#1109 - Matthew Walker

Joe Rogan (0:06)

And we're live.

What's going on? Did you sleep well last night?

Matthew Walker (0:10)

I did, I didn't sleep too badly. I mean, hotels are a tough thing.

And we actually know the science that one half of your brain will actually not sleep as deeply than the other when you're sleeping in an unusual room, like a hotel room.

Joe Rogan (0:25)

Really, that's what fucks me up. Because when I'm on the road, I'll do three different hotels in a week, because I'll do a Thursday, Friday, Saturday with gigs, and then by the time Sunday rolls around, I'm a mess.

Matthew Walker (0:38)

In rough shape.

Joe Rogan (0:38)

Yeah, is that what it is?

Matthew Walker (0:39)

Yeah, and it's a threat detection thing. I mean, if you look at other species, they can do this much more impressively than we can. So dolphins or any sort of sea dwelling mammal can actually sleep with half a brain.

So one half of their brain goes into deep sleep, the other half is wide awake.

Joe Rogan (1:00)

That's how people at the DMV do it.

Those people that work at the Department of Motor Vehicles, they work half asleep. You ever meet them?

Matthew Walker (1:08)

I haven't, no.

Joe Rogan (1:09)

Just teasing you. It's your DMV listening going, fuck you man, next time you come in to get your license renewed.

Matthew Walker (1:14)

There's my next NIH grant, I think, looking at the DMV in sleep.

Joe Rogan (1:18)

But yeah, TSA workers, same thing, same type of human.

Matthew Walker (1:21)

That I've come across.

Joe Rogan (1:22)

Yeah, them too. I'm just kidding, fuckers, relax.

So when you're in a hotel room, what is happening that half your brain is not really sleeping?

Matthew Walker (1:34)

Yeah, so there's different stages of sleep. There are two principal types. One is non-rapid eye movement sleep or non-REM sleep. The other is REM sleep, which is also known as dream sleep.

And non-rapid eye movement sleep is further divided into four separate stages, which are unimaginatively called stages one through four. We're a creative bunch of sleep researchers. It is true, but I think it's also our low IQ. But it's the deep stages of sleep, three and four of that non-rapid eye movement. That's where a lot of sort of body replenishment takes place, great for the cardiovascular system, metabolism, all of those good things. But that's the deep sleep that one half of your brain will resist going into when you're sleeping in a foreign environment. So it stays in this kind of lighter stage, almost like a threat detection system.

And you can imagine why, you know, it's an unusual context. Evolutionarily, it would make a lot of sense to just have that sort of on guard one half of the brain.

Joe Rogan (2:33)

That makes so much sense. And that really, for me, it fills in the blanks of like why, even if I get, you know, seven, eight hour sleep on the road, I'm still kind of just out of it.

Matthew Walker (2:44)

Yeah. And that's in fact probably one of the, I think the most impressive parts of new research on sleep. It's not just about quantity. It's also about quality.

And quality can be as detrimental if you don't get it as a reduction in total quality. I mean, both are essential, but I think it speaks exactly to your point. You just don't feel like it's a refreshing sort of deep sleep.

Joe Rogan (3:07)

Yeah, it feels totally different. It just feels like, I guess I would say, it feels like half a sleep. I mean, it's really kind of how it does feel. One of the things that I noticed, I did this thing with my friends called Sober October, where we didn't smoke any pot or do any, no drinking at all, nothing, for a month. And when I did it, one of the things I found was that after about, I don't know how many days, but it was noticeable that I would have these incredibly vivid dreams. And then I had read that marijuana does something to suppress heavy REM sleep.

Like, what is happening there?

Matthew Walker (3:46)

Yeah, so both of those chemicals, both of which are used as a sleep aid, alcohol and marijuana, are actually very good at blocking your dream sleep, your rapid eye movement sleep. And so what happens is that the brain is quite clever in this regard. It builds up a clock counter of how much dream sleep you should have had, but have not been getting.

And it starts to develop this increasing appetite and hunger for dream sleep, so that finally when the alcohol actually gets out of your system, sober October, that's all of a sudden where you get what's called a REM sleep rebound effect, where you not only get the normal amount of REM sleep that you would normally have, you get that, plus the brain tries to get back some of that dream sleep that it's been losing over the past maybe 11 months.