Polyvagal Theory by Dee Wagner
Stephen Porges’ polyvagal theory developed out of his experiments with the vagus nerve. The vagus nerve serves the parasympathetic nervous system, which is the calming aspect of our nervous system mechanics. The parasympathetic part of the autonomic nervous system balances the sympathetic active part, but in much more nuanced ways than we understood before polyvagal theory.
Our three-part nervous system
Before polyvagal theory, our nervous system was pictured as a two-part antagonistic system, with more activation signaling less calming and more calming signaling less activation. Polyvagal theory identifies a third type of nervous system response that Porges calls the social engagement system, a playful mixture of activation and calming that operates out of unique nerve influence.
The social engagement system helps us navigate relationships. Helping our clients shift into use of their social engagement system allows them to become more flexible in their coping styles.
The two other parts of our nervous system function to help us manage life-threatening situations. Most counselors are already familiar with the two defense mechanisms triggered by these two parts of the nervous system: sympathetic fight-or-flight and parasympathetic shutdown, sometimes called freeze-or-faint. Use of our social engagement system, on the other hand, requires a sense of safety.
Polyvagal theory helps us understand that both branches of the vagus nerve calm the body, but they do so in different ways. Shutdown, or freeze-or-faint, occurs through the dorsal branch of the vagus nerve. This reaction can feel like the fatigued muscles and lightheadedness of a bad flu. When the dorsal vagal nerve shuts down the body, it can move us into immobility or dissociation. In addition to affecting the heart and lungs, the dorsal branch affects body functioning below the diaphragm and is involved in digestive issues.
The ventral branch of the vagal nerve affects body functioning above the diaphragm. This is the branch that serves the social engagement system. The ventral vagal nerve dampens the body’s regularly active state. Picture controlling a horse as you ride it back to the stable. You would continue to pull back on and release the reins in nuanced ways to ensure that the horse maintains an appropriate speed. Likewise, the ventral vagal nerve allows activation in a nuanced way, thus offering a different quality than sympathetic activation.
Ventral vagal release into activity takes milliseconds, whereas sympathetic activation takes seconds and involves various chemical reactions that are akin to losing the horse’s reins. In addition, once the fight-or-flight chemical reactions have begun, it can take our bodies 10–20 minutes to return to our pre-fight/pre-flight state. Ventral vagal release into activity does not involve these sorts of chemical reactions. Therefore, we can make quicker adjustments between activation and calming, similar to what we can do when we use the reins to control the horse.
If you go to a dog park, you will see certain dogs that are afraid. They exhibit fight-or-flight behaviors. Other dogs will signal a wish to play. This signaling often takes the form that we humans hijacked for the downward-facing-dog pose in yoga. When a dog gives this signal, it cues a level of arousal that can be intense. However, this playful energy has a very different spirit than the intensity of fight-or-flight behaviors. This playful spirit characterizes the social engagement system. When we experience our environment as safe, we operate from our social engagement system.
Trauma’s effect on nervous system response
If we have unresolved trauma in our past, we may live in a version of perpetual fight-or-flight. We may be able to channel this fight-or-flight anxiety into activities such as cleaning the house, raking the leaves or working out at the gym, but these activities will have a different feel than they would if they were done with social engagement biology (think “Whistle While You Work”).
For some trauma survivors, no activity successfully channels their fight-or-flight sensations. As a result, they feel trapped and their bodies shut down. These clients may live in a version of perpetual shutdown.
Peter Levine, a longtime friend and colleague of Porges, has studied the shutdown response through animal observations and bodywork with clients. In Waking the Tiger: Healing Trauma, he explains that emerging from shutdown requires a shudder or shake to discharge suspended fight-or-flight energy. In a life-threatening situation, if we have shutdown and an opportunity for active survival presents itself, we can wake ourselves up. As counselors, we might recognize this shift from shutdown to fight-or-flight in a client’s move from depression into anxiety.
But how can we help our clients move into their social engagement biology? If clients live in a more dissociative, depressed, shutdown manner, we must help them shift temporarily into fight-or-flight. As clients experience fight-or-flight intensity, we must then help them find a sense of safety. When they can sense that they are safe, they can shift into their social engagement system.
The body-awareness techniques that are part of cognitive behavior therapy (CBT) and dialectical behavior therapy (DBT) can help clients move out of dissociative, shutdown responses by encouraging them to become more embodied. When clients are more present in their bodies and better able to attend to momentary muscular tension, they can wake up from a shutdown response. As clients activate out of shutdown and shift toward fight-or-flight sensations, the thought-restructuring techniques that are also part of CBT and DBT can teach clients to evaluate their safety more accurately. Reflective listening techniques can help clients feel a connection with their counselors. This makes it possible for these clients to feel safe enough to shift into social engagement biology.
Specific aspects of ventral vagal nerve functioning
Porges chose the name social engagement system because the ventral vagal nerve affects the middle ear, which filters out background noises to make it easier to hear the human voice. It also affects facial muscles and thus the ability to make communicative facial expressions. Finally, it affects the larynx and thus vocal tone and vocal patterning, helping humans create sounds that soothe one another.
Since publishing The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication and Self-Regulation in 2011, Porges has studied the use of sound modulation to hierarchytrain middle-ear muscles. Clients with poor social engagement system functioning may have inner ear difficulties that make it hard for them to receive soothing from others’ voices. As counselors, we can be conscious of our vocal patterns and facial expressions and curious about the effects those aspects of our communication have on our clients.
Based on his understanding of the effects of the vagus nerve, Porges notes that extending exhales longer than inhales for a period of time activates the parasympathetic nervous system. Porges was a clarinet player in his youth and remembers the effect of the breath patterns required to play that instrument.