Dr. Matt Walker

So think about it.

You're on the beach.

And when you're awake, the waves are coming in very, very quickly, but the small waves.

And they're coming in in a random fashion.

But deep, slow-wave sleep are these kind of epic things that would happen in Hawaii, where you just get these 20, 30-foot waves.

And they're coming in very slowly, but they are epically big.

That is deep, slow-wave sleep.

And then what happens is riding on top of those big slow waves are these sleep spindles.

They just keep coming.

So according to the sort of the sleep sonification project, what you would hear now, these slow waves would be... That's the slow wave and the sleep spindle.

What is it that happens in your brain though to your question to produce these slow waves?

Well, let's go back to the football stadium analogy.

There before the game, that's wakefulness.

Everyone is having a different conversation in a different part of the stadium and you just get this kind of incoherent sort of blabber that's going on.

That's wake.

Your brain is doing different things at different sort of locations of the brain processing, different information at different moments in time.

And that's the fast frenetic activity of wakefulness.

When you go into deep sleep, all of a sudden, for reasons that we still don't quite understand, hundreds of thousands of brain cells in your cortex all decide to unite in their singular voice of firing.

And they all fire together and they all go silent together.

They all fire together and they all go silent together.