Oxytocin enhances the recovery of eye-contact induced autonomic arousal: A treatment mechanism study with placebo-controlled design

The neuropeptide oxytocin (OT) is suggested to exert a pivotal role in a variety of complex human behaviors, including trust, attachment, social perception and fear-regulation. Previous studies have demonstrated that intranasal administration of OT reduces subjective and neuroendocrine stress responses and dampens amygdala reactivity. Moreover, OT has been proposed to modulate activity of the autonomic nervous system. Here, we conducted a double-blind, placebo-controlled study with 56 men, to investigate whether a single-dose of OT (24 IU) modulates sympathetic autonomic arousal upon live dyadic gaze interactions. To do so, electro-dermal recordings of skin conductance were performed during the engagement of eye contact with a live model in a naturalistic two-person social context. In accordance to prior research, direct eye gaze elicited a significant enhancement in skin conductance responses, but OT did not specifically enhance or dampen the overall magnitude (amplitude) of the autonomic arousal response. Administration of OT did facilitate the recovery of skin conductance responses back to baseline (increased steepness of recovery slope), indicating a role of OT in restoring homeostatic balance. Notably, the treatment-effect on autonomic recovery was most prominent in participants with low self-reported social responsiveness and high attachment avoidance, indicating that person-dependent factors play a pivotal role in determining OT treatment-responses. Behaviorally, OT significantly reduced self-reported feelings of tension and (at trend-level) worrying about how one presents oneself. Together, these observations add further evidence to a role of OT in reducing subjective and autonomic stress responses, primarily by facilitating restoration of homeostatic balance after (social) stress-induced perturbation.