back to indexUnderstanding and Using Dreams to Learn and to Forget | Huberman Lab Podcast #5
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Welcome to the Huberman Lab Podcast,
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where we discuss science and science-based tools
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for everyday life.
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I'm Andrew Huberman,
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and I'm a professor of neurobiology and ophthalmology
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at Stanford School of Medicine.
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This podcast is separate from my teaching
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and research roles at Stanford.
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It is, however, part of my desire
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to bring you zero cost to consumer information
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about science and science-related tools.
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In keeping with that theme,
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I'd like to thank the sponsors of today's podcast.
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Our first sponsor is Helix Sleep.
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Helix Sleep makes mattresses
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that are ideally suited to your sleep needs.
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Helix mattresses are amazing.
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I can say this because I've been sleeping on one,
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and I've been sleeping better than I've ever slept before.
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The interesting thing about Helix mattresses
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is that they're tailored to your unique body type
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and sleeping style.
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What's a sleeping style?
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Well, if you go to the Helix site,
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you can take a quick quiz.
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It takes about two minutes
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as to whether or not you sleep on your stomach,
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your side, your back,
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whether or not you flip back and forth,
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or whether or not you don't know
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in what position you sleep,
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as well as whether or not you tend to run hot or run cold,
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wake up cold, wake up hot, et cetera.
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If you do that, then it will match you to the mattress
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that's perfect for your sleep needs.
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If you want to try a Helix mattress,
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you can go to helixsleep.com slash Huberman,
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and if you do that, you'll get $200 off your order
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as well as two free pillows.
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That's helixsleep.com slash Huberman.
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The second sponsor of today's podcast is Athletic Greens.
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Athletic Greens is an all-in-one
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vitamin mineral probiotic drink.
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I've been using Athletic Greens since 2012,
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and I started using it because I had a lot of confusion
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about what vitamins and minerals I should take,
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and taking Athletic Greens allowed me to get the foundation
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or sort of the base of everything I need
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in one easy-to-consume formula.
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I mix mine with water and a little bit of lemon juice,
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and I like drinking it,
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and the probiotics in there are important to me as well,
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because there are a lot of data out there now
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identifying the gut microbiome
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and the importance of the gut brain axis
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for immune function, metabolic function, and so forth.
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If you want to try Athletic Greens,
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you can go to athleticgreens.com slash Huberman,
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and if you do that, they'll also send you a year's supply
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of liquid vitamin D3K2.
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There are a lot of data starting to surface
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about the importance of vitamin D3 for immune function,
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metabolic function, endocrine function, and so forth.
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In addition, if you go to athleticgreens.com slash Huberman,
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you'll get the year's supply of D3 and K2,
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as well as five free travel packs,
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which are little packets of Athletic Greens
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in addition to your normal order,
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and those are great for when you're on the plane
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or you're otherwise traveling.
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They mix up really easily without any mess
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or the need to spoon out powder and things of that sort,
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so the things that are easy to do at home
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are kind of harder on the road.
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Those packets make it easy while on the road.
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Today, we're going to talk about dreaming,
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learning during dreaming, and unlearning during dreaming,
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in particular, unlearning of troubling emotional events.
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Now, my interest in dreaming goes way back.
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When I was a child, I had a friend,
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and he came over one day and he brought with him a mask
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that had a little red light in the corner.
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He had purchased this thing through some magazine ad
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and this mask was supposed to trigger lucid dreaming.
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Lucid dreaming is the experience of dreaming during sleep,
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but being aware that one is dreaming,
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and in some cases, being able to direct
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one's dream activities.
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So if you're in a lucid dream
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and you want to fly, for instance,
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some people report being able to initiate
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that experience of flying or to contort themselves
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into an animal or to transport themselves
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to wherever they want within the dream.
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I tried this device.
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The way it worked is you put on the mask
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during the waking state, wide awake,
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and you'd look at the little light flashing in the corner,
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and then you'd also wear it when you went to sleep at night.
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And indeed, while I was asleep,
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I could see the red light presumably through my eyelids,
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although for all I know, I had opened my eyes.
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I don't know, I was asleep.
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And then because I was dreaming
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and I was experiencing something very vivid,
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I was able to recognize that I was dreaming
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and then start to direct some of the events
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within that dream.
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Now, lucid dreaming occurs in about 20% of people,
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and in a small percentage of those people,
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they lucid dream almost every night,
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so much so that many of them report their sleep
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not being as restorative as it would be otherwise.
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Now, all of this is to say that lucid dreaming and dreaming
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are profound experiences.
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We tend to feel extremely attached to our dream experience.
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This may explain the phenomenon
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of people who have a very intense dream,
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they need to somehow tell everybody about that dream
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or tell someone about that dream.
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I don't really know what that behavior is about,
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but sometimes we wake up and we feel so attached
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to what happened in this state that we call dreaming
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that there seems to be an intense need
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to share it with other people,
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presumably to process it and make sense of it.
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Now, numerous people throughout history
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have tried to make sense of dreams
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in some sort of organized way.
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The most famous of which, of course, is Sigmund Freud,
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who talked about symbolic representations in dreams.
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A lot of that has been kind of debunked,
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although I think that there's some interest
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in what the symbols of dreaming are,
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and this is something that we'll talk about
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in more depth today,
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although not Freudian theory in particular.
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So I think in order to really think about dreams
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and what to do with them
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and how to maximize the dream experience
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for sake of learning and unlearning,
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the best way to address this
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is to look at the physiology of sleep,
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to really just what do we know concretely about sleep?
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So first of all, as we get sleepy,
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we tend to shut our eyes,
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and that's because there are some autonomic centers
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in the brain, some neurons that control closing
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of the eyelids when we get sleepy,
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and then we transition into sleep.
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And sleep, regardless of how long we sleep,
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is generally broken up into a series of 90-minute cycles,
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these ultradian cycles.
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So early in the night,
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these 90-minute cycles tend to be comprised
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more of shallow sleep and slow-wave sleep,
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so stage one, stage two, et cetera,
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and what we call slow-wave sleep.
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I'll go into detail about what all this means in a moment.
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And we tend to have less so-called REM sleep,
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R-E-M sleep, which stands for rapid eye movement sleep,
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and I'll talk about rapid eye movement sleep in detail.
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So early in the night, a lot more slow-wave sleep
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For every 90-minute cycle that we have
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during a night of sleep,
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we tend to start having more and more REM sleep.
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So more of that 90-minute cycle is comprised of REM sleep
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and less of slow-wave sleep.
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Now, this is true regardless of whether or not
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you wake up in the middle of the night to use the restroom
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or your sleep is broken.
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The more sleep you're getting across the night,
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the more REM sleep you're going to have.
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And REM sleep and non-REM, as I'll refer to it,
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have distinctly different roles in learning and unlearning,
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and they are responsible for learning and unlearning
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of distinctly different types of information.
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And this has enormous implications
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for learning of motor skills,
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for unlearning of traumatic events
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or for processing emotionally challenging
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as well as emotionally pleasing events.
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one can actually leverage their daytime activities
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in order to access more slow-wave sleep
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or non-REM sleep as we'll call it,
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or more REM sleep depending on your particular
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emotional and physical needs.
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So it's really a remarkable stage of life
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that we have a lot more control and power over
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than you might believe.
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We'll also talk about lucid dreaming.
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We're also going to talk about hallucinations
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and how drug-induced hallucinations
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have a surprising similarity to a lot of dream states
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and yet some really important differences.
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Okay, so let's start by talking about slow-wave sleep
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Now I realize that slow-wave sleep and non-REM sleep
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aren't exactly the same thing.
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So for you sleep aficionados out there,
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I am lumping right now, as we say in science,
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there are lumpers and there are splitters, and I am both.
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Sometimes I lump, sometimes I split.
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For sake of clarity and ease of conversation right now,
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I'm going to be a lumper.
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So when I say slow-wave sleep,
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I mean non-REM sleep generally,
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although I acknowledge there is a distinction.
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So slow-wave sleep is characterized
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by a particular pattern of brain activity
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in which the brain is metabolically active,
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but that there's these big sweeping waves of activity
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that include a lot of the brain.
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If you want to look this up there,
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you can find evidence for sweeping of waves
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of neural activity across association cortex,
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across big swaths of the brainstem,
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the so-called Pons geniculate occipital pathway.
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This is brainstem, thalamus, and then cortex,
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for those of you that are interested,
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although more of that is going to occur in REM sleep.
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Now, the interesting thing about slow-wave sleep
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are the neuromodulators that tend to be associated with it
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that are most active and least active
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during slow-wave sleep.
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To remind you, neuromodulators are these chemicals
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that act rather slowly,
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but their main role is to bias particular brain circuits
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to be active and other brain circuits to not be active.
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These are like the music playlist.
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So think of neuromodulators,
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and these come in the names of acetylcholine,
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norepinephrine, serotonin, and dopamine.
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Think of them as suggesting playlists on your audio device.
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So classical music is distinctly different in feel and tone
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and a number of other features from like third-wave punk
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or from hip hop, right?
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So think of them as biasing toward particular genres
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of neural circuit activity, okay?
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Mellow music versus really aggressive fast music
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or rhythmic music that includes lyrics
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versus rhythmic music that doesn't include lyrics.
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That's more or less the way
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to think about these neuromodulators.
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And they are associated as a consequence
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with certain brain functions.
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So we know for instance,
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and just to review acetylcholine in waking states
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is a neuromodulator that tends to amplify the activity
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of brain circuits associated with focus and attention.
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Norepinephrine is a neuromodulator
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that tends to amplify the brain circuits associated
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with alertness and the desire to move.
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Serotonin is the neuromodulator that's released
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and tends to amplify the circuits in the brain and body
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that are associated with bliss and the desire to remain still
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and dopamine is the neuromodulator that's released
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and is associated with amplification of the neural circuits
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in the brain and body associated with pursuing goals
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and pleasure and reward, okay?
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So in slow wave sleep,
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something really interesting happens.
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There's essentially no acetylcholine.
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Acetylcholine production and release and action
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from the two major sites, which are in the brainstem,
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which from a nucleus,
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it's a parabigeminal nucleus if you really want to know
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or from the forebrain, which is nucleus basalis
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and you don't need to know these names,
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but if you like, that's why I put them out there.
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Acetylcholine production plummets.
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It's just almost to zero and acetylcholine,
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as I just mentioned, is associated with focus.
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So you can think of slow wave sleep
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as these big sweeping waves of activity through the brain
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and a kind of distortion of space and time
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so that we're not really focusing on any one thing.
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Now, the other molecules that are very active at that time
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are norepinephrine, which is a little bit surprising
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because normally in waking states,
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norepinephrine is going to be associated
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with a lot of alertness and the desire to move,
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but there's not a ton of norepinephrine
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around in slow wave sleep, but it is around.
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So there's something associated
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with the movement circuitry going on in slow wave sleep.
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And remember, this is happening mostly
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at the beginning of the night.
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Your sleep is dominated by slow wave sleep.
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So no acetylcholine, very little norepinephrine,
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although there is some, and a lot of serotonin.
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And serotonin, again, is associated with this desire,
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the sensation of kind of bliss or wellbeing,
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but not a lot of movement.
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And during sleep, you tend not to move.
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Now, in slow wave sleep, you can move.
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You're not paralyzed, so you can roll over.
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If people are going to sleepwalk,
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typically it's going to be during slow wave sleep.
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And what studies have shown
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through some kind of sadistic experiments
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where people are deprived specifically of slow wave sleep,
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and that can be done by waking them up
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as soon as the electrode recording show
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that they're in slow wave sleep,
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or by chemically altering their sleep
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so that it biases them away from slow wave sleep.
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What studies have shown is that motor learning
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is generally occurring in slow wave sleep.
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So let's say the day before you go to sleep,
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you were learning some new dance move,
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or you were learning some specific motor skill,
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either a fine motor skill or a course motor skill.
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So let's say it's a new form of exercise
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or some new coordinated movements.
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This could be coordinated movement
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at the level of the fingers,
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or it could be coordinated movement
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at the level of the whole body and large limb movements.
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It could involve other people,
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or it could be a solo activity.
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Learning of those skills is happening
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primarily during slow wave sleep
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in the early part of the night.
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In addition, slow wave sleep has been shown to be important
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for the learning of detailed information.
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Now, this isn't always cognitive information.
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We're going to talk about cognitive information,
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but the studies that have been done along these lines
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involve having people learn very detailed information
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about very specific rules
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and the way that certain words are spelled.
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They tend to be challenging words.
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So if people are tested in terms of their performance
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on these types of exams,
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and they're deprived of slow wave sleep,
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they tend to perform very poorly.
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So we can think of slow wave sleep
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as important for motor learning, motor skill learning,
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and for the learning of specific details
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about specific events.
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And this turns out to be fundamentally important
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because now we know that slow wave sleep
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is primarily in the early part of the night,
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and motor learning is occurring primarily early in the night
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and detail learning is occurring early in the night.
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Now, for those of you that are waking up
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after only three, four hours of sleep,
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this might be informative.
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This might tell you a little something
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about what you are able to learn and not able to learn
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if that were to be the only sleep that you get,
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although hopefully that's not the only sleep that you get.
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But we're going to dive deep into how it is
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that one can maximize motor learning
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in order to extract, say, more detail information
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about coordinated movements
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and how to make them faster or slower.
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So that might be important for certain sports.
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It might be almost certainly important for certain sports.
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It's going to be important
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for any kind of coordinated movement,
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like, say, learning to play the piano,
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or, for instance, how to learn synchronized movements
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with somebody else.
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So maybe I mentioned the example of dance earlier.
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If you, like me, a few years ago,
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I set out to learn tango
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because I have some Argentine relatives and I was abysmal.
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I need to return to that at some point.
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I was just abysmal.
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And one of the worst things
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about being abysmal at learning dance
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is that there's somebody else
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has to suffer the consequences also.
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So I don't know, maybe in a month on neuroplasticity,
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I'll explore that again as a self-experimentation.
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But the key things to know are slow-wave sleep
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involved in motor learning and detailed learning.
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There's no acetylcholine around at that time.
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Has this big amplitude activity
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sweeping throughout the brain.
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And that there's the release of these neuromodulators,
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norepinephrine and serotonin.
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And again, that's all happening early in the night.
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So athletes, people that are concerned about performance,
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if you happen to wake up after just a couple hours
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of three, four hours of sleep
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because you're excited about a competition the next day,
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presumably, if you've already trained the skills
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that you need for the event,
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you should be fine to engage in that particular activity.
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Now, it's always going to be better
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to get a full night's sleep.
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And a full night's sleep for you is six hours,
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and it's always going to be better to get more sleep
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than it is to get less.
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However, I think some people
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get a little bit overly concerned
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that if they didn't get their full night's sleep
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before some sort of physical event,
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that their performance is going to plummet.
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Presumably, if you've already learned what you need to do
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and it's stored in your neural circuits,
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and you know how to make those coordinated movements,
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what the literature on slow-wave sleep suggests
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is that you would be replenished.
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That the motor learning and the recovery from exercise
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is going to happen early in the night.
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So we'll just pause there
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and kind of shelve that for a moment,
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and then we're going to come back to it.
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But I want to talk about REM sleep,
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or rapid eye movement sleep.
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REM sleep and rapid eye movement sleep,
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as I mentioned before, occurs throughout the night,
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but you're going to have more of it.
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A larger percentage of these 90-minute sleep cycles
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is going to be comprised of REM sleep
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as you get toward morning.
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REM sleep is fascinating.
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It was discovered in the 50s
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when a sleep laboratory in Chicago,
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the researchers observed that people's eyes
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were moving under their eyelids.
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Now, something very important that we're going to address
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when we talk about trauma later
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is that the eye movements are not just side to side.
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They're very erratic in all different directions.
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One thing that I don't think anyone,
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I've never heard anyone really talk about publicly
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is why eye movements during sleep, right?
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Eyes are closed, and sometimes people's eyelids
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will be a little bit open and their eyes are darting around,
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especially in little kids.
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I don't suggest you do this.
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I'm not even sure it's ethical,
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but it has been done where you pull back the eyelids
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of a kid while they're sleeping
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and their eyes are kind of darting all over the place.
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I think people do this to their passed out friends
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at parties and things like that.
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So again, I don't suggest you do it,
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but I'm telling you it because it's been done before
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and therefore you don't have to do it again.
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But rapid eye movement sleep is fascinating
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and occurs because there are connections
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between the brainstem, an area called the pons,
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and areas of the thalamus and the top of the brainstem
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that are involved in generating movements
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in different directions, sometimes called saccades,
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although sometimes during rapid eye movement sleep,
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it's not just rapid, it's kind of a jittery side-to-side
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thing and then the eyeballs kind of roll.
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It's really pretty creepy to look at if you see.
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So what's happening there is the circuitry
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that is involved in conscious eye movements
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is kind of going haywire, but it's not haywire.
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It's these waves of activity from the brainstem
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up to the so-called thalamus,
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which is an area that filters sensory information
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and then up to the cortex.
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And the cortex, of course,
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is involved in conscious perceptions.
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So in rapid eye movement sleep,
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there are a couple of things are happening
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besides rapid eye movements.
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The main ones are that they're, I should say,
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in contrast to slow wave sleep.
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In REM sleep, serotonin is essentially absent, okay?
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So this molecule, this neuromodulator
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that tends to create the feeling of bliss and wellbeing
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and just calm, placidity is absent, all right?
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So that's interesting.
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In addition to that, norepinephrine,
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this molecule that's involved in movement and alertness
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is absolutely absent.
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It's probably one of the few times in our life
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that epinephrine is essentially at zero activity
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within our system.
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And that has a number of very important implications
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for the sorts of dreaming that occur during REM sleep
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and the sorts of learning that can occur
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in REM sleep and unlearning.
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First of all, in REM sleep, we are paralyzed.
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We are experiencing what's called atonia,
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which just means that we're completely laid out
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We also tend to experience whatever it is
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that we're dreaming about as a kind of hallucination
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or a hallucinatory activity.
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Long ago, I looked into hallucinations and dreaming.
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I was just fascinated by this in high school.
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And there's some great books on this if you're interested
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in exploring the relationship
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between hallucinations and dreaming.
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The most famous of which are from a guy,
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researcher at Harvard, Alan Hobson.
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I wrote a book called Dream Drugstore
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and talked all about the similarities
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between drugs that induce hallucinations
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and dreaming in REM.
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So you can explore that if you like.
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So in REM, our eyes are moving,
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but the rest of our body is paralyzed
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and we are hallucinating.
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There's no epinephrine around.
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Epinephrine doesn't just create a desire
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to move and alertness.
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It is also the chemical signature of fear and anxiety.
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It's what's released from our adrenal glands
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when we experience something that's fearful or alerting.
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So if a car suddenly screeches in front of us
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or we get a troubling text message,
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adrenaline is deployed into our system.
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Adrenaline is epinephrine.
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Those are equivalent molecules.
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And epinephrine isn't just released from our adrenals.
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It's also released within our brain.
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So there's this weird stage of our life
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that happens more toward morning that we call REM sleep
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where we're hallucinating
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and having these outrageous experiences in our mind,
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but the chemical that's associated
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with fear and panic and anxiety is not available to us.
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And that turns out to be very important.
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And you can imagine why that's important.
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It's important because it allows us to experience things,
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both replay of things that did occur
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as well as elaborate contortions
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of things that didn't occur.
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And it allows us to experience those
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in the absence of fear and anxiety.
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And that it turns out is very important
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for adjusting our emotional relationship
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to challenging things that happened to us
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while we were awake.
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Those challenging things can sometimes be
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in the form of social anxiety
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or just having been working very hard
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or concern about an upcoming event,
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or sometimes people report, for instance,
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dreams where they find themselves late to an exam
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or naked in public or in some sort of situation
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that would be very troubling to them.
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And that almost certainly occurs during REM sleep.
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So we have this incredible period of sleep
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in which our experience of emotionally laden events
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is dissociated, it's chemically blocked
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from us having the actual emotion.
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Now, probably immediately some of you are thinking,
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well, what about nightmares? I have nightmares
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and those carry a lot of emotion,
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or sometimes I'll wake up in a panic.
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Let's consider each of those two things separately
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because they are important in understanding REM sleep.
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There's a good chance that nightmares
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are occurring during slow wave sleep.
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There are actually some drugs
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that I don't suggest people take,
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in fact, so much so I'm not gonna mention them,
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that give people very kind of scary or eerie dreams
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and this kind of feeling that things are pursuing them
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or that they can't move when they are being chased.
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That's actually a common dream that I've had,
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I guess it's more or less a nightmare,
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the feeling that one is paralyzed
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and can't move and is being chased.
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A lot of people have said, oh, that must be in REM sleep
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because you're paralyzed
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and so you're dreaming about being paralyzed
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and you can't move.
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I think that's probably false.
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The research says that because norepinephrine
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is absent during REM sleep,
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it's very unlikely that you can have these intense,
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So those are probably occurring in slow wave sleep,
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although there might be instances
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where people have nightmares in REM sleep.
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The other thing is some people experience,
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certainly I've had this experience of waking up
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and feeling very stressed about whatever it was
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that I happened to be thinking about
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or dreaming about in the moments before.
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And that's an interesting case of an invasion
link |
of the dream state into the waking state
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and the moment you wake up, epinephrine is available.
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So the research on this isn't fully crystallized,
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but most of it points in the direction
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of the experience of waking up and feeling very panicked.
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Maybe, I wanna highlight may,
link |
but maybe that you were experiencing something
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that was troubling in the daytime,
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you're repeating that experience in your sleep,
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epinephrine is not available
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and therefore the brain circuits associated
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with fear and anxiety are shut off
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and so you're able to process those events.
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And then suddenly you wake up
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and there's a surge of adrenaline, of epinephrine
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that's now coupled to that experience.
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So nightmares very likely in slow wave sleep
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and that kind of panic on waking from something
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very likely to be an invasion of the thoughts and ideas,
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however distorted in REM sleep, invading the waking state.
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In fact, that brings to mind something
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that I've mentioned once before,
link |
but I wanna mention again, this atonia,
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this paralysis that we experienced during sleep
link |
can invade the waking state.
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Many people report the experience of waking up
link |
and being paralyzed.
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They're legitimately waking up, it's not a dream.
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Waking up and being paralyzed and it is terrifying.
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I've had this happen before.
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It is, I can tell you, terrifying to be wide awake
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and as far as I could tell, fully conscious,
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but unable to move.
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And then generally you can jolt yourself out of it
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in a few seconds, but it is quite frightening.
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Now, some people actually experience waking up,
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being fully paralyzed and hallucinating.
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And there is a theory in the academic
link |
and scientific community at least
link |
that what people report as alien abductions
link |
have a certain number of core characteristics
link |
that map quite closely, eerily similarly
link |
to these experiences.
link |
A lot of reports of alien abduction
link |
involve people being unable to move,
link |
seeing particular faces, hallucinating,
link |
extensively feeling like their body is floating
link |
or they were transported.
link |
This is very similar to the experience
link |
of invasion of atonia into the waking state.
link |
Waking up and still being paralyzed
link |
as well as the hallucinations that are characteristic
link |
of dreaming in REM sleep.
link |
Now, I'm not saying that people's alien abductions
link |
were not legitimate alien abductions.
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And if I was there, I wouldn't tell you
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because that would make me an alien.
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And I wouldn't want you to know.
link |
But it is quite possible
link |
that people are experiencing these things
link |
and they are an invasion of the sleep state
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into the waking state.
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And they can last several minutes or longer.
link |
And because in dreams, space and time are distorted,
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our perception of these events could be
link |
that they lasted many hours
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and we can really feel as if they lasted many hours
link |
when in fact they took only moments.
link |
And we're going to return to distortion of space and time
link |
So to just recap where we've gone so far,
link |
slow wave sleep early in the night,
link |
it's been shown to be important for motor learning
link |
and for detail learning.
link |
REM sleep has a certain dream component
link |
when which there's no epinephrine.
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Therefore we can't experience anxiety.
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Those dreams tend to be really vivid
link |
and have a lot of detail to them.
link |
And yet in REM sleep, what's very clear
link |
is that the sorts of learning that happen in REM sleep
link |
are not motor events.
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It's more about unlearning of emotional events.
link |
And now we know why,
link |
because the chemicals available
link |
for really feeling those emotions are not present.
link |
Now that has very important implications.
link |
So let's address those implications from two sides.
link |
First of all, we should ask
link |
what happens if we don't get enough REM sleep?
link |
And a scenario that happens a lot
link |
where people don't get enough REM sleep is the following.
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I'll just explain the one that I'm familiar with
link |
because it happens to me a lot,
link |
although I figured out ways to adjust.
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I go to sleep around 10, 30, 11 o'clock.
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I fall asleep very easily.
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And then I wake up around three or 4 a.m.
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I now know to use a NSDR, a non-sleep deep rest protocol.
link |
And that allows me to fall back asleep.
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Even though it's called non-sleep deep rest,
link |
it's really allows me to relax my body and brain.
link |
And I tend to fall back asleep and sleep till about 7 a.m.
link |
during which time I get a lot of REM sleep.
link |
And I know this because I've measured it.
link |
And I know this because my dreams tend to be very intense
link |
of the sort that we know as typical of REM sleep.
link |
I've gotten my slow wave sleep early in the night
link |
and I've got my REM sleep toward morning.
link |
However, there are times when I don't go back to sleep.
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Maybe I have a flight to catch, that's happened.
link |
Sometimes I've got a lot on my mind
link |
and I don't go back to sleep.
link |
I can tell you and you've probably experienced
link |
that the lack of REM sleep
link |
tends to make people emotionally irritable.
link |
It tends to make us feel
link |
as if the little things are the big things.
link |
So it's very clear from laboratory studies
link |
where people have been deprived selectively of REM sleep
link |
that our emotionality tends to get a little bit unhinged
link |
and we tend to catastrophize small things.
link |
We tend to feel like the world is really daunting.
link |
We're never going to move forward in the ways that we want.
link |
We can't unlearn the emotional components
link |
of whatever it is that's been happening,
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even if it's not traumatic.
link |
The other thing that happens in REM sleep
link |
is a replay of certain types of spatial information
link |
about where we were and why we were in those places.
link |
And this maps to some beautiful data
link |
and studies that were initiated
link |
by a guy named Matt Wilson at MIT years ago
link |
showing that in rodents,
link |
and it turns out in other non-human primates and in humans,
link |
there's a replay of spatial information during REM sleep
link |
that almost precisely maps to the activity
link |
that we experienced during the day
link |
as we move from one place to another.
link |
So here's a common world scenario.
link |
You go to a new place,
link |
you navigate through that city or that environment.
link |
This place doesn't have to be at the scale of a city.
link |
It can be a new building,
link |
could be finding particular rooms, new social interaction.
link |
You experience that and if it's important enough,
link |
that becomes solidified a few days later
link |
and you won't forget it.
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If it's unimportant, you'll probably forget it.
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During REM sleep, there's a literal replay
link |
of the exact firing of the neurons that occurred
link |
while you were navigating that same city
link |
you're building earlier.
link |
So REM sleep seems to be involved in the generation
link |
of this detailed spatial information.
link |
But what is it that's actually happening in REM sleep?
link |
So there's this uncoupling of emotion,
link |
but most of all what's happening in REM sleep
link |
is that we're forming a relationship
link |
with particular rules or algorithms.
link |
We're starting to figure out
link |
based on all the experience that we had during the day,
link |
whether or not it's important
link |
that we avoid certain people
link |
or that we approach certain people.
link |
Whether or not it's important that when we enter a building
link |
that we go into the elevator and turn left
link |
where the bathroom is, for instance,
link |
these general themes of things and locations
link |
and how they fit together.
link |
And that has a word, it's called meaning.
link |
During our day, we're experiencing all sorts of things.
link |
Meaning is how we each individually piece together
link |
the relevance of one thing to the next, right?
link |
So if I suddenly told you that this pen
link |
was downloading all the information to my brain
link |
that was important to deliver this information,
link |
you'd probably think I was a pretty strange character
link |
because typically we don't think of pens
link |
as downloading information into brains.
link |
But if I told you that I was getting information
link |
from my computer that was allowing me to say things to you,
link |
you'd say, well, that's perfectly reasonable.
link |
And that's because we have a clear
link |
and agreed upon association with computers
link |
and information and memory.
link |
And we don't have that same association with pens.
link |
You might say, well, duh,
link |
but something in our brain
link |
needs to solidify those relationships
link |
and make sure that certain relationships don't exist.
link |
And it appears that REM sleep is important for that
link |
because when you deprive yourself or people of REM,
link |
they start seeing odd associations.
link |
They tend to lump or batch things.
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I know this from my own experience,
link |
if I've ever been sleep deprived,
link |
which unfortunately happens too often
link |
because I'm terrible with deadlines, pulling all nighter,
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the word the starts to look like it's spelled incorrectly.
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And the is a very simple word to spell,
link |
but things start to look a little distorted.
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And we know that if people are deprived of REM sleep
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for very long periods of time, they start hallucinating.
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They literally start seeing relationships
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and movement of objects that isn't happening.
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And so REM sleep is really
link |
where we establish the emotional load,
link |
but where we also start discarding
link |
of all the meanings that are irrelevant.
link |
And if you think about emotionality,
link |
a lot of over emotionality or catastrophizing
link |
is about seeing problems everywhere.
link |
And you could imagine why that might occur
link |
if you start linking the web
link |
of your experience too extensively.
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It's very important in order to have healthy emotional
link |
and cognitive functioning,
link |
that we have fairly narrow channels
link |
between individual things.
link |
If we see something on the news that's very troubling,
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well, then it makes sense to be very troubled.
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But if we're troubled by everything
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and we start just saying, everything is bothering me
link |
and I'm feeling highly irritable
link |
and everything's just distorting and troubling me,
link |
chances are we are not actively removing the meaning,
link |
the connectivity between life experiences
link |
as well as we could.
link |
And that almost always maps back to a deficit in REM sleep.
link |
So REM sleep is powerful and has this amazing capacity
link |
to eliminate the meanings that don't matter.
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It's not that it exacerbates the meanings that do matter,
link |
but it eliminates the meanings that don't matter.
link |
And that bears a striking resemblance
link |
to what happens early in development.
link |
This isn't a discussion about early in development,
link |
but early in development,
link |
the reason a baby can't generate coordinated movements
link |
and the reason why children can get very emotional
link |
about what seems like trivial events
link |
or what adults know to be trivial events,
link |
like, oh, the ice cream shop is closed
link |
and then the kid just dissolves
link |
into a puddle of tears and the parents can say,
link |
okay, well, it'll be open again another time.
link |
The children, one of the reasons
link |
that they can't generate coordinated movement
link |
or place that event of the ice cream shop being closed
link |
into a larger context
link |
is because they have too much connectivity
link |
and much of the maturation of the brain and nervous system
link |
that brings us to the point of being emotionally stable,
link |
reasonable, rational human beings
link |
is about elimination of connections between things.
link |
So REM sleep seems to be where we uncouple
link |
the potential for emotionality between various experiences.
link |
And that brings us
link |
to the absolutely fundamental relationship
link |
and similarity of REM sleep
link |
to some of the clinical practices
link |
that have been designed to eliminate emotionality
link |
and help people move through trauma
link |
and other troubling experiences,
link |
whether or not those troubling experiences
link |
are a death in the family or of a close loved one,
link |
something terrible that happened to you or somebody else,
link |
or an entire childhood or some event
link |
that in your mind and body is felt as
link |
and experienced as bad, terrible or concerning.
link |
Many of you perhaps have heard of trauma treatments
link |
such as EMDR, eye movement desensitization reprocessing
link |
or ketamine treatment for trauma,
link |
something that recently became legal
link |
and is in fairly widespread clinical use.
link |
Interestingly enough, EMDR and ketamine
link |
at kind of a core level bear very similar features
link |
So let's talk about EMDR first.
link |
EMDR, eye movement desensitization reprocessing
link |
is something that was developed
link |
by a psychologist Francine Shapiro.
link |
She actually was in Palo Alto and the story goes
link |
that she was walking not so incidentally
link |
in the trees and forest behind Stanford
link |
and she was recalling a troubling event in her own mind.
link |
So this would be from her own life.
link |
And she realized that as she was walking,
link |
the emotional load of that experience
link |
was not as intense or severe.
link |
She extrapolated from that experience
link |
of walking and not feeling as stressed
link |
about the stressful event to a practice
link |
that she put into work with her clients, with her patients
link |
and that now has become fairly widespread.
link |
It's actually one of the few behavior treatments
link |
that are approved by the American Psychological Association
link |
for the treatment of trauma.
link |
What she had her clients and patients do
link |
was move their eyes from side to side
link |
while recounting some traumatic or troubling event.
link |
Now this was of course in the clinic
link |
and I'm guessing that she removed the walking component
link |
and just took the eye movement component to the clinic
link |
because while it would be nice to go on therapy sessions
link |
with your therapist and take walks,
link |
there are certain boundaries to that
link |
such as confidentiality.
link |
If there are a lot of people around,
link |
the person might not feel as open to discussing things
link |
or weather barriers and things like that.
link |
If it's raining or hailing outside, it gets tough to do.
link |
Why eye movements?
link |
Well, she never really said why eye movements
link |
but soon I'll tell you why the decision
link |
to select these lateralized eye movements
link |
for the work in the clinic was the right one.
link |
So these eye movements, they look silly.
link |
I'll do them because that's why I'm here.
link |
They look silly, but they basically involve
link |
sitting in a chair and moving one's eyes from side to side,
link |
not while talking, but for me,
link |
and then recounting the event.
link |
So it's sometimes talking while moving the eyes
link |
but usually it was moving the eyes from side to side
link |
for 30, 60 seconds
link |
then describing this challenging procedure.
link |
Now, as a vision scientist who also works on stress,
link |
when I first heard this, I thought it was crazy, frankly.
link |
People would ask me about EMDR
link |
and I just thought, that's crazy.
link |
I went and looked up some of the theories
link |
about why EMDR might work.
link |
And there were a bunch of theories.
link |
Oh, it mimics the eye movements during REM sleep.
link |
It turns out that's not true and I'll explain why.
link |
The other one was, oh, it synchronizes the activity
link |
on the two sides of the brain.
link |
Well, sort of, I mean, when you look into both sides
link |
of the binocular visual field,
link |
you activate the visual cortex,
link |
but this whole idea of synchrony
link |
between the two sides of the brain
link |
is something that I think modern neuroscience
link |
is starting to, let's just say,
link |
gently or not so gently move away from,
link |
this whole right brain, left brain business.
link |
It turns out, however,
link |
that eye movements of the sort that I just did
link |
and that Francine Shapiro took from this walk experience
link |
and brought to her clients in the clinic
link |
are the sorts of eye movements that you generate
link |
whenever you're moving through space,
link |
when you are self-generating that movement.
link |
So not so much when you're driving a car,
link |
but certainly if you were riding a bicycle
link |
or you were walking or you were running,
link |
you don't realize it
link |
but you have these reflexive subconscious eye movements
link |
that go from side to side
link |
and they are associated with the motor system.
link |
So when you move forward, your eyes go like this.
link |
There've been a number of studies showing
link |
that these lateralized eye movements helped people
link |
move through or dissociate the emotional experience
link |
of particular traumas with those experiences
link |
such that they could recall those experiences
link |
after the treatment and not feel stressed about them
link |
or they didn't report them as traumatic any longer.
link |
Now, the success rate wasn't 100%,
link |
but they were statistically significant
link |
in a number of studies.
link |
And yet there are still some critics of EMDR
link |
and frankly, for a long time, I still thought,
link |
well, I don't know, this just seems like kind of a hack.
link |
It just seems like kind of a,
link |
this is something that for which we don't know the mechanism
link |
and we can't explain.
link |
But in the last five years,
link |
there have been no fewer than five
link |
and there's a sixth on the way,
link |
high quality peer-reviewed manuscripts
link |
published in Journal of Neuroscience,
link |
Neuron, Cell Press Journal, Excellent Journal,
link |
Nature, Excellent Journal.
link |
These are very stringent journals and papers
link |
showing that lateralized eye movements
link |
of the sort that I just did
link |
and if you're just listening to this,
link |
it's just sweep that moving the eyes from side to side
link |
with eyes open, that those eye movements,
link |
but not vertical eye movements,
link |
suppress the activity of the amygdala,
link |
which is this brain region
link |
that is involved in threat detection,
link |
stress, anxiety, and fear.
link |
There are some forms of fear
link |
that are not amygdala dependent,
link |
but the amygdala, it's not a fear center,
link |
but it is critical for the fear response
link |
and for the experience of anxiety.
link |
So that's interesting.
link |
We've got a clinical tool now
link |
that indeed shows a lot of success
link |
in a good number of people
link |
where eye movements from side to side
link |
are suppressing the amygdala
link |
and the general theme is to use those eye movements
link |
to suppress the fear response
link |
and then to recount or repeat the experience
link |
and over time uncouple the heavy emotional load,
link |
the sadness, the depression, the anxiety, the fear
link |
from whatever it was that happened that was traumatic.
link |
This is important to understand
link |
because I'd love to be able to tell somebody
link |
who had a traumatic experience
link |
that they would forget that experience,
link |
but the truth is you never forget the traumatic experience.
link |
What you do is you remove the emotional load.
link |
Eventually it really does lose its potency.
link |
The emotional potency is alleviated.
link |
Now, EMDR, I should just mention,
link |
tends to be most successful for single event
link |
or very specific kinds of trauma that happen over and over
link |
as opposed to say an entire childhood or an entire divorce.
link |
They tend to be, it tends to be most effective
link |
for single event kinds of things, car crashes, et cetera,
link |
where people can really recall the events
link |
in quite a lot of detail.
link |
So it's not for everybody and it should be done,
link |
if it's going to be done for trauma,
link |
it should be done in a clinical setting
link |
with somebody who's certified to do this,
link |
but that bears a lot of resemblance to REM sleep, right?
link |
This experience in our sleep where our eyes are moving,
link |
although in a different way,
link |
but we don't have the chemical epinephrine
link |
in order to generate the fear response
link |
and yet we're remembering the event
link |
from the previous day or days.
link |
Sometimes in REM sleep,
link |
we think about things that happened a long, long time ago.
link |
So that's interesting.
link |
And then now there's this new treatment,
link |
this chemical treatment with the drug ketamine,
link |
which also bears a lot of resemblance
link |
to the sorts of things that happen in REM sleep.
link |
Ketamine is getting a lot of attention now.
link |
And I think a lot of people
link |
just don't realize what ketamine is.
link |
Ketamine is a dissociative anesthetic.
link |
It is remarkably similar to the drug called PCP,
link |
which is certainly a hazardous drug for people to use.
link |
Ketamine and PCP both function
link |
to disrupt the activity of a particular receptor
link |
in the brain called the NMDA receptor,
link |
N-methyl-D-aspartate receptor.
link |
This is a receptor that's in the surface of neurons
link |
or on the surface of neurons
link |
for which most of the time it's not active.
link |
But when something very extreme happens
link |
and there's a lot of activity in the neural pathway
link |
that impinges on that receptor,
link |
it opens and it allows the entry of molecules, ions,
link |
that trigger a cellular process
link |
that we call long-term potentiation.
link |
And long-term potentiation translates
link |
to a change in connectivity
link |
so that later you don't need that intense event
link |
for the neuron to become active again.
link |
Let me clarify a little bit of this.
link |
The NMDA receptor is gated by intense experience.
link |
One way you could think about this
link |
is typically I walk in my home,
link |
I might make some food and sit down at my kitchen table,
link |
and I don't think anything about explosions.
link |
But were I to come home one night,
link |
sit down to a bowl of chicken soup,
link |
and there was a massive explosion,
link |
the neurons that are associated with chicken soup
link |
in my kitchen table would be active
link |
in a way that was different than they were previously
link |
and would be coupled to this experience of explosions
link |
such that the next time and perhaps every other time
link |
that I go to sit down at the kitchen table,
link |
no matter how rational I am
link |
about the origins of that explosion,
link |
maybe it was a gas truck that was down the road
link |
and there's no reason to think it's there today,
link |
but I would have the same experience.
link |
Those neurons would become active
link |
and I'd get an increase in heart rate,
link |
I'd get an increase in sweating, et cetera.
link |
Ketamine blocks this NMDA receptor
link |
and prevents that crossover and the addition of meaning
link |
to the kitchen table, kitchen soup, excuse me,
link |
chicken soup explosion experience.
link |
So how is ketamine being used?
link |
Ketamine is being used to prevent learning of emotions
link |
very soon after trauma.
link |
So ketamine is being stocked
link |
in a number of different emergency rooms
link |
where if people are brought in quickly
link |
and these are hard to describe even,
link |
but a horrible experience of somebody seeing a loved one
link |
next to them killed in a car accident
link |
and they were driving that car,
link |
this isn't for everybody certainly
link |
and you need to talk to your physician,
link |
but ketamine is being used
link |
so they might infuse somebody with ketamine
link |
so that their emotion is, it can still occur,
link |
but that the plasticity,
link |
the change in the wiring of their brain
link |
won't allow that intense emotion
link |
to be attached to the experience.
link |
Now, immediately you can imagine
link |
the sort of ethical implications of this, right?
link |
Because certain emotions need to be coupled to experiences.
link |
I'm not saying that people should be using ketamine
link |
or shouldn't be using ketamine,
link |
certainly not recreationally, it's quite dangerous.
link |
It can be lethal and like PCP,
link |
it can cause pretty dramatic changes
link |
in perception and behavior.
link |
But in the clinical setting,
link |
the basis of ketamine-assisted therapies
link |
is really to remove emotion.
link |
And I think the way I've been hearing about it,
link |
talked about in the general public
link |
is a lot of people think it's a little bit more like
link |
the kind of psilocybin trials or the MDMA trials
link |
where it's about becoming more emotional
link |
or getting in touch with a certain experience.
link |
Ketamine is about becoming dissociative
link |
or removed from the emotional component of the experience.
link |
So now we have ketamine,
link |
which chemically blocks plasticity
link |
and prevents the connection
link |
between an emotion and an experience.
link |
That's a pharmacologic intervention.
link |
We have EMDR, which is this eye movement thing
link |
that is designed to suppress the amygdala
link |
and is designed to remove emotionality
link |
while somebody recounts an experience.
link |
And we have REM sleep,
link |
where the chemical epinephrine that allows for signaling
link |
of intense emotion and the experience of a tense emotion
link |
in the brain and body is not allowed.
link |
And so we're starting to see a organizational logic,
link |
which is that a certain component of our sleeping life
link |
is acting like therapy.
link |
And that's really what REM sleep is about.
link |
So we should really think about REM sleep
link |
and slow wave sleep as both critical,
link |
slow wave sleep for motor learning and detailed learning,
link |
REM sleep for attaching of emotions
link |
to particular experiences,
link |
and then for making sure that the emotions
link |
are not attached to the wrong experiences
link |
and for unlearning emotional responses
link |
if they're too intense or severe.
link |
And this all speaks to the great importance
link |
of mastering one's sleep,
link |
something that we talked about
link |
in episode two of the podcast
link |
and making sure that if life has disruptive events,
link |
either due to travel or stress or changes in school
link |
something that we talked about in episodes three and four,
link |
that one can still grab a hold and manage one's sleep life.
link |
Because fundamentally the unlearning of emotions
link |
that are troubling to us
link |
is what allows us to move forward in life.
link |
And indeed the REM deprivation studies show
link |
that people become hyper-emotional,
link |
they start to catastrophize.
link |
And it's no surprise therefore
link |
that sleep disturbances correlate
link |
with so many emotional and psychological disturbances.
link |
It's just by now it should just be obvious
link |
why that will be the case.
link |
In fact, the other day I was in a discussion
link |
with a colleague of mine who's down in Australia,
link |
I've known her for two decades now
link |
from the time she was at Oxford.
link |
And Sarah studies among other things,
link |
menopause in the brain.
link |
And she was saying that a lot of the emotional effects
link |
of menopause actually are not directly related
link |
There've been some really nice studies showing
link |
that the disruptions in temperature regulation in menopause
link |
map to changes in sleep regulation
link |
that then impact emotionality
link |
and an inability to correctly adjust the circuits
link |
related to emotionality.
link |
And I encourage you to look at her work.
link |
We'll probably have her as a guest on the podcast
link |
at some point in the future
link |
because she's so knowledgeable about those sorts of issues
link |
as well as issues related to testosterone
link |
and in people with all sorts
link |
of different chromosomal backgrounds.
link |
So sleep deprivation isn't just deprivation of energy.
link |
It's not just deprivation of immune function.
link |
It is deprivation of self-induced therapy
link |
every time we go to sleep, okay?
link |
So these things like EMDR and ketamine therapies
link |
are in clinic therapies,
link |
but REM sleep is the one that you're giving yourself
link |
every night when you go to sleep,
link |
which raises I think the other important question,
link |
which is how to get and how to know
link |
if you're getting the appropriate amount
link |
of REM sleep and slow wave sleep.
link |
So that's what we'll talk about next.
link |
So how should one go about getting the appropriate amount
link |
of slow wave sleep and REM sleep
link |
and knowing that you're getting the right amount?
link |
Well, short of hooking yourself up to an EEG,
link |
it's going to be tough to get exact measurements
link |
of brain states from night to night.
link |
Some people nowadays are using things
link |
like the aura ring or a whoop band
link |
or some other device to measure the quality
link |
and depth and duration of their sleep.
link |
And for many people, those devices can be quite useful.
link |
Some people are only gauging their sleep
link |
by way of whether or not they feel rested,
link |
whether or not they feel like they're learning
link |
and they're getting better or not.
link |
There are some things that one can really do.
link |
And the first one might surprise you
link |
in light of everything I've said
link |
and probably everything you've heard about sleep.
link |
There was a study done by a Harvard undergraduate,
link |
Emily Hoagland, who was in Robert Strickgold's lab
link |
And that study explored how variations
link |
in total sleep time related to learning
link |
as compared to total sleep time itself.
link |
And to summarize the study, what they found
link |
was that it was more important
link |
to have a regular amount of sleep each night
link |
as opposed to the total duration.
link |
In other words, and what they showed
link |
was that improvements in learning
link |
or deficits in learning were more related
link |
to whether or not you got six hours, six hours,
link |
five hours, six hours, that was better
link |
than if somebody got, for instance,
link |
six hours, 10 hours, seven hours, four or five hours.
link |
So you might say, well, that's crazy
link |
because I thought we were just all supposed
link |
to get more sleep and there's more REM towards morning.
link |
Turns out that for sake of learning new information
link |
and performance on exams in particular,
link |
that's what was measured,
link |
limiting the variation in the amount of your sleep
link |
is at least as important and perhaps more important
link |
than just getting more sleep overall.
link |
And I think this will bring people great relief,
link |
many people great relief who are struggling
link |
to quote unquote get enough sleep.
link |
Remember a few episodes ago,
link |
I talked about the difference between fatigue and insomnia.
link |
Fatigue tends to be when we are tired,
link |
insomnia tends to lead to a sleepiness during the day
link |
when we're falling asleep and you don't want that,
link |
you don't want either of those things really.
link |
But I found it striking that the data from this study
link |
really point to the fact that consistently getting
link |
about the same amount of sleep
link |
is better than just getting more sleep.
link |
And I think nowadays so many people
link |
are just aiming for more sleep
link |
and they're rather troubled about the fact
link |
that they're only getting five hours
link |
or they're only getting six hours in some cases.
link |
It may be the case that they are sleep deprived
link |
and they need more sleep,
link |
but some people just have a lower sleep need.
link |
And I find great relief personally in the fact
link |
that consistently getting for me about six hours
link |
or six and a half hours is going to be more beneficial
link |
than constantly striving for eight or nine
link |
and finding that some nights I'm getting five
link |
and sometimes I'm getting nine and varying around the mean.
link |
As I recall and I think I'm going to get this precisely right
link |
but if not, I know that I'm at least close
link |
for every hour variation in sleep,
link |
regardless of whether or not it was more sleep
link |
than one typically got,
link |
there was a 17% reduction in performance
link |
on this particular exam type.
link |
And so this is powerful.
link |
This means that we should strive
link |
for a regular amount of sleep.
link |
And for some of us, that means falling asleep
link |
and waking up and going back to sleep.
link |
For some people it means falling asleep
link |
and waking up and not getting back to sleep.
link |
Now, ideally you're getting the full compliment
link |
of slow wave sleep early at night
link |
and sleep toward morning, which is REM sleep,
link |
which brings us to how to get more REM sleep.
link |
Well, there are a couple of different ways,
link |
but here's how to not get more REM sleep.
link |
First of all, drink a lot of fluid
link |
right before going to sleep.
link |
One of the reasons why we wake up
link |
in the middle of the night to use the bathroom
link |
is because when our bladder is full,
link |
there is a neural connection,
link |
literally a set of neurons and a nerve circuit
link |
that goes to the brainstem that wakes us up.
link |
And actually some people that I know
link |
and I won't be mentioned actually use this
link |
to try and adjust for their jet lag
link |
when they're trying to stay awake.
link |
Having to use the bathroom, having to urinate
link |
is one of the most anxiety evoking experiences
link |
If you really have to go to the bathroom,
link |
it's very hard to fall asleep or stay asleep.
link |
And bedwetting, which happens in kids very early on
link |
is a failure of those circuits to mature
link |
until I think we all assume that babies
link |
are going to pee in their sleep,
link |
but adults aren't supposed to do that.
link |
And the circuits take some time to develop
link |
and in some kids they develop
link |
a little bit later than others.
link |
So having a full bladder is one way to disrupt your sleep.
link |
You don't want to go to bed dehydrated, but that's one way.
link |
On the other hand, there is evidence
link |
that if you want to remember your dreams more
link |
or remember more of your dreams,
link |
there is a tool that you can use.
link |
I don't necessarily recommend it,
link |
which is to drink a bunch of water before you go to sleep.
link |
And then what happens is you tend to break
link |
in and out of REM sleep.
link |
It tends to be fractured.
link |
And with a sleep journal,
link |
then they've done these laboratory studies,
link |
believe it or not,
link |
people will recall more of their dreams
link |
because they're in this kind of semi-conscious state
link |
because they're constantly waking up throughout the night.
link |
I suggest not having a full bladder before you go to sleep.
link |
That one's kind of an obvious one, but nonetheless.
link |
The other one is if you recall that during REM sleep,
link |
we have a shift in neurotransmitters
link |
such that we have less serotonin, right?
link |
Just want to make sure I got that right.
link |
Excuse me, less serotonin.
link |
There are a lot of supplements out there
link |
geared toward improving sleep.
link |
I've taken some of them
link |
and I'm taking many of them,
link |
if not all of them at this point,
link |
so I could report back to you.
link |
And I think I mentioned on a previous episode
link |
that when I take tryptophan
link |
or anything that contains 5-HTP,
link |
which is serotonin or a precursor to serotonin,
link |
serotonin is made from tryptophan,
link |
I tend to fall very deeply asleep
link |
and then wake up a few hours later.
link |
And that makes sense now based on the fact
link |
that you just don't want a lot of REM sleep early on.
link |
What was probably happening
link |
is that I was getting a lot of REM sleep early on
link |
because low levels of serotonin
link |
are typically associated with slow wave sleep
link |
and that comes early in the night.
link |
So for some people, those supplements might work,
link |
but beware serotonin supplements
link |
could disrupt the timing of REM sleep and slow wave sleep.
link |
And in my case, led to waking up
link |
very shortly after going to sleep
link |
and not being able to get back to sleep.
link |
Now, if you want to increase your slow wave sleep,
link |
that's interesting.
link |
There are ways to do that.
link |
One of the most powerful ways to increase slow wave sleep,
link |
the percentage of slow wave sleep,
link |
apparently without any disruption
link |
to the other components of sleep and learning
link |
is to engage in resistance exercise.
link |
It's pretty clear that resistance exercise
link |
triggers a number of metabolic and endocrine pathways
link |
that lend themselves to release of growth hormone,
link |
which happens early in the night.
link |
And resistance exercise therefore
link |
can induce a greater percentage of slow wave sleep.
link |
It doesn't have to be done very close to going to bedtime.
link |
In fact, for some people that the exercise
link |
could be disruptive
link |
for reasons I've talked about in previous episodes,
link |
but resistance exercise, unlike aerobic exercise
link |
does seem to increase the amount of slow wave sleep,
link |
which as we know is involved in motor learning
link |
and the acquisition of fine detailed information,
link |
not general rules or the emotional components of experiences.
link |
For those of you that are interested in lucid dreaming
link |
and would like to increase the amount of lucid dreaming
link |
that you're experiencing,
link |
I haven't been able to track down that device
link |
with the red light that I described at the beginning,
link |
but there are a number of just simple zero technology tools
link |
that one could use in principle.
link |
One is to set a cue.
link |
The way this works is you come up with a simple statement
link |
about something that you'd like to see
link |
or experience later in dreams.
link |
You can, for instance, write down, you know,
link |
something like, I want to remember the red apple.
link |
I know it sounds silly and trivial.
link |
And you look at that,
link |
you would probably want to write it down
link |
on a piece of paper.
link |
You might even want to draw a red apple.
link |
And then before you go to sleep, you would look at it.
link |
And then you would just go to sleep.
link |
There are some reports that doing that
link |
for several days in a row can lead to a situation
link |
in which you are suddenly in your dream
link |
and you remember the red apple.
link |
And that gives you a sort of tether to reality
link |
between the dream state and reality
link |
that allows you to navigate and shape
link |
and kind of adjust your dreams.
link |
Lucid dreaming does not have to be
link |
or include the ability to alter features of the dream,
link |
you know, to be able to control things in the dream.
link |
Sometimes it's just the awareness that you are dreaming.
link |
But nonetheless, some people enjoy lucid dreaming.
link |
And then for people that have a lot of lucid dreams
link |
that feel kind of overwhelmed by those,
link |
that's going to involve trying to embrace protocols
link |
that can set the right duration of sleep.
link |
There's a little bit of literature, not a lot,
link |
that shows that keeping the total amount of sleep per night
link |
to say six hours such that you begin sleep
link |
and end at the beginning and end
link |
of one of these ultradian cycles
link |
can be better than waking up
link |
in the middle of one of these ultradian cycles.
link |
So try and find the right amount of sleep that you need
link |
that's right for you
link |
and then try and get that consistently night to night.
link |
If you're a lucid dreamer and you don't like it,
link |
then you may want to start to make sure
link |
that you're waking up at the end
link |
of one of these ultradian cycles.
link |
So in this case, it would be better
link |
to wake up after six hours than after seven.
link |
And if you did sleep longer than six hours,
link |
maybe you'd want to get to seven and a half hours
link |
because that's going to reflect the end
link |
of one of these 90 minute cycles
link |
as opposed to waking up in the middle.
link |
Alcohol, alcohol and marijuana are well known
link |
to induce states that are pseudo sleep-like,
link |
especially when people fall asleep
link |
after having consumed alcohol or THC,
link |
the active component,
link |
one of the active components in marijuana.
link |
Alcohol, THC, and most things like them,
link |
meaning things that increase serotonin or GABA
link |
are going to disrupt the pattern of sleep.
link |
They're going to disrupt the depth.
link |
They're going to disrupt the overall sequencing
link |
of more slow wave sleep early in the night
link |
and more REM sleep later in the night.
link |
That's just the reality.
link |
There are some things that,
link |
at least in a few studies that I could find,
link |
seem to suggest that you could increase
link |
the amount of slow wave sleep using things like arginine,
link |
the amino acid arginine,
link |
although you really want to check arginine
link |
can have effects on heart, et cetera,
link |
has other effects.
link |
not going to be great for sleep and depth of sleep.
link |
You might feel like you can fall asleep faster,
link |
but the sleep that you're accessing
link |
really isn't the kind of deep restorative sleep
link |
that you should be getting.
link |
Now, of course, if that's what you need in order to sleep
link |
and that's within your protocols,
link |
I've said here before,
link |
I'm not suggesting people take anything.
link |
I'm not a medical doctor.
link |
So I'm not trying to regulate anyone's behavior.
link |
I'm just telling you what the literature says.
link |
Some of you may want to explore your dreams
link |
and meaning of dreams, et cetera.
link |
There's not a lot of hard data about how to do this,
link |
but a lot of people report keeping a sleep journal
link |
where a dream journal can be very useful.
link |
So they mark when they think they fell asleep
link |
the night before, when they woke up.
link |
And if they wake up in the middle of the night,
link |
early in the morning,
link |
they'll just write down what they can recall
link |
And even if they recall nothing,
link |
many people have the experience of mid-morning
link |
or later afternoon that suddenly comes to them
link |
that they had a dream about something and writing that down.
link |
I kept a dream journal for a while.
link |
It didn't really afford me much.
link |
I didn't really learn anything
link |
except that my dreams were very bizarre.
link |
But there are some things that happen in dreams
link |
that are associated with REM sleep
link |
as it compared to slow wave sleep,
link |
which can tell you whether or not your dream
link |
likely happened in REM sleep or slow wave sleep.
link |
And the distinguishing feature it turns out
link |
is something called theory of mind.
link |
Theory of mind is actually an idea that was developed
link |
for the study and assessment of autism.
link |
And it was initially that phrase theory of mind
link |
was brought about by Simon Baron Cohen,
link |
who is Sasha Baron Cohen, the comedian's brother.
link |
Simon Baron Cohen is a psychologist
link |
and to some extent a neuroscientist at Oxford.
link |
And theory of mind tests are done on children.
link |
And the theory of mind test is somewhat like the following.
link |
A child is brought into a laboratory
link |
and watches a video of a child
link |
playing with some sort of toy.
link |
And then at the end of playing with that toy,
link |
they put the toy in a drawer and they go away.
link |
And then another child comes in and is looking around.
link |
And then the experimenter asks the child
link |
who's in the experiment, the real child,
link |
and says, what does the child think?
link |
What are they feeling?
link |
And most children of a particular age,
link |
five or six or older will say,
link |
oh, you know, he or she is confused.
link |
They don't know where the toy is.
link |
Or they'll say something that implies
link |
what we call theory of mind,
link |
that they can put their ideas and their mind
link |
into what the other child is likely to be feeling
link |
That's theory of mind.
link |
And it turns out that this is used
link |
as one of the assessments for autism
link |
because some children, not all,
link |
but some children that have autism
link |
or that go on to develop autism
link |
don't have this theory of mind.
link |
They tend to fixate on the fact
link |
that the first child put the toy in the drawer.
link |
They'll say it's in the drawer
link |
as opposed to answering the question,
link |
which is how does the second child feel about it
link |
or what are they experiencing?
link |
So theory of mind is something that emerges early in life
link |
as a part of the maturation of the circuits in the brain
link |
associated with emotional learning
link |
and social interactions.
link |
And we experience this in certain dreams.
link |
So if you had a dream that you're puzzled about
link |
or that you're fixated on and you're thinking about,
link |
you might ask, in that dream,
link |
was I assessing somebody else's emotion and feeling
link |
or was I very much in my own first person experience?
link |
And the tendency is that theory of mind
link |
tends to show up most in these REM associated dreams.
link |
Now, this isn't a hard and fast rule,
link |
but chances are if you were in a dream
link |
and you were thinking about other people
link |
who wanted to do something to you,
link |
you were thinking about their desire to chase you
link |
or help you or something that was related
link |
to someone else's emotional experience,
link |
it was probably a REM dream.
link |
That dream occurred in rapid eye movement sleep
link |
as opposed to slow wave sleep.
link |
And that makes sense when you think about the role of REM
link |
in emotional unlearning of associations
link |
with particular life events,
link |
that REM is rich with all sorts of exploration
link |
of the emotional load of being chased
link |
or the emotional load of having to take an exam the next day
link |
or being late for something.
link |
But again, if you're fixated
link |
or you can recall thinking a lot about
link |
or feeling a lot about what somebody else's motivations were
link |
then chances are it was in REM.
link |
And if not, chances are it was in slow wave sleep.
link |
Today, we've been in a deep dive of sleep and dreaming,
link |
learning and unlearning.
link |
And I just want to recap a few of the highlights
link |
and important points.
link |
A lot more slow wave sleep and less REM early in the night,
link |
more REM and less slow wave sleep later in the night.
link |
REM sleep is associated with intense experiences
link |
without this chemical epinephrine
link |
that allows us the anxiety or fear
link |
and almost certainly has an important role
link |
in uncoupling of emotion from experiences,
link |
kind of self-induced therapy that we go into each night.
link |
That bears striking resemblance to things like EMDR
link |
and ketamine therapies and so forth.
link |
Slow wave sleep is critical however,
link |
it's critical mostly for motor learning
link |
and the learning of specific details.
link |
So REM is kind of emotions and general themes
link |
and meaning and slow wave sleep, motor learning and details.
link |
I personally find it fascinating that consistency of sleep,
link |
meaning getting six hours every night
link |
is better than getting 10 one night, eight the next,
link |
five the next, four the next.
link |
I find that fascinating and I think I also like it
link |
because it's something I can control better
link |
than just trying to sleep more,
link |
which I think I'm not alone in agreeing
link |
that that's just hard for a lot of people to do.
link |
This episode also brings us to the conclusion
link |
of a five episode streak where we've been focusing on sleep
link |
and transitions in and out of sleep, non-sleep depressed.
link |
We've talked about a lot of tools, morning light,
link |
evening light, avoiding lights, blue blockers, supplements,
link |
tools for measuring sleep duration and quality.
link |
We've been covering a lot of themes.
link |
I like to think that by now you're armed
link |
with a number of tools and information,
link |
things like knowing when your temperature minimum is,
link |
knowing when you might want to view light or not,
link |
when you might want to eat or take hot showers
link |
or God forbid, a cold shower,
link |
something that most people, including me,
link |
more or less loathe but can have certain benefits.
link |
And that will allow you to shape your sleep life
link |
and get this consistent or more or less consistent amount
link |
of sleep on a regular basis.
link |
In fact, I have this little joke
link |
that I sometimes tell it's not funny.
link |
Like most of the jokes I tell, I'm told they're not funny,
link |
but there's so much excitement now about intermittent
link |
Sometimes I think that someone should start something
link |
on intermittent sleep deprivation,
link |
although we're already doing that.
link |
We are all experiencing lack of sleep from time to time.
link |
And I don't think we should catastrophize that too much.
link |
I think that what we want to do rather than accumulate
link |
a sleep anxiety is to, if we get a bad night's sleep,
link |
we want to adjust, we want to get back on track
link |
and just get the consistent amount of sleep,
link |
use those non-sleep deep rest protocols
link |
to help us relax when we're feeling anxious,
link |
we're having trouble waking up in the middle of the night.
link |
There are a lot of tools out there
link |
and most of them are zero cost.
link |
And so I hope you'll find those beneficial.
link |
If you've been hearing Costello snoring
link |
throughout this episode, I apologize on his behalf.
link |
As I said in the welcome video to this podcast,
link |
he's an integral part of the podcast.
link |
A few people have said,
link |
hey, that noise in the background is really disruptive.
link |
Hey, what can I say?
link |
Costello is a 10 year old bulldog mastiff.
link |
The lifespan on those animals is about 10 years.
link |
So I'm not trying to make you feel guilty,
link |
but after he's gone, there won't be any snoring,
link |
although I'll probably get a different dog.
link |
So sort of a, what would the kids say?
link |
Sorry, not sorry about the snoring.
link |
And I'm sorry if it's disruptive genuinely,
link |
but he's here for the haul.
link |
So that's what that's about.
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As we close out this segment on sleep,
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we are moving into a new theme and topic
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for the next four to five episodes.
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We are going to discuss the science
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and the tools related to neuroplasticity.
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Neuroplasticity is a remarkable feature
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of the nervous system.
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In fact, it's the defining feature of the nervous system,
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which is its ability to change itself
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in response to experience.
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That is unlike every other tissue
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and collection of cells and organ in our body.
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It's really what makes us as a species
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and it's what makes us as individuals.
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And it's really where our potential lies.
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Everything that we know, everything we can do
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and our true potential in terms of what we will ever
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be able to know, do, say in life
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is set by the limits of neuroplasticity.
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So we're going to explore learning in childhood,
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learning in adulthood.
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We're going to discuss detailed protocols
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as they relate to sensory plasticity,
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learning new sensory information versus motor plasticity
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or sensory motor integration.
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We're going to talk about language acquisition.
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We're going to be talking about emotional acquisition
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and breadth, as well as I think a topic
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a lot of people are going to find fascinating
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is the relationship between plasticity set
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during childhood attachment to parent or other caregiver
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and how that maps onto adult relationships.
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Now there's many of you have probably heard
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about secure attached or insecure attached
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the A, B and C babies as they're called
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from the classic studies of Bowlby and others.
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But now there's actual neuroscience that can say
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which circuits were active
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during those early life attachment
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and how those map to adult attachment styles, challenges
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and what makes us more likely to select certain partners
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and styles of attachment
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as well as how to change those.
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It's really fascinating.
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And I think neurosciences time has come
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for neuroplasticity.
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We're also going to talk of course
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about supplements and chemicals and machines and devices
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that can assist in speeding up the plasticity process
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or believe it or not, there are some cases
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where you might want to delay plasticity
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in order to get more depth of learning
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and have that learning last longer.
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Something that is just absolutely spectacular literature.
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So I'm very excited to move on to that topic soon.
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I hope that the tools that you've acquired so far
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and the knowledge that you've acquired so far
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is helping you with your self evaluation
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and experimentation as you see fit
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and is allowing you to not just sleep better
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but feel better while you're awake
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and hopefully has set the stage for you to learn better
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as we start to march into the month on neuroplasticity.
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Many of you have asked how you can help support
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the Huberman Lab Podcast
link |
and we greatly appreciate the question.
link |
You can help support the podcast by subscribing
link |
to the YouTube channel if you haven't already
link |
and leaving comments and questions in the comment section.
link |
If you could subscribe on Apple and or Spotify,
link |
that's helpful and there's a place on Apple Podcast
link |
to leave a rating as well as comments
link |
about how you feel about the podcast.
link |
If you could suggest the podcast to friends and coworkers
link |
and anyone else that you think would benefit
link |
from the information,
link |
that also really helps us get the word out.
link |
And of course, check out our sponsors
link |
because that's a very direct way to help us continue
link |
to get this information out to the general public.
link |
Many of you have asked about supplements
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and where I personally get my supplements.
link |
I've partnered with Thorne
link |
and I get my supplements from Thorne
link |
because by my view,
link |
they have the highest level of stringency
link |
and precision in terms of what's in the bottle.
link |
And they also have very, very high quality standards.
link |
They're partnered with the Mayo Clinic
link |
and all the major sports organizations.
link |
If you want to try Thorne supplements,
link |
you can go to Thorne.com.
link |
So that's Thorne spelled T-H-O-R-N-E.com
link |
slash the letter U slash Huberman.
link |
And if you do that,
link |
you can see the formulations that I take
link |
and you'll also get 20% off, not just those formulations,
link |
but anything that Thorne makes.
link |
That's Thorne.com slash U slash Huberman
link |
to get 20% off anything that they provide.
link |
Last but not least,
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a few people wrote to me with some questions
link |
slash corrections about things that I said
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in previous podcasts.
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So in keeping with my goal
link |
of making the information accurate and clear,
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I just want to correct myself
link |
about a few things that I said.
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and I'm guessing it probably came from an endocrinologist
link |
or somebody else that knows a lot about testicles,
link |
said, Huberman, you mentioned that testosterone
link |
is made by the Sertoli cells of the testes,
link |
and it's not, it's made by the Leydig cells of the testes,
link |
and indeed you are correct.
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And so I want to make sure that I clarify that.
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Testosterone is made by the Leydig cells of the testes,
link |
not by the Sertoli cells.
link |
The Sertoli cells make 5-alpha reductase and aromatase
link |
and some other enzymes involved in conversion of testosterone
link |
into things like DHT and estrogen.
link |
So thank you for that correction.
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I genuinely appreciate it.
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The other thing I said was at one point I said,
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typical temperature is 96.8
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when I actually meant to say 98.6.
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So it was a dyslexic slip on my part.
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I don't know that I'm dyslexic.
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I know I'm being clinically diagnosed with dyslexia,
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but I swapped them,
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which sometimes happens when I'm going fast.
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I'll use this as a moment to just say
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temperature varies a lot across the day and night.
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That was a theme of previous podcasts.
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So we can't really talk about average temperature anyway,
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but I do want to be clear that most people think
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about average temperature as 98.6.
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I misspoke my error and I apologize.
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Thank you for joining me in this journey
link |
of the nervous system and biology
link |
and trying to understand the mechanisms
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that make us who we are and how we function
link |
in sleep and in wakefulness.
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It's really an incredible landscape to consider.
link |
And I hope that you're getting a lot
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out of the information.
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As always, thank you for your interest in science.
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I'll see you next time.