Nervous System Foundations 07 What is the Polyvagal Theory

In this video,

We're going to go over the polyvagal theory.

The polyvagal theory expands on our knowledge of the autonomic nervous system and the vagus nerve.

So far,

We've talked previously about the autonomic nervous system and the parasympathetic and sympathetic nervous systems.

The polyvagal theory adds a third system or a third layer to the autonomic nervous system.

Poly is the Latin word for many,

And vagal is the word referring to the vagus nerve.

So the polyvagal theory was introduced in the in the 90s by a scientist named Dr.

Stephen Porges.

As we evolved from invertebrates,

Our nervous system has become more and more sophisticated and more and more complex.

And so with that,

As has our autonomic nervous system.

So what Porges has theorized is that we have three vagal or three autonomic nervous system components,

The first of which is what we would call the dorsal vagal complex.

So this is the most primitive part of our vagus nerve and our autonomic nervous system,

And it developed around 500 million years ago when we were totally invertebrates.

The main response to danger as an invertebrate or when we use our dorsal vagal system is to freeze and to play dead.

That's the best bang for your buck when it comes to survival when you're in the dorsal vagal mode.

This part lives in the dorsal part of our brain,

So the most primitive part of our brain.

Complex number two is the sympathetic complex,

And this is the complex that we're familiar with in the fight or flight system in the sympathetic nervous system.

And as we evolved,

This came into play around 400 million years ago.

So this was a little bit more of an evolution,

A little bit more of a sophistication on the and its primary response to danger or threat is to fight or to flight.

So to fight,

Combat said threat,

Or to run away from the threat.

So active,

Activating.

Previously,

We had lumped fight,

Flight,

And freeze all into the sympathetic complex,

Whereas the polyvagal theory theorizes that the freeze aspect is actually a much more primitive response that's been around much longer than the sympathetic response has.

So the third complex here,

The third layer to this is the ventral vagal system.

And this is our most sophisticated aspect of our nervous system and of the autonomic nervous system.

And this developed around 200 million years ago as humans became what we are.

And as we transitioned to upright mammals,

Our more parasympathetic responses started to come online.

So the ventral vagal complex tends to be the more parasympathetic responses in our gut and in our body.

So this is said to live more in the gut and in the ventral stomach aspects of the human being.

So this is to say that as we have evolved and become more complex,

As have our survival strategies.

So our survival strategies 500 million years ago were to just freeze.

400 million years ago,

We developed the ability to fight and to flee from danger.

And then 200 million years ago,

We actually developed the ability to be calm and connect with others for survival.

So the polyvagal theory states that as we go about our day,

We're typically hovering somewhere between a ventral vagal,

Sometimes a bit of a sympathetic response.

And we typically have the ability to bounce back and forth between these efficiently and eloquently.

And as we become triggered to a threat,

Then what happens is the more of a threat and the more triggered we become,

The more primitive the response becomes to that threat.

So if I'm exposed to a threat and I'm starting to revert to something a little more primitive,

I might go into more of a sympathetic response.

So this is where I become more activated.

I'm ready to run.

I'm ready to fight.

However,

If I continue to become more and more and more triggered,

I might actually go into an even more primitive manifestation of that.

And I might just totally freeze and shut down.

So in this phase,

This is where systems actually start to shut down and the opposite of a fight or flight response starts to happen.

So in our more primitive iterations of life,

That response to danger was to freeze and to collapse,

To survive.

And as we become more sophisticated,

We've learned to fight,

We've learned to run.

And as we continue to develop evolutionarily,

We learned that connection and presence and love and community became the best way to survive.

And this is how we began to form tribes and families.

And as this became more sophisticated,

Our ventral vagal system became the more predominant strategy for survival.

So it's an amazing system when you think about how evolutionarily we've developed these more sophisticated iterations of it.

So the polyvagal theory describes that the more threatened we become,

The more primitive our response becomes.

And the most primitive of that is to freeze and collapse.

And our least primitive,

Our most sophisticated is human connection and community.

So I hope that that is a helpful understanding of the polyvagal theory.

Thanks for listening.