Dr. David Eagleman

And the way we keep looking at it in science currently is, ah, here's acetylcholine or here's serotonin or so on.

And it's probably not the right way to look at it.

It's certainly not how the neurons are looking at it.

Okay.

That said, acetylcholine really feels to me like the main one involved in plasticity when you are –

a baby, you've got acetylcholine going everywhere whenever you're trying to figure out the world, whenever something's not matching a prediction and you've got acetylcholine going everywhere that says, hey, I gotta figure out what just happened and how to link this with what I did and so on.

As you get older,

It's more like a pointillist artist who just dabs things here or there.

You get acetylcholine release very locally in small places, and that's where you make changes.

Why?

That's because as you get to be an adult, you've got a better and better model of the world.

You don't want to change everything.

You just change like, oh, I didn't realize there was that button on the coffee machine that did this new thing or whatever.

So you just change little bits at a time here.

We're in this really interesting situation in the history of our species where now we can do things like, hey, what if we just crank up acetylcholine?

Obviously, we've done lots of things with dopamine.

We always find when we tweak these things that it's complicated.

Just as one example, with Parkinson's, people have less dopamine, and so the medications are to crank up the dopamine.

What that led to, you may know this fascinating story, it's probably 25 years ago now, where

You know, observant clinicians noted that people on these Parkinson's medications were becoming hypercompulsive gamblers.