VIVA LAS VAGUS: NERVES BEYOND REASON
Every so often there’s a “new” thing for the movement and wellness field to buzz over … there were feet … then the mysterious core … the even more mysterious Psoas muscle … the totally described but not understood at all fascial system … and now we have The Vagus Nerve.
If you’re a movement teacher or therapist of some sort, here’s some relief: If your clients are leaving more often than not with a smile on their face and consistently returning to you and your space for more time together … you’re already working with the Vagus Nerve in a positive way.
THE END.
If you want more info on “what is” the vagus nerve and a relatively brief outline of its jobs (as concisely as I can skim over the details of neuroscience and being mammalian) … read on.
The nuts and bolts -
The Vagus Nerve is the tenth of twelve cranial nerves (CN X). It’s the longest running and most complex of the cranial nerves, stretching from the brain through the face, thorax, and abdominal regions. The vagus gets its name from its vagrant wandering demeanor as it branches throughout the body touching viscera / other nerves / and muscles. It’s between 80%-90% afferent, meaning that it brings information from the body (what it’s sensing and how it’s functioning) and delivers the information to the brain. If you’re familiar with the term “gut instinct” this is THAT nerve.
Two main branches -
The vagus nerve should really be called the vagus nerves, as there are two main branches, and many limbs that deviate off. The two main branches of the vagus nerve are:
The dorsal vagal complex - This is the most primitive branch of the nerve and it’s present in animals ranging from fish to lizards to humans. It’s tasked with things like keeping digestion going and primarily regulates sub-diaphragmatic viscera. This complex responds to cues of immense danger and mitigates keeping you alive. (Think of its mantra as: Am I in danger?)
The ventral vagal complex - Present in mammals and considered the “smart vagus” because it’s associated with the sympathetic nervous system (fight / flight). The ventral vagal complex affects the body above the diaphragm and connects with the cranial nerves that serve facial expression and vocalization, and it is the branch that serves the Social Engagement System (we’ll talk about soon). This complex responds to cues of safety. (Think of its mantra as: Am I safe?)
Three stages of being -
Without getting too complex and risking not only losing your attention but my credibility as I try to describe things that are over my pay grade (it happens) … I’ll do my best to introduce you to three neural circuits of the autonomic nervous system.
Decades ago the terms fight / flight entered into our vernacular. They describe being scared or frightened, and sensing the need to run away or fight, and referred to the sympathetic nervous system. The terms rest / digest were then added as the counterpart, and described the parasympathetic nervous system. Meaning that either we were in a fight mode or a relaxed restful mode. It’s a very simplistic way of understanding Para/Sympathetic autonomic nervous system function, but it works in a pinch.
Dr. Stephen Porges coined the term Polyvagal Theory describing many vagal nerve branches (dorsal / ventral complexes) that have a sophisticated range of neural circuitry responses that allow us “to be” a number of different ways, including some specific to being human. He notes that there is a hierarchy to the autonomic nervous system that is an evolutionary adaptation. Here is a brief introduction to what he considers to be the role of the vagus nerve response systems:
Immobilization - It’s the oldest pathway and involves the immobilization (freeze) response. This stems from the primitive dorsal vagal complex that is designed to keep us safe and alive in the face of danger. Here it is as if our parasympathetic nervous system kicks into hyperdrive and we are immobilized / frozen due to lack of safety and a great perception of danger.
Mobilization - The Polyvagal Theory suggests this was the next evolutionary step in our autonomic nervous system. Within this response we tap into our sympathetic nervous system (fight / flight). We mobilize when we don’t feel safe, spring into action when needed, and call our Self into readiness.
Social Engagement - This circuitry response is uniquely mammalian (as far as science knows), and is the latest development in the hierarchy of responses. This response stems from our ventral vagus nerve, and specifically the highly myelinated portions of that ventral vagus nerve around the heart and through the face and ears. This system allows us to connect with people and our environment / feel anchored and secure / calm / engaged / and communal.
I want to be clear when I say that these response circuitries exist on a hierarchy and are NOT a balanced state. They are also highly dependent upon our personal history with fear / trauma / feeling safe / etc.. There are shades and textures to the responses ranging from all out frightened (imagine being pinned down by a mountain lion and what you response may look like), to scared (thinking someone is following you), to uncomfortable (going to a party you’d rather not be at) … all the way to the perception of total safety (lying in a comfortable bed in the space you love with someone you adore). Our responses to stimuli (environmental and internal alike) depend upon our comprehensive personal history and our unique history with the present stimuli to distinguish whether we perceive the stimuli as safe or unsafe, and whether we feel fear or not. (I don’t know, maybe someone out there LOVES to be pinned down by mountain lions and that would register as very safe and social … while someone else might find it highly immobilizing to consider lying in bed with anyone at all)
Dr. Porges named the ability for our neurophysiology to identify and interpret danger through the vagal complex “neuroception.” Neuroception explains why we view certain situations and people as either safe / dangerous / or life-threatening, and why we make subconscious autonomic unaware decisions about these situations and people in an effort to keep our Self safe and alive before we’ve made conscious decisions about the situation or person. The important point to consider is that this neurophysiologic process of neuroception (detecting un/safety) is happening at a subconscious level and often without cognitive reasoning (sometimes in spite of cognitive reasoning). We are constantly evaluating risks through our senses, and our nervous system guides us to be either pro-social or defensive in the face of situations and people, without “reasoning.”
Because our autonomic nervous system exists on that hierarchy and is full of textures (immobilization / mobilization / social engagement) how we experience feelings of un-safety and safety come in a spectrum ranging from very private sensations like rapid heart beating and muscle tension, to overt public displays like trembling, sweating, dizziness and even fainting. We may have a gut response to danger - accurately or doubtful. Contrastingly when we feel safe we may simply metabolically adjust or we may communicate more effortlessly and/or play together freely. Regardless of how we symptomize the experience of neuroception, it is a physiologic response to how we perceive our world around us to be - safe or not / real or imagined - that then tunes our state of being to either one of defensiveness or actively pro-social, or somewhere in between.
If your students are consistently leaving with a genuine smile (a pro-social signal of engagement) and returning to your space to spend more time with you (demonstrations of interpreting both you and your space as being safe) … you’re doing good Vagal Toning work, and maybe ya’ didn’t even know it!
You now have some science to share or lean into whether you are a teacher or student … or just someone interested in human-ness.
Next week I’ll expand on some of the ideas introduced here, and we’ll go into WHY this might all be important … and give some ideas as to HOW we can all begin to feel better and do better when we increase our self-security.
HOMEWORK: Click here to listen to Stephen Porges talk about the Vagus Nerve
~ james CRADER
