• Aisha Marie Sho

Polyvagal Theory: How the trauma response works

Updated: Jun 5, 2020


You are weak if you have to fight everything. That is why it is important to pick and choose your battles. If you are faced with adversity at every step in your attempts to progress, you will be fighting enemies at all times, resulting in a weakened ability to combat adversity, as both your mental and physical resources are spread too thin. In the current political climate there has been a series of controversial events involving racism and the violent abuse and killing of African Americans and minorities at the hands of police, hence the need for a hashtag “trigger warning” on many posts. This has led many people, specifically members of the African American community, to either react in rage or emotional numbness. Police brutality against African Americans can trigger PTSD in members of the Black community. This is due not only to the frequent viewing of Blacks being killed on social media and the news, but also the generational trauma at the hands of their oppressors, which Black people have endured for almost one thousand years.

This article you are reading was initially intended to be only about Polyvagal Theory. Given the recent events with George Floyd, Ahmaud Arbery, and Breonna Taylor, and many more unnamed African Americans, I decided to start off this introduction with a nod to our current situation as Black people and the fact that these recurring acts of hatred are tied to our generational and ancestral trauma. Polyvagal Theory explains how trauma and our reactions to it naturally and unconsciously occur within our bodies. Throughout this article I will explain to you how this process takes place and I will end it with how we can move out of a state of trauma to one of wellness and healing.


Polyvagal Theory was first presented by Stephen Porges in 1994. The theory is based on the vagus nerve, which is located at the brain stem, and acts as our parasympathetic nervous system, innervates organs, and influences hormone secretions and digestion. The vagus nerve also operates our sense of safety, survival, and emotional shut down. Both the parasympathetic nervous system (vagus nerve) and the sympathetic nervous system are part of the autonomic nervous system, which is part of the peripheral nervous system. The autonomic nervous system regulates involuntary responses of the body. The parasympathetic nervous system is associated with immobilization and connection. It is also responsible for the rest and digest reaction that occurs when the body feels safe. It also regulates sleep, regeneration, and calms a person down after engaging in a stressful situation. The sympathetic nervous system is associated with mobilization and the fight or flight response. This is the system which produces cortisol to prepare us to either fight or flee in the event of a dangerous or stressful situation.

Trauma and the Autonomic Nervous System

When traumatic events take place the body goes into an involuntary reaction of fight, flight or freeze. Sometimes we can experience each of these reactions as different regions of the nervous system are activated. When we experience trauma we operate out of either the dorsal vagus nerve, which is responsible for freezing in the face of danger and is part of the parasympathetic nervous system or we operate out of the sympathetic nervous system which is responsible for the fight or flight response. To heal from trauma we need to activate the ventral vagus nerve which is part of the parasympathetic nervous system and is responsible for lowering the heart rate and the process of self soothing. We also need to have social engagement with our environment, other people, and ourselves. We need to engage with and reconnect with ourselves if we want to heal - this is the exact opposite of dissociating and immobilization.

Parts of the Autonomic Nervous System

Parasympathetic and Sympathetic

The parasympathetic nervous system, which is the vagus nerve, consists of two parts. The front of the vagus nerve, the ventral vagus nerve, and the dorsal nerve, which is the back of the vagus nerve. The dorsal vagus nerve is in the back of the brain stem and innervates into the gut. This nerve is responsible for gut feelings we can experience and refer to as intuition. The dorsal vagus nerve is responsible for several different reactions of the nervous system and our reactions to danger and trauma. These reactions include immobilization, emotional shut down; derealization and dissociation, and digestive issues such as irritable bowel syndrome. Other reactions of the dorsal vagus nerve are rest, digest, and sleep. This part of the vagus nerve will calm you down in moments of distress by dissociating from the environment and shutting down emotionally, this is known as the freeze response. Which part of the dorsal vagus nerve you are operating in (fight, flight or freeze) is dependent on which emotional state you reside in.

The ventral part of the vagus nerve goes around the front of the brain stem. It is attached to the ears, face, nose, throat, lungs, and larynx, and heart. It is essentially connected to everything above the diaphragm. When babies are born the ventral vagus nerve is not myelinated. The ventral vagus nerve becomes myelinated as a baby learns how to self soothe; this is taught by caregivers as the crying baby is nurtured and soothed. This process of self soothing is called the Social Engagement System and through it we learn how to engage in social environments and respond to stressful situations. The heart rate is actually lowered through the ventral vagus nerve as a baby masters how to self soothe and create a state of calmness.

The sympathetic nervous system is part of the autonomic nervous system but is not part of the vagus nerve. It is associated with mobilization, it addresses immediate danger by sending blood to muscles, increasing cortisol, and speeding up the heart rate to prepare the body to either fight or run from danger. The sympathetic nervous system is also associated with the mobilization that is needed to just get up and do things in everyday life.

Social Engagement System

The Social Engagement System is part of the ventral vagus nerve. Both parts of the vagus nerve enable an individual to calm down when triggered. The dorsal vagus nerve aids in calming down by causing immobilization and dissociation, the freeze response. The Social Engagement System calms us down in a more socially productive way. As I stated previously, the ventral vagus nerve is connected to organs above the diaphragm; the eyes, ears, nose, and voice are all intercepted by the ventral vagus nerve. Vocal tones and facial expressions are regulated and noticed in others through the Social Engagement System (SES). This system soothes us in distressing moments and overrides the stress response. While everyone has the potential to have a healthy SES not everybody does. The SES has to be myelinated in infancy in order to work properly. Myelination is defined as, “the process of forming a myelin sheath around a nerve to allow nerve impulses to move more quickly,” (, n.d.). In babies the SES is activated when a caregiver soothes a crying baby, overtime the baby learns how to soothe itself. At any age if someone experiences a traumatic event and is soothed immediately after the distressing event the SES is triggered through the ventral vagus nerve and the likelihood of that person developing PTSD is greatly reduced.

Activating the Social Engagement System

In the brains of healthy children neural pathways are formed which activate the Social Engagement System to prevent anxiety that can result in trauma. The child unconsciously envisions the face of a caregiver who would provide them with comfort in the advent of a stressful situation. A child who was not adequately soothed by caregivers will not possess these neural pathways and will experience anxiety with no conscious or unconscious sense of protection. If you did not experience adequate soothing by caregivers in childhood you can still access the SES by remembering the face of an individual who comforted you in a distressing moment and reduced your anxiety. Remember the interaction in as much detail as you can and remember the sensations you experienced as your anxiety faded away. If you do this in future stressful encounters you should see a reduction in anxiety and an innate knowing of your own ability to handle the situation productively.


Bunn, T. (2012). Using the social engagement system: Control flight anxiety with your most powerful regulation system. Retrieved from:

Cherry, K. (2020). How the peripheral nervous system works. Retrieved from

Schwartz, A. (2016). The neurobiology of Trauma-Dr. Arielle Schwartz. Retrieved from:

Wagner, D. (2016). Polyvagal theory in practice. Retrieved from:

Myelination. (n.d.). Retrieved from:

44 views0 comments

Recent Posts

See All