The Science of Sleep

dilemmas of modern medicine. Abraham Lincoln at the Civil War, History of the artistic genius, Michelangelin When intuition changed American mystic psychology of religion. One Day University. The most acclaimed and popular professors from top colleges. They're best lectures, fascinating conversations. Hi, I'm Richard Davies. Let's learn the fact that here we are in and we are still needing this process called sleep, the fact that it is been demonstrated in every single

animal speech. My name is Jessica Paine, and the name of my lecture is the science of stress and sleep, how they affect creativity, concentration, and memory. And our ancestors did in fact, as we build more tissue in the fernal cortices of our brain, which is the most recently evolved part of our brains. We may be actually sleeping a little bit more. In your one day university lecture,

what do you hope people take away from it? You know, if there's one thing I'd like them to take away from it, it's understanding that the sleeping brain is highly intensively active. Because if you go out and you talk to your average person on the street and you ask him what is sleep, what does it do? You'll inevitably get answers like, well, it's just a time where the brain is sort of switched off and it's recovering, you know,

it's rejuvenating. And that's partly true. But what they don't understand is that the sleeping brain is actually busily at work. For you, the hippocampus, which is important for memory, the amygdala parts of the pre final cortex, are actually highly active during rapid eye movement sleep, and then there's an actual communication that goes on during non realm sleep between cortical areas and hippocampal areas, which we know are essential

for memory consolidation. So if people respect that, they're not wasting time when they're sleeping, that they're sleeping brains are actually doing something for them, something important, helping them remember, helping them process emotions, helping them make creative connections. Then the last thing we should do is curtail sleep and have be the first thing to go. And we get stressed out and busy, but it should be one of those things we retain because it's where incredible feats of

cognitive prowers happen. It's some of our most creative ideas come from, and it's absolutely necessary to truly learn and remember things in the long run. So when when people think about sleep, very often they think about length of sleep. Is that the most important thing? Or is it type of sleep? Actually it's a little bit of both. The length of sleep is important. Although I object to this idea that everybody needs to get their eight hours. I

just want you to shout it out at me. How many hours when we talk about sleep, how many hours do human beings need to get at night? Okay? So eight? All right, that's what I'm hearing. And you know something, I'll tell you that that's both true and false, And it's not that advice necessarily, but sleep, like many human variables, is actually normally distributed. It just turns out that between seven and nine hours and night is with the vast

majority of us needs somewhere between seven and nine. But that doesn't mean that you have to, you know, get exactly eight hours. It's also true there are lucky souls out there who literally only need and I don't mean you can get buy on, I mean need four hours of sleep. But they statistically so rare that when somebody tells me that this is what you know they need,

I don't believe them. When I meet people who say that they are just fine on four hours, usually we look at their performance in the lab and in terms of objective performance that are terrible. Uh. And when I hear people saying that they need twelve hours, that is possible, but more often than not, it actually raises the specter of sleep apnea. Tell me about sleep apnia. What is that? So?

Sleep apnea is a complete cessation of breathing. So each time you have an apnea, you stop breathing, which means that your brain is deprived of oxygen. And every time you have an apnea event, your brain has to wake up or arouse in order to get a breath and so when people talk about, well, hey, Dr Pain, I think I might be one of your long sleepers. I

think I might need twelve hours. And when I ask them why they think that, they'll say, well, because I'm constantly sleep being a lot, and yet I never feel well rested. In many cases, when you look at those people's sleep, the reason they feel that way is because their brains are actually waking up over and over and over again, sometimes up to a hundred times or more

an hour in severe cases of sleep apnea. What's really disturbing about this is every time that happens, your brain has to wake up to get a breath, but the person doesn't remember that, So their perception is that they're just sleeping all the time and they never feel rested. You bring them into the sleep lab and you see awakening, awakening, awakening, awakening.

Of course, they're exhausted and their sleep is shattered. And what the reason I like to talk about this that these events is that we now know that there is a very strong and very real relationship between sleep apnea and heart attack and stroke. It's very common to hear people say, oh, I only need four or five or six hours of sleep. Does that kind of talk drive

you crazy. As a sleep researcher, it does drive me crazy. Well, on one hand, I find it fascinating, and I'm still looking for a group of people that really are functioning at their best on only four hours. When you get to six, that's a little bit more possible. But yeah, it drives me crazy because where I think that really comes from is this cultural message. The problem there is that we live in a puritanical culture. We live in a culture where there's this first one in, last one

out mentality. There's this idea that you know, in order to work better, you always have to work longer, right, And you know students they wear their sleep deprivation as a badge of honor. You hear it all the time. This drives me crazy as a sleep scientist. Oh well, I only got two hours of sleep last night because I was studying. Oh well, I pulled an all matter. Well.

As a memory researcher, there's nothing that makes me more crazy because the two things you want to do if you want to consolidate memories, which is literally the ability to sort of store them long term and actually be able to remember them later. You don't just visit something once you need to actually sort of inter leave your practice. You want to revisit a concept over and over again. You don't want to cram and you espect actually don't

want to cram across the night of sleep deprivation. Instead, you want to be sort of revisiting this concept and you want to sleep on it right after you study it for the last time. And yet students across the United States do this exactly the wrong way. So, yes, it drives me absolutely crazy. What does sleep deprivation due to us? If if we are sleep deprived, what happens? Well, a lot of really bad things happen, increased traffic accidents, lapses,

and concentration to memory impairment over time. I think most of us have experience with temporary payers of sleep deprivation, and our brains are plastic, you know, and we really are rugged. We've evolved to tolerate some amount of sleep deprivation. So I'm not worried about the person who has one poor night of sleep or goes through a difficult patch, or even think about new parents. They're going to go through several months of poor sleep. We're designed to be

able to handle that. What I worry about are the people who are doing that for these long periods of time where people aren't sleep being that kind of sleep deprivation actually builds up. You accumulate what's called sleep debt, which is a pressure that your brain actually has to pay back this depth that it's accumulated. The more sleep deprived you become, the more your performance is going to suffer, in the same exact way that the more alcohol you consume,

the more your performance suffers. And what's interesting is that in both of these cases people don't have awareness of it. People are not necessarily aware that they're impaired when they're drunk, and people are definitely not aware that they're impaired when they're sleep deprived. You have to bring them into the lab and show them their their own data. So we've all met that person who thinks they're fine to drive after drinking, but we know they're not. It's the same

exact relationship for sleep deprivation. And then what I fear, especially somebody dealing without a lessons and people in college, is when you mix those things, you can get into a really deadly situation. So if you have even a little bit of alcohol but you're sleep deprived on top of it, then your risk for traffic accidents and a whole host of other mistakes skyrockets. So how do you know if you're sleeping well or if you're getting enough sleep?

There are two ways I can answer that question. The first is if you feel like you're at your best. Most of us have a sense of when we're at our best, and one way to look at that is to is to do what I urge everybody to do, which is to put twenty extrements of sleep into your daily routine, which most of us can benefit from, even

people who are sleeping pretty well. And if that makes you feel better, makes you feel happier and more positive, then that's one way to tell the But the real answer is I think we should have a sleep study done.

This is where you go into a sleep laboratory. There are physicians that are trained in sleep medicine, and I think everybody ought to get a baseline when they're saying years old, so that we actually have an objective measure of how we're sleeping, so that we can screen for things like apnea, so that we can address insomnia before it gets bad and difficult, because that's a in part A learned cycle that can be very difficult to undo.

And it blows my mind that when you go to your doctor that's not even a question most physicians ask is how are you sleeping? Which is crazy in my mind because sleep is a real barometer of health, both mental and physical health. Talk about naps and why you think they're important. Yeah, I actually think we never should

have stopped napping in kindergarten. The first thing that I really want you to try to do, this is the single most important takeaway, is just try to get twenty extra minutes a day on as many days as you can. And there are, obviously there are three different ways to do that. You can either go to bed earlier, you can sleep later, meaning don't hit the snooze button, which is a very bad idea actually just let your brain

stay locked in. But you're going to get the most bang for your buck if you start to incorporate daytime napping. But the idea here, okay, is that when it comes to napping, you do not want to nap any longer than twenty minutes. And I am mean set your alarm for twenty minutes, because I don't even want you to

sleep that long. Because if you're sleep deprived and your brain is built up the sleep debt, you're going to run the risk of going into slow wave sleep, and if you wake up out of that, you're gonna be groggy, feel terrible. It's not gonna help. Napping is a great way to recharge your brain in the middle of the day, and depending on the length of the nap, you can do anything from boosting memory and cognition to rejuvenate in

the brain and cleaning the cash if you will. I'm a big advocate for nap pods in corporate culture because people actually, we know that they perform better if they're able to get even a very brief nap. I envisioned a world will where one day, you know, somebody told me recently that they could get fired. It's in a contract that they could get fired for sleeping on the job, and that to me, it's just so backward. I imagine one day companies will want to actually harness the power

of the sleeping brain. So if you can imagine people in their cubicles with little signs that say sleeping brain at work, innovation and progress, that's the world I imagine where it's okay to go offline, whether that's taking a twenty minute nap, or just getting out for a relaxing walk or reflective walk, or doing a meditation or relaxation exercise.

All of these ways of taking the brain offline actually allow their brain to perform better and people will be much more productive, not to mention, happier and and just in a better mood. You make a really compelling case for sleep helping your creativity, helping your memory. What about emotion? Does it help regulate your emotion? Calm you down? Sleep absolutely helps regulate emotion. In fact, it's a built in

stress and emotion regulator. So as I just mentioned, if you're sleep deprived, if you're not getting enough sleep that is a stressor your body will secrete stress hormones like cortisol. When you're sleeping, that system gets regulated number one and number two, you tend to it. It doesn't just calm you down, but it regulates the way that you process difficult to negative things that happened during the day. So

we like to think of sleep doing two things. For emotional experiences, Sleep actually helps you remember the emotional, even the negative, which, if you think about it, you need to do because you need to be able to learn from your mistakes. It's also incredibly adaptive at a species level. But you also want sleep to help strip away the

emotional tone of that experience. The amigula is incredibly important for emotion, and especially for negative emotion motions like fear also more active during sleep than wink, which is both

good and bad. Right, Like, you need to process emotion in order to be healthy, but you don't want to process it without also regulating, which is why it's also a good thing that parts of your what we call medial prefernal cortex, Okay, in here in the front of the brain, there's a region within that called the anterior cingulate.

It's job is to literally put a break on the amigala, so they kind of talk to each other, and when the imigia leaguets out of control, it breaks it so that you don't actually get out of control in terms of your emotions. So there's a cross top going on between these two structures that allow you to process emotional

experience that you've had, but while also regulating it. Okay, well, when I like, what I like to say about this in terms of memory, for example, is you don't want to forget all of the negative experiences that happen to you,

because you'd never be able to learn from them. You need to be able to remember the most negative things from your life, but you also need to regulate the negative emotion that comes along with that, so you don't develop an anxiety, right, so that you don't develop depression. So you're not only processing your emotions and your emotional experiences, but you're regulating your affect or your emotion to them.

So that's one of the reasons we think that most many actually mental health conditions, and definitely affective disorders like depression and anxiety are often associated with sleep deficits. In your lecture, your talk about memory, and I know that as people get older, especially over the age of fifty or sixty, they worry about will I suffer from dementia? Will I be someone who gets Alzheimer's? Is there any relationship between getting your eight hours a night and lowering

your risk for dementia? Well, again, it's early days, you know. As a scientist, I like to see data replicated over and over again. But there is a link. It's preliminary, but it's important. One. There are two lines of evidence that suggesting there's a correlation there. One, it is true that people who have a history of poor sleep are at higher risk for developing dementia, including Alzheimer's disease. So we've known that for a long time that there's a

link there. Now that's just a correlation. Correlations does not imply causation. But that's one link. The other link is new research showing that you need to get sleep, especially deep slow wave sleep, which again is the deepest stay of sleep you get in order to literally clean out the brain. So your brain produces metabolite, right, I mean, as you go about your day to day, your brain is working away and all the by products, all the waste of that metabolism needs to get cleaned out somehow.

Beta amyloid is one of the waste products that needs to get cleaned out of the brain. So when you sleep, when you achieve especially the deep slow wave sleep that's so important also for memory consolidation, you're also getting the benefit of cleaning out what's called the interstitial space, So cleaning out the spaces and the blaine. You can really think about it is cleaning out the gunk, you know, or taking out the trash, and sleep is clearly linked

to the ability to do that. So if you don't clean out the beta amyloid, the problem, obviously is that that is what causes the plaques. That's what the plaques are made out of, and that's one of the defining

characteristics of Alzheimer's disease. So I'll say they're preliminary, but I think that this is a very interesting line of work that's going on now, looking at poor sleep in its relation to dementing diseases on the one hand, and of course you can flip that are good sleepers at much less risk for dementing diseases, and that those data are coming And as I said earlier, it takes a long time and a lot of replications for me to become convinced of something. But that's certainly a story I'm

paying attention to. I like that cleaning out the gunk, taking out the trash. You talk about how good sleep helps creativity in what sort of ways. There are a whole host of different theories about that, and the truth is we don't know exactly how it works. We do know that it does, so it's very clear that sleep

is one means to reach creative insight. There have been many studies showing that I can tell you what I think is going on, and this is shared by other sleep neuroscientists, is that during sleep, especially during rapid eye movement sleep, you have areas of the brain communicating in ways that they simply don't during wakefulness. And I just can't resist it. I have to tell you that there's another area called the Doris lateral prefrontal cortex and it

is completely deactivated. It is literally switched off during rapid eye movement sleep. And what's fascinating about this is that this structure of the brain. We literally call this the executive control center of the brain. It is the CEO of the brain. Yet it's a very it's a very sort of literal and linear CEO. This is not a This is like not a CEO CEO who thinks outside of the box. Okay, this is the We're gonna do it in exactly the same way we've always done it.

This is logical, this is rational. It's also good though, because it tells me like I can't walk through that wall and I can't fly out to the back of the room, So this is good, right. However, it also keeps you kind of contained in terms of your creative thinking.

So during rapid eye movement sleep, with it being switched off, while all the while you're doing all of this cognitive and information processing, you're you're allowed to kind of run them up and have ideas and activate neural representations and combine them in new and novel ways in a manner that you simply can't do when you're awake. And this is one of the reasons why people have Aha moments

when they wake up from sleep. So it may be that all of these different modes of communication, all of the ways that your memories are being processed, the information that you've learned in the past, is being processed in rem sleep is occurring in a way that's really different than the way it occurs during wakefulness or even other

stages of sleep. And because of this regional pattern of activation that occurs only in rapid eye movement sleep, it really allows us, we think, to take different types of information, different fragments of memory, and recombine them in totally novel ways. Now, does that lead to the completely bizarre, fragmented nature of

our dreams? Probably, But those dreams may be a bip product of a process that's incredibly important because it can also at least at times lead to creative connections, lead to insights, and really just new novel ways of looking at things. So the best thing to do if you are at an impasse, if you're trying to solve a problem and you're at an impast you're stuck, is to take the brain offline. So in other words, if you have a big decision to make that phrase go and

sleep on it, you should take that literally. You should take that literally, whether it's a good problem like you're trying to decide which job to take, an emotional problem like how to deal with an issue having with your spouse or your child, And even if you're trying to achieve creative insight, one of the best things you can do you have to put the hard work in, but then go offline, take that break, and ideally get some sleep. That's a great way to end. Jessica Payne, thank you

very much. Well, thank you very much. I'm Richard Davies. Thanks for listening. Sign up on our website one day you dot com to become a member and access over six hundred full length video lectures for the world's finest professors