The Dreaming Brain with Matt Walker

What’s the real difference between dreaming and waking consciousness? Neil deGrasse Tyson and co-hosts Chuck Nice and Gary O’Reilly sit down with sleep expert Matt Walker to answer fan questions about the most mysterious thing humans do every single night: sleeping & dreaming.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  I'm a little sleepy.

• 0:02Gary O'Reilly?

  Well, I have the solution for that. We're about to talk to sleep expert Matt Walker.

• 0:07Neil deGrasse Tyson?

  Matt Walker?

• 0:08Gary O'Reilly?

  Yeah.

• 0:08Neil deGrasse Tyson?

  Second time on the show.

• 0:10Gary O'Reilly?

  Mm hmm.

• 0:10Neil deGrasse Tyson?

  Looking forward to that.

• 0:11Chuck Nice?

  Hmm, I'm looking forward to a nap now.

• 0:14Neil deGrasse Tyson?

  Coming up on StarTalk Special Edition.

• 0:19Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:32Neil deGrasse Tyson?

  This is StarTalk Special Edition, which means I got Gary O'Reilly here.

• 0:38Gary O'Reilly?

  Hi Neil.

• 0:39Neil deGrasse Tyson?

  All right, and Chuck Nice, baby.

• 0:40Chuck Nice?

  That's right.

• 0:41Neil deGrasse Tyson?

  And we've been calling you the Lord of Nice, not just Lord Nice.

• 0:44Chuck Nice?

  The Lord of Nice.

• 0:45Neil deGrasse Tyson?

  Lord of Nice, very nice. So Gary, we're talking about sleep today, I'm told.

• 0:50Gary O'Reilly?

  Yes.

• 0:50Neil deGrasse Tyson?

  Which is people spend like a third of their life doing just that.

• 0:53Gary O'Reilly?

  I know.

• 0:54Chuck Nice?

  If you're lucky.

• 0:55Neil deGrasse Tyson?

  If you're lucky.

• 0:56Chuck Nice?

  If you're lucky.

• 0:57Neil deGrasse Tyson?

  If you don't have kids, you spend a third of...

• 0:59Gary O'Reilly?

  There you go.

• 1:00Chuck Nice?

  I mean, I sleep like absolute dog crap, so.

• 1:04Neil deGrasse Tyson?

  I don't know what that means, but.

• 1:07Gary O'Reilly?

  Can you guess?

• 1:08Neil deGrasse Tyson?

  I haven't checked how much dog crap sleep. So what do you got for the show today?

• 1:11Gary O'Reilly?

  All right, sleep, as we've decided, is an inescapable part of our daily lives. Um, it's weird. It can transport us into a psychotic state. It can even leave us experiencing time dilation. Uh, it can heal us. It's, um, anyway, the last time we had a sleep expert on, our audience were very, very impressed. And so it's been a couple of years in the making, but we have brought him back along with Neil, our audience's curiosity. So we're gonna have some questions from our audience tagged on to our conversation.

• 1:44Neil deGrasse Tyson?

  Nice, nice, nice. Okay.

• 1:47Gary O'Reilly?

  Yeah.

• 1:47Neil deGrasse Tyson?

  So let us introduce our returning champion, sleep champion, our returning guest, Professor Matt Walker. Matt, welcome back to StarTalk.

• 1:56Speaker 03

  It's lovely to be back, gents. Thank you so much for having me.

• 1:59Neil deGrasse Tyson?

  Excellent. And we last we caught up with you, you were at UC Berkeley, just tearing down the house. And, but you've got new digs. What's the latest with you?

• 2:07Speaker 03

  I have, I have shifted. I am now a professor of neuroscience and biomedical engineering at UT Dallas at the Center for Brain Health. And here I'm starting a new center for advanced brain performance and sleep innovation. So I thought I would try and mix it up a little bit and, uh.

• 2:24Neil deGrasse Tyson?

  Wait, wait, wait. Advanced brain performance while you're sleeping? Or is that a separate thing from sleeping?

• 2:30Speaker 03

  It's 24 hour. So we're going to try to augment the human brain both when we are wide awake as well as when we are sleeping.

• 2:37Neil deGrasse Tyson?

  Okay, now you're spooking me out here.

• 2:40Chuck Nice?

  Look at that.

• 2:41Neil deGrasse Tyson?

  The word augment, I think, is what spooks me a little bit.

• 2:44Chuck Nice?

  He's gonna make sleep zombies.

• 2:46Gary O'Reilly?

  We have those already.

• 2:48Chuck Nice?

  Exactly.

• 2:50Neil deGrasse Tyson?

  You've also been a TED Talker and, and you've got the podcast, the Matt Walker Podcast. You couldn't be a little more creative than that?

• 3:01Speaker 03

  I know, it took years to come to that creative decision. I mean, there was the, the, the marketing there, the research dollars spent just to come up with that task. You know, I mean, it was, I thought it was borderline genius. There's so much go, there's so much going on in that title, isn't there really? The depth of it, which, which reflects my own personality. I am, um, I am desperately, um, shallow, but I have a very deep surface.

• 3:24Neil deGrasse Tyson?

  There you go.

• 3:26Chuck Nice?

  Desperately shallow with a deep surface.

• 3:28Gary O'Reilly?

  See, what he did there.

• 3:30Neil deGrasse Tyson?

  So what we wanna know is what, you know, it's been a couple of years. What's some new sleep research over those couple of years? And what a lingering question that I've just always had is, why do we need sleep at all? Is it, is it too early in the show to start off with that question?

• 3:48Gary O'Reilly?

  You went there.

• 3:49Neil deGrasse Tyson?

  I did, I kinda went there. Because I, I think about aliens, if they visit us, and then you say, excuse me, Mr. Alien, I have to lie down horizontally and go semi-comatose for one third of Earth's rotation. I'll be back to you. The alien might just look at you like, what the hell's wrong with you? And so could, could you reflect on this so that when the alien comes, I'll have an excuse?

• 4:15Speaker 03

  Arguably the best question I've ever received in my entire career. Let me try. So I, but I love the way that you frame it, because imagine the birth of your first child and the doctor comes into the room, they say, congratulations, healthy baby girl. Everything looks good, we've done all the tests. And they're walking out the room and just before they exit, they turn around to you, maybe like the alien, and they say, there is just one thing, though. From this moment forward and for the rest of your child's entire life, they are going to lapse into a state of non-consciousness. It's going to look like death, but don't worry, it's reversible. And whilst their body lies still, their mind will be filled with bizarre hallucinogenic experiences. And we have absolutely no idea why this happens.

• 5:00Speaker 03

  Good luck, take care, all the best.

• 5:03Chuck Nice?

  Well, I, my response would be, I'll have what the baby's having.

• 5:08Chuck Nice?

  Yeah, sign me up for that. That sounds really damn good.

• 5:13Speaker 03

  But it's, it's so perplexing because from an evolutionary perspective, sleep is the most idiotic of all behaviors. You're not finding a mate, you're not reproducing, you're not foraging for food, you're not caring for your young, and you're vulnerable to predation. On any one of those five grounds, sleep should have been strongly selected against in the course of evolution, unless it serves an absolutely vital set of functions. And 50 years ago, to your question, we used to say, well, why do we sleep? And the best answer we had was we sleep to cure sleepiness, which is the idiotic equivalent of saying that we eat to cure hunger. No, you eat for all sorts of physiological reasons.

• 5:53Speaker 03

  Now, 50 years later, based on the wealth of the data, we've had to upend the question and ask, is there any major physiological system of your body? Or is there any operation of your mind that isn't wonderfully enhanced by sleep when you get it? Or demonstrably impaired when you don't get enough? And so far, the answer seems to be no. And we can dive into the different functions, but I would say to your first part of the question, what's kind of fresh and new or just amazing? I would say two things. The first, we've been looking at what we call genetic short sleepers. So these are people who, based on the evidence, can get away with as little as about

• 6:34Speaker 03

  five to six hours of sleep and show no impairment in their brain or their body. Whereas everyone else, it's a nosedive, like a dart into the ground in terms of functions.

• 6:44Neil deGrasse Tyson?

  I fear I may be one of those, by the way, Matt, because I'm completely content with five and a half hours of sleep.

• 6:51Chuck Nice?

  Yeah, but you can also sleep anywhere at any time.

• 6:54Neil deGrasse Tyson?

  That's true.

• 6:54Chuck Nice?

  Yeah.

• 6:55Speaker 03

  Ah, that's a, that's a giveaway, actually.

• 6:58Neil deGrasse Tyson?

  Don't keep describing, because then he's gonna have a word for it. And I worry when, anytime to have a word for something I do.

• 7:05Chuck Nice?

  It's called a Tyson nap.

• 7:08Speaker 03

  I was going to say, we call it chronic, uh, sleep deprivation, but I mean, if you can actually fall asleep rapidly almost anywhere, sometimes we wonder, is there a lingering sleep debt somewhere in the system? Where you have such a pressure for sleep that literally you can sleep, you know, within a heartbeat? That tends to wanna bring a few sort of warning bells. But, but I mean, most people like you, Neil, would say, I wonder if I'm one of those sleepers. Just to put it in context, statistically, based on the evidence, you're more likely to be struck by lightning in your lifetime than you are to be one of these genetic short sleepers. The probability of which is, is very small.

• 7:48Gary O'Reilly?

  Have you been struck by lightning?

• 7:49Neil deGrasse Tyson?

  No, he didn't say both would happen to you. He's comparing two separate statistical facts.

• 7:55Chuck Nice?

  Maybe that's the progression. You get struck by lightning and then you can't go to sleep anymore.

• 7:59Gary O'Reilly?

  That's it.

• 8:01Neil deGrasse Tyson?

  That is not what the man said. Okay, Matt, continue.

• 8:05Speaker 03

  That's what we call augment, augmenting the human brain with a bolt of lightning.

• 8:09Gary O'Reilly?

  Yeah.

• 8:09Neil deGrasse Tyson?

  And there's at least one movie on that, the phenomenon with, uh, John Travolta.

• 8:13Gary O'Reilly?

  Yeah.

• 8:13Neil deGrasse Tyson?

  Yes, he's hit by lightning and he turns out into, he turns completely brilliant.

• 8:17Chuck Nice?

  Get out.

• 8:18Neil deGrasse Tyson?

  And he can predict earthquakes and move stuff with his hands and things.

• 8:21Speaker 03

  But we're actually just coming back to, we're doing a mini version of that. We've actually developed, um, a headband which inserts a small amount of voltage into the brain. And it's so small, you typically don't feel it, but it has a measurable impact on your brainwaves. And what we've managed to do is create a stimulation, um, protocol. We just wear it for 10 minutes before bed and it's like a child on a swing. They're moving their feet and nothing happens. But if you start pushing them and giving them some momentum, at some point you can stop pushing them and they keep swinging. And that's what we're doing with the brain. We're sort of singing in time with your electrical brainwaves and we're amplifying those brainwaves. Almost, it's almost like, um, electrically fertilizing the soil on your prefrontal cortex.

• 9:05Speaker 03

  So that when you go into sleep, you germinate more powerful, deep, slow brainwaves. So it's, it's quite far away from John Travolta's experience in terms of the voltage magnitude, but not dissimilar. But coming back to the short sleepers, sorry, I keep losing track. What this tells us is something absolutely remarkable. Not just that this exists and there's a genetic modification for it, but it means that somewhere along the way, Mother Nature has figured out how to zip file sleep.

• 9:36Speaker 03

  She's been able to essentially compress eight down into six. And if we can start to find out the mechanisms and when digging into this now, we think you've got some good understanding as to how these genetic sort of mutants are able to accomplish this short of sleep. What that means is that maybe think about, you know, a world of CRISPR and gene editing. Could it be that at some point, everyone selects to be a genetic short sleeper?

• 10:02Chuck Nice?

  Let me ask you this, Matt, based on what you just said. Is it possible that the genetic anomaly, this mutation?

• 10:10Neil deGrasse Tyson?

  Don't call me a mutation.

• 10:13Chuck Nice?

  Is it possible that mutant Tyson, the Tyson mutant? The Tyson mutant gene?

• 10:20Gary O'Reilly?

  He turned him into an X-Man.

• 10:26Chuck Nice?

  The most obscure X-Man ever. Tyson, what's your power? Watch. Ah, I just slept eight hours. Okay. Okay.

• 10:36Speaker 03

  That's so cruel to you. I'm so sorry.

• 10:38Neil deGrasse Tyson?

  No respect.

• 10:39Chuck Nice?

  Okay. Is it possible that when you find this anomaly, that you may not be able to make that a reality for every other person? Because sometimes genes are expressed in sets, not just one particular gene, especially when it comes to mutations like that.

• 11:00Speaker 03

  Yeah, so the, the nice thing is that we've been able to identify exactly which specific gene. In fact, there are actually, right now, there are four of these genetic short sleeping genes. If you want to select from the sort of catalog menu that I'm sure is going to be on offer any time in the next 10 years, maybe go for what's called the DEC2 gene, D E C two gene. It's one of the shorter sleeping genes, genetic mutations. But yes, you don't have to run into that problem because of the selectivity and specificity of the gene identified. You can go right in there.

• 11:32Chuck Nice?

  Are you serious? I mean.

• 11:35Gary O'Reilly?

  He's a professor, of course he's.

• 11:37Chuck Nice?

  Hey, Matt, this is all I'm saying. I'm gonna email you offline. I need in on this. This, I mean, do you know how much money you're sitting on? Like, people, people don't, like, you don't need stimulants, you don't need, like, you're actually getting what you need in the amount of time that you're supposed to get it. You just shorten what the brain, the time the brain needs to regenerate for that coming day. That's insane.

• 12:02Speaker 03

  Exactly. Isn't that amazing as a concept?

• 12:05Gary O'Reilly?

  Yeah, absolutely. Do we take this to the nth degree and say, well, we can reprogram our brains to need no sleep at all?

• 12:12Chuck Nice?

  Ooh.

• 12:13Gary O'Reilly?

  Is that, is this the sort of, is that too far out or is that achievable?

• 12:17Chuck Nice?

  That's too weird.

• 12:18Speaker 03

  It's interesting concept.

• 12:21Chuck Nice?

  Would you want to stay up 24 hours a day, seven days a week if you could? Now, believe me, I used to do meth, so I've done it. But thank you for laughing at that, Matt, because these two are just as silent as church mouses right now.

• 12:33Speaker 03

  Tumbleweeds. I can see them across the screen right now.

• 12:36Chuck Nice?

  We're not laughing at your meth jokes, Chuck, I'm sorry.

• 12:38Neil deGrasse Tyson?

  He's in Texas now to, gets to reference tumbleweed.

• 12:41Chuck Nice?

  I know.

• 12:41Neil deGrasse Tyson?

  You see, that's how that works.

• 12:44Speaker 03

  But would I want to? I don't know. There's something magical about the state of, A, the deep sense of relaxation and restoration that I feel when I come out of deep sleep, but also dreaming. I would be so sad to lose the optionality of dreaming. So I don't think I would.

• 13:15Speaker 04

  Hey, this is Kevin the Sommelier, and I support StarTalk on Patreon. You're listening to StarTalk with Neil deGrasse Tyson.

• 13:30Neil deGrasse Tyson?

  Before we go to Q and A, because with, with, this is a, this is a queries episode, right?

• 13:35Chuck Nice?

  Yes, it is.

• 13:36Gary O'Reilly?

  Yeah.

• 13:36Neil deGrasse Tyson?

  Yes, it is.

• 13:37Gary O'Reilly?

  From our Patreon members.

• 13:37Chuck Nice?

  From the Patreon people.

• 13:38Neil deGrasse Tyson?

  And because you know they're thinking about sleep. So there's the value of sleep as a restorative force on our bodies and minds, perhaps. But then, what is the value of dreaming? And, and is that any different from daydreaming?

• 13:54Speaker 03

  Oh, yes, it is, based on the architecture of the, based on the patterns of brain activity. They're not quite the same thing. But to your first part of the question, what does dreaming do? And we have to be clear, what does dreaming do above and beyond the stage of sleep that it comes from? So we have too many types of sleep, non-REM sleep and REM sleep. And most dreaming comes from REM sleep or rapid eye movement sleep. And it's not just whether you have REM sleep. REM sleep has a series of different physiological functions, but dreaming on top of REM sleep also has selective benefits, and there are at least two.

• 14:34Speaker 03

  The first is that dreaming provides a form of informational alchemy, which is that every morning when you wake up, having gone through dreaming, you wake up with a revised mind-wide web of associations. Because it's during dreaming that we take all of the information that we've recently learned, and we collide it with this back catalog of information that we've stored up across a lifetime. And we don't start to make the obvious connections during dreaming. That is what we do when we're awake. Dreaming is biased towards building the more distant, non-obvious associations.

• 15:10Neil deGrasse Tyson?

  So the whole thing is, they say, sleep on it.

• 15:13Chuck Nice?

  Yeah.

• 15:13Gary O'Reilly?

  Right.

• 15:14Neil deGrasse Tyson?

  That's where you get that phrase from, sleep on it.

• 15:16Speaker 03

  Correct. How many times has someone ever said to you, you know, Neil, you should really stay awake on a problem?

• 15:21Chuck Nice?

  Right.

• 15:22Speaker 03

  No one tells you that.

• 15:23Neil deGrasse Tyson?

  No one says that.

• 15:23Speaker 03

  They tell you to sleep on a problem. And that's exactly one of the functions. It's almost, it's like group therapy for memories. Everyone gets a name badge, and then dream sleep gathers all of these sort of people, and it forces you to speak to the people at the back of the room that you don't think you've got any association with whatsoever. But when you do, you find it's a distant, non-obvious connection. Because when you start to fuse things together that shouldn't normally go together, but when they do, they cause a marked advance in evolutionary fitness, that sounds like the basis of biological creativity. And so that's one of the functions of, of dreaming.

• 15:57Chuck Nice?

  Well, it would have to be, especially when you have associations like a zebra in women's lingerie smoking a cigar while drinking a martini. How do you actually relate that to anything in your life?

• 16:08Gary O'Reilly?

  Tell me that.

• 16:09Chuck Nice?

  Not that I had that dream.

• 16:10Gary O'Reilly?

  Was it a friend?

• 16:11Chuck Nice?

  Not that I had that dream.

• 16:13Neil deGrasse Tyson?

  A friend, a friend of yours.

• 16:14Chuck Nice?

  Yeah.

• 16:14Neil deGrasse Tyson?

  A friend of yours told you.

• 16:15Chuck Nice?

  I'm just saying it.

• 16:17Speaker 03

  You know, there's, there's very few sleep questions that have ever left me dumbfounded.

• 16:24Speaker 03

  However.

• 16:25Neil deGrasse Tyson?

  So let's get to the questions. We have a bunch of questions here.

• 16:27Gary O'Reilly?

  With Matt's explanation about dreaming, then to take sleep out of our lives completely wouldn't make any sense at all, would it?

• 16:36Speaker 03

  No, especially because, and I mentioned, the, the second function is perhaps even more relevant to, to that want of keeping it, which is that dreaming provides a form of overnight therapy. Dreaming is emotional first aid. And it's during dreaming at night when we take difficult, sometimes painful experiences, and dreaming acts like a nocturnal soothing balm, and it just takes the sharp edges off those painful, difficult memories, so that you come back the next day and you feel better about that experience.

• 17:09Neil deGrasse Tyson?

  I got one, I'll tell you what happened to me. The night of September 11th, 2001, I'm four blocks from the collapse of the towers. And so I have to get my family out.

• 17:21Chuck Nice?

  I was gonna say, you were still, you, go ahead.

• 17:22Neil deGrasse Tyson?

  No, no, it was, it was, it was traumatic. I, I maintained composure.

• 17:28Chuck Nice?

  Right.

• 17:28Neil deGrasse Tyson?

  But it was traumatic.

• 17:30Chuck Nice?

  Yeah.

• 17:30Neil deGrasse Tyson?

  I get my two kids, one is nine months old, one is four and a half, and I collect my wife in Midtown, because we live downtown, and, and we went up to my parents in Westchester, New York, okay? Very safe distance from, and they were running trains in one direction.

• 17:45Chuck Nice?

  Yeah.

• 17:46Neil deGrasse Tyson?

  But they weren't taking people back in, okay?

• 17:47Chuck Nice?

  Right.

• 17:48Neil deGrasse Tyson?

  So, the reason why I'm saying this is, at the end of the day, I went to sleep and I woke up 11 hours later. And I, I was astonished, because it didn't feel like 11 hours, but I'm, I'm echoing your point. My brain had to process what the hell just happened.

• 18:12Chuck Nice?

  Exactly.

• 18:12Neil deGrasse Tyson?

  And that was more than a day's worth of content, I would, I would say. And so is it just the easy explanation here that my brain wasn't ready for me to wake up yet? It was still processing all this disparate content that didn't happen in a typical day?

• 18:30Speaker 03

  We see this time and time again, whether it's whether you're learning vast amounts of information that requires memory consolidation and the cementing of new information to the architecture of the brain, or that you've had difficult emotional experiences. There is a selective drive and a demand from your brain and your body to get more sleep to see if it can reconcile the weight of the kind of burden of life that you've given it that prior day. And so it fits exactly, I think, with with your experience. You know, there's a beautiful, an American entrepreneur, E. Joseph Cusman, had a wonderful phrase. He once said that the best bridge between despair and hope is a good night of sleep.

• 19:12Speaker 03

  And I would say that in the past 20 years of studying sleep and mental health, we have not been able to discover a single psychiatric condition in which sleep is normal. And I think that tells me everything that I need to know about the intimate relationship between your sleep health.

• 19:29Neil deGrasse Tyson?

  Your body knows.

• 19:30Speaker 03

  And your mental health.

• 19:31Neil deGrasse Tyson?

  You were saying your body knows.

• 19:33Chuck Nice?

  Hmm. That explains a lot about me. Thank you, Matt.

• 19:37Speaker 03

  You're very welcome.

• 19:37Chuck Nice?

  I'm understanding myself much better now.

• 19:39Speaker 03

  It's just a therapy session here.

• 19:40Gary O'Reilly?

  Shall we dive in?

• 19:41Neil deGrasse Tyson?

  Exactly. Send us the bill for that. Let's get some Patreon questions.

• 19:46Gary O'Reilly?

  Okay, Matt. Sit up straight. Here we go. Ronald, great name, Ronald Nigel McWilliams from Selma, Alabama. Thank you for what you do. You're welcome. Thank you for being one of our Patreon group. Let's put the glass on. If the brain can generate a fully immersive reality during dreams without external input, what does that reveal about waking consciousness? Are dreams just neural noise? Or do they expose that what we call reality is always a controlled construction of the brain? Would sleep revealing the machinery more clearly? That's quite a deep one.

• 20:22Chuck Nice?

  That's quite a big one.

• 20:24Neil deGrasse Tyson?

  Just to understand the question, is it that the brain is processing your awake state? I was gonna say your woke state, but that's that's got baggage today. Okay, your awakened state. And does your brain know that that is an objective reality versus what it dreams about? Is that is that where he's trying to get at here?

• 20:46Chuck Nice?

  I think what he's saying is that no, all of reality is a perception of our brain.

• 20:51Neil deGrasse Tyson?

  Yeah.

• 20:51Chuck Nice?

  So when we go to sleep, does that kind of perceptive reality then just become neural noise? Or does it serve a purpose to reveal the machinery more clearly?

• 21:06Neil deGrasse Tyson?

  That was good. That was good, Chuck.

• 21:07Speaker 03

  Great question. Wonderful synopsis. I would say what this question to me reveals is an uncomfortable truth about your dreams, which is that your brain can build an entire universe. So space, time, faces, emotions, memory, narrative, coherent, out of nothing. There's no light hitting your eyes. There's no sound. There's no world. You're cut off from reality. But in the dark of this thing that we call our skull, it is manufacturing a fully convincing reality, and it does it every single night. And that has an implication.

• 21:49Speaker 03

  Because if the brain can do it when essentially the doors are closed, what makes you so sure that what you experience when your eyes are open?

• 21:59Neil deGrasse Tyson?

  Don't mess with us like that now. Stop messing with us.

• 22:03Speaker 03

  I'm gonna have to go further because the reality is, it actually isn't any different than that. So what we call reality right now is also a construction. It's a model that your brain is building behind your eyes. And the only difference is that the waking perception is, it's almost like a controlled hallucination, one that's essentially tethered to time, second by second by second. And that information is streaming from your senses. That's the only difference between your waking consciousness and your dreaming consciousness.

• 22:38Neil deGrasse Tyson?

  My name is Neo.

• 22:44Neil deGrasse Tyson?

  Yeah, you're coming in and out of the matrix there, just in case you don't know.

• 22:48Speaker 03

  Programs, hacking programs.

• 22:49Neil deGrasse Tyson?

  Yes.

• 22:50Speaker 03

  But no, so it's a wonderful demonstration that I think there's, there are these hard boundaries that we think of that are actually much more porous than we imagined. That there's this thing called the dreaming state and the waking state. They're very similar in some ways, except that dreaming has a feature to it that really gives it away, which is that you have no logical, rational reasoning or control. And that's why you start to believe things which are not there. So you hallucinate, you are delusional, you get confused about time, place, and person. You're suffering from disorientation. And then how wonderful, you wake up in the morning and you forget most, if not all of that dream experience.

• 23:34Speaker 03

  So you're suffering from amnesia. If you were to experience any one of those five things when you're awake, you'd be seeking some psychological treatment. But for reasons that we now understand based on the patterns of brain activity when you go into dreaming, this seems to be a normal biological and psychological process. And the principal reason that dreams are the way that they are is because the thing that makes us most human, which is called the prefrontal cortex, that part of the brain, unlike the rest of the brain, the brain lights up when you go into REM sleep. In fact, some parts of your brain are 30% more active than when you're awake, which is nothing except for the prefrontal cortex. That goes offline.

• 24:16Speaker 03

  So now you have these emotional centers, these memory centers, the visual centers, the motoric centers of the brain, they're all active. But the kind of the prison guards, they've left the building. And the prisoners are running amok. And that's the beauty of dream sleep. There is no sort of CEO in control with top-down regulation. There's no logical, rational control.

• 24:41Chuck Nice?

  The inmates are running the asylum.

• 24:43Speaker 03

  Yeah. Basically, that's exactly what it is. And we believe that there's good utility to that. That's where you get kind of the loosey-goosey, everything starts to get connected together in these wacky, strange ways. No wonder you can solve problems in your sleep in a way that you can't with this very rigid way of thinking that is the waking state.

• 25:04Gary O'Reilly?

  Wow. Now you've scared me.

• 25:06Chuck Nice?

  Yeah, that's, however, that's.

• 25:08Neil deGrasse Tyson?

  So your dreams were the world's first psychologist, first of all, right?

• 25:12Speaker 03

  They were. Exactly. It is your therapist.

• 25:14Neil deGrasse Tyson?

  Yes, your therapist.

• 25:15Gary O'Reilly?

  Yeah, you're in a therapist.

• 25:16Neil deGrasse Tyson?

  You're a therapist.

• 25:18Chuck Nice?

  Well, what you just said there, Matt, actually answered Aaron Gannon's question as well. So Aaron, thank you for your question. So let's move on to Sam, who says, greetings, Dr. Tyson, Lord Nice, Gary, and Mr. Walker. My name is Sam, and I'm writing to you from the home of Casey Jones, Jackson, Tennessee.

• 25:40Neil deGrasse Tyson?

  Is that right?

• 25:41Chuck Nice?

  Ah, look at that. He says, I recently read a study by Laura Lewis from the Boston University about cerebral spinal fluid washing the brain during sleep.

• 25:52Neil deGrasse Tyson?

  Ooh.

• 25:53Chuck Nice?

  My question is, Dr. Walker, could the waves of cerebral spinal fluid that wash through the brain during sleep actually be generating the dream state rather than the other way around? And if so, what does that mean for what we think dreams are for? Thank you for your time and consideration. Live long and prosper. Well, thank you, Sam, you big nerd.

• 26:21Neil deGrasse Tyson?

  All right.

• 26:22Chuck Nice?

  Well, I mean, just just generally, what is this cerebral spinal fluid? And its relation to sleep? Because Sam has already read the study. We have not. So maybe if you start there, we'll be able to unfold an answer for him.

• 26:37Gary O'Reilly?

  Does it have any validity?

• 26:39Chuck Nice?

  Well, that's that, that, you know, whatever you know about it, does it have?

• 26:42Speaker 03

  An immense amount of validity. I think it's one of the most stunning new discoveries in the field of sleep.

• 26:47Chuck Nice?

  Wow.

• 26:48Speaker 03

  It is, we used to think that the brain didn't have its own cleansing system. The body did, which is called the lymphatic system. We've known that for several centuries, in fact. But then a scientist at the University of Rochester, Macon Nedergaard, made an incredible discovery working in mice. First, she found out the brain does have a cleansing system. It's called the glymphatic system, named after the cells that make it up called glial cells. The second thing that she discovered is that this cleansing system, which uses cerebrospinal fluid, this sort of, it's almost like the WD-40 of the brain, it uses the cerebrospinal, terrible, it uses cerebrospinal fluid to essentially flush out all of the metabolic detritus that builds up during the waking day. And that was her second discovery.

• 27:32Speaker 03

  This glymphatic washing cycle is not switched on in high-flow volume across the 24-hour period. It's only when you go into sleep, and specifically, deep sleep, and this will come back to Sam's question. It's only when you go into deep sleep that this cleansing system kicks into high gear. So it's good night's sleep clean. It's a power cleanse for the brain. The final thing that she discovered, which makes it really relevant for disease states, is that two of the pieces of metabolic detritus that the glymphatic system cleanses when you go into deep sleep are beta amyloid and tau protein. These are the two underlying culprits of Alzheimer's disease. And it explained why for now of over 10 years, and we've done some of these early studies,

• 28:15Speaker 03

  we were seeing a very strong relationship between people who were getting less than six hours of sleep across the lifespan and a markedly higher risk for developing Alzheimer's. But it was an association in search of a mechanistic causal answer. And she discovered it. And we've now actually developed a silent fMRI, science MRI scanning protocol. And we're having people sleep inside the MRI scanner. And we can now see this pulsing cleansing system in real time.

• 28:44Chuck Nice?

  Wow.

• 28:44Speaker 03

  As people are sleeping in the scan. It's absolutely beautiful. But it actually comes back to Sam's question, though, which is, it turns out that dreaming comes from principally a different stage of sleep. It comes from rapid eye movement sleep, whereas this glymphatic system happens during deep, non-REM sleep. So the two are disconnected.

• 29:04Chuck Nice?

  But while we're here, because we keep. Referencing stages of sleep. I think it'd be nice to have a baseline and you give us the actual stages of sleep. And how many cycles would that happen throughout the night, these stages themselves?

• 29:21Speaker 03

  So when everyone's head hits the pillow tonight, you're going to go on this incredible roller coaster ride in and out of different stages of sleep. And as I mentioned, we have two main types of sleep, non-REM sleep and REM sleep. Now, non-REM sleep has been further subdivided into four separate stages, unimaginatively called stages one through four, increasing in their depth. So stages three and four, that's that really deep restorative sleep. So what happens is that when you fall asleep, you go into the light stages of sleep and then you go down into the deeper stages of non-REM sleep. And after about 70 or 80 minutes, you'll start to rise back up and you'll pop up and you'll have a short REM sleep period.

• 30:04Speaker 03

  And then you go down again, down into non-REM sleep and then up into REM sleep. And you do that, on average, about 90 minutes is each cycle's length. What changes, however, is the ratio of non-REM to REM within that 90 minute cycle as you move across the night. And what I mean by that is, in the first half of the night, the majority of those 90 minute cycles are comprised of lots of deep non-REM sleep and very little REM sleep. But as you push through to the second half of the night, that titter totter bounce, that shifts. And now, more of that 90 minute cycle is comprised of REM sleep, dreaming sleep, and very little deep sleep. And that's the reason if you've been woken up from a phone call at sort of 1 o'clock in the morning,

• 30:48Speaker 03

  you almost never remember a dream. But if it's late in the morning, sort of 5, 6, 7 in the morning, and you get woken up, typically, that's when you'll remember a dream because you're moving into the REM sleep-rich phase of your night of sleep. Does that make some sense?

• 31:03Chuck Nice?

  Absolutely.

• 31:04Neil deGrasse Tyson?

  By the way, I discovered these cycles when I was in college and I was studying my sleep cycles. And so, 90 minutes is a bang-on unit of time for me. If I don't have time to do five and a half hours, 90 minutes, I don't even need an alarm.

• 31:20Chuck Nice?

  So you got an hour and a half and you go back out.

• 31:22Neil deGrasse Tyson?

  Correct. And I have several of these throughout the night, which are hugely useful when you were apportioning the times of day where you gotta get stuff done versus when you're gonna go to sleep.

• 31:34Speaker 03

  But I would say though, to your point, Neil, I love the fact that you can almost get that quartz-like precision. There is a bit of a myth though, that I say, on average, it's 90 minutes. It can be as little as 70 minutes and it can be as long as 120 minutes, depending on who you're studying.

• 31:51Neil deGrasse Tyson?

  Got it. I'm not 120. If I wake up after 120, I'm groggy. But if I wake up after 90, I'm not.

• 31:59Speaker 03

  Perfect, because you've gone down into the deep stages of sleep again.

• 32:03Neil deGrasse Tyson?

  I discovered this empirically is my point. You know how I did it? Did I say this the last time?

• 32:09Chuck Nice?

  Are we going back to my meth joke?

• 32:10Neil deGrasse Tyson?

  No, no, no, no. So what I did was, I drank like, you know, half a gallon of water.

• 32:19Chuck Nice?

  That's the Native American alarm clock.

• 32:20Neil deGrasse Tyson?

  And then I went to sleep. And then, throughout the night, I woke up to go pee. But my body woke itself up to go pee and those were bang-on to the cycles. When I'm in deep REM, it doesn't wake me up. So I made note of those timings. And then that's how I used to... So that's just me, I don't know. I'm the one who was hit by lightning, apparently.

• 32:44Chuck Nice?

  Well, I've done the same thing, except it's just my failing prostate.

• 32:50Gary O'Reilly?

  Did you need to share?

• 32:53Speaker 03

  What I love about it is, you spoke a little bit about if I go past that 90 minute mark and I then wake maybe an hour and...

• 33:02Neil deGrasse Tyson?

  It doesn't work.

• 33:03Speaker 03

  45 minutes, it doesn't work. Because as you said, we've gone down to that other cycle. And when you come out of deep non-REM sleep, that's very unusual. Your brain never naturally does that. And what happens is that when you go into deep sleep, a large amount of cerebral space, particularly your frontal cortex and other areas, they all go power down. And it's almost as though when you come out of deep non-REM sleep, you try to go from the basement to the penthouse and you get stuck on the 13th floor and you get this grogginess, it's almost like a sleep hangover effect. And it's just, it's what we call sleep inertia. And when you come out of deep sleep, it takes much longer for the brain, like a classic car engine, for example. It just needs time to gradually warm up before it gets to operating temperature.

• 33:48Speaker 03

  Which uses, I was just about to go... I love it, you know, simpatico.

• 33:53Neil deGrasse Tyson?

  So...

• 33:54Speaker 03

  You and me, Neil.

• 33:55Neil deGrasse Tyson?

  The value of this to me is, often I take very early airplane flights. So I gotta leave home at 4 to catch a 6 o'clock plane. If I'm up till midnight or something, or if I'm working, I can combine two one and a half hours, that's three hours. I'm not gonna go to sleep at midnight and wake up at 4. Because that's out of sync, right? So I will stay up another hour so that I'll wake up on another...

• 34:24Chuck Nice?

  And you'll come out of the cycle at the right time.

• 34:26Neil deGrasse Tyson?

  At the right time. And so, sometimes it's staying up another 15 minutes or 20 minutes or a half hour. And so, this works with precision, thank you. What's the term you use? Quartz, quartz precision, I love that.

• 34:37Speaker 03

  Quartz-like precision. But I would say that people sort of have this, you've got to be a bit careful for these kind of gadgets that say, "I'll wake you up at the perfect moment", because they all assume the average 90 minute cycle. But the problem is, no one is the average.

• 34:50Neil deGrasse Tyson?

  Well, I'm the average, but yeah.

• 34:51Speaker 03

  Except, except the sublimely extraordinary, but yet average. Can you all digress now?

• 35:00Gary O'Reilly?

  Feel better now?

• 35:03Neil deGrasse Tyson?

  Next question.

• 35:04Gary O'Reilly?

  All right, we've got Kenny McFarlane. McFarlane, really precious about pronunciation. Kenny's from Washington DC and thank you Kenny for sharing your own personal story here. We're gonna get the thoughts of Matt. As a kid, I experienced a number of parasomnia's, sleepwalking, sleep terrors, nightmare disorders, sleep paralysis. Still some occur. Why do we grow out of these conditions? Why do some seem to go away and others continue to be consistent? Does our brain chemistry change and that allows for them to cease? Or better, what does experiencing parasomnia's tell us about our brain chemistry? Thanks for taking the question, you're welcome.

• 35:47Gary O'Reilly?

  And he cites himself as an all-too-lucid dreamer.

• 35:51Speaker 03

  Ooh, wow. So much going on in the question. Okay, I'll try and be efficient, but what Kenny's describing are the parasomnia's. So these are parasomnia's, these are things that happen sort of in and around sleep, but aren't quite sleep itself. So sleepwalking, sleep talking, night terrors. People often think that if someone is sleepwalking or they go over to the refrigerator, they open the door, they kind of have some... That they must be dreaming and they're just acting out their dreams. That's actually not the case. When you have a sleepwalking or sleep talking event, sleep eating event, what's happening is that your brain is in the deepest stages of non-REM sleep and we can record it and we can see people walking around enacting these, what seem like complex behaviors.

• 36:32Speaker 03

  But the brainwaves look like deep, slow brainwave sleep. And what they're doing is simply acting out fairly routinized, just simple kind of more sort of basic motor behaviors. And if you wake people up, and typically you shouldn't, you should just sort of make sure that they're safe, but just let them go through it. But if you wake them up and you say, "What was going through your mind just before I woke you up?" And they'll say, "Nothing, my mind was blank." And the reason is because they were in deep, dreamless sleep. They weren't having a dream.

• 37:04Neil deGrasse Tyson?

  So going to the refrigerator is different from asking to start a game of chess, right? Where you said that they tend to do routine, you know, open the window.

• 37:15Speaker 03

  Exactly, yeah.

• 37:16Neil deGrasse Tyson?

  Something that is very repeatable.

• 37:20Speaker 03

  Yes, yep, these are... This is not sort of... Well, some people have enacted things such as they get in their car and they actually drive. But most of this happens much lower down the sort of the food chain of basic behaviors. However, sleep paralysis is something a little bit different. And I will get to Kenny's question as to why does it change as we get older? Why do we have less of these events? But sleep paralysis is a beautiful demonstration of how normally two things go lockstep, hand in hand, which is that as we're waking up, well, let me go back. When you go into dream sleep, your brain paralyzes your body so your mind can dream safely.

• 38:02Speaker 03

  So every time you go into dreaming, there's a signal sent down your spinal cord and it paralyzes all of the voluntary muscles. Not the involuntary ones that keep you breathing, but the voluntary muscles that you use to kind of reach over and grab a glass. All of those are paralyzed. But normally, when we're waking up out of a dream, your consciousness, as it's starting to return to you, as that's starting to come up, the paralysis is gradually released in perfect lockstep, so that you wake up and you can move and you can talk and you don't even think twice about it. Sleep paralysis happens where your consciousness gets a little bit ahead of its skis and you're starting to wake up, but you've not been released from the paralysis.

• 38:47Speaker 03

  So you can't move, you can't talk, but you're aware of your surroundings. And typically, this happens with a sense of something else or someone else being in the room. And it turns out that if you look at all of the characteristics of sleep paralysis, they often explain quite a large majority of so-called alien abductions, correct? Because when was the last time anyone here heard this news story? You know, they were saying, "Today in downtown Dallas, Jimmy was just whooshed away by aliens." You know, "We were sitting around the board table and all of a sudden, whoosh, Jimmy was gone." It never happens like that. It's usually at night, when we're in bed. People described that the aliens injected them with a paralyzing agent. They couldn't move, they couldn't talk, they couldn't fight them off.

• 39:32Speaker 03

  This is classic sleep paralysis. And so this is one of the other features. It's not sleepwalking or sleep talking. It's a distinctly different sort of component of this broad collection of things that we call the parasomias. Why do these things, however, change as we get older? Well, it turns out that the boundaries between sort of waking consciousness and these sleep events is quite porous when we're young. And in part, it's because of the prefrontal cortex developing. The more that your prefrontal cortex develops, the more capable your brain is of creating hard boundaries between being awake and being asleep. But when we're younger, because of that prefrontal cortex not yet being fully matured,

• 40:16Speaker 03

  the states have been very much kind of awake and conscious versus being very much asleep and non-conscious, they're a little bit more sort of free-flowing. And that's why you can have intrusions of essentially wakefulness into sleeping states. And that's what we call parasomias. Now, as we get older, we can still maintain some of these things. And I think Kenny is describing that he still has some of these things too. That's fine. It doesn't mean that there's anything necessarily wrong with you as long as it's not causing safe issues.

• 40:48Chuck Nice?

  It just means that your prefrontal cortex never developed, Kenny.

• 40:53Speaker 03

  Not saying that at all.

• 40:54Chuck Nice?

  You have no executive function, Kenny. I'm sorry to tell you, Kenny.

• 40:58Gary O'Reilly?

  You're not medically trained enough to die.

• 40:59Chuck Nice?

  That's what Matt said, Kenny. Matt just told you.

• 41:01Speaker 03

  Kenny, you're fine. Kenny, you are absolutely golden. As long as, as long as there's no safety concerns, you are A.O.K.

• 41:08Chuck Nice?

  However, wouldn't it, wouldn't it depend on how old Kenny is? Because from what I understand, the prefrontal cortex and executive function is the very last thing to harden in the development of the brain.

• 41:18Speaker 03

  It is. And that's why essentially these things can even be extended into late teenage years. And I would say to Kenny's question too, I think he mentioned, sort of, is it something about the chemistry of the brain? It's not really the chemistry of the brain. It's the structural architecture of the brain that's changing. And that's why those episodes will start to dissipate the further into adulthood we go because of the structural development rather than the chemistry itself. By the way, stress and sleep deprivation, both of those markedly increase the probability of those parasomnia clustering events happening, just as an FYI.

• 41:55Chuck Nice?

  Interesting.

• 42:16Chuck Nice?

  All right, here we go. This is Anna Ivinco. And Anna says, "Hi, Dr. Tyson, Dr. Walker, Lord Nice and Gary. Greetings from Croatia." My name is Ivinco and I have a question about the importance of sleep scheduling.

• 42:29Neil deGrasse Tyson?

  Ooh.

• 42:30Chuck Nice?

  I work as a doctor in the emergency medicine department and my shifts are as follows. 12 hours, day shift, 7:00 a.m. to 7:00 p.m., night shift the next day, 7:00 p.m. to 7:00 a.m., and then one day of rest. Often, I work two day shifts and then a night shift for two nights and then a day shift. How to preserve? How do I preserve my circadian rhythm and therefore my physical and mental health on this job? I really like my job, but I also want to live long. Longtime fan and recent Patreon patron. And yeah, so why don't you go ahead, Matt, and tell Ivinco that she is screwed?

• 43:07Neil deGrasse Tyson?

  No, would you stop?

• 43:10Chuck Nice?

  She needs a union, that's what she needs. You need sleep, you need a union, girl! You need sleep!

• 43:15Speaker 03

  Anna, Anna, Anna, oh my goodness, okay.

• 43:18Neil deGrasse Tyson?

  But first, start off, what is a circadian rhythm?

• 43:20Speaker 03

  Circadian rhythm is simply a rhythm that lasts approximately one day. So circadias, sort of essentially the circling of one day of time. So that's your circadian rhythm. We all have one. And it's almost like this sinusoidal sort of wave where we are more awake throughout the day because we are a diurnal species. And then our biology ramps down as we go throughout the night and then we step and repeat it. And you have a circadian rhythm. It's driven by a 24-hour clock in your brain and it just beats out that beautiful 24-hour rhythmic pattern.

• 43:52Neil deGrasse Tyson?

  Okay, briefly, I heard that they took people underground and took away all their watches and had them just live their own understanding of day and night. And when they did this, they lived 25-hour days. They didn't live a 24-hour day, none of them? So that we might be fighting our own rhythms by staying with the sun? Are you familiar with that study? Was it replicated? What was that about?

• 44:17Speaker 03

  It is. It's been one of the most replicated findings. And rather than think of it that we're fighting our biology, it's simply that our biology has a little bit of sort of error margin in it. And it simply needs the sun, which has been the most consistent signal since the dawn of time for a rhythmic circadian rhythm. And it latches on to the sun. And the sun acts like a set of fingers on a wristwatch. And it simply just kind of tweaks your 24-hour rhythm back to precisely 24 hours each and every day.

• 44:51Neil deGrasse Tyson?

  Okay, so we're not fighting a 24-hour day. We, the sun tunes us to it. And without the sun, our circadian rhythm gets sloppy.

• 45:01Gary O'Reilly?

  It's a little Rayword.

• 45:02Speaker 03

  It does. It runs, on average, for most people, it runs about 24 hours and about 11 minutes. So it's different for different people, but on average, that's the... So you drift forward in time by a little bit each and every day.

• 45:17Chuck Nice?

  So we need a, we need a leap rhythm.

• 45:19Neil deGrasse Tyson?

  Leap rhythm.

• 45:20Chuck Nice?

  We need to insert a leap rhythm. Yeah. From what I understand, blind people have a problem with this as well. They can develop a problem with this as well.

• 45:28Speaker 03

  Yes, they do. Depending on the nature of the blindness, if it's at the level of the retina, there are cells inside of your eye that whose principal job is not to construct vision. They have no interest in vision. All they simply are doing, they are light meters. And they are there to tell your brain is, do you have light or do you have dark? And if you lose those cells, your brain is never able to receive that signal of light. And you can start to have difficulties in your circadian rhythm. But to come back to Anna's question with night shift work. Firstly, I love the fact that Anna loves her work and that she wants a longer life. That's exactly the right instinct, of course.

• 46:13Speaker 03

  But I should probably be honest and trying to be practical at the same time. The hard truth is that rotating night shifts are tough on your circadian biology. And there are health consequences that have been associated with it. In fact, the World Health Organization some years ago, and they repeated this mandate just recently, they classified any form of nighttime shift work as a probable carcinogen because of the relationship between a disruption of your sleep-wake rhythms and the relationship with cancer. And that's not meant to frighten you. It's meant just for us to earn the respect for the risk that...

• 46:52Speaker 03

  You take by giving us the opportunity that if I have an appendicitis at 3am in the morning, there's someone there to save my life, which is unbelievably incredible. So firstly, thank you for that. But because your body runs on that natural 24-hour sort of cycle, when you fight your biology, you typically lose. And the way you know you've lost is disease and sickness.

• 47:17Chuck Nice?

  Yeah.

• 47:18Speaker 03

  And so what to do, what can we sort of help here? There's probably a few things. The first I would say is that direction matters, that if you are a shift worker and you have to do these rotating shifts, try to shift clockwise with the clock. So do sort of a morning shift, then an evening shift, then a night shift, then a morning shift. If you get the, and some people don't have this flexibility, but if you are someone who is creating these shifts or you have the optionality, try to shift forward in time and your biology is much harder to go in reverse. The second thing I would say to Anna is be careful of your drive home. That is the most dangerous part of your shift.

• 48:01Speaker 03

  And so if you can try and get a lift home, try and take public service, whatever it is, just try to be careful because a tired driver is, based on the evidence, not dissimilar to a drunk driver, if you look at some of the data. The next thing I would say is try to defend your daytime with as much nighttimeness signaling as possible. What do I mean? When you get home, make sure that your home is blackout curtains, you are ensconced in darkness. Get the room cold because your body is expecting a temperature drop at night. Eye mask, earplugs, and then try to take a little bit of melatonin

• 48:43Speaker 03

  about two to three hours before you expect to try to sleep during the day. You can also take a hot bath or a shower about an hour before bed. Why would you do that? Your brain and your body need to drop their core temperature by about one degree Celsius, two to three degrees Fahrenheit to fall asleep and stay asleep. It's the reason that you'll always find it easier to fall asleep in a room that's too cold than too hot because too cold, it's the right temperature direction. So why the hot bath or shower? You think, well, I get out in the bath and I'm all kind of toasty and that's why I sleep well. It's the opposite, that when you get into the hot bath or shower, it draws all of the blood from, that's trapped at the core of your body out to the surface. It's almost like a snake charmer, that you're drawing the hot blood out.

• 49:27Speaker 03

  And when you get out of the bath, all of the heat that's trapped in the body is radiated out because it's been lifted to the surface and your core body temperature actually plummets. And that can help you because your body temperature-

• 49:40Chuck Nice?

  You're tricking your body into thinking that you're-

• 49:43Speaker 03

  It's nighttime.

• 49:44Chuck Nice?

  It's nighttime, yeah.

• 49:45Speaker 03

  Exactly.

• 49:46Chuck Nice?

  That's very cool.

• 49:46Speaker 03

  So I would say those are the things that you could try to do. Again, just be careful of the drive home and then make your home, when you get home, like a cave. Cold, dark, quiet.

• 49:55Chuck Nice?

  So Matt, real quick, I just want to say, uh, because I think this is important from my own personal experience, and maybe you could speak to it. I had a job where I had to get up at three o'clock in the morning and I was still doing comedy at night. So I wasn't getting any sleep, okay? And I've been very open about the mental illness issues that I have. And all I can say is what you just talked about, anyone who suffers from mental illness of any kind, whether it's depression, bipolarism, or anything along those lines, the sleep is so very important.

• 50:33Chuck Nice?

  And I went into a very dark period because I just wasn't getting sleep. And so the sleep health that you just described is really important for those of you who suffer from mental, uh, mental health issues.

• 50:50Speaker 03

  I want to salute that flag every single time you hoist it because sleep is, it's not part of the equation. It is the foundation on which your mental health sits. And there's, this is almost, you can't clean eat your way out of insufficient sleep. You can't exercise your way out of insufficient sleep. And trying to protect your sleep when you are, when you know you are vulnerable from a mental health context, or if you know someone who is suffering from mental health conditions, try to see if you can help stabilize someone's sleep. That means the circadian rhythm, giving them bright, lovely summer exposure to daylight

• 51:33Speaker 03

  in the first 60 minutes when they wake up. That actually sets like an hourglass turned over, a timer to instigate the release of a healthy dose of melatonin at night that can stabilize your sleep rhythms. And then when it's nighttime, digital detox, try to turn down almost all of the lights in the home. Try to disengage the mind, but I cannot just emphasize more than what you just said. It is such an essential ingredient. And when it goes away, goodness, can we become vulnerable? And we become vulnerable very quickly based on the studies that we've done.

• 52:06Neil deGrasse Tyson?

  Digital detox means put away the phone and the tablet?

• 52:09Speaker 03

  Mm-hmm, that's right.

• 52:10Chuck Nice?

  I'd rather die.

• 52:16Chuck Nice?

  I'm sorry, I was channeling my children.

• 52:18Neil deGrasse Tyson?

  Time for a couple more.

• 52:19Gary O'Reilly?

  All right, we've got John Giffen from Wynwood, PA. I have been fascinated by the recent discussions of consciousness in StarTalk. So what does our understanding of non-REM sleep tell us about consciousness? Can consciousness really turn off during sleep? Or might it continue throughout and just be blocked from our memory when we wake?

• 52:42Speaker 03

  Oh, what a good question.

• 52:46Neil deGrasse Tyson?

  So in other words, if you're asleep and you're not in REM, what is your state of consciousness?

• 52:51Speaker 03

  From everything that we can tell, you are absent consciousness. Meaning that if I wake you up from deep non-REM sleep and I say, what was going through your mind? Nothing, nothing will come to mind. Wake you up out of light non-REM sleep, often you can have these sort of little mini dreams, sort of LITE dreaming, as it were. But when you go into REM sleep, that's full-blown dreaming. But there was a beautiful kind of twist in that story, which is, well, is it just simply that my memory is blocked? Now, that actually is the case for most of us with REM sleep dreaming. Because as I mentioned earlier, you have all of these florid experiences and you typically forget a lot of your dreams.

• 53:36Speaker 03

  But I don't know if that's true or not. Yes, and we think we understand why it is that dreams dissolve so quickly when you wake up. It comes back to the prefrontal cortex because it's your prefrontal cortex that is capturing all of the information and then sending it to another part of your brain called the hippocampus, which sits on the either left and right side of your brain. And the hippocampus packages that, those experiences as memories. But it needs the prefrontal cortex as a spotlight to direct those memories into the packets. And if you don't have a prefrontal cortex that's active, which you don't when you're dreaming, it's very difficult, we believe, to package and send those memories into storage. I've got a wacky theory that we don't forget our dreams.

• 54:21Speaker 03

  In fact, I would argue we may remember every single one of our dreams. And it's the difference between what I call accessibility versus availability. How many times have you had that experience where you woke up and you think, I was dreaming? I know I was dreaming. And as hard, the harder you try, the further you push it away and you just give up. And then two days later, you get into your car and you see maybe a pack of chewing gum. And it's a cue that all of a sudden unlocks that full dream memory from several days ago. What that tells me is that you, your brain is storing the memory. But what you've lost at the moment of waking up is the IP address for that memory.

• 55:03Speaker 03

  So the memory has been stored and is available. It's just that you've lost the connection for its accessibility. So availability, accessibility, which means that if that's true, that we can have these spontaneous queued recollections of dreams days later. What if we store all of our dreams? And we know for a fact that there's a lot of information that sits below the radar of consciousness that is changing our human behavior and our decisions and our actions? What that leads to is a bit of a mind-bending possibility that all of our dreams are stored throughout our life and those dreams are constantly shaping and changing the decisions

• 55:47Speaker 03

  and the beliefs and the thoughts that we have in our waking life and we're completely unaware of it.

• 55:54Chuck Nice?

  Wow.

• 55:55Gary O'Reilly?

  Yes.

• 55:56Chuck Nice?

  That, first of all, that's just nuts. I don't mean like nuts as in like you're a quack. I mean, it's nuts as in to think about-

• 56:06Speaker 03

  Many people have said that, but-

• 56:07Chuck Nice?

  But no, I'm saying it's nuts to think about the implications of what you just said, you know? Um, but it definitely works for creativity. I can speak to that personally because I have had dreams that I wake up and I'm like, I can't remember. And I know that they're like, I wrote a joke or I, something happened. But then I'll be sitting down doing something completely unrelated at a different time and that dream will pop in my head and I'm like, oh, man, there it is. And I was like, oh, that's the joke. And then I'll tell the joke and people will be like, you suck. No, I'm joking, I'm joking. No, yeah, but it's useful, it's useful is what I'm saying.

• 56:49Speaker 03

  Yeah, and isn't that, I mean, and I, there's a couple of experiments that I think I could design to try to prove that that's the case. And then we could get into the whole world of, okay, if you can understand where memories are stored during dreaming, could you start to manipulate those memories during the dream state itself? Can you alter memories or can you selectively decide which memories that your sleeping brain brings up and remembers? And which it wants to selectively forget? We're starting to get to the stage now where we've developed experimental tools, where almost like a playlist, I can select what it is from your waking day that you decide to remember and what you lose.

• 57:30Chuck Nice?

  The even deeper implication of what you just said is if that's the case, then maybe all memories are stored that way. And if that is so, and you're able to manipulate it, Alzheimer's patients, you would be able to find a way to raise their memories like the way we dust for fingerprints or something. You know, you'd be able to raise those memories and they wouldn't suffer the, they might still have Alzheimer's, but they'll still be able to access the memories.

• 58:02Speaker 03

  And the question is, is Alzheimer's a condition of availability but impaired accessibility? And the sad part is that because of the neural degeneration that happens, particularly in the memory centers, we think that in fact those memories are no longer available at all.

• 58:21Neil deGrasse Tyson?

  Oh.

• 58:22Chuck Nice?

  So it's like a damaged, it's like a corrupted file.

• 58:24Neil deGrasse Tyson?

  Yeah.

• 58:24Chuck Nice?

  It's like a corrupted file.

• 58:26Neil deGrasse Tyson?

  Files there, but it's inaccessible.

• 58:27Chuck Nice?

  Files there, but you can't get to it.

• 58:28Neil deGrasse Tyson?

  Yeah.

• 58:28Chuck Nice?

  Ah, that's a shame.

• 58:30Gary O'Reilly?

  Good idea, though.

• 58:31Speaker 03

  Yeah, tragic.

• 58:31Chuck Nice?

  I tried. I tried to help you people.

• 58:33Neil deGrasse Tyson?

  Can we take one more question, but we gotta do it like in 30 seconds?

• 58:37Speaker 03

  Rapid fire. Yep, come on, Walker.

• 58:39Gary O'Reilly?

  Um, okay, Brian Edair, uh, I was wondering how the astronauts on Artemis II sleep on the shuttle. Do they have any special procedures? And would we expect them to have different types of dreams or nightmares based on being in zero gravity in space? Thank you so much.

• 58:57Neil deGrasse Tyson?

  Okay, they weren't on the shuttle, just to, just to clarify that.

• 59:00Gary O'Reilly?

  Sophie Edair is aged 11. She's given a pass.

• 59:03Chuck Nice?

  Okay.

• 59:04Gary O'Reilly?

  I got you.

• 59:06Chuck Nice?

  By the way, great question, Sophie.

• 59:09Speaker 03

  It's a great, great question. I think it's one of the best questions of, of the night. How do astronauts sleep up there? I would say honestly, with some difficulty and a lot of Velcro, because when you're on the space station, astronauts will actually climb into a sleeping bag that is strapped on the wall. And the reason is because so they don't drift around and start bumping into things. And there is no up or down. And as a result, you actually, because of that zero gravity, you don't need a pillow pressed against your head. So astronauts will actually describe sleeping almost like this sort of gentle floating experience. And some of them love it, some of them never get used to it.

• 59:49Speaker 03

  But the real troublemaker is actually not the gravity or lack thereof, it's the sun. Because circling the earth, the crew will actually see a sunrise and a sunset roughly every 90 minutes. So they will see 16 sunrises and sunsets every single day. Now, as we spoke about with your circadian rhythm, your brain carries this internal clock and it's carried it for three and a half million years. And it's been set to only one sunrise and one sunset every 24 hours, not 16.

• 1:00:22Neil deGrasse Tyson?

  So it scrambles the brain, is what you're saying?

• 1:00:24Speaker 03

  Your clock gets shouted at 16 times a day in a completely unexpected manner. So astronauts will typically black out the windows, they'll wear eye masks, and they will keep a very strict schedule that is sort of determined to make sure that they get timed light in accordance with when their biology is wanting it, and they will get timed darkness, together with a little dose of melatonin, to try to help convince their brains that it's nighttime when mission control says it is something different.

• 1:00:55Neil deGrasse Tyson?

  And of course, they only orbited Earth a few times before they did a trans lunar injection.

• 1:00:59Gary O'Reilly?

  Yeah.

• 1:00:59Neil deGrasse Tyson?

  And headed to the moon.

• 1:01:00Gary O'Reilly?

  Right.

• 1:01:01Neil deGrasse Tyson?

  So then they're no longer orbiting Earth, because now Earth is not blocking their view of the sun, putting them into nighttime. And so they still have to think about a rhythm, because now they're just floating in space towards the moon.

• 1:01:13Gary O'Reilly?

  Yeah.

• 1:01:13Chuck Nice?

  Yeah.

• 1:01:13Gary O'Reilly?

  They don't get any sunrise or sunset.

• 1:01:15Neil deGrasse Tyson?

  They'll get no sunrise or sunset.

• 1:01:16Chuck Nice?

  No nothing. Yeah, well, I was trying to say, though, that's probably better than 16. Like, I'd rather have no sun. Like, can you imagine somebody saying to you, like, "Let's take a romantic stroll on the beach and watch the sunset."

• 1:01:28Gary O'Reilly?

  Again?

• 1:01:28Chuck Nice?

  Like, "F that sunset." You know how many sunsets I've seen? I don't give a damn about no sunset.

• 1:01:35Neil deGrasse Tyson?

  So news flash, Christina Koch, one of the Artemis II astronauts, came back and said she had some of the best sleep she ever had in her life.

• 1:01:44Chuck Nice?

  Oh.

• 1:01:44Neil deGrasse Tyson?

  I'm just saying.

• 1:01:45Chuck Nice?

  Well, that's kind of sad, because you're not going back to space to sleep. Like, you're never gonna find that here on Earth.

• 1:01:52Neil deGrasse Tyson?

  Well, here's a funny one. So Tempur-Pedic, when they first came on the scene, they marketed themselves as being the material under the seat of astronauts.

• 1:02:04Chuck Nice?

  Right.

• 1:02:04Neil deGrasse Tyson?

  Okay, that go into space. And you say, "Wow, I want to wear, sleep on what the astronauts sleep on." Except, when they're in zero G, there is no pressure on a phone.

• 1:02:14Chuck Nice?

  On the phone.

• 1:02:15Neil deGrasse Tyson?

  There's no.

• 1:02:15Chuck Nice?

  There's no memory for the memory phone to remember.

• 1:02:19Neil deGrasse Tyson?

  Exactly. Yeah, so it was a little, it was a little spurious there, as I saw.

• 1:02:25Chuck Nice?

  Well, I hate to tell you, I have a Tempur-Pedic mattress at home.

• 1:02:28Neil deGrasse Tyson?

  You do?

• 1:02:28Chuck Nice?

  I do.

• 1:02:29Neil deGrasse Tyson?

  Yeah, so in space, there's no bed sores, there's no, half the reason why you turn at night is to change the pressure on your body.

• 1:02:38Chuck Nice?

  On your body.

• 1:02:38Neil deGrasse Tyson?

  Yeah, if you're in zero G.

• 1:02:40Chuck Nice?

  Yeah, there is no pressure anywhere.

• 1:02:41Neil deGrasse Tyson?

  You're just floating.

• 1:02:42Chuck Nice?

  Yeah.

• 1:02:42Speaker 03

  I think that there was a mention of, you know, what, what about dreams and how would that change? My, we don't have actually good data on this, but my scientific hunch is that your dreams are probably not altered by anything to do with gravity. It's the emotion of being, you know, a tiny crew in a tin can, thousands and thousands and thousands of miles from everyone that you love, looking back at the whole Earth through a window. I'd wager that probably shows up somewhere in their dreams. And I would love to see the emotional kind of arc of acceptance of the monumental nature of what I'm experiencing in this moment, what this means to me, and then the integration of all of that. Could you imagine?

• 1:03:26Chuck Nice?

  Yeah.

• 1:03:26Speaker 03

  What an absolute mind twisting.

• 1:03:29Chuck Nice?

  I, I like to imagine that they all wake up and go, "I had a dream I was falling. Really? I had that same dream." They all had the dream that they were falling. Like, yeah, guess why?

• 1:03:39Gary O'Reilly?

  All right.

• 1:03:41Neil deGrasse Tyson?

  Matt, we gotta call it quits there. It's been a delight to have you back on.

• 1:03:44Speaker 03

  Absolute pleasure.

• 1:03:46Neil deGrasse Tyson?

  And clearly, our, our fan base, our Patreon fan base agrees with me.

• 1:03:51Chuck Nice?

  Yeah.

• 1:03:51Neil deGrasse Tyson?

  That you, you, you're taking us to places we don't typically go. And special edition is all about the human condition.

• 1:03:59Chuck Nice?

  Yeah.

• 1:03:59Gary O'Reilly?

  Yeah.

• 1:03:59Neil deGrasse Tyson?

  And so, thanks for helping us gain some insight there.

• 1:04:04Speaker 03

  It was lovely to chat, gents. As always, I suspect I will have some very interesting dreams tonight as a consequence of this.

• 1:04:12Neil deGrasse Tyson?

  And, and we're gonna find you on your podcast, eponymously named, is that, do I say that right?

• 1:04:18Gary O'Reilly?

  That's correct.

• 1:04:18Neil deGrasse Tyson?

  The Matt Walker Podcast. I presume you talk about sleep topics?

• 1:04:23Speaker 03

  I do, indeed.

• 1:04:23Neil deGrasse Tyson?

  And is there, is there a website or a Twitter handle we can find you on?

• 1:04:27Speaker 03

  You can just go to sleepdiplomat.com. And if you want to find me on X, I am also there, sleepdiplomat. And on Instagram, I am DrMattWalker, D R M A T T W A L K E R.

• 1:04:42Neil deGrasse Tyson?

  All right, we'll find you there.

• 1:04:43Chuck Nice?

  All right.

• 1:04:43Neil deGrasse Tyson?

  All right, dude. And any books you writing?

• 1:04:46Speaker 03

  Um, my, uh, previous book, Why We Sleep, has been out for, uh, now some time. And I will simply say that there is a second one that apparently should be being written at this time.

• 1:04:57Chuck Nice?

  Uh-oh.

• 1:04:58Gary O'Reilly?

  Good dear.

• 1:05:00Neil deGrasse Tyson?

  Okay.

• 1:05:01Gary O'Reilly?

  Deadline.

• 1:05:02Chuck Nice?

  That one's gonna be called, "Why We Procrastinate."

• 1:05:05Speaker 03

  The, the tagline will be, um, torpa hibernation and what happens when you dream about going to Mars. Anyway, um, that, yeah, there is a second book, uh, soon to be arriving on shelves.

• 1:05:19Neil deGrasse Tyson?

  No great piece of writing is ever finished. It only comes due.

• 1:05:24Chuck Nice?

  Woo! Look at that.

• 1:05:27Speaker 03

  Give me that t-shirt, please.

• 1:05:29Neil deGrasse Tyson?

  All right, Chuck.

• 1:05:30Chuck Nice?

  Always a pleasure.

• 1:05:31Neil deGrasse Tyson?

  Chuck, you baby.

• 1:05:32Chuck Nice?

  Always.

• 1:05:32Neil deGrasse Tyson?

  Yeah, Ray.

• 1:05:33Gary O'Reilly?

  Hey, Neil.

• 1:05:33Neil deGrasse Tyson?

  In the house. Neil deGrasse Tyson, and another edition of StarTalk Special Edition, this one on sleep. Thanks for joining us. Until next time, keep looking out.