Physiological responses of peripheral autonomic nervous system are critical to maintaining homeostasis, physiological flexibility, and acute adaptation to stressful situations mediated by a variety of chemical coding systems, thus maintaining body homeostasis. The autonomic nervous system is also responsible for cognitive, affective, and behavioral responses, and its deregulation is manifested in a variety
of neuropsychological disorders. Both the sympathetic and parasympathetic branches of the autonomic nervous system promote social functioning and communication, with activation of the sympathetic nervous system (SNS) reflecting a threat-oriented response, and the
dominance of the parasympathetic nervous system (PNS) facilitating adaptive social interaction. PNS plays an important role in social functioning, innervating several organs of the face and neck and influencing various functions, including cardiac activity related to social behavior and communication
