The effects of transcutaneous vagus nerve stimulation on romantic couples’ physiology and behavior during conflict

BACKGROUND: Conflicts with close others and subsequent affective reactions can have long-term consequences for mental and physical health. Building on recent studies using transcutaneous vagus nerve stimulation (tVNS) highlighting the role of the vagus nerve in social functioning, we examined if tVNS can modulate the emotional, physiological, and behavioral responses to a romantic conflict. METHODS: 134) were randomly assigned to tVNS or sham stimulation. Both partners received continuous tVNS or sham stimulation for 15 min before and during a six-minute discussion about a recurring conflict topic. We examined each partner's emotional and respiratory sinus arrhythmia (RSA) reactivity to conflict and the partners' physiological and behavioral attunement to each other. RESULTS: Our results revealed no condition differences in emotional experiences, but individuals receiving tVNS (vs. sham stimulation) experienced greater decreases in RSA during conflict. Further, while RSA reactivity synchrony did not differ between conditions, couples in the tVNS (vs. sham stimulation) condition showed greater behavioral synchrony. CONCLUSIONS: This work provides experimental evidence supporting the role of the vagus nerve in modulating reactions to stressful social interactions, highlighting the potential of tVNS to subtly influence couple dynamics at physiological and behavioral levels.