Hi, I'm Konrad Marshall and from the Sydney Morning Herald and The Age. Welcome to Good Weekend Talks, a magazine for your ears, featuring in-depth conversations with fascinating people from sport and politics, science and culture, business and beyond. Every week, you can download new episodes in which top journalists from across our newsrooms talk to compelling people about the definitive stories of the day. In this episode, we speak with Matthew Walker, the British neuroscience professor is the author of Why We Sleep Unlocking the Power of Sleep and Dreams, and he's coming to Australia shortly to speak at Vivid Sydney in conjunction with the Sydney Writers Festival. Walker has become the sleep expert of choice around the world for his deep research and clear thinking into one of life's great mysteries and necessities. This student of the Sandman will be on stage in front of a packed audience at Sydney Town Hall on May 27th. But for the moment, I've got him all to myself for a chat about dozing and snoozing siestas and slumber. Welcome, Matthew.

Hi, I'm Konrad Marshall and from the Sydney Morning Herald and The Age. Welcome to Good Weekend Talks, a magazine for your ears, featuring in-depth conversations with fascinating people from sport and politics, science and culture, business and beyond. Every week, you can download new episodes in which top journalists from across our newsrooms talk to compelling people about the definitive stories of the day. In this episode, we speak with Matthew Walker, the British neuroscience professor is the author of Why We Sleep Unlocking the Power of Sleep and Dreams, and he's coming to Australia shortly to speak at Vivid Sydney in conjunction with the Sydney Writers Festival. Walker has become the sleep expert of choice around the world for his deep research and clear thinking into one of life's great mysteries and necessities. This student of the Sandman will be on stage in front of a packed audience at Sydney Town Hall on May 27th. But for the moment, I've got him all to myself for a chat about dozing and snoozing siestas and slumber. Welcome, Matthew.

It's a pleasure to be here. Thank you so much for the kind introduction, and I'm so looking forward to coming over and connecting with everyone there.

It's a pleasure to be here. Thank you so much for the kind introduction, and I'm so looking forward to coming over and connecting with everyone there.

I think audiences will be in for a treat. So as I mentioned in the intro, you've become one of the leading voices in sleep science around the world. Maybe you could just take us into kind of briefly how that happened. Like, were you getting bad sleep or great.

I think audiences will be in for a treat. So as I mentioned in the intro, you've become one of the leading voices in sleep science around the world. Maybe you could just take us into kind of briefly how that happened. Like, were you getting bad sleep or great.

Sleep.

Sleep.

Or no sleep? Like, was there anything personal that led you to explore this topic?

Or no sleep? Like, was there anything personal that led you to explore this topic?

I think most of us in the field are accidental sleep scientists. You know, I don't think when you are 5 or 6 and the teacher's going around the room and saying, you know, what would you like to be when you grow up? No one's rocketing their hand up and saying, I would desperately love to be a sleep scientist. So we all fall into it by accident. And I did, too. I was, um, I was back at medical school and I was doing my PhD looking at brainwave patterns. And this was in people with early stage dementia. And I was trying to see what type of dementia they had very early on, and I was failing miserably, couldn't get any good data for the first couple of years. And then one weekend I was reading in the journals that some of these dementias, they would have their sleep centers attacked by dementia, and others, they would leave the sleep centers untouched. So I thought, well, I'm measuring my patients at the wrong time of day. I'm measuring them whilst they're awake. I should be measuring them when they're asleep. I started doing that, got great results and then I started to ask, I wonder if the sleep problems are not just a symptom of dementia. I wonder if it's an underlying cause of dementia. And that was, gosh, almost 20 years ago now, and I just read everything I could about sleep. I fell in love with this topic called sleep. It is, I think, the most beguiling topic in all of science. And I'm desperately biased. I know that, And it's a love affair that has lasted me well over two decades. And it will always be, uh, the topic I study. So I am. I'm a humble servant, uh, of this thing called slumber. And, um, I thought back then, 20 years ago, you know, no one could answer a very simple question. Why do we sleep? And the answer back then was we sleep to cure sleepiness. Yes. Which is the fatuous equivalent of saying, well, I eat to cure hunger. No, you don't eat to cure hunger. You eat for lots of physiological, biological reasons. But now, 20 years later, because of the work of all of my colleagues, not not of my own. We've had to upend the question. And instead, now we have to 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 we get it, or demonstrably impaired when we don't get enough? And the answer seems to be no so far.

I think most of us in the field are accidental sleep scientists. You know, I don't think when you are 5 or 6 and the teacher's going around the room and saying, you know, what would you like to be when you grow up? No one's rocketing their hand up and saying, I would desperately love to be a sleep scientist. So we all fall into it by accident. And I did, too. I was, um, I was back at medical school and I was doing my PhD looking at brainwave patterns. And this was in people with early stage dementia. And I was trying to see what type of dementia they had very early on, and I was failing miserably, couldn't get any good data for the first couple of years. And then one weekend I was reading in the journals that some of these dementias, they would have their sleep centers attacked by dementia, and others, they would leave the sleep centers untouched. So I thought, well, I'm measuring my patients at the wrong time of day. I'm measuring them whilst they're awake. I should be measuring them when they're asleep. I started doing that, got great results and then I started to ask, I wonder if the sleep problems are not just a symptom of dementia. I wonder if it's an underlying cause of dementia. And that was, gosh, almost 20 years ago now, and I just read everything I could about sleep. I fell in love with this topic called sleep. It is, I think, the most beguiling topic in all of science. And I'm desperately biased. I know that, And it's a love affair that has lasted me well over two decades. And it will always be, uh, the topic I study. So I am. I'm a humble servant, uh, of this thing called slumber. And, um, I thought back then, 20 years ago, you know, no one could answer a very simple question. Why do we sleep? And the answer back then was we sleep to cure sleepiness. Yes. Which is the fatuous equivalent of saying, well, I eat to cure hunger. No, you don't eat to cure hunger. You eat for lots of physiological, biological reasons. But now, 20 years later, because of the work of all of my colleagues, not not of my own. We've had to upend the question. And instead, now we have to 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 we get it, or demonstrably impaired when we don't get enough? And the answer seems to be no so far.

Well, I was going to ask about that link between Alzheimer's and Sleep later on, because I knew that it had been an area. So what did you find? Was there an underlying sort of causative factor rather than just a correlation?

Well, I was going to ask about that link between Alzheimer's and Sleep later on, because I knew that it had been an area. So what did you find? Was there an underlying sort of causative factor rather than just a correlation?

Yeah. It's been we've been studying this now for probably over 17 years now, and lots of other colleagues likewise. And we now have we started off with correlation, um, where we just knew that people across the lifespan who were getting less than seven hours of sleep, especially less than six hours of sleep, they were at a far higher risk of developing Alzheimer's disease in later life. But correlation is not causation. So then, um, we started to do experimental studies where we could actually measure the amount of toxic Alzheimer's proteins circulating either in the bloodstream or in the cerebrospinal fluid. If we punctured that and took a sample or even in the brain using special brain scans.

Yeah. It's been we've been studying this now for probably over 17 years now, and lots of other colleagues likewise. And we now have we started off with correlation, um, where we just knew that people across the lifespan who were getting less than seven hours of sleep, especially less than six hours of sleep, they were at a far higher risk of developing Alzheimer's disease in later life. But correlation is not causation. So then, um, we started to do experimental studies where we could actually measure the amount of toxic Alzheimer's proteins circulating either in the bloodstream or in the cerebrospinal fluid. If we punctured that and took a sample or even in the brain using special brain scans.

Things like.

Things like.

Tau. And we would either like tau and amyloid protein. Those are the two culprits. And if we deprive people for a whole night of sleep, or even if we selectively deprive them of just deep sleep the next day, we could see an immediate build up in these Alzheimer's proteins, in the bloodstream, in the spinal fluid, and in the brain as well. So correlation went to causation. At that point, causation begged a question which was mechanism. Why is it when you don't get your sleep that Alzheimer's proteins build up? And there's some great work. A pioneer in the field, Maiken Nedergaard from the University of Rochester in the United States. And what she discovered was three things. The first thing that she discovered is that your brain has a cleansing system. We didn't think it had it. Now, everyone has heard of the cleansing system of the body. It's called the lymphatic system. But she discovered that the brain has one. It's called the glymphatic system. After the cells that make it up called these glial cells. Okay. The second thing that she discovered was that this cleansing system, the sewage system for the brain, isn't always switched on in high flow volume across the 24 hour period. Right. But instead, it's specifically during sleep and particularly during deep sleep, where you get this power cleanse for the brain. Sort of good night sleep clean, as it were. Yes. The third thing that she discovered, which finally brought us to mechanism, was that two of the pieces of metabolic detritus that sleep was washing away every night. Beta amyloid and tau protein, the two culprits of Alzheimer's disease. And so we've gone from correlation to causation to mechanism. And now things start to get very interesting. There's a recent study by that same group just a few weeks ago, demonstrating that one of the typical sleep medications that are used by many people around the world, something called Ambien, that drug, even though it puts you to. YouTube. Well, let's just say that it's what we call a sedative. Hypnotic. You're not necessarily naturally asleep. You're just sedated. That's what these medications do. And so I'm not going to argue. You're awake. You're not. But are you a natural sleep? Maybe not. And what they demonstrated is that when they were dosing animals with Ambien, yes, they slept longer. So you would think that if the brain is sleeping longer, it would have more time to cleanse the Alzheimer's proteins and it would be even better. What they found was that the Ambien decreased the amount of activity in the brain centers that were meant to do the cleansing by about 50%, and reduce the amount of amyloid and tau protein removal by about 30%. So here was a case where you're getting more sleep, but that more sleep, quote unquote, doesn't seem to be functional. It's not transacting the natural benefits of sleep. And it may potentially explain, although I don't think so at this stage because it's not causal. But it may explain why we see people who take those. Typical sleeping pills are also at a higher risk of getting Alzheimer's disease. Now, again, no good evidence that those two things are correlational. It could simply be, for example, people who are taking Ambien across their lifespan have had bad sleep for most of their life, and it was the bad sleep for most of their life, even before they started taking the medication that was predicting their Alzheimer's disease. You've always got to be so careful in not conflating association with causation.

Tau. And we would either like tau and amyloid protein. Those are the two culprits. And if we deprive people for a whole night of sleep, or even if we selectively deprive them of just deep sleep the next day, we could see an immediate build up in these Alzheimer's proteins, in the bloodstream, in the spinal fluid, and in the brain as well. So correlation went to causation. At that point, causation begged a question which was mechanism. Why is it when you don't get your sleep that Alzheimer's proteins build up? And there's some great work. A pioneer in the field, Maiken Nedergaard from the University of Rochester in the United States. And what she discovered was three things. The first thing that she discovered is that your brain has a cleansing system. We didn't think it had it. Now, everyone has heard of the cleansing system of the body. It's called the lymphatic system. But she discovered that the brain has one. It's called the glymphatic system. After the cells that make it up called these glial cells. Okay. The second thing that she discovered was that this cleansing system, the sewage system for the brain, isn't always switched on in high flow volume across the 24 hour period. Right. But instead, it's specifically during sleep and particularly during deep sleep, where you get this power cleanse for the brain. Sort of good night sleep clean, as it were. Yes. The third thing that she discovered, which finally brought us to mechanism, was that two of the pieces of metabolic detritus that sleep was washing away every night. Beta amyloid and tau protein, the two culprits of Alzheimer's disease. And so we've gone from correlation to causation to mechanism. And now things start to get very interesting. There's a recent study by that same group just a few weeks ago, demonstrating that one of the typical sleep medications that are used by many people around the world, something called Ambien, that drug, even though it puts you to. YouTube. Well, let's just say that it's what we call a sedative. Hypnotic. You're not necessarily naturally asleep. You're just sedated. That's what these medications do. And so I'm not going to argue. You're awake. You're not. But are you a natural sleep? Maybe not. And what they demonstrated is that when they were dosing animals with Ambien, yes, they slept longer. So you would think that if the brain is sleeping longer, it would have more time to cleanse the Alzheimer's proteins and it would be even better. What they found was that the Ambien decreased the amount of activity in the brain centers that were meant to do the cleansing by about 50%, and reduce the amount of amyloid and tau protein removal by about 30%. So here was a case where you're getting more sleep, but that more sleep, quote unquote, doesn't seem to be functional. It's not transacting the natural benefits of sleep. And it may potentially explain, although I don't think so at this stage because it's not causal. But it may explain why we see people who take those. Typical sleeping pills are also at a higher risk of getting Alzheimer's disease. Now, again, no good evidence that those two things are correlational. It could simply be, for example, people who are taking Ambien across their lifespan have had bad sleep for most of their life, and it was the bad sleep for most of their life, even before they started taking the medication that was predicting their Alzheimer's disease. You've always got to be so careful in not conflating association with causation.

Absolutely. All right. I'm going to come in hot with my own personal questions about sleep, because when am I going to get this chance otherwise? Um, so right now I'm coming around to the conclusion that I probably have sleep apnea. I have a lot of the symptoms, and I'm going to get tested and and check this stuff out, because I know it's something that I need to address. And I know a lot of other people who feel like they're in the same boat and they're like, oh, no, I'm not going to worry about it. You know, I think they don't want to wear the the sleep mask. They don't want to be hooked up to the CPAp machine or whatever it is. Yeah. Um, what are they what what are they missing in if they don't treat this kind of thing to their detriment? Or. I guess the broader question is here, what happens when you get routinely bad sleep? Because there'll be a lot of people out there that are getting really bad sleep.

Absolutely. All right. I'm going to come in hot with my own personal questions about sleep, because when am I going to get this chance otherwise? Um, so right now I'm coming around to the conclusion that I probably have sleep apnea. I have a lot of the symptoms, and I'm going to get tested and and check this stuff out, because I know it's something that I need to address. And I know a lot of other people who feel like they're in the same boat and they're like, oh, no, I'm not going to worry about it. You know, I think they don't want to wear the the sleep mask. They don't want to be hooked up to the CPAp machine or whatever it is. Yeah. Um, what are they what what are they missing in if they don't treat this kind of thing to their detriment? Or. I guess the broader question is here, what happens when you get routinely bad sleep? Because there'll be a lot of people out there that are getting really bad sleep.

If you are snoring or you have a partner who snores, or your partner is telling you that you snore, you need to get tested. It will shorten not only your lifespan, but what it will also shorten is your healthspan. That's what most of us care about. We don't necessarily want to live for decades and decades and decades longer. We just want to live longer, free of disease and sickness. That's your healthspan. Yes, sleep apnea will encourage a shorter life, and that shorter lifespan will be filled with greater amount of disease and sickness based on the evidence. So that's the first thing. It is consequential to frame that for you. What we the way that we measure sleep apnea is by looking at how many obstructions or how many times, let's say that you have these events where you stop breathing and your oxygen saturation starts to drop. And very mild sleep apnea is where you have, let's say, 5 to 15 of these events every hour that you're asleep. So let's just call it ten events per hour. And let's say that tonight, you you sort of listen to this odd, strange British guy and you say, I'm going to have my eight hours of sleep. Okay. So for 80 times throughout the next night. Imagine if I were to come into your bedroom and I were to throttle you to the point where your oxygen saturation dropped, and I were to do that repeatedly, ten times every hour for eight hours. So 80 events like that. Do you think your body would and your brain would feel well rested and restored and with life and biological health the next day as a consequence? And of course, I'm being hyperbolic, but the answer, of course, is no. And this is very mild sleep apnea that we're talking about. Many people out there, we estimate about 80% of people with sleep apnea are undiagnosed, which is staggering.

If you are snoring or you have a partner who snores, or your partner is telling you that you snore, you need to get tested. It will shorten not only your lifespan, but what it will also shorten is your healthspan. That's what most of us care about. We don't necessarily want to live for decades and decades and decades longer. We just want to live longer, free of disease and sickness. That's your healthspan. Yes, sleep apnea will encourage a shorter life, and that shorter lifespan will be filled with greater amount of disease and sickness based on the evidence. So that's the first thing. It is consequential to frame that for you. What we the way that we measure sleep apnea is by looking at how many obstructions or how many times, let's say that you have these events where you stop breathing and your oxygen saturation starts to drop. And very mild sleep apnea is where you have, let's say, 5 to 15 of these events every hour that you're asleep. So let's just call it ten events per hour. And let's say that tonight, you you sort of listen to this odd, strange British guy and you say, I'm going to have my eight hours of sleep. Okay. So for 80 times throughout the next night. Imagine if I were to come into your bedroom and I were to throttle you to the point where your oxygen saturation dropped, and I were to do that repeatedly, ten times every hour for eight hours. So 80 events like that. Do you think your body would and your brain would feel well rested and restored and with life and biological health the next day as a consequence? And of course, I'm being hyperbolic, but the answer, of course, is no. And this is very mild sleep apnea that we're talking about. Many people out there, we estimate about 80% of people with sleep apnea are undiagnosed, which is staggering.

That is.

That is.

So that's the first thing I would or the first two things I would say it's consequential. And that is exactly what's happening. And if you have if people are listening and you just want to try this for Android and Apple and I have no affiliation with them, there is an app called Snore Lab, Snore Lab, and you can download it and it's on your phone, and then you just hit record and you place it by your bedside, and it's going to record your breathing and your snoring throughout the night. The next morning you open it up, there's your eight hours and it will show you like Richter shocks on a scale, the severity of your story and it ranks it from mild, moderate, significant and then epic.

So that's the first thing I would or the first two things I would say it's consequential. And that is exactly what's happening. And if you have if people are listening and you just want to try this for Android and Apple and I have no affiliation with them, there is an app called Snore Lab, Snore Lab, and you can download it and it's on your phone, and then you just hit record and you place it by your bedside, and it's going to record your breathing and your snoring throughout the night. The next morning you open it up, there's your eight hours and it will show you like Richter shocks on a scale, the severity of your story and it ranks it from mild, moderate, significant and then epic.

Oh man, I'm gonna do this. And I know it's going to be confronting.

Oh man, I'm gonna do this. And I know it's going to be confronting.

And well, the more.

And well, the more.

Confronting part of this is you can then go into any part of your night. You can tap on any one of the Richter shocks, and then you can listen to yourself gasping for breath.

Confronting part of this is you can then go into any part of your night. You can tap on any one of the Richter shocks, and then you can listen to yourself gasping for breath.

Um.

Um.

And it really is, I mean, it just imagine if someone were, you know, during the day in your office and they were constraining your oxygen so that you were gasping all the time. You know, you would never stay at that job and you would actually file a claim. That's preposterous. But that's what we're suffering with undiagnosed sleep apnea. So to the the issue of the treatment, though, we used to think of this kind of almost fighter pilot esque, you know, Top Gun mask and big tube coming off, you know, your significant other walks into the bedroom. You've got to thinking, you know, I've never wanted you more. It's not like that anymore. It's there are some great companies and I think probably the best out there right now in the business is called ResMed. And they have a great presence there in Australia. And really now just comes down to this little nasal pillow that just sits just over your nose and it's just connected to the airway. And what happens is that in severe or moderate to severe apnea, you will need a CPAp machine normally, and it will just place gentle air up the airway. And it acts like a splint, but it's actually a pressure splint that will keep the airway open. So you breathe freely. And many people will say, but I still don't sleep very well with the mask on. I promise you that even if you're sleeping not as well as you think you were before, the quality of that sleep with the airway splint activated is so much better that even if it's shorter duration, the quality versus quantity is that much better. It's well worth it. That said, though, there are great advances in what we call these mandibular devices. And it looks like a sports car.

And it really is, I mean, it just imagine if someone were, you know, during the day in your office and they were constraining your oxygen so that you were gasping all the time. You know, you would never stay at that job and you would actually file a claim. That's preposterous. But that's what we're suffering with undiagnosed sleep apnea. So to the the issue of the treatment, though, we used to think of this kind of almost fighter pilot esque, you know, Top Gun mask and big tube coming off, you know, your significant other walks into the bedroom. You've got to thinking, you know, I've never wanted you more. It's not like that anymore. It's there are some great companies and I think probably the best out there right now in the business is called ResMed. And they have a great presence there in Australia. And really now just comes down to this little nasal pillow that just sits just over your nose and it's just connected to the airway. And what happens is that in severe or moderate to severe apnea, you will need a CPAp machine normally, and it will just place gentle air up the airway. And it acts like a splint, but it's actually a pressure splint that will keep the airway open. So you breathe freely. And many people will say, but I still don't sleep very well with the mask on. I promise you that even if you're sleeping not as well as you think you were before, the quality of that sleep with the airway splint activated is so much better that even if it's shorter duration, the quality versus quantity is that much better. It's well worth it. That said, though, there are great advances in what we call these mandibular devices. And it looks like a sports car.

Top and.

Top and.

Bottom mouthguard. Yeah. And it's hinged at the back. And it simply just moves the jaw just a few millimeters forward. And everyone can do this test. You lie on your bed, on your back, and you can try and make the snoring noise. And every everyone can do it. Then just grab your thumbs, put them under the jaw and move your jaw forward, and then try and make the snoring sound again. And it's immensely difficult. And just that slight alteration in the anatomy of the jaw opens up the airway and you can breathe. So many people may not have to go for a CPAp machine if they're in the mild category, they can do this. And then there's other sort of you know, there are some dental and surgical procedures. Some people will opt to actually have a very small sort of stimulator implanted just under the skin that will stimulate the airway open so they don't have to use the the nasal pillow. So lots of different treatment options out there for people. But start with snolab. See if you're snoring. Do 5 or 6 nights sleep are so idiosyncratic. 1 or 2 nights you're not going to be representative. Get five nights, have a look at it, and then really ask yourself, I think I need to go and get tested and reach out to your doctor. They will give you an at home test. You don't even need to go to a sleep lab.

Bottom mouthguard. Yeah. And it's hinged at the back. And it simply just moves the jaw just a few millimeters forward. And everyone can do this test. You lie on your bed, on your back, and you can try and make the snoring noise. And every everyone can do it. Then just grab your thumbs, put them under the jaw and move your jaw forward, and then try and make the snoring sound again. And it's immensely difficult. And just that slight alteration in the anatomy of the jaw opens up the airway and you can breathe. So many people may not have to go for a CPAp machine if they're in the mild category, they can do this. And then there's other sort of you know, there are some dental and surgical procedures. Some people will opt to actually have a very small sort of stimulator implanted just under the skin that will stimulate the airway open so they don't have to use the the nasal pillow. So lots of different treatment options out there for people. But start with snolab. See if you're snoring. Do 5 or 6 nights sleep are so idiosyncratic. 1 or 2 nights you're not going to be representative. Get five nights, have a look at it, and then really ask yourself, I think I need to go and get tested and reach out to your doctor. They will give you an at home test. You don't even need to go to a sleep lab.

I have a question for you about naps. I love a good nap. Short and sweet. They kind of revive me and I and I get up and I'm ready to go. Go a little bit longer an hour or so, and I am groggy as a result of it. It's almost it's counterproductive. It has the opposite effect. I understand that Thomas Edison was a massive napper, a very enthusiastic napper. Um, and I feel like he had a novel method for kind of hitting the sweet spot on a nap.

I have a question for you about naps. I love a good nap. Short and sweet. They kind of revive me and I and I get up and I'm ready to go. Go a little bit longer an hour or so, and I am groggy as a result of it. It's almost it's counterproductive. It has the opposite effect. I understand that Thomas Edison was a massive napper, a very enthusiastic napper. Um, and I feel like he had a novel method for kind of hitting the sweet spot on a nap.

Yeah, it's interesting that sort of sleep hangover for effect. Isn't it when you nap for a quote unquote too long? And why is that? And I've got no idea. It was just theoretical. But no, no, I do I can explain it. It's so it's what we call sleep inertia. And here's what happens. If you want, I've got a friend over here in the United States, a guy called Andrew Huberman. He's always telling me protocolized everything. What's the protocol for? Everything. Okay, if what's the protocol for napping? I would say the optimal nap is around 20 minutes. It's not to say we've done lots of studies that if you nap longer, you continue to get more and more brain and body benefits. But 20 minutes is the sweet spot because it's enough to give you what most people want, which is a restoration and refreshment of my alertness, my focus, my concentration, my energy. But when you are going into that 20 minute territory, you haven't gone all the way down into deep non-rapid eye movement. Sleep yet. Deep dreamless sleep. So that when you wake up, you kind of go back up to operating temperature like a classic car engine pretty quickly. But if you nap maybe 30 or 40 minutes, you're now down into the deeper stages of sleep. And then when you wrench yourself out of that, it's like going from the basement to the penthouse and you get stuck on the 13th floor. Now, if you wait for an hour or so like a classic car engine, gradually the oil temp will start to come up, and then you'll be firing on all cylinders and you will feel even better than when you did, you know, an hour or so before. So you will get more benefits. You just have to suffer the consequence of that initial dip. But for most people, 20 minutes is the sweet spot. Thomas Edison used naps. He was a very sort of vociferous suggester of the the uselessness of sleep. And he would say he would survive on 4 or 5 hours of sleep. There are lots of pictures of him, and he was a habitual napper. There's I've got a great picture of him on his inventor's bench. A picture of him in the garden. Looks like after a pretty good garden party. He's out for the count. And he understood the creative brilliance of sleep. And he used it ruthlessly as a tool. Here's what he would do. He would take two steel ball bearings, put them in his hand, sit at his desk in his inventor's studio, have a pad of paper and a pencil next to him, and then he would take a metal saucepan and put it underneath the armrest. And then he would gradually settle his arm back down with his palm facing to the ceiling, and he would relax back. And so he didn't go too far into sleep. At some point, his muscle tone would relax. They would release the steel ball bearings, they would crash on the saucepan, wake him up, and then he would write down all of the ideas that he was getting from sleep. And he coined the phrase, it was beautiful. He described it as the genius gap, this gap between lucid waking consciousness and the depths of almost non-conscious, deep sleep. And in that transitional, that kind of liminal state, you had all of these creative ideas. And it's probably one of the reasons why no one's ever told you that you really should stay awake on a problem. And he recognized that.

Yeah, it's interesting that sort of sleep hangover for effect. Isn't it when you nap for a quote unquote too long? And why is that? And I've got no idea. It was just theoretical. But no, no, I do I can explain it. It's so it's what we call sleep inertia. And here's what happens. If you want, I've got a friend over here in the United States, a guy called Andrew Huberman. He's always telling me protocolized everything. What's the protocol for? Everything. Okay, if what's the protocol for napping? I would say the optimal nap is around 20 minutes. It's not to say we've done lots of studies that if you nap longer, you continue to get more and more brain and body benefits. But 20 minutes is the sweet spot because it's enough to give you what most people want, which is a restoration and refreshment of my alertness, my focus, my concentration, my energy. But when you are going into that 20 minute territory, you haven't gone all the way down into deep non-rapid eye movement. Sleep yet. Deep dreamless sleep. So that when you wake up, you kind of go back up to operating temperature like a classic car engine pretty quickly. But if you nap maybe 30 or 40 minutes, you're now down into the deeper stages of sleep. And then when you wrench yourself out of that, it's like going from the basement to the penthouse and you get stuck on the 13th floor. Now, if you wait for an hour or so like a classic car engine, gradually the oil temp will start to come up, and then you'll be firing on all cylinders and you will feel even better than when you did, you know, an hour or so before. So you will get more benefits. You just have to suffer the consequence of that initial dip. But for most people, 20 minutes is the sweet spot. Thomas Edison used naps. He was a very sort of vociferous suggester of the the uselessness of sleep. And he would say he would survive on 4 or 5 hours of sleep. There are lots of pictures of him, and he was a habitual napper. There's I've got a great picture of him on his inventor's bench. A picture of him in the garden. Looks like after a pretty good garden party. He's out for the count. And he understood the creative brilliance of sleep. And he used it ruthlessly as a tool. Here's what he would do. He would take two steel ball bearings, put them in his hand, sit at his desk in his inventor's studio, have a pad of paper and a pencil next to him, and then he would take a metal saucepan and put it underneath the armrest. And then he would gradually settle his arm back down with his palm facing to the ceiling, and he would relax back. And so he didn't go too far into sleep. At some point, his muscle tone would relax. They would release the steel ball bearings, they would crash on the saucepan, wake him up, and then he would write down all of the ideas that he was getting from sleep. And he coined the phrase, it was beautiful. He described it as the genius gap, this gap between lucid waking consciousness and the depths of almost non-conscious, deep sleep. And in that transitional, that kind of liminal state, you had all of these creative ideas. And it's probably one of the reasons why no one's ever told you that you really should stay awake on a problem. And he recognized that.

You mentioned just there that he, he, um, described himself as, uh, as a very short sleeper, someone who didn't need a lot to get by on. And, you know, history is littered with, um, people, uh, who are like that. I mean, Barack Obama likes to say that he can exist on five. Martha Stewart only needs four hours a night. I think Nikola Tesla was said to believe that he could get by on 2 or 3 hours of sleep. Is there any optimal optimal amount? I mean, is eight hours what we should be striving for?

You mentioned just there that he, he, um, described himself as, uh, as a very short sleeper, someone who didn't need a lot to get by on. And, you know, history is littered with, um, people, uh, who are like that. I mean, Barack Obama likes to say that he can exist on five. Martha Stewart only needs four hours a night. I think Nikola Tesla was said to believe that he could get by on 2 or 3 hours of sleep. Is there any optimal optimal amount? I mean, is eight hours what we should be striving for?

It's a very interesting.

It's a very interesting.

Question, and there is definitely a range. And you know, the people like, you know, Margaret Thatcher, who was claimed to be, you know, the Iron Lady claimed to sleep 4 to 5 hours. Her compadre in the United States, Ronald Reagan, an equal chest beater about 4 to 5 hours of sleep a night. Nothing more. Um, I don't know if it's coincidental that both Thatcher and Reagan succumb to the terrible disease of Alzheimer's. You know, towards the end of their life. Um, but there is an absolute range for most average adults. It's 7 to 9 hours of sleep once you get less than seven hours of sleep. We can start to measure impairments in your brain and your body. And chronically sleeping less than seven hours is associated with a number of disease risk predictors cardiovascular disease, diabetes, immune and inflammation issues, certain forms of cancer, hormonal issues, and then of course, issues around Alzheimer's disease and dementia. So that said, though, it turns out that there are a very small subset of the population that we now call natural short sleepers, and they are genetically determined. We know that there are at least two or maybe now three genes that will allow you to get away with as little as about. If you look at the data six hours and 12 minutes, and these people can sleep literally consistently six hours and 12 minutes or around there and they show no impairment. We just can't measure any impairment. And so it does seem to be that. Yeah. And at that point, you know, probably there's lots of people listening, thinking, okay, I think, I think I'm one of those genetic abnormal people. And just to frame this in context, statistically, based on the evidence, you're probably more likely to be struck by lightning in your lifetime than you are to be a natural short sleeper genetically.

Question, and there is definitely a range. And you know, the people like, you know, Margaret Thatcher, who was claimed to be, you know, the Iron Lady claimed to sleep 4 to 5 hours. Her compadre in the United States, Ronald Reagan, an equal chest beater about 4 to 5 hours of sleep a night. Nothing more. Um, I don't know if it's coincidental that both Thatcher and Reagan succumb to the terrible disease of Alzheimer's. You know, towards the end of their life. Um, but there is an absolute range for most average adults. It's 7 to 9 hours of sleep once you get less than seven hours of sleep. We can start to measure impairments in your brain and your body. And chronically sleeping less than seven hours is associated with a number of disease risk predictors cardiovascular disease, diabetes, immune and inflammation issues, certain forms of cancer, hormonal issues, and then of course, issues around Alzheimer's disease and dementia. So that said, though, it turns out that there are a very small subset of the population that we now call natural short sleepers, and they are genetically determined. We know that there are at least two or maybe now three genes that will allow you to get away with as little as about. If you look at the data six hours and 12 minutes, and these people can sleep literally consistently six hours and 12 minutes or around there and they show no impairment. We just can't measure any impairment. And so it does seem to be that. Yeah. And at that point, you know, probably there's lots of people listening, thinking, okay, I think, I think I'm one of those genetic abnormal people. And just to frame this in context, statistically, based on the evidence, you're probably more likely to be struck by lightning in your lifetime than you are to be a natural short sleeper genetically.

Right. Okay. We've spoken a little bit about the the benefits of sleep in terms of your brain. Um, I've been exercising a lot recently and have and have been reading a whole lot about runners and athletes and sport and sleep now seems to be one of the big areas that they're trying to kind of unlock. It's like they've focused on hydration, they've focused on fuel. They know about strength this and stretching that. But it seems now like sleep has become the the thing that they want to use to unlock true high performance. Is that something you've come across in your research?

Right. Okay. We've spoken a little bit about the the benefits of sleep in terms of your brain. Um, I've been exercising a lot recently and have and have been reading a whole lot about runners and athletes and sport and sleep now seems to be one of the big areas that they're trying to kind of unlock. It's like they've focused on hydration, they've focused on fuel. They know about strength this and stretching that. But it seems now like sleep has become the the thing that they want to use to unlock true high performance. Is that something you've come across in your research?

Yeah. So I've, I've worked with a number of sort of professional teams around the world and several athletes and several who are, uh, have been wonderfully vocal about how much sleep that they get, because there is a terrible stigma in society about getting sufficient sleep that you're lazy or you're slothful, or if you've got, you know, enough time to get seven hours of sleep, then you must not be busy enough. And busy is equated to importance. And so there's this stepping stone chain of shame that happens. And I think it's great that athletes have been embracing it. You know, a couple that I'm familiar with, um, you know, Federer is Roger Federer has been great in terms of advocating that LeBron James equally so. Um, Usain Bolt was was fantastic and would, um, one of the times he'd literally, I think, been awake for about, um, 36 minutes before after a nap, um, and went out and broke a world record, you know. So I think there is.

Yeah. So I've, I've worked with a number of sort of professional teams around the world and several athletes and several who are, uh, have been wonderfully vocal about how much sleep that they get, because there is a terrible stigma in society about getting sufficient sleep that you're lazy or you're slothful, or if you've got, you know, enough time to get seven hours of sleep, then you must not be busy enough. And busy is equated to importance. And so there's this stepping stone chain of shame that happens. And I think it's great that athletes have been embracing it. You know, a couple that I'm familiar with, um, you know, Federer is Roger Federer has been great in terms of advocating that LeBron James equally so. Um, Usain Bolt was was fantastic and would, um, one of the times he'd literally, I think, been awake for about, um, 36 minutes before after a nap, um, and went out and broke a world record, you know. So I think there is.

Right.

Right.

But nevertheless, I used to say about 7 or 8 years ago that sleep was perhaps the greatest legal performance enhancing drug that not enough athletes were abusing. But now the game, I think, has moved on. And because you're absolutely right, they've optimized, you know, almost all they can from nutrition, from exercise physiology, from different regiments of Determinants of mental health. Sleep now has come on to the map as a professional edge, and it doesn't take much. You know, if you look at the difference between, let's say, first place and sixth place or a first round pick in the NBA versus a seventh round pick, you know, the stats aren't that different. Everyone is much more similar than they are different. So every sort of edge counts. So we we work with a lot of teams and but particularly individual athletes to try to help them improve. And it's an especially difficult challenge for two reasons. With athletes, the first is usually before the game. Anxiety and stress is high. Yeah. And anxiety and stress are probably they are probably the leading, not the only, but the leading principle underlying cause of insomnia in society. And I think we you know, and I'm happy to speak about that. I think the second component of that is just the travel that almost no athlete that I've worked with simply performs locally. They all perform nationally or globally, and they're always traveling, so you've always got to try to augment a regiment that is under the duress of jetlag. And so the challenge is how do we get them to sleep to begin with? 5 or 6 years ago, the challenge was, how do we convince them that they need to sleep? Now it's the challenge. We accept that. How do we get it? Yeah.

But nevertheless, I used to say about 7 or 8 years ago that sleep was perhaps the greatest legal performance enhancing drug that not enough athletes were abusing. But now the game, I think, has moved on. And because you're absolutely right, they've optimized, you know, almost all they can from nutrition, from exercise physiology, from different regiments of Determinants of mental health. Sleep now has come on to the map as a professional edge, and it doesn't take much. You know, if you look at the difference between, let's say, first place and sixth place or a first round pick in the NBA versus a seventh round pick, you know, the stats aren't that different. Everyone is much more similar than they are different. So every sort of edge counts. So we we work with a lot of teams and but particularly individual athletes to try to help them improve. And it's an especially difficult challenge for two reasons. With athletes, the first is usually before the game. Anxiety and stress is high. Yeah. And anxiety and stress are probably they are probably the leading, not the only, but the leading principle underlying cause of insomnia in society. And I think we you know, and I'm happy to speak about that. I think the second component of that is just the travel that almost no athlete that I've worked with simply performs locally. They all perform nationally or globally, and they're always traveling, so you've always got to try to augment a regiment that is under the duress of jetlag. And so the challenge is how do we get them to sleep to begin with? 5 or 6 years ago, the challenge was, how do we convince them that they need to sleep? Now it's the challenge. We accept that. How do we get it? Yeah.

I imagine there's also you hear this a lot from Australian rules football players. Anyway, they play a night game and the adrenaline that's been coursing through their bodies for 2 or 3 hours while they play in front of 100,000 people under lights, is is wild. And then they're not finished and warm down and kind of changed and ready to go to bed until midnight. And it's still kind of coursing through their body. I mean, how are they expected to to get to sleep then?

I imagine there's also you hear this a lot from Australian rules football players. Anyway, they play a night game and the adrenaline that's been coursing through their bodies for 2 or 3 hours while they play in front of 100,000 people under lights, is is wild. And then they're not finished and warm down and kind of changed and ready to go to bed until midnight. And it's still kind of coursing through their body. I mean, how are they expected to to get to sleep then?

Yeah. And we see this in society a lot too. or a derivation of this. It's called the tired but wired phenomenon. Now for them, the wired is a chemical physiological wired in the sense that they're just coursing with endorphins, dynorphins, adrenaline, cortisol. Everything's racing through their veins. And it's completely antithetical to the physiological state that is needed to to sleep. So no wonder they can't. Even though they could tell you I'm really tired. There's no way I'm going to be able to sleep for the next two hours because they're just so wired. And in society, we have that version which again comes back to just stress and anxiety. You know, we see people at the sleep center all the time saying, I'm so tired. I am so desperately, desperately tired. But I'm just so wired that the Rolodex of anxiety and stress begins and I just cannot fall asleep. Or I wake up and I just cannot get back to sleep.

Yeah. And we see this in society a lot too. or a derivation of this. It's called the tired but wired phenomenon. Now for them, the wired is a chemical physiological wired in the sense that they're just coursing with endorphins, dynorphins, adrenaline, cortisol. Everything's racing through their veins. And it's completely antithetical to the physiological state that is needed to to sleep. So no wonder they can't. Even though they could tell you I'm really tired. There's no way I'm going to be able to sleep for the next two hours because they're just so wired. And in society, we have that version which again comes back to just stress and anxiety. You know, we see people at the sleep center all the time saying, I'm so tired. I am so desperately, desperately tired. But I'm just so wired that the Rolodex of anxiety and stress begins and I just cannot fall asleep. Or I wake up and I just cannot get back to sleep.

Just speaking about anxiety and stress and depression, um, those kinds of, um, mental health problems. Do you think sleep is kind of overlooked by the medical community, either GPS or psychologists or whoever it is, as, as a potential kind of underlying cause, or at least a contributing factor to those issues that people face?

Just speaking about anxiety and stress and depression, um, those kinds of, um, mental health problems. Do you think sleep is kind of overlooked by the medical community, either GPS or psychologists or whoever it is, as, as a potential kind of underlying cause, or at least a contributing factor to those issues that people face?

I think clinicians, um, are becoming more aware of the fact of sleep's integral role that, ah, sleep health is intimately tied to our mental health. And I would say, and this is probably the other largest area of research that we do at my center is in mental health. In the past 20 years of studying it, I've not been able to discover a single psychiatric condition in which sleep is normal. And for me, that tells me everything I need to know about the intimacy and the strength of that connection. So I think psychiatry in the 80s and 90s and early 2000, would see the sleep problems in mental illness as a as a symptom as a consequence of the mental illness. Now if you look at the data, I think people are at least seeing it as a two way street, and it really is a two way street. We know that insufficient sleep can predispose and even trigger mental health conditions. And we also know that on the flip side, mental health conditions will themselves, once they get started, instigate sleep disruption. So it is a vicious cycle. And once those those things start sort of working, it's almost like that tornado that just starts to spin out of control.

I think clinicians, um, are becoming more aware of the fact of sleep's integral role that, ah, sleep health is intimately tied to our mental health. And I would say, and this is probably the other largest area of research that we do at my center is in mental health. In the past 20 years of studying it, I've not been able to discover a single psychiatric condition in which sleep is normal. And for me, that tells me everything I need to know about the intimacy and the strength of that connection. So I think psychiatry in the 80s and 90s and early 2000, would see the sleep problems in mental illness as a as a symptom as a consequence of the mental illness. Now if you look at the data, I think people are at least seeing it as a two way street, and it really is a two way street. We know that insufficient sleep can predispose and even trigger mental health conditions. And we also know that on the flip side, mental health conditions will themselves, once they get started, instigate sleep disruption. So it is a vicious cycle. And once those those things start sort of working, it's almost like that tornado that just starts to spin out of control.

That flywheel.

That flywheel.

Yeah, exactly. Precisely. And in some ways it's a message of hope, though, because sleep at least gives you a sort of an entry point in to try to break that cycle, that sometimes it's fiendishly difficult to try to stabilize the mind with either therapy or medication. But if you can try to stabilize sleep through its natural sort of emotional first aid through its what I've described as overnight therapy benefit, it can come in and it can short circuit that constant negative spiral. And when you kind of right the ship and you course correct sleep, you often it's usually very uncommon that you don't at least see some improvement in the mental health symptoms.

Yeah, exactly. Precisely. And in some ways it's a message of hope, though, because sleep at least gives you a sort of an entry point in to try to break that cycle, that sometimes it's fiendishly difficult to try to stabilize the mind with either therapy or medication. But if you can try to stabilize sleep through its natural sort of emotional first aid through its what I've described as overnight therapy benefit, it can come in and it can short circuit that constant negative spiral. And when you kind of right the ship and you course correct sleep, you often it's usually very uncommon that you don't at least see some improvement in the mental health symptoms.

When I was a teenager, I could sleep until 2:00, 3:00 in the afternoon on a on a Saturday or a Sunday. Now, granted, I was sitting up late watching movies, and so that sort of only makes sense, but I always felt like I was actually just clawing back some of the sleep that I missed during the week from getting up early to go to school. Um, school does kind of start early for kids all, all around the world, and I feel like you have some pretty specific views on this, on how early, um, we get kids up and out the door and into the classroom.

When I was a teenager, I could sleep until 2:00, 3:00 in the afternoon on a on a Saturday or a Sunday. Now, granted, I was sitting up late watching movies, and so that sort of only makes sense, but I always felt like I was actually just clawing back some of the sleep that I missed during the week from getting up early to go to school. Um, school does kind of start early for kids all, all around the world, and I feel like you have some pretty specific views on this, on how early, um, we get kids up and out the door and into the classroom.

Yeah, I think this consistent and you can see it across almost all first world nations. There's this incessant model of marching school start times back and back and back earlier and earlier and earlier. And as we go through those adolescent teen years, something biologically interesting happens on natural rhythms. Start getting forced forward in time. So when before when we were, say, you know, ten years old, you know, you could get into bed and you could fall asleep nine, ten, you know, maybe earlier, but now once you're 15 years old, you now can't go to sleep or get sleepy until, let's say, midnight. And it's not because you're trying to be rebellious. There is actual biology. There's physiological machinery that shifts during that adolescent phase to push teenagers to a later to bedtime and later wake up time. It's not their fault, is point number one. The second point is that you're absolutely right. They have been lumbered with this incessant chronic sleep debt by forcing them to wake up so early. And if you look at these, um, models throughout the world where they've decided to kind of push back against this mentality and delay school start times, what you typically see when school start times are delayed are academic grades increase truancy rates, decrease attendance rates as a consequence, increase psychiatric and psychological referrals decrease. And then something also interesting happened. The lifespan of these individuals increased on average. And you think, well, wow, hang on a second. I don't understand how you could measure or track that. Well, the leading cause of death in adolescent teens from 16 to 18 is actually not suicide. That's second. It's road traffic accidents. And here sleep matters enormously. There's a great study from, um. It was Teton County in Wyoming in the United States. They shifted their school start times from 735 in the morning to 855 in the morning. And what they found was that not only were those kids getting an extra one hour of sleep the next following year, road traffic accidents dropped by 70%, so car crashes dropped seven zero in that 816 to 18 range. Now, to put that in context, you know, the advent of ABS technology, anti-lock brake systems in cars that dropped accident rates from 20 to 25%. But here is a physiological thing which is called giving your teenagers enough sleep that will drop accident rates by up to 70%. So, you know, I don't mean to trivialize it. Getting children to school at a certain time is not easy. Parents have got to get to work themselves. Bus unions and school buses, they've all got to sort of try to find. So it's not a it's not an easy thing I understand that. I also think, however, that we've been able to put people on the moon. So I think we can solve this because if you look at the data, when sleep is abundant, minds flourish. And when it is not, they don't. And I fear that we are we are doing a disservice to our children in the most sort of incredibly spectacular manner with this incessant model of early school start times. So I've been trying to lobby it throughout the throughout the United States and go state by state in terms of legislative law. And we're starting to make it happen, but it's very, very difficult.

Yeah, I think this consistent and you can see it across almost all first world nations. There's this incessant model of marching school start times back and back and back earlier and earlier and earlier. And as we go through those adolescent teen years, something biologically interesting happens on natural rhythms. Start getting forced forward in time. So when before when we were, say, you know, ten years old, you know, you could get into bed and you could fall asleep nine, ten, you know, maybe earlier, but now once you're 15 years old, you now can't go to sleep or get sleepy until, let's say, midnight. And it's not because you're trying to be rebellious. There is actual biology. There's physiological machinery that shifts during that adolescent phase to push teenagers to a later to bedtime and later wake up time. It's not their fault, is point number one. The second point is that you're absolutely right. They have been lumbered with this incessant chronic sleep debt by forcing them to wake up so early. And if you look at these, um, models throughout the world where they've decided to kind of push back against this mentality and delay school start times, what you typically see when school start times are delayed are academic grades increase truancy rates, decrease attendance rates as a consequence, increase psychiatric and psychological referrals decrease. And then something also interesting happened. The lifespan of these individuals increased on average. And you think, well, wow, hang on a second. I don't understand how you could measure or track that. Well, the leading cause of death in adolescent teens from 16 to 18 is actually not suicide. That's second. It's road traffic accidents. And here sleep matters enormously. There's a great study from, um. It was Teton County in Wyoming in the United States. They shifted their school start times from 735 in the morning to 855 in the morning. And what they found was that not only were those kids getting an extra one hour of sleep the next following year, road traffic accidents dropped by 70%, so car crashes dropped seven zero in that 816 to 18 range. Now, to put that in context, you know, the advent of ABS technology, anti-lock brake systems in cars that dropped accident rates from 20 to 25%. But here is a physiological thing which is called giving your teenagers enough sleep that will drop accident rates by up to 70%. So, you know, I don't mean to trivialize it. Getting children to school at a certain time is not easy. Parents have got to get to work themselves. Bus unions and school buses, they've all got to sort of try to find. So it's not a it's not an easy thing I understand that. I also think, however, that we've been able to put people on the moon. So I think we can solve this because if you look at the data, when sleep is abundant, minds flourish. And when it is not, they don't. And I fear that we are we are doing a disservice to our children in the most sort of incredibly spectacular manner with this incessant model of early school start times. So I've been trying to lobby it throughout the throughout the United States and go state by state in terms of legislative law. And we're starting to make it happen, but it's very, very difficult.

I'm one of those people who does not remember my dreams, at least unless I wake up and go, remember that dream, remember it, focus on it. And I've got to say, I also can't think of anything more boring than hearing about someone else's dreams. I hate it when someone says you won't believe what I dreamed last night. It was so bizarre.

I'm one of those people who does not remember my dreams, at least unless I wake up and go, remember that dream, remember it, focus on it. And I've got to say, I also can't think of anything more boring than hearing about someone else's dreams. I hate it when someone says you won't believe what I dreamed last night. It was so bizarre.

Imagine if.

Imagine if.

You're walking.

You're walking.

Through the world as a sleep scientist. That's all people want to tell you about. Either that or how to fix my sleep. But. But keep going. Yeah.

Through the world as a sleep scientist. That's all people want to tell you about. Either that or how to fix my sleep. But. But keep going. Yeah.

So I was going to ask, though, what did you dream about last night? And and what, uh, what purpose do dreams serve? I mean, dreams were referenced in the, in the subtitle of your book, so they're not a small part of what you, um, what you study and consider.

So I was going to ask, though, what did you dream about last night? And and what, uh, what purpose do dreams serve? I mean, dreams were referenced in the, in the subtitle of your book, so they're not a small part of what you, um, what you study and consider.

Yeah. Dreams are fascinating. They, you know, we used to think of dreams as just epiphenomenal that they are just the byproduct of the stage of sleep from which they arise, from which is principally rapid eye movement sleep. And the analogy would be coming back to Thomas Edison, let's say, you know, think about a light bulb. The reason that you've constructed the apparatus of a light bulb is to create this thing called light. But when you create light in that way, you also produce something called heat. Heat was never the design, purpose or brief of the light bulb. It's just epiphenomenal what happens when you create light in that way? And so too, we believe dreams were the heat of the REM sleep light bulb, right? But now I think we've got substantive evidence that dreams serve at least two unique functions above and beyond the stage of sleep from which they come, which is rapid eye movement. The first is that dreaming is almost like a form of informational alchemy. It's that during dreaming we start to collide. All of the recent things that we've learned with all of the back sort of catalog of information that we've got stored up in our brain, and as a consequence, we wake up with a revised mind wide web of associations that is capable of divining solutions to previously impenetrable problems.

Yeah. Dreams are fascinating. They, you know, we used to think of dreams as just epiphenomenal that they are just the byproduct of the stage of sleep from which they arise, from which is principally rapid eye movement sleep. And the analogy would be coming back to Thomas Edison, let's say, you know, think about a light bulb. The reason that you've constructed the apparatus of a light bulb is to create this thing called light. But when you create light in that way, you also produce something called heat. Heat was never the design, purpose or brief of the light bulb. It's just epiphenomenal what happens when you create light in that way? And so too, we believe dreams were the heat of the REM sleep light bulb, right? But now I think we've got substantive evidence that dreams serve at least two unique functions above and beyond the stage of sleep from which they come, which is rapid eye movement. The first is that dreaming is almost like a form of informational alchemy. It's that during dreaming we start to collide. All of the recent things that we've learned with all of the back sort of catalog of information that we've got stored up in our brain, and as a consequence, we wake up with a revised mind wide web of associations that is capable of divining solutions to previously impenetrable problems.

Okay, so it's sort of this, this period in which we knit together the the past and the present.

Okay, so it's sort of this, this period in which we knit together the the past and the present.

Yeah, yeah. You know, it's it's almost like group therapy for memories. You know, everyone gets a name badge, and you all go into this room of REM sleep at night and REM sleep. What's interesting, though, relative to wakefulness during wake, we build the obvious first kind of order connections. The logical ones. Dream sleep is like the Google search algorithm gone wrong that you input, you know, into this sort of, you know, um, you know, vivid Sydney. And all of a sudden you get something that is about a field hockey game in Utah in the United States. And you think, hang on a second. But if you look, there's a very strange, non-obvious association that seems to happen. And dream sleep has this kind of almost biased algorithm to seeking out the very distant non-obvious associations. Because when you start to fuse things together that shouldn't normally go together, but when they do, they offer marked advances in evolutionary fitness. It sounds like the basis of biological creativity, and that's one of the functions of dream sleep. The second function of dream sleep is radically different. It is a form of, as I sort of said before, overnight therapy. That is during dream sleep and the special chemical cocktail that happens during dream sleep that the brain is able to strip away the emotion from our memory experiences the day before. So a better analogy would be, um, dreaming. It's almost like a nocturnal, soothing balm. Okay, that dreaming sort of comes along and it just takes the sharp edges off those painful, difficult experiences so that you come back the next day and they're not as painful anymore. So you went to bed with an emotional memory, and you wake up the next day with a memory of an emotional event. But it's no longer emotional itself. Dreaming comes along and it almost divorces the emotion from the memory. It strips the bitter emotional rind from the informational orange, as it were. And that's why it provides this sort of mental health therapy overnight.

Yeah, yeah. You know, it's it's almost like group therapy for memories. You know, everyone gets a name badge, and you all go into this room of REM sleep at night and REM sleep. What's interesting, though, relative to wakefulness during wake, we build the obvious first kind of order connections. The logical ones. Dream sleep is like the Google search algorithm gone wrong that you input, you know, into this sort of, you know, um, you know, vivid Sydney. And all of a sudden you get something that is about a field hockey game in Utah in the United States. And you think, hang on a second. But if you look, there's a very strange, non-obvious association that seems to happen. And dream sleep has this kind of almost biased algorithm to seeking out the very distant non-obvious associations. Because when you start to fuse things together that shouldn't normally go together, but when they do, they offer marked advances in evolutionary fitness. It sounds like the basis of biological creativity, and that's one of the functions of dream sleep. The second function of dream sleep is radically different. It is a form of, as I sort of said before, overnight therapy. That is during dream sleep and the special chemical cocktail that happens during dream sleep that the brain is able to strip away the emotion from our memory experiences the day before. So a better analogy would be, um, dreaming. It's almost like a nocturnal, soothing balm. Okay, that dreaming sort of comes along and it just takes the sharp edges off those painful, difficult experiences so that you come back the next day and they're not as painful anymore. So you went to bed with an emotional memory, and you wake up the next day with a memory of an emotional event. But it's no longer emotional itself. Dreaming comes along and it almost divorces the emotion from the memory. It strips the bitter emotional rind from the informational orange, as it were. And that's why it provides this sort of mental health therapy overnight.

So what about what about, um, the opposite then? So if I, I have to sleep in, like, boxer shorts. Probably too much information for you there, but I can't sleep in heavy layers. I need a sheet rather than a big doona, whereas my my wife is sort of, um, cuddled under a bunch of different layers. But the long point I was getting to is if if I am wearing too much, if I'm too warm, I can guarantee I'm going to have a nightmare. So I just wanted to ask, what's the purpose of nightmares then? Or why do we have nightmares? Um, given, you know, the value of dreams that you were just talking about.

So what about what about, um, the opposite then? So if I, I have to sleep in, like, boxer shorts. Probably too much information for you there, but I can't sleep in heavy layers. I need a sheet rather than a big doona, whereas my my wife is sort of, um, cuddled under a bunch of different layers. But the long point I was getting to is if if I am wearing too much, if I'm too warm, I can guarantee I'm going to have a nightmare. So I just wanted to ask, what's the purpose of nightmares then? Or why do we have nightmares? Um, given, you know, the value of dreams that you were just talking about.

And it is interesting, you know, to your first point, sleep is immensely temperature sensitive. And we know that there is this unique kind of three part stanza to good temperature sleep, which is that you have to warm up to begin with at your surface to draw all of the blood out of the core. So you have to warm up to cool down. So you bring the blood to the surface by warming it. And then you radiate the heat out from the core that's trapped there like a snake charmer. And then your core body temperature plummets. So you have to warm up, to cool down, to fall asleep. And then you have to stay cool to stay asleep. And then you have to warm up to wake up. And I'm absolutely like you, you know, I, I have to sleep now. I sleep hot, and I'm usually there in kind of like a kind of like. And like you, you know, my wife, it looks like it's, you know, it's somewhat polar vortex, you know, because. And I'm, you know, I don't know, I may have lost it during the night. It's somewhere down the rabbit hole of covers. It's this monstrosity. So. So with rescue parties, most mornings it works out. But to your point, what's also interesting is that we don't just need to warm up to wake up, we need to warm up to go into dream sleep.

And it is interesting, you know, to your first point, sleep is immensely temperature sensitive. And we know that there is this unique kind of three part stanza to good temperature sleep, which is that you have to warm up to begin with at your surface to draw all of the blood out of the core. So you have to warm up to cool down. So you bring the blood to the surface by warming it. And then you radiate the heat out from the core that's trapped there like a snake charmer. And then your core body temperature plummets. So you have to warm up, to cool down, to fall asleep. And then you have to stay cool to stay asleep. And then you have to warm up to wake up. And I'm absolutely like you, you know, I, I have to sleep now. I sleep hot, and I'm usually there in kind of like a kind of like. And like you, you know, my wife, it looks like it's, you know, it's somewhat polar vortex, you know, because. And I'm, you know, I don't know, I may have lost it during the night. It's somewhere down the rabbit hole of covers. It's this monstrosity. So. So with rescue parties, most mornings it works out. But to your point, what's also interesting is that we don't just need to warm up to wake up, we need to warm up to go into dream sleep.

Right?

Right?

But if you get too hot, your dream sleep starts to get fragmented. So normally.

But if you get too hot, your dream sleep starts to get fragmented. So normally.

Okay.

Okay.

Dream sleep or REM sleep has what we call a thermoneutral sweet spot. Which means that if you get the ambient around you in underneath that blanket and it's just a small little layer, if you get that ambient temperature close to your core body temperature, then you are going to be riding nicely high on this thing called REM sleep. But if you get too warm, your REM sleep starts to become fragmented and you wake up more. And it could be that waking up more, that fragmented nature of REM sleep makes that dream sleep committed more to memory, which can also lead to frustration or sort of embedding some of the, you know, the negative parts of the dream or the fearful parts. And that can lead you to think I'm having more nightmares. As a consequence, nightmares per se aren't necessarily problematic. Many people will have nightmares. It just seems to be part and parcel of natural sleep. However, if the nightmares are causing you daytime distress or nighttime distress where you actually are starting to fear the notion of going to bed because you don't want a nightmare, then seek out a specialist. We now have some great treatments for nightmares. One of the treatments that people can just Google and find someone locally, um, who will provide this service is called image rehearsal therapy or I r t. Okay. And you work with a therapist and you start recalling the dream during the therapy session. But what you do is you take the traumatic part of the memory of the dream and you change it. It's like going into a word document of a nightmare and saying, you know, towards the end it got really scary and I don't like that. So I'm just going to rehearse. I'm just going to kind of cross it out, and I'm going to go in there and do some suggested edits, some track changes. And if you do that time and time again, the memory circuit actually gets rewritten. So you're going to rewrite your own nightmare autobiographical history. And if you keep doing that day after day and then sleep to strengthen that newly updated memory, over time the nightmare frequency decreases.

Dream sleep or REM sleep has what we call a thermoneutral sweet spot. Which means that if you get the ambient around you in underneath that blanket and it's just a small little layer, if you get that ambient temperature close to your core body temperature, then you are going to be riding nicely high on this thing called REM sleep. But if you get too warm, your REM sleep starts to become fragmented and you wake up more. And it could be that waking up more, that fragmented nature of REM sleep makes that dream sleep committed more to memory, which can also lead to frustration or sort of embedding some of the, you know, the negative parts of the dream or the fearful parts. And that can lead you to think I'm having more nightmares. As a consequence, nightmares per se aren't necessarily problematic. Many people will have nightmares. It just seems to be part and parcel of natural sleep. However, if the nightmares are causing you daytime distress or nighttime distress where you actually are starting to fear the notion of going to bed because you don't want a nightmare, then seek out a specialist. We now have some great treatments for nightmares. One of the treatments that people can just Google and find someone locally, um, who will provide this service is called image rehearsal therapy or I r t. Okay. And you work with a therapist and you start recalling the dream during the therapy session. But what you do is you take the traumatic part of the memory of the dream and you change it. It's like going into a word document of a nightmare and saying, you know, towards the end it got really scary and I don't like that. So I'm just going to rehearse. I'm just going to kind of cross it out, and I'm going to go in there and do some suggested edits, some track changes. And if you do that time and time again, the memory circuit actually gets rewritten. So you're going to rewrite your own nightmare autobiographical history. And if you keep doing that day after day and then sleep to strengthen that newly updated memory, over time the nightmare frequency decreases.

Fantastic. I can't believe we've eaten up so much time. I've got so many other questions I could ask you about sleep. I wanted to talk about the the kind of growing commercial field of sleep, wellness and what's next on the horizon in sleep research and whatnot, but I feel like I've made listeners wait long enough for the thing that they probably want from this and that, the thing that people probably want from you every time they run into you. It's the it's got to be the top tips for for good sleep, right? What what can people do to ensure that they get better sleep and enjoy all these benefits that you've been talking about today?

Fantastic. I can't believe we've eaten up so much time. I've got so many other questions I could ask you about sleep. I wanted to talk about the the kind of growing commercial field of sleep, wellness and what's next on the horizon in sleep research and whatnot, but I feel like I've made listeners wait long enough for the thing that they probably want from this and that, the thing that people probably want from you every time they run into you. It's the it's got to be the top tips for for good sleep, right? What what can people do to ensure that they get better sleep and enjoy all these benefits that you've been talking about today?

Yeah, I would say the the first set is probably the really boring stuff that everyone's heard, which is sleep hygiene. You know, we think about dental hygiene. Well, there's sleep hygiene and that's things like, you know, making sure that you are trying to stay away from too much caffeine in the afternoon, certainly in the evening, trying to limit your alcohol use. Alcohol. People will say, if I have a cup of nightcaps in the evening, I fall asleep. Great. Alcohol is in a class of drugs that we call the sedatives, and sedation is not sleep, so you're just mistaking the former for the latter in that regard. The other thing I would say is alcohol will also fragment your sleep. So even if you fall asleep, you will wake up many times throughout the night. But you don't commit the wakening, the wake ups to memory. So you wake up the next day and now you're kind of reaching for 3 or 4 cups of coffee because you don't feel restored and refreshed. And now what happens is that you get overactivated on stimulants during the day, and you have to take on board more alcohol in the evening to try to bring you back down. So it's basically a kind of a go pill and a stop pill. It's this, sort of this, this real sort of, um, unfortunate cycle and dependency that starts to develop, um, some of the sleep hygiene, keep it cool. Bedroom temperature probably around about, sort of about sort of 17 to 18 degrees. Um, sounds cold for most people, but you need to sort of keep it around. There were socks, you know, put a hot water bottle at the end of the bed. That's fine too, but the ambient has to be cold. Um, as for the kind of unconventional tips, the first thing I would probably tell people is do this experiment for the next seven days, and if it doesn't work, just say that guy is full of absolute nonsense. Set an alarm for one hour before you expect to go to bed. When that alarm goes off, shut down almost all of the lights in your house. You will be stunned by how sleepy and soporific that will make you feel. And it does a number of things. Firstly, we're a dark, deprived society in this modern era, and we need darkness at night to trigger the release of a hormone called melatonin to help structure our sleep. The second thing is that it stops you being so mentally active when it's dark around you, it's hard to get activated and agitated. It also starts to reduce down. The likelihood doesn't stop it, but the likelihood that you then want to jump onto your laptop or on your phone because you're looking at the screen with the dark ambient around you, it's almost a little bit too much. The second tip, I would say, is the devices that we use are we used to think were a problem for sleep because of the blue light. And there was some good studies suggesting that now really based on a fantastic, uh, sleep scientist from Australia, Michael Gradisar, single handedly has really just converted the field. He's demonstrated it's not really the blue light, it's that these devices are attention capture devices, and they are designed to fleece you of your attention economy, and they do it ruthlessly well. And so it's because these devices are so activating that you could be very sleepy. And if you took them away and it was just pitch black, you'd say, gosh, actually I'm surprised. I'm actually quite sleepy. But they hit the mute button on your sleepiness and they and they cause what's called sleep procrastination. So I would say in the last hour before bed lights go out, it will bring you back down physiologically and psychologically. Try to limit the use of those devices not because of the blue light, but because they are activating. And then the following rule of thumb if you absolutely have to take your phone into your bedroom, and I know I understand that the following rule is this you can only use your phone in the bedroom standing up. And then at that point after about 7 or 8 minutes, you then you think, ah, I'm just I'm just going to have a bit of a sit down. Sorry. At that point phone goes away. The other thing I would say the probably the biggest issue that people face with sleep, either falling asleep or staying asleep is anxiety, stress. It's the Rolodex of anxiety because in the modern era, we're constantly on reception and very rarely do we do reflection. And the only time we now do Reflection in society is when we turn the light out and our head hits the pillow. And that's the worst time to be doing reflection, right? And so at that point, if you can't fall asleep and that stress has started to happen in the mind at that point, you start to ruminate. When you ruminate, you catastrophize. And when you catastrophize, you're dead in the water for the next two hours. Because everything, at least to me, feels twice as bad in the dark of night as it does in the light of day. So your job at 3 a.m. in the morning is the following. Get your mind off itself. How do you do that? At least five different ways. First, meditation. It's well proven to help people. It may not be your thing. So what else do you have for me? The next thing that you can do is just do what's called a body scan. Start at the top of the head. Just start to feel the tension in your body. Is your forehead too tense? Start to relax it. Feel the tension in your neck. Start to relax and just move throughout the body. If you don't like the sound of that do box breathing, you can inhale in for five seconds, hold it for five seconds, and then exhale for 7 or 8 seconds. And there's lots of different versions of that you can do. Another thing that you can do is take yourself on a mental walk.