I think one of the most misunderstood things about this cranial nerve is that it has many different functions which SHIFT based on environment, external stimuli, personal internal capacity, our trauma history, and social situations.
1 – There is a social engagement portion that innervates ‘stuff’ above the diaphragm, this portion makes mammals and humans what they are (social creatures), and it also directly links to our heart to calm us when we are in connection to other human beings – unless that wiring was never correctly set up as a young one, and then we may feel scared of people and not have access to this function.
2 – There is a rest-digest portion that helps us slow down in a very soft and easy way, and helps us go into repair and regeneration mode after eating or when resting – unless our system is too much in survival mode, and only knows how to default to the next branch I describe.
3 – There is a shutdown/immobility portion that slows us down but in a fast, abrupt kind of way, like an emergency brake. It helps us disconnect and “freeze” in those rare situations where our system senses it is in mortal peril and we can’t do anything about it – but throw the reality of early/developmental trauma in there and the system will often learn to go directly to freeze when it encounters any stress at all (even the good kinds!).
The concept and suggestion that we can simply stimulate and “tone” this entire nerve so as to regulate and “heal” it, say with an electrical device or with a deep breathing exercise, is ill-informed to say the least. This superhighway of nerves is way too complex to respond well to a “do this and this will happen” kind of paradigm.
Sure, this simple “stimulus-effect” situation might work very well for some things in the human body, like if someone needs a shot of adrenaline when they are having an anaphylactic reaction, or maybe a 1st or 2nd degree burn on our finger from a hot stovetop, and then it is best to get cooling water or compresses on it to stop the burning and soothe it. But with the complex nature of our autonomic nervous system COUPLED with our higher brain capacities to override and dissociate all reality or physical sensory input, not to mention the diversity of how humans are raised in our socialized societies and the all too common reality of early/developmental trauma …. Well, I hope you can see that it is not that black and white, cut and dry, “stimulus-effect” when it comes to restoring regulation to a nervous system (and the entire human being) when perhaps they’ve never had regulation from the start.
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Since writing the above I have created a video where I go more in-depth into these points. Check it out below.
I share all this because the program curriculum in my online offerings acknowledges this complexity, and is designed to teach neurobiological regulation at ALL these vagus nerve – parasympathetic – levels.
**I’ve created a few pieces of content around the vagus nerve and the polyvagal theory:
Article + Video – The polyvagal theory explained
Article + Video – Polyagal and phylogentics in action: a simple example
Special Topic Lecture – All Things Polyvagal