Polyvagal theory describes how the body reacts and relates to challenges we face in our lives. Traditionally, we have understood the autonomic nervous system (ANS) to consist of two primary responses: one of activating signals (up-regulation) and one of calming signals (down-regulation). These nervous system reactions help us manage and survive life-threatening situations. Most know these system responses as “fight-flight” and “freeze-faint,” respectively. Polyvagal theory identifies a third type of ANS response called the social engagement system, a subtle combination of activation and calming that helps us navigate relationships and other interpersonal interactions. In the context of a perceived safe environment, the social engagement system tells the body to act or behave in a way that enhances or contributes to that sense of safety. So, we can have intense emotional or somatic experiences and move through the full experience because the presence of a perceived threat is removed. As Wagner (2016) aptly summarizes, “When we experience our environment as safe, we operate from our social engagement system.”
Polyvagal theory and trauma treatment
Polyvagal theory orients us to a crucial awareness of how ANS responses interface with our perceptions and memory of traumatic events or situations. That is, once a situation has moved our functioning outside of the realm of the social engagement system (i.e., we are no longer safe in our environment), we essentially lose our conscious choice about how we react or respond. In other words, our body makes the decision on our behalf. For better or worse, that ANS hyper- or hypo-arousal response is all about survival.
As noted in other pages, trauma disrupts the normal processing and storage of memory, which has both dramatic and subtle consequences on the ANS. For example, many trauma survivors live in chronic states of ANS hyper-arousal (i.e., fight or flight) or ANS hypo-arousal (i.e., freeze or dissociation).
Therapists informed by polyvagal theory understand these reactions and symptoms as indicators of ANS health and well-being. These also indicate the sequence for ANS treatment. For example, a person who experiences panic attacks (i.e., a symptom of ANS hyper-arousal) needs treatment that focuses on calming the ANS from its flight/flight response and then activating the social engagement system once the environment is safe. Considering the hierarchy of ANS responses, a person who experiences emotional numbness in the days following the panic attack (i.e., a symptom of ANS hypo-arousal), treatment must follow the reverse sequence that, first, activates the fight/flight system, next, calms the flight/flight system, and finally, activates the social engagement system.