Today we will go a little deeper in trauma. Dr. Stephen Porges developed Polyvagal theory to expand our understanding of how the nervous system responds to threat and trauma.
In our last post we briefly talked about the nervous system and it's role in trauma. Dr. Porges added a third factor: the vagus nerve. The vagal nerve plays a role in regulating the heart, face, stomach, and breath. The nerve also communicates with the brain. When talking about the nervous system, we will need to use some anatomical terms to orient ourselves:
Ventral: towards the front of the torso. The navel (belly button) is on the ventral or anterior part of the body.
Dorsal: towards the back of the torso. For example, the shoulder blades are dorsal or posterior to the ribs.
The vagus nerve, or more specifically the ventral branch of the vagus nerve, controls the muscles of the face. The face, heart, and lungs are all used when we interact with others (e.g. smiling or making eye contact, feeling our heart beating faster, using our lungs to speak and breathe). This is what Dr. Porges calls "social engagement". In other words, it is through our face, heart, and brain connection that we learn to respond to interpersonal threats and challenges. Let's use a worst-case scenario as an example of how this works. Imagine this: you are walking down a dark alley alone and you see a dark shadow in the distance approaching you. Your face (eyes, nose, and ears) capture the image, hear the footsteps, and smell any scents or aromas in the air. Your brain takes in all the information your sensory organs are sending and tries to make sense of the shadowy figure. As this takes place, your heart begins pumping a lot harder to disperse blood flow to your muscles just in case you need to fight or make a run for it (flee/flight) from this unfamiliar and potentially dangerous shadowy figure. So what just happened? Your vagal nerve was working in overdrive, working hard as gatekeeper of your body's responses to the environment, moderating a conversation between your brain and body during a moment of possible danger. Another branch of the vagus, the dorsal vagus, regulates organs below the diaphragm (e.g. stomach, intestines). The dorsal vagus activates what we call "shutting down" during overwhelming trauma.
Polyvagal theory emphasizes that our nervous system has more than one defense strategy and whether we use fight-or-fight or shut down, is not a decision we actively decide to use. But if we are trapped, or feel unsafe, our nervous system reads those cues and makes a decision from there. I should note these responses were adaptive to the environment or situation that an event or trauma occurred at a moment in time. This is where Somatic and Attachment-focused EMDR (Eye Movement Desensitization Reprocessing) can really help clients identify these patterns and work WITH the vagal responses to process painful memories and heal. Somatic and Attachment-Focused EMDR or SAFE EMDR model is compatible in treating most psychiatric diagnoses including but not limited to PTSD, trauma, anxiety, and depression.
This concludes our discussion about the neurobiology of trauma. If you or a loved one have any questions, would like further information on EMDR, or would like to set up an appointment. Please feel free to give me a call at 904.404.1763.
Amy Pope-Latham, LCSW is a clinical psychotherapist in Ponte Vedra Beach, FL.