¿Qué es el sueño? Transcript: Andrew Huberman Talked about sleep and its utility and its challenges and how to conquer it, so to speak. Let’s start off very basic. What is sleep? Matt Walker Sleep is probably the single most effective thing you can do to reset your brain and body health. So that’s a functional answer in terms of 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 changes in brainwave 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’re awake. So again, it’s kind of violating this idea that our mind is dormant and our body is just simply quiescent and resting. So I would happy (Time 0:06:59)
¿Qué fue primero? ¿El sueño o la vigilia? Transcript: Matt Walker Evolutionary adaptive benefit and system. That said, though, I would almost push back against an evolved system. 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 there’s 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 (Time 0:08:43)
El sueño paradójico (REM): Mente activa y cuerpo paralizado Transcript: Matt Walker From the perspective of what sleep is. It’s also practically impactful for our daily lives. And I’d love to sort of go down that route too, but you navigate, you tell me I can. Andrew Huberman Let’s definitely go down that route. So you mentioned how active the brain is during certain phases of sleep. When I was coming up in science, REM sleep, rapid eye movement sleep was referred to as paradoxical sleep. Is that still a good way to think about it? Paradoxical because the brain is so active and yet we are essentially paralyzed, correct? Matt Walker Yeah, it really is a paradox. And where that came from was simply the brainwave recordings that if all I’m measuring about you is your brainwave 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 patterns 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 you’re sort of sitting up you’re’re clearly conscious and awake. But yet when you go into REM sleep, 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 (Time 0:10:20)
El tronco encefálico paraliza el cuerpo durante el sueño REM Transcript: Matt Walker It’s not always like it can be sometimes horizontal but can also have diagonal and also vertical in that plane. But then the muscle activity is the real dead giveaway. Just before you enter REM sleep, your brainstem, 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 body. When we go into REM sleep and just a few seconds before that happens, the brainstem sends a signal all the way down the spinal cord and it communicates with what are called the alpha motor Neurons in the spinal cord, which control the voluntary skeletal muscles. And it’s a signal of paralysis. And when you go into dream sleep, you are locked into a physical incarceration of your own body. Amazing. You know, 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 gene pool. You know, if I think I’m, you know, one of the best skydivers who can just 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’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 lockdown of (Time 0:12:19)
Tormentas autonómicas durante el sueño REM Transcript: Andrew Huberman Is this why men have erections during REM sleep and women have vaginal lubrication during sleep? Matt Walker That’s one of the reasons. Part of the other reason though there is because of the autonomic activity. So there is a nervous, a part of our nervous system called the autonomic nervous system, and it controls many of the automatic behaviors. And some of those are aspects of our 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 because it’s anything but sympathetic. It’s very aggravating. That all of a sudden fires up, and then it shuts down again. (Time 0:14:03)
Arquitectura típica del sueño Transcript: Andrew Huberman Up between 5 a.m. And 5 30 and 7 30. Yeah. Matt Walker Yeah. Um, at least in, if you look at sort of first world nations, that’s, that’s a typical sleep profile. Um, so when I first fall asleep, I’ll go into the light stages of non REM sleep stages one and two of non REM. 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 I’m in the shallows of sleep stages one and two, my heart rate starts to Drop a little bit. And then my brainwave pattern activity starts to slow down. Normally, when I’m awake, it’s going up and down maybe 20, 30, 40, 50 times a second. As I’m going into light non-REM sleep, (Time 0:19:02)
Descargas neuronales coordinadas durante NREM4 Transcript: Matt Walker Rate really does start to drop. Oh, and I’ll come back to temperature. I’m going to write temperature down because I always forget these things. Now I’m sadly in the foothills of middle age. So as I’m starting to go into those deeper stages of non-REM 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 coordination of the likes that we just don’t see at during any other brain state it’s really interesting having recorded from the Andrew Huberman Brains of animals and a little bit from humans i don’t think i’ve ever seen the entire cortex or even entire regions of cortex light up like that. Yeah, it’s stunning. Matt Walker It’s almost like this beautiful sort of mantra (Time 0:20:21)
¿Cómo evaluamos la función de cada tipo de sueño? Transcript: Matt Walker Begin with. And part of that is just because of how sleep works based on how long I’ve been awake. Longer I’m awake, there is a significantly greater pressure for deep sleep. 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 deprivation 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 an experimental outcome is not the sleep time because they’ve both slept for the same amount it’s the contribution of those different stages (Time 0:26:51)
Our Ability to Smell and Sense Pressure: The Impact on Wakefulness and Sleepiness Transcript: Matt Walker Sleep-activating, sleep-promoting. Biology is so beautiful. Andrew Huberman It’s always a push-pull. I mean, and we could have a larger discussion at some point about that everything, seeing dark edges, seeing light edges, our ability to smell or to sense pressure on this, everything’s A push-pull in biology. So this is another example where as I am awake longer, adenosine is released in the brain and my wakefulness areas are being actively shut down by that adenosine and my sleepiness brain Areas, so to speak, are being promoted to be more active. Is that correct? Matt Walker That’s right. And it’s a very progressive process. It’s not like a step function. 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 caffeine 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 a zero to the one of sleepiness within a short period of time what explains the fatigue after a hard conversation the desire Andrew Huberman To go to sleep or the desire to go to sleep during a hard conversation um that’s an interesting i think it’s usually just based on personality type interactions. Matt Walker And for the most part, not that I’ve ever experienced that. No, people with you don’t, but with me, they always, no, no, no, no, no, no. Andrew Huberman I mean, I’ve experienced the desire to, (Time 0:54:18)
Alcohol afecta negativamente la calidad del dormir. Transcript: Andrew Huberman We call falling asleep. Alcohol, it seems, is helpful for some people to turn off their thoughts or their planning. Is that right? Matt Walker Yes, it is. And so I think, you know, if we look at the pattern of brain activity, if I were to place you inside an MRI scanner where we’re looking at the activity of your brain and watch you drifting Off, some parts of your brain will become less active. Other parts will become more active. And this is the push-pull model. It’s 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 cortex. 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 sedation for sleep saying, well, I always when I have a couple of whiskeys 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 fragments your sleep. And we spoke about the quality of your sleep being just as important as the quantity. And 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 those 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 way is usually not good quality sleep that you feel great on the next day. The third part of alcohol in terms of an equation is that it’s quite potent at blocking your REM sleep, your rapid eye movement sleep. And REM sleep is critical for a variety of cognitive functions, some aspects of learning and memory. It seems to be critical for (Time 1:09:48)