The body’s rapid-response survival system is orchestrated by our autonomic nervous system (ANS). To briefly review, the ANS operates two branches: the sympathetic and the parasympathetic. The sympathetic branch mobilizes us to defend against danger via the fight or flight or cry/attach for help response. The somewhat less understood parasympathetic branch is typically viewed as having the opposite effect on the body, helping us dampen our defences and regain a state of balance and calm.
But, as they say, it’s a bit more complicated than that. The parasympathetic system is made up of the vagus nerve which runs from the brain through the face and thorax to the abdomen. It branches into two major pathways, each responsible for a distinct neurophysiological state. One pathway, known as the ventral vagal, responds to cues of safety and supports restoration, procreation and readiness for social engagement. By contrast, the dorsal vagal pathway responds to cues of life-threat, causing us to shut down, become numb, and disconnect from others. A person who dissociates has found refuge in a dorsal vagal state.
While simplistic, it can be helpful to understand that the ANS is more than just the oscillation between the state of “fight or flight” and “rest and digest”. In fact, as we go about our day the ANS is constantly shifting between these states (+ hybrids!) continually working to bring about regulation and homeostasis to the body.