Science of Breath Part 1: Intro to Polyvagal Theory

Written by Melissa Hemphill

Breath is a simple and wondrous thing. We often take it for granted because it doesn’t require our conscious awareness. When we consider its life-sustaining function and how long we can survive without it; the gravity of its importance is clear. One can survive without food for about three weeks, without water for about three days, and without oxygen for about three minutes. If we prioritize our lives around (1) breath, (2) hydration, (3) nourishment, and (4) movement, we might find ourselves thriving and not simply surviving. In this three part blog series, we will investigate the science of breath and how the simple action of becoming present to your breath can change everything.

The vagus nerve has been labeled the parasympathetic nerve throughout history. It is largely responsible for signalling primitive, life-sustaining functions like metabolism, growth, and repair. This nerve is part of the Autonomic Nervous System (ANS) as its functions are more or less automatic and believed to be outside of our conscious control. The ANS is still taught as existing in two mutually exclusive states: Sympathetic (fight or flight) and Parasympathetic (rest and digest). This overly-simplified explanation had been widely accepted until the research of Dr. Stephen Porges offered an evolutionary perspective of both the vagus nerve and the ANS called the Polyvagal Theory.

The Polyvagal Theory analyzes the structural and functional differences of the three branches of the vagus nerve. Over the course of time, we have evolved a collective sense of safety. With new environmental circumstances came new phylogenetic circuits. Briefly, those are: Socialization (most recent; shared with mammals), Mobilization (traditional sympathetic system of fight or flight), and Immobilization (most primitive; shared with invertebrates). What’s super cool is that each circuit responds differently in states of safety vs. threat.

We are designed to live in the “safety” side of vagal activation 80% of the time. It’s when safety is threatened that we respond. The greater the threat, the more recent circuits are abandoned for more primitive ones. For example, your partner cancels your dinner plans last minute. You may respond with your socialization circuit by entering into negotiation, defensiveness, maybe even some passive-aggressive comments. In another example, your partner reveals they have been cheating on you. A calm discussion may be inaccessible. Instead, you may be more inclined to mobilize (physically fight, throw objects, or run away). In our last example, “freezing” during a sexual assault is the most primitive response in times of extreme threat: immobilization. Doing nothing wasn’t a conscious choice; it was your body’s best strategy for survival. 

On the flip side, when we live in safety, these circuits enable creative and wondrous ways of being. In safety, the socialization circuit fosters play, consent, and sensuality. In safety, the mobilization circuit enables eustresses like working out, sex, and active labor. In safety, the immobilization circuit fosters digestion, metabolism, growth, repair, and orgasm.

This juxtaposition is not intended to say “safety = good; non-safety = bad.” We cannot escape threats and stresses in this life. It’s a losing battle. But what we CAN do is train our range of motion and resiliency; our ability to move between these different vagal activations. We can do this by using our powerful tools of breath, sound, and movement, which will follow in Parts 2 and 3 of this Science of Breath Series!