Andrew Huberman

override some of those spindle mechanisms, even the GTO mechanisms, but especially the spindle mechanisms at the neuromuscular and muscular spinal junction.

I'll give you a brief example of this that you've already done in your life and that we all have the capacity for.

What I'm referring to is the monosynaptic stretch reflex.

This is something that every first year neuroscience graduate student learns, which is that if you were to step on a sharp object with a bare foot, you would not need to make the decision to retract your foot.

You would automatically do that, provided you have a healthy nervous system.

There are mechanisms in place that cause the retraction of that limb by way of ensuring that the proper muscles contract and other muscles do not contract.

In fact, that they fully relax, okay?

So in the case of stepping on a sharp object, like a piece of glass or a nail or a tack, you would essentially activate the hip flexor to lift up your foot as quickly as possible.

In doing so, that same neural circuit would activate a contralateral meaning opposite side of the body circuit to ensure that the leg, the foot that's not stepping on the sharp object would do exactly the opposite and would extend to make sure that you don't fall over.

All of that happens reflexively.

It does not require any thought or decision-making.

However,

if your life depended on walking across some sharp objects, let's say, let's make it a little less dramatic.

So it's not like the diehard movie or something where he has to run barefoot across the glass.

Although that's a pretty good example of what I'm describing here.

But let's say you had to walk across some very hot stones to get away from something that you wanted to avoid.

you could override that stretch reflex by way of a decision made with your upper motor neurons, your insula and your cognition, and almost certainly those van Economo neurons, which would be screaming, don't do this, don't do this, don't do this, could shuttle that information to brain areas that would allow you to override the reflex and essentially push through the pain.

And maybe even, in fact, even not experience the pain to the same degree or even at all.

So these van Economo neurons sit at a very important junction within the brain.

They pay attention to what's going on in your body, pain, pleasure, et cetera.