze direction and dynamic facial expressions on observers' autonomic and rapid facial reactions (RFRs). We recorded facial electromyography activity over 4 muscle regions (Corrugator Supercilli, Zygomaticus Major, Lateral Frontalis, and Depressor Anguli Oris), skin conductance response and heart rate changes in participants passivel...