Dr. Michael Kilgard

And the psychologist knew this.

You ring a bell, you feed the dog, the dog starts to salivate.

So these classic experiments by Ivan Pavlov simply show that the brain can change.

Why does the salivation change?

Because of a ringing bell.

Because that's the thing that leads to this event being useful.

It's useful to the dog to prepare for this activity.

And so you condition this particular synapse to be strengthened.

Where normally bells just ring.

Dogs don't care about bells.

Bells don't matter.

It's just a church.

It's just the end of the hour.

Ignore it.

But if over time you repeatedly teach, then you make this change.

When we teach undergraduates what does acetylcholine do, we will sometimes say it's the memory neurotransmitter.

And when we say what does norepinephrine do, we'll sometimes say it's the attention one.

And we say what does dopamine do, we'll sometimes say it's the reward one.

And we say what does serotonin do, we'll sometimes say it's the mood one.

And there's reasons for that.