Sleep is probably the single most effective thing you can do to reset your brain and body. So that’s a functional answer in terms of, you know, what is sleep in terms of its benefits? Sleep as a process, though, is an incredibly complex physiological ballet. And if you were to recognize or see what happens to your brain and your body at night during sleep, you would be blown away. And the paradox is that most of us, and i would think this too, you know, if i wasn’t a sleep scientist, we go to bed, we lose consciousness for seven to nine hours, and then we sort of wake Up in the morning and we generally feel better. And in some ways, that denies the physiological and biological beauty of sleep. So, upstairs in your brain, when you’re going through these different stages of sleep, the the changes in brain wave activity are far more dramatic than those that we see when we’re Awake. And we can speak about deep sleep, and what happens there. Rem sleep is a fascinating time, which is another stage of sleep, often called dream sleep, which is rapid eye movement sleep. That stage of sleep, some parts of your brain are up to 30 % more active than when you are awake. So again, it’s kind of violating this idea that our mind is dormant and our body is just simply quiescent and unresting. So i would hap pit a a sort of double click on either one of those, and also what changes in the body as well. But it is an intense evolutionary adaptive benefit and system. (Time 0:06:59)
¿Qué fue primero? ¿El sueño o la vigilia? Transcript: Speaker 1 When we think about the question of sleep and what sleep is, our assumption has always been that we evolved to sleep. And i’ve actually questioned that. And i have no way to get in a time capsule and go back and prove this, but what if we started off sleeping, and it was from sleep that wakefulness emerged? Why do we assume that it’s the other way around? And i think probably some really good evidence that sleep may have been the proto state, that it was the basic fundamental living state. And when we became awake, as it were, we always had to return to sleep in some ways. At that point. Sleep was the price that we paid for wakefulness. And that’s another way of describing what sleep is. But again, i think it sort of denies that the active state of sleep is not a passive state of sleep either. (Time 0:08:43)
El sueño paradójico (REM): Mente activa y cuerpo paralizado Transcript: Speaker 2 So, um, you mention how active the brain is during certain phases of sleep. When i was coming up in science, remsleep, rapid eye movement sleep, was referred to as paradoxical sleep. Yes, that’s still a good way to think about it, paradoxical, because the brain is so active, and yet we are essentially paralyzed, correct? Speaker 1 Yes, it really is a paradox. And where that came from was simply the brain wave recordings. That if all i’m measuring about you is your brain wave activity, it’s very difficult for me, sitting outside of the sleep laboratory room, to figure out, are you awake or are you in rem Sleep? Because those two pattens of brain activity are so close to one another, you can’t discriminate between them. Yet the paradox is that when you are awake, i go in there and yourestead of sitting up, you’re clearly conscious and awake. But yet, when you go intorems, you are completely paralyzed. And that’s one of the, i think that’s part of the paradox. But the paradox really just comes down to two dramatically different conscious states, yet brain activity is dramatically more similar than different. And the way i can figure out which of the two you are in is by measuring two other signals, the activity from your eyes and the activity from your muscles. So when we’re awake, we will occasionally have these blinks, and we’ll have set of scads. But during ram sleep, you have these really bizarre horizontal, shuttling eye movements that occur. And that’s where the name comes from, rapid eye movements. (Time 0:10:20)
The Paradox of Wakefulness and Rem Sleep Brain Activity Transcript: Speaker 1 Yes, it really is a paradox. And where that came from was simply the brain wave recordings. That if all i’m measuring about you is your brain wave activity, it’s very difficult for me, sitting outside of the sleep laboratory room, to figure out, are you awake or are you in rem Sleep? Because those two pattens of brain activity are so close to one another, you can’t discriminate between them. Yet the paradox is that when you are awake, i go in there and yourestead of sitting up, you’re clearly conscious and awake. But yet, when you go intorems, you are completely paralyzed. And that’s one of the, i think that’s part of the paradox. But the paradox really just comes down to two dramatically different conscious states, yet brain activity is dramatically more similar than different. And the way i can figure out which of the two you are in is by measuring two other signals, the activity from your eyes and the activity from your muscles. So when we’re awake, we will occasionally have these blinks, and we’ll have set of scads. But during ram sleep, you have these really bizarre horizontal, shuttling eye movements that occur. And that’s where the name comes from, rapid eye movements. Speaker 2 They are always horizontal, mostly they are horizontal. Speaker 1 And that’s one of the ways that we can differentiate them from other waking eye movement activity, because it’s not alwaysit can be sometimes horizontal, but can also have diagonal And also vertical in that plane. But then the muscle activity is the real dead give away. (Time 0:10:38)
El tronco encefálico paraliza el cuerpo durante el sueño REM Transcript: Speaker 1 Just before you enter rem sleep, your brain stem, which is where the dynamics of non rem and rem are essentially played out and then expressed upstairs in the cortex and downstairs in The bodyad when we go into rem sleep. And just a few seconds before that happens, the brain stem sends a signal all the way down the spinal cord, and it communicates with what are called the alpha motor nurons in the spinal Cord, which control the voluntary scaletal muscles. And it’s a signal of paralysis. And when you go into dream sleep, you are locked in a physical incarceration of your own body. Mas, you know, why? Why would mother nature do such a thing? And it’s, in some ways very simple. The brain paralyzes the body so that the mind can dream safely. Because think about how quickly we would have all been popped out of the jean pool. You know, if i think i’m, you know, one of the best sky divers who canjust simply fly, and i’ve had sometimes those dreams too, you know, and i get up on my apartment window and i leap out. You’e done. You’re done, you know. So that’s one of the sort of, that’s part of the paradox of rem sleep, both its brain activity similarity, despite the behavioral state being so different, and this bizarre lock down Of the the sort of brain of the body itself. Now, of course, the involuntary muscles, thankfully, aren’t ar paralyzed, so you keep breathing, your heart keeps beating. (Time 0:12:19)
rem sueño parálisis tronco_encefálico
Tormentas autonómicas durante el sueño REM Transcript: Speaker 1 So there is a nervous a part of our nervous system, called the autonomic nervous system, and it controls many of the automatic behaviours. And some of those are aspects of ar reproductive facilities during rem sleep. What we later discovered is that you go through these bizarre what we call autonomic storms, which sounds dramatic, but it actually is, when you measure them, that you’ll go through Periods where your heart rate decelerates and drops, and your blood pressure goes down. And then utterly, randomly, your heart rate accelerates dramatically. And what we call the fight or flight branch of the autonomic nervous system, or the sympathetic nervous system, badly named cause it’s anything but sympathetic. It’s very aggravating, a that all of a sudden fires up, and then it shuts down again, and it’s not in any regular way. And it’s when you get those autonomic storms, you get very activated, from a physiology perspective, that you can have these erections, and you have vaginal discharge. (Time 0:14:03)
rem simpático sistema_nervioso_autónomo
Arquitectura típica del sueño Transcript: Speaker 1 So when i first fall asleep, i’ll go into the light stages of noram sleep, stages one and two of nonrem. And then i’ll start to descend down into the deeper stages of non rem sleep. So after about maybe 20 minutes, i’m starting to head down into stage three, non rem and then into stage four, non rem sleep. And as i’m starting to fall asleep, as i’ve cast off from the usually with me murky waters of wakefulness, and am in the shallows of sleep stages one and two, my heart rate starts to drop A litt bit. And then my brain wave patent activity starts to slow down. Normally, when i’m awake, it’s going up and down maybe 20, 30, forty, 50 times a second. As i’m going into light non rem sleep, it will slow down to maybe 15, 20. And then really starts to slow down down to about ten or eight cycles per second, eight cyc waves per second. (Time 0:19:02)
Descargas neuronales coordinadas durante NREM4 Transcript: Speaker 1 So as i’m starting to go into those deeper stages of ram sleep, all of a sudden, hundreds of thousands of cells in my cortex all decide to fire together, and then they all go silent together. And it’s this remarkable physiological co ordination of the likes that we just don’t see during any other brain state. Speaker 2 Tit’s really interesting, having recorted from the brains ofof animals and a little bit from humans, i don’t think i seing the entire cortex, or even entire regions of cortex, light Up like that. I it’s stunning. Speaker 1 It’s almost like this beautiful sort of mantre chant all this sort of, you know, it’s a slow inhale and then a meditative exhale inhale, exhale. And these waves are just enormous in their size. (Time 0:20:21)
¿Cómo evaluamos la función de cada tipo de sueño? Transcript: Speaker 1 But we actually use exactly what you just described as an experimental technique to selectively deprive people of one of those stages of sleep or the other. So we will do first half of the night privation and then let you sleep the second half. So that means that you will be mostly deep sleep deprived, and you will still get mostly all of your rem sleep. And then we switch it so you only get your first four hours, which means you will mostly get deep, non rem sleep, but you will get almost no rem sleep. So in both of those groups, they’ve both had four hours of sleep. So the difference between them, in terms of experimental outcome, is not the sleep time, because they’ve both slept for the same amount. It’s the contribution of those different stages. Now we actually have more elegant methods for sort of selectively going in there and scooping out different stages of sleep. But that’s the way we used to do at old school, was just using this timing difference. (Time 0:26:51)
The Effects of Deep Sleep on Autonomic Function, Hormones, and Alcohol Transcript: Speaker 1 No, i think much of that is correct. And it’s sort of that plus. So for example, during deep, nonrem sleep, that’s where we get this. It’s almost a form of atural blood pressure medication. And so when i take that away from you the next day, we’re usually going to see autonomic disfunction, we’re usually going to see abnormalities in heart rate, blood pressure. We also know that during deep, non rem sleep that there is a certain control of specific hormones. For example, we know that the insolent regulation of sort of metabolism, meaning how will you look from a regulated blood sugar perspective versus disregulated, pre diabetic look Of profile? That’s where deep sleep seems to matter. If we selectively deprive you of that. We grosnim growth ormer is different. Achley, so that’s, that’s a beautiful demonstration where growth hormont seems to be more rem sleep dependent. And that’s why we can come on to the effects of alcohol. And theres some really impressive, frightening data on on alcohol in its disruption of of sleep. But then we also know test osterome pique, levels of test osterone, happen during rem sleep, the second half of the night, the second half of the night. So it really just means that the your profile of mental and physical disfunction will be different under both of those conditions. Which one would you prefer? I would prefer neither of them. And it really depends on what you’re trying to optimize for. So it. (Time 0:28:59)
The Effects of Alcohol on Blood Pressure Transcript: Speaker 1 So for example, during deep, nonrem sleep, that’s where we get this. It’s almost a form of atural blood pressure medication. And so when i take that away from you the next day, we’re usually going to see autonomic disfunction, we’re usually going to see abnormalities in heart rate, blood pressure. We also know that during deep, non rem sleep that there is a certain control of specific hormones. For example, we know that the insolent regulation of sort of metabolism, meaning how will you look from a regulated blood sugar perspective versus disregulated, pre diabetic look Of profile? (Time 0:29:04)
The Impact of Mid-Night Wakeups on Sleep Quality and Daily Functioning Transcript: Speaker 2 I want to introduce another, a gdunkin experiment, other thought experiment. So in this ark of the night, a slowy sleep pre nates early in the night, and then rem sleep. There’s a scenario that many people, including myself, experience on a regular basis, which is, they go to sleep, sleeping just fine, three, four hours into it, they wake up. They wake up for whatever reason. Maybe there’s a noise, maybe the temperature isn’t right, we will certainly talk about sleep hygiene, et cetera. They get up, they go to the rest room. They might flip on the lights, they might they’ll get back in bed, hopefully they’re not picking up their phone and starting to rouse and wake up the brain through various mechanisms Light and cognive stimulation, et cetera. They go back to sleep. Let’s say after about ten, fiftyen minutes, they’re able to fall back asleep. Then they sleep till theyre more typical wake time. How detrimental is that wake up episode or or a event, in terms of longevity, learning, et cetera. I would love to sleep the entire night through every night, but in most nights i don’t. And yet i feel pretty good throughout the day. Some days better than others. So if you were to t to evaluate that waking episode and compare it to sleeping the whole night through whata, what are your thoughts on that? (Time 0:32:22)
The Importance of Sunlight Stimulation and Morning Routines Transcript: Speaker 2 And all you did was just spend some time working in front of windows. That’s great. Robably, um, folks might want to consider spending a little less time with sun glasses, provided they can do that safely. No driving, et cetera. You’re not alone with your exercise behaviour in facing east. So a, the one and only tim ferris, told me recently that his morning routine nowadays consists of jumping rope while facing east to get the sunlight stimulation ofthe eyes. And a, as mat and i both know, it has to be of the ithese portals are the only way to am convey to the rest of the brain and body. About the time of day and wakefulness. Um, along the lines of wakefulness, i’ve a number of questions about katine, the dreaded and beloved kafin. I love kati, but i like it in relativelya restricted periods of time. (Time 0:48:40)
How does caffeine work to make us feel more alert? Transcript: Speaker 2 And that idea came to me on the basis of my understanding of how kafine and the denisene eceptor interact. I’ve a feeling you’re gong to pronounce a denisene differently than inoiill go with the denisil. I’ll try to go with your skiletl instead of skeletalsinasan, sinaps sche duan it. There we go. But im but to make it really simple for folks, how does kafine work to make us feel more alert? And does the timing in which we injest kafine play an important role in whether or not it works for us or against us? So may we just start with how does cafine work? Why is it that when i drink mate or coffee, which are my preferred sources of caffine, do i feel a mental and physical lift? Speaker 1 Yes. So i am going to suggest count to what most people would think, drink coffee. Or mate is mate, whatever form you willwill come on to sot of why i suggest that. But when it comes to coffee, i would say the dose and the timing makes the poison. So let’s start with how kafine works. A kaffine is in a class of drugs that we call the psychoactive stimulants. So it works through a variety of mechanisms. One is a dopermine mechanism. (Time 0:49:53)
Our Ability to Smell and Sense Pressure: The Impact on Wakefulness and Sleepiness Transcript: Speaker 2 Ahour ability to to smell or to sense pressure on the s, everything’s a push. H, it’s greaty. So this is another example, where as i am awake longer, a denisene is released in the brain, and my wakefulness areas are being actively shut down by that denosene, and my sleepiness Brain areas, so to speak, are being promoted to be more active. Is that correct? That’s right. And it’s a very progressive process. Speaker 1 It’s not like a step function. We and sometimes that happens occasionally, but it’s usually because you’ve been sort of driving through and, as we’ll come on, to have kaffine in the system, and then all of a sudden, You just hit a wall, and it just, you know, engulfs you, and you go from oto the wone of sleepiness within a short period of time. Speaker 2 What explains the fatigue after a hard conversation, the desire to go to sleep, or the desire to go to sleep during a hard conversation? Speaker 1 I that’s an interesting ot. I think it’s usually just based on personality, tivinsurrections, and for the most part, not bat i’ve ever experienced that. Speaker 2 No, people with you don’t, but with me, they all o ont. Speaker 1 Know, i idono the desire to some conversations, i’m half way through them, and i’ feel like i want to take a nap, ye, right? A. And i would love to look at, you know, people’s sleep history. We’ve sort of seen that time and time again. (Time 0:54:18)
The Impact of Caffeine on Sleep Quality Transcript: Speaker 2 And it’s interesting, because the kaffine crash at two o’clock in the afternoon, when you have work to do, is a terrible thing. But what about the person, maybe this person is me in my twenties, who says, i want to drink kaffine all day long, and then i want the crash. Because at nine or ten p m, if i stop drinking kafine at, say, six p m, and i crash, then i crash to a slumber, a deep night of sleep. Is that sleep really as deep as i think it is? Because given the half life of kafine that you mentioned a few moments ago. I have to imagine that having some of that kafine circulating in my system might disrupt the depth of sleep, or somehow the architecture of sleep in a way that even if i get eight, or, who Knows, even ten hours of sleep, it might not be as restorative as i would like it to be, yes? Speaker 1 And that is the danger, just of that. You know, those people that you describe who say, and i a lot of them will a speak with me too, say, look, i can have two expresses with dinner, and i fall asleep fine, and i stay asleep. (Time 1:00:25)
The Impact of Alcohol on Sleep Transcript: Speaker 2 And and i think am it’s clear that we all need that we all can and should do certain things better, including being gentle with ourselves from time to time when we deviate from these, these Ideal circumstances. Along these lines, i do want to talk about alcohol, because i think kaffine and alcohol represent the o account of two opposite ends of the spectrum. Clearly, there are other stimulants. There re your aderals and your a high energy drinks that people uset but alcohol and kaffine are the most commonly consumed stimulantsd and sedatives, depressens, as they are sometimes Called. So a, what happens when somebody has a glass, we always a glass or two of wine in the evening, or or a a cocktail after dinner or before dinner? How does that impact their sleep? And then we’ll be sure to circle back in terms of what is reasonable ranges of behavior when it comes to avoiding alcohol, or if it’s age appropriate, et cetera, enjoying alcohol. Speaker 1 E so alcohol, if we’re thinking about classes of drugs, they’re in a class of drugs that we call the sedatives. And i think one of the first problems that people often mistake, alcohol is often used as a sleep aid for people who are struggling with sleep whern. Things like over the counter remedies, et cetera, or herbal remedies, have just not worked out for them. (Time 1:07:36)
Alcohol afecta negativamente la calidad del dormir. Transcript: Speaker 1 If we look at the pattern of brain activity, if i were to place you inside and m ri skenner werwre looking at the activity of your brain and watch you drifting off, some parts of your brain Will become less at other parts will become more active. And this is the push polle model, inhibition, excitation. But alcohol is quite different in that regard. Alcohol is because it’s a sedative. What it’s really doing is trying to essentially knock out your quortex. It’s sedating your cortex. And sedation is not sleep. But when we have a couple of drinks in the evening, when we have a couple of nightcaps, we mistake sedatian for sleep. Saying, while i always, when i havea a couple of whiskis or a couple of cocktails, it always helps me fall asleep faster, in truth, what’s happening is that you’re losing consciousness Quicker, but you’re not necessarily falling naturalistically asleep any quicker. So that’s one of the first sort of things just to keep in mind. The second thing with alcohol is that it mence your sleep. And we spoke about the quality of your sleep being just as important as the quantity. An alcohol, through a variety of mechanisms, some of which are activation of that autonomic nervous system, that fight or flight branch of the nervous system, alcohol will actually Have you waking up many more times throughout the night. So your sleep is far less continuous. Now, some of tose awakenings will be of conscious recollection. The next day, you’ll just remember waking up. Many of them won’t be and so but yet, your sleep will be littered with these sort of punctured awakenings throughout the night. And again, when you wake up the next morning, you don’t feel restored by your sleep. You know, fragmented sleep, or non continuous sleep in this alcohol induced is usually not good quality sleep that you feel great on the next day. The the third part of alcohol, in terms of an equation, is that it’s quite potent blocking your rem sleep, your rapid eye movement. Sleep and rem sleep is critical for a variety of cognitive functions, ar some aspects of learning and memory. Seems to be critical for aspects of emotional and mental health. You’ve described it before as a sort of self generated therapy that occurs while we sleep. Yes, it’s overnight therapy. You know, it’s emotional first aid. (Time 1:09:48)
alcohol calidad dormir efectos
CBD and Sleep: The Impact and Benefits Explained Transcript: Speaker 2 And actually it’s, it’s a perfect segwav from we’ve talked about, katine, alcohol, thc and cbd, a sort of, we’ve framed them anyway, as things that done in moderation at the appropriate Times, are probably ok for most people, certainly not for everybody. There will be differences in sensitivity. But that done at the incorrect times and certainly in the incorrect amounts, will greatly disrupt this vital stage of life we call sleep. Cbd, it seems, represents a kind of bridge to the topic i’d like to talk about next, which is things that promote more healthy sleep, or somehow contribute to enhancing the architecture And quality of sleep. So i’d love to chat for a moment about the kind of grant, the original, i should say, tha, not the grand daddy, but the o g of sleep supplementation, which is melotonin, eh, the so called Hornmone of dark that’s inhibited by light, et cetera frame for us melotonan in the context of its naturally occurring form. And then i’d like to talk about melotone an, the supplement becauses, in my experience, any time i say the word melotonan, people think about the supplement melotonin, which in itself Is an interesting, a, a phenomenon that people are so cued to its role as something you take. We often for that this is something that we make indognously. I’d love for you to comment in particular on, even though e without necessarily getting intos precise nanograms per destilete or values, what are the typical amounts of melotonin That we release each night? And then i’d like to compare that to what is contained in, say, a three milligram or six milligram tablet that one might buy at the pharmacy, right? So i go to sleep at night, has melotonin ready kicked in before i shut my eyes and lay down my head? (Time 1:35:19)
The Biological Clock and its Regulation Transcript: Speaker 2 It’s correct. Speaker 1 So ye, essentially, your brain has a central maste 24 hour clock called the super csmatic nucleus, keeps internal time. Now, it’s not a precise clock. If left to its own devices, nothing that a swiss clock maker would be proud of. Speaker 2 It runs a little bit long and laggy, like an american clock sothe’re a couple of good american watches, by the way, hamiltons are very, very much likea bo we’re not famous for our timekeeping Or our punctuality for them. But the swiss ar it’s veryi it’s not quite swiss like, more berkely like, which is very relaxed, no, you know, whatever. Speaker 1 So in most adults, the average adult, i should say, your biological clock normally runs a little bit long. It’s about, ar about 24 hours and 13 minutes, i think was the last calculation. But the reason that we don’t keep drifting forward in time and cand of running consistently, you know, more later and later, 30 minutes by 30 minutes by 30 minutes each day, is because Your central brain clock is regulated by external things such as daylight and temperature, as well as food and activity. (Time 1:39:26)
Do You Take a Nap? Transcript: Speaker 2 Soi, i a, agree with everything you said, and i’m a, i personally never taking trip to fan or seratonan again, unless there’s some clinical reason for that that i would need to do that. I want to ask about some other pro sleep behaviors. But before i do that, let’s talk about naps. I love naps. I come from a long history of nappers. A, my ad always took a nap in the afternoon. I take a 20 or 30 minute nap. Or i do a practice which i a took the liberty of coining n s d r, non sleep, deep rest, some sort of just passive laying chine out there, feet up, elevated. Sometimes people do. Or i’ll do yoganidra, i’ll do hypnosis or something of that sort. But 20 or 30 minutes of that has been very beneficial for me to get up from that nap, or period of minimal wakefulness, we’ll call it, and go about my day quite well, and also fall asleep Just fine. What are the data on naps? A, do you nap? And what are your thoughts about keeping naps short, meaning 20 to 30 minutes, versus getting out past 90 minutes, two hours? (Time 2:19:10)
Or i don’t nap Transcript: Speaker 1 Or i don’t nap im and i’ve just never been a habitual napper. Speaker 2 Is that because you don’t feel sleepy in the afternoon? Speaker 1 Or becausee don’t feel sleepy, you’re just hardier than i am? I wouldn’t say hardier. I may be a less capable of falling asleep, but yu got the rag ry afternoon. No, no, i don’t drag through. Speaker 2 I don’t nap because you don’t feel a needto. That’s right now. Speaker 1 It’s not that i am immune to what we call the post prandial dip in alertness. I definitely feel as though there can be thisn afternall, afternoon lull wer. You know, i’m not quite as on as i was at 11 o’clock in the morning. And we know the physiology to that. Which brings us back to whether we were designed to nap. So for naps, we’ve done lots of different study, and other colleagues have done these thities too. Naps can have some really great benefits. Wev found benefits for codiovescular health, blood pressure, for example. We found benefits for levels of cartusal. We found benefits for learning and memory and also emotional regulation. How long are the naps? Typically in those studies, anywhere between 20 minutes to 90 minutes. Sometimes we like to use a 90 minute window so that the part but can have a full cycle of sleep, and therefore they get both non rem and rem sleep within that time period. (Time 2:20:24)
The benefits and dark side of napping Transcript: Speaker 1 And what they found was that naps of little as 26 minutes improved a a mission performance by 34 % and improved daytime alertness by 50 %. And it birthed what was then called the nassa nap culture throughout all terrestrial nassa staff during that time period. So it’s long been known that naps can have a benefit. Naps, however, can have a double edged sword. There is a dark side to naps. And it comes back to our story of a denisene and sleep pressure. The longer we’re awake, the more of that sleep pressure, denosene, that we build up. But what i didn’t tell you is that when we sleep, the brain gets the chance to essentially clear out that adenisene. And after about 16 hours of wakefulness, and then after about eight hours of sleep, eight hours of sleep seems o able to allow the brain to decrease its adenicene levels back to normal. And so naturally we should start to wake up, which also allines with your cicadian rhythm. And those are two separate processes. But with about eight hours of good quality sleep, seven to nine hours for the average adult, we are free of all f that adenisene. We’ve evacuated it essentially out of the brain. And we wake up natr feeling refreshed. (Time 2:22:51)