Dr. Matthew Walker

Those are very important for logical, rational thinking and decision-making.

Those parts of the brain went down in their activity, almost as though they were suppressed during REM sleep, dreaming.

So now let's go back to our map.

You're having a visual experience.

It's filled with movement and memories and emotions.

But it's utterly bizarre, completely illogical, and totally irrational.

If that's not a perfect neural definition of this thing called dreaming, I don't know what is.

And I should mention, by the way, that your dreams based on those brain scans still remained your own.

You were the only person privy to the experience of the dream itself.

I could stick you in a scanner and I could say, you know, were you having a visual dream and was it, you know, filled with motor activity and emotions and memories?

That tells me how you're dreaming.

It doesn't tell me what you're dreaming.

So at that point, you still had this degree of security and privacy.

No longer, it seems.

There was a great study done by a Japanese group using very advanced brain imaging technology and techniques such as multi-voxel pattern analysis.

Again, word salad.

But it's a very clever technique.

And they were able to start to understand exactly what you, Andrew Huberman, were dreaming.

And they would know what you were dreaming even before you woke up and told us what you were dreaming.

And they did a two-part experiment.