Understand and Use Dreams to Learn and Forget

00:00:00.000 | - Welcome to Huberman Lab Essentials,

00:00:02.320 | where we revisit past episodes

00:00:04.380 | for the most potent and actionable science-based tools

00:00:07.560 | for mental health, physical health, and performance.

00:00:10.320 | I'm Andrew Huberman,

00:00:12.760 | and I'm a professor of neurobiology and ophthalmology

00:00:15.960 | at Stanford School of Medicine.

00:00:17.480 | Today, we're going to talk about dreaming,

00:00:19.880 | learning during dreaming,

00:00:21.680 | as well as unlearning during dreaming.

00:00:23.980 | In particular, unlearning of challenging emotional events.

00:00:28.800 | Now, numerous people throughout history

00:00:30.320 | have tried to make sense of dreams

00:00:31.720 | in some sort of organized way.

00:00:33.480 | The most famous of which, of course, is Sigmund Freud,

00:00:35.840 | who talked about symbolic representations in dreams.

00:00:38.520 | A lot of that has been kind of debunked,

00:00:40.600 | although I think that there's some interest

00:00:43.560 | in what the symbols of dreaming are.

00:00:46.000 | And this is something that we'll talk about

00:00:47.400 | in more depth today,

00:00:48.460 | although not Freudian theory in particular.

00:00:53.200 | So I think in order to really think about dreams

00:00:56.960 | and what to do with them and how to maximize

00:01:00.280 | the dream experience for sake of learning and unlearning,

00:01:04.360 | the best way to address this

00:01:05.840 | is to look at the physiology of sleep,

00:01:07.800 | to really address what do we know concretely about sleep.

00:01:11.680 | So first of all, as we get sleepy,

00:01:14.040 | we tend to shut our eyes,

00:01:16.960 | and that's 'cause there are some autonomic centers

00:01:19.060 | in the brain, some neurons that control

00:01:21.040 | closing of the eyelids when we get sleepy.

00:01:23.280 | And then we transition into sleep.

00:01:24.960 | And sleep, regardless of how long we sleep,

00:01:27.800 | is generally broken up into a series of 90-minute cycles,

00:01:31.240 | these ultradian cycles.

00:01:33.000 | So early in the night,

00:01:35.340 | these 90-minute cycles tend to be comprised

00:01:37.980 | more of shallow sleep and slow-wave sleep.

00:01:40.960 | And we tend to have less so-called REM sleep,

00:01:43.560 | R-E-M sleep, which stands for rapid eye movement sleep.

00:01:46.800 | For every 90-minute cycle that we have

00:01:49.240 | during a night of sleep,

00:01:51.180 | we tend to start having more and more REM sleep.

00:01:55.120 | So more of that 90-minute cycle

00:01:56.660 | is comprised of REM sleep and less of slow-wave sleep.

00:02:00.380 | Now, this is true regardless of whether or not

00:02:02.240 | you wake up in the middle of the night

00:02:03.300 | to use the restroom or your sleep is broken.

00:02:06.980 | The more sleep you're getting across the night,

00:02:09.700 | the more REM sleep you're going to have.

00:02:11.820 | And REM sleep and non-REM, as I'll refer to it,

00:02:15.620 | have distinctly different roles in learning and unlearning,

00:02:18.440 | and they are responsible for learning and unlearning

00:02:20.720 | of distinctly different types of information.

00:02:23.180 | And this has enormous implications

00:02:26.500 | for learning of motor skills,

00:02:29.000 | for unlearning of traumatic events,

00:02:31.420 | or for processing emotionally challenging,

00:02:33.580 | as well as emotionally pleasing events.

00:02:36.300 | And as we'll see,

00:02:37.860 | one can actually leverage their daytime activities

00:02:41.020 | in order to access more slow-wave sleep,

00:02:43.540 | or non-REM sleep, as we'll call it,

00:02:45.880 | or more REM sleep,

00:02:46.980 | depending on your particular emotional and physical needs.

00:02:50.580 | So it's really a remarkable stage of life

00:02:52.480 | that we have a lot more control and power over

00:02:55.160 | than you might believe.

00:02:57.080 | So let's start by talking about slow-wave sleep,

00:03:00.400 | or non-REM sleep.

00:03:01.740 | So slow-wave sleep is characterized

00:03:04.540 | by a particular pattern of brain activity

00:03:07.620 | in which the brain is metabolically active,

00:03:10.540 | but that there's these big sweeping waves of activity

00:03:13.500 | that include a lot of the brain.

00:03:15.260 | Now, the interesting thing about slow-wave sleep

00:03:17.620 | are the neuromodulators that tend to be associated with it

00:03:21.580 | that are most active and least active during slow-wave sleep.

00:03:24.660 | And here's why.

00:03:26.340 | To remind you, neuromodulators are these chemicals

00:03:29.820 | that act rather slowly,

00:03:31.580 | but their main role is to bias particular brain circuits

00:03:35.660 | to be active and other brain circuits to not be active.

00:03:38.440 | And they are associated, as a consequence,

00:03:40.380 | with certain brain functions.

00:03:41.960 | So we know, for instance,

00:03:43.340 | and just to review, acetylcholine in waking states

00:03:46.580 | is a neuromodulator that tends to amplify the activity

00:03:49.420 | of brain circuits associated with focus and attention.

00:03:52.760 | Norepinephrine is a neuromodulator

00:03:54.500 | that tends to amplify the brain circuits

00:03:56.260 | associated with alertness and the desire to move.

00:04:00.060 | Serotonin is the neuromodulator that's released

00:04:03.220 | and tends to amplify the circuits in the brain and body

00:04:06.140 | that are associated with bliss and a desire to remain still.

00:04:10.060 | And dopamine is the neuromodulator that's released

00:04:13.580 | and is associated with amplification

00:04:16.080 | of the neural circuits in the brain and body

00:04:17.740 | associated with pursuing goals and pleasure and reward.

00:04:21.940 | So in slow-wave sleep,

00:04:24.300 | something really interesting happens.

00:04:26.500 | There's essentially no acetylcholine.

00:04:29.500 | And acetylcholine, as I just mentioned,

00:04:31.340 | is associated with focus.

00:04:33.260 | So you can think of slow-wave sleep

00:04:34.900 | as these big sweeping waves of activity through the brain

00:04:37.620 | and a kind of distortion of space and time

00:04:40.100 | so that we're not really focusing on any one thing.

00:04:43.180 | Now, the other molecules that are very active at that time

00:04:47.900 | are norepinephrine, which is a little bit surprising

00:04:50.600 | 'cause normally in waking states,

00:04:52.440 | norepinephrine is going to be associated

00:04:54.260 | with a lot of alertness and the desire to move.

00:04:57.340 | But there's not a ton of norepinephrine

00:04:59.760 | around in slow-wave sleep, but it is around.

00:05:01.880 | So there's something associated

00:05:03.280 | with the movement circuitry going on in slow-wave sleep.

00:05:06.720 | And remember, this is happening mostly

00:05:08.280 | at the beginning of the night.

00:05:09.400 | Your sleep is dominated by slow-wave sleep.

00:05:11.880 | So no acetylcholine, very little norepinephrine,

00:05:15.400 | although there is some, and a lot of serotonin.

00:05:18.160 | And serotonin, again, is associated with this desire,

00:05:21.340 | this sensation of kind of bliss or wellbeing,

00:05:23.800 | but not a lot of movement.

00:05:24.880 | And during sleep, you tend not to move.

00:05:27.580 | Now, in slow-wave sleep, you can move.

00:05:29.520 | You're not paralyzed, so you can roll over.

00:05:32.060 | If people are going to sleepwalk,

00:05:33.980 | typically it's going to be during slow-wave sleep.

00:05:36.760 | And what studies have shown

00:05:39.680 | through some kind of sadistic experiments

00:05:42.840 | where people are deprived specifically of slow-wave sleep,

00:05:46.240 | and that can be done by waking them up

00:05:48.600 | as soon as the electrode recordings show

00:05:50.640 | that they're in slow-wave sleep,

00:05:52.180 | or by chemically altering their sleep

00:05:54.820 | so that it biases them away from slow-wave sleep.

00:05:57.520 | What studies have shown is that motor learning

00:06:00.080 | is generally occurring in slow-wave sleep.

00:06:04.540 | So let's say the day before you go to sleep,

00:06:07.140 | you were learning some new dance move,

00:06:10.060 | or you were learning some specific motor skill,

00:06:12.740 | either a fine motor skill or a coarse motor skill.

00:06:15.860 | Learning of those skills is happening

00:06:19.420 | primarily during slow-wave sleep

00:06:21.420 | in the early part of the night.

00:06:22.900 | In addition, slow-wave sleep has been shown to be important

00:06:26.380 | for the learning of detailed information.

00:06:29.240 | So we can think of slow-wave sleep

00:06:31.100 | as important for motor learning, motor skill learning,

00:06:34.560 | and for the learning of specific details

00:06:37.060 | about specific events.

00:06:39.060 | And this turns out to be fundamentally important

00:06:41.860 | because now we know that slow-wave sleep

00:06:45.660 | is primarily in the early part of the night,

00:06:47.720 | and motor learning is occurring

00:06:49.300 | primarily early in the night,

00:06:51.060 | and detail learning is occurring early in the night.

00:06:54.140 | I want to talk about REM sleep or rapid eye movement sleep.

00:06:57.860 | REM sleep and rapid eye movement sleep,

00:07:00.620 | as I mentioned before, occurs throughout the night,

00:07:03.060 | but you're going to have more of it,

00:07:04.580 | a larger percentage of these 90-minute sleep cycles

00:07:07.120 | is going to be comprised of REM sleep

00:07:09.140 | as you get toward morning.

00:07:11.720 | REM sleep is fascinating.

00:07:13.280 | It was discovered in the '50s

00:07:14.820 | when a sleep laboratory in Chicago,

00:07:18.120 | the researchers observed that people's eyes

00:07:20.380 | were moving under their eyelids.

00:07:21.960 | Now, something very important that we're going to address

00:07:25.220 | when we talk about trauma later

00:07:27.580 | is that the eye movements are not just side to side,

00:07:30.480 | they're very erratic in all different directions.

00:07:33.160 | One thing that I don't think anyone,

00:07:34.880 | I've never heard anyone really talk about publicly

00:07:37.060 | is why eye movements during sleep, right?

00:07:40.260 | Eyes are closed,

00:07:41.100 | and sometimes people's eyelids will be a little bit open

00:07:43.040 | and their eyes are darting around,

00:07:44.060 | especially in little kids.

00:07:45.320 | I don't suggest you do this.

00:07:46.580 | I'm not even sure it's ethical,

00:07:47.680 | but it has been done where you pull back the eyelids

00:07:50.300 | of a kid while they're sleeping

00:07:51.260 | and their eyes are kind of darting all over the place.

00:07:53.300 | Rapid eye movement sleep is fascinating

00:07:55.940 | and occurs because there are connections

00:07:58.540 | between the brainstem, an area called the pons,

00:08:02.580 | and areas of the thalamus and the top of the brainstem

00:08:07.220 | that are involved in generating movements

00:08:09.760 | in different directions, sometimes called saccades,

00:08:11.860 | although sometimes during rapid eye movement sleep,

00:08:13.700 | it's not just rapid,

00:08:14.580 | it's kind of a jittery side to side thing,

00:08:16.420 | and then the eyeballs kind of roll.

00:08:17.860 | It's really pretty creepy to look at if you see.

00:08:20.420 | So what's happening there is the circuitry

00:08:23.940 | that is involved in conscious eye movements

00:08:25.740 | is kind of going haywire, but it's not haywire.

00:08:27.880 | It's these waves of activity from the brainstem

00:08:31.500 | up to the so-called thalamus,

00:08:33.020 | which is an area that filters sensory information

00:08:36.140 | up to the cortex.

00:08:37.860 | And the cortex, of course,

00:08:39.180 | is involved in conscious perceptions.

00:08:41.620 | In REM sleep, serotonin is essentially absent, okay?

00:08:46.620 | So this molecule, this neuromodulator

00:08:49.340 | that tends to create the feeling of bliss and wellbeing

00:08:52.360 | and just calm placidity is absent.

00:08:56.900 | In addition to that, norepinephrine,

00:09:00.480 | this molecule that's involved in movement and alertness

00:09:03.220 | is absolutely absent.

00:09:04.880 | It's probably one of the few times in our life

00:09:08.580 | that epinephrine is essentially

00:09:10.940 | at zero activity within our system.

00:09:13.540 | And that has a number of very important implications

00:09:16.580 | for the sorts of dreaming that occur during REM sleep

00:09:20.200 | and the sorts of learning that can occur

00:09:22.740 | in REM sleep and unlearning.

00:09:24.060 | First of all, in REM sleep, we are paralyzed.

00:09:26.980 | We are experiencing what's called atonia,

00:09:29.940 | which just means that we're completely laid out

00:09:32.320 | and paralyzed.

00:09:33.600 | We also tend to experience whatever it is

00:09:36.480 | that we're dreaming about as a kind of hallucination

00:09:40.080 | or a hallucinatory activity.

00:09:42.560 | So in REM, our eyes are moving,

00:09:44.600 | but the rest of our body is paralyzed

00:09:46.720 | and we are hallucinating.

00:09:48.400 | There's no epinephrine around.

00:09:51.140 | Epinephrine doesn't just create a desire

00:09:54.160 | to move and alertness.

00:09:55.840 | It is also the chemical signature of fear and anxiety.

00:10:00.840 | It's what's released from our adrenal glands

00:10:04.900 | when we experience something that's fearful or alerting.

00:10:08.700 | So if a car suddenly screeches in front of us

00:10:10.740 | or we get a troubling text message,

00:10:12.980 | adrenaline is deployed into our system.

00:10:14.740 | Adrenaline is epinephrine.

00:10:16.260 | Those are equivalent molecules.

00:10:18.580 | And epinephrine isn't just released from our adrenals.

00:10:21.340 | It's also released within our brain.

00:10:23.460 | So there's this weird stage of our life

00:10:26.700 | that happens more toward morning that we call REM sleep,

00:10:30.140 | where we're hallucinating

00:10:32.460 | and having these outrageous experiences in our mind,

00:10:35.980 | but the chemical that's associated with fear and panic

00:10:40.300 | and anxiety is not available to us.

00:10:43.700 | And that turns out to be very important.

00:10:47.020 | And you can imagine why that's important.

00:10:49.180 | It's important because it allows us to experience things,

00:10:53.780 | both replay of things that did occur,

00:10:56.580 | as well as elaborate contortions

00:10:59.000 | of things that didn't occur.

00:11:01.220 | And it allows us to experience those

00:11:03.300 | in the absence of fear and anxiety.

00:11:06.260 | So we have this incredible period of sleep

00:11:09.280 | in which our experience of emotionally laden events

00:11:13.780 | is dissociated.

00:11:15.100 | It's chemically blocked from us having the actual emotion.

00:11:19.980 | So to just recap where we've gone so far,

00:11:24.180 | slow-wave sleep early in the night,

00:11:26.420 | it's been shown to be important for motor learning

00:11:29.220 | and for detailed learning.

00:11:31.140 | REM sleep has a certain dream component

00:11:33.980 | when which there's no epinephrine,

00:11:36.020 | therefore we can't experience anxiety.

00:11:37.820 | We are paralyzed.

00:11:39.300 | Those dreams tend to be really vivid

00:11:41.780 | and have a lot of detail to them.

00:11:44.020 | And yet in REM sleep, what's very clear

00:11:47.340 | is that the sorts of learning that happened in REM sleep

00:11:49.820 | are not motor events.

00:11:51.220 | It's more about unlearning of emotional events.

00:11:54.620 | And now we know why,

00:11:55.540 | because the chemicals available

00:11:56.980 | for really feeling those emotions are not present.

00:12:01.980 | Now that has very important implications.

00:12:06.380 | So let's address those implications from two sides.

00:12:09.060 | First of all, we should ask what happens

00:12:10.820 | if we don't get enough REM sleep?

00:12:12.900 | And a scenario that happens a lot

00:12:15.140 | where people don't get enough REM sleep is the following.

00:12:18.180 | I'll just explain the one that I'm familiar with

00:12:20.500 | 'cause it happens to me a lot,

00:12:22.140 | although I've figured out ways to adjust.

00:12:25.420 | I go to sleep around 10, 30, 11 o'clock.

00:12:28.380 | I fall asleep very easily.

00:12:30.060 | And then I wake up around three or 4 a.m.

00:12:33.980 | I now know to use a NSDR, a non-sleep deep rest protocol.

00:12:38.460 | And that allows me to fall back asleep.

00:12:40.500 | Even though it's called non-sleep deep rest,

00:12:42.180 | it's really allows me to relax my body and brain.

00:12:44.900 | And I tend to fall back asleep and sleep till about 7 a.m.,

00:12:48.220 | during which time I get a lot of REM sleep.

00:12:51.820 | And I know this because I've measured it.

00:12:53.900 | And I know this because my dreams tend to be very intense

00:12:57.620 | of the sort that we know is typical of REM sleep.

00:13:00.060 | In this scenario,

00:13:03.180 | I've gotten my slow wave sleep early in the night

00:13:06.060 | and I've got my REM sleep toward morning.

00:13:08.100 | However, there are times when I don't go back to sleep.

00:13:11.540 | Maybe I have a flight to catch, that's happened.

00:13:13.500 | Sometimes I've got a lot on my mind

00:13:14.820 | and I don't go back to sleep.

00:13:16.260 | I can tell you, and you've probably experienced that,

00:13:19.860 | the lack of REM sleep

00:13:21.100 | tends to make people emotionally irritable.

00:13:23.980 | It tends to make us feel

00:13:25.820 | as if the little things are the big things.

00:13:28.320 | So it's very clear from laboratory studies

00:13:31.420 | where people have been deprived selectively of REM sleep,

00:13:35.020 | that our emotionality tends to get a little bit unhinged

00:13:38.460 | and we tend to catastrophize small things.

00:13:41.540 | We tend to feel like the world is really daunting.

00:13:45.300 | We're never going to move forward in the ways that we want.

00:13:47.780 | We can't unlearn the emotional components

00:13:50.060 | of whatever it is that's been happening,

00:13:52.020 | even if it's not traumatic.

00:13:54.300 | The other thing that happens in REM sleep

00:13:56.020 | is a replay of certain types of spatial information

00:13:59.760 | about where we were and why we were in those places.

00:14:02.700 | And this maps to some beautiful data

00:14:05.100 | and studies that were initiated

00:14:06.700 | by a guy named Matt Wilson at MIT years ago,

00:14:09.980 | showing that in rodents,

00:14:11.480 | and it turns out in other non-human primates and in humans,

00:14:14.840 | there's a replay of spatial information during REM sleep

00:14:18.480 | that almost precisely maps to the activity

00:14:21.940 | that we experienced during the day

00:14:23.060 | as we move from one place to another.

00:14:24.740 | So here's a common world scenario.

00:14:26.400 | You go to a new place,

00:14:28.180 | you navigate through that city or that environment.

00:14:31.100 | This place doesn't have to be at the scale of a city.

00:14:33.540 | It can be a new building,

00:14:34.780 | could be finding particular rooms, new social interaction.

00:14:38.460 | You experience that, and if it's important enough,

00:14:42.020 | that becomes solidified a few days later

00:14:44.860 | and you won't forget it.

00:14:45.800 | If it's unimportant, you'll probably forget it.

00:14:48.960 | During REM sleep, there's a literal replay

00:14:52.160 | of the exact firing of the neurons that occurred

00:14:55.140 | while you were navigating that same city

00:14:56.980 | you're building earlier.

00:14:58.220 | So REM sleep seems to be involved

00:14:59.820 | in the generation of this detailed spatial information.

00:15:04.160 | But what is it that's actually happening in REM sleep?

00:15:08.460 | So there's this uncoupling of emotion,

00:15:10.360 | but most of all, what's happening in REM sleep

00:15:12.820 | is that we're forming a relationship

00:15:15.160 | with particular rules or algorithms.

00:15:18.220 | We're starting to figure out,

00:15:19.940 | based on all the experience that we had during the day,

00:15:22.900 | whether or not it's important that we avoid certain people

00:15:26.060 | or that we approach certain people,

00:15:27.420 | whether or not it's important that, you know,

00:15:30.520 | when we enter a building that we go into the elevator

00:15:33.820 | and turn left where the bathroom is, for instance,

00:15:36.640 | these general themes of things and locations

00:15:39.280 | and how they fit together.

00:15:40.860 | And that has a word, it's called meaning.

00:15:43.660 | During our day, we're experiencing all sorts of things.

00:15:46.100 | Meaning is how we each individually piece together

00:15:51.100 | the relevance of one thing to the next, right?

00:15:54.040 | So if I suddenly told you that, you know,

00:15:57.220 | this pen was downloading all the information to my brain

00:16:00.220 | that was important to deliver this information,

00:16:02.380 | you'd probably think I was a pretty strange character

00:16:04.460 | because typically we don't think of pens

00:16:06.180 | as downloading information into brains.

00:16:08.540 | But if I told you that I was getting information

00:16:10.440 | from my computer that was allowing me to say things to you,

00:16:14.740 | you'd say, well, that's perfectly reasonable.

00:16:16.300 | And that's because we have a clear

00:16:18.060 | and agreed upon association with computers

00:16:20.260 | and information and memory.

00:16:22.540 | And we don't have that same association with pens.

00:16:25.660 | You might say, well, duh,

00:16:27.140 | but something in our brain needs to solidify

00:16:31.900 | those relationships and make sure

00:16:33.400 | that certain relationships don't exist.

00:16:35.900 | And it appears that REM sleep is important for that

00:16:38.080 | because when you deprive yourself or people of REM,

00:16:41.540 | they start seeing odd associations.

00:16:43.900 | And we know that if people are deprived of REM sleep

00:16:46.940 | for very long periods of time, they start hallucinating.

00:16:49.740 | They literally start seeing relationships

00:16:52.560 | and movement of objects that isn't happening.

00:16:55.420 | And so REM sleep is really where we establish

00:16:58.540 | the emotional load, but where we also start discarding

00:17:02.020 | of all the meanings that are irrelevant.

00:17:04.220 | And if you think about emotionality,

00:17:06.260 | a lot of over-emotionality or catastrophizing

00:17:10.260 | is about seeing problems everywhere.

00:17:12.700 | It's very important in order to have healthy,

00:17:15.140 | emotional, and cognitive functioning

00:17:16.980 | that we have fairly narrow channels

00:17:18.940 | between individual things.

00:17:20.100 | If we see something on the news that's very troubling,

00:17:22.800 | well, then it makes sense to be very troubled.

00:17:25.100 | But if we're troubled by everything

00:17:26.660 | and we start just saying, everything is bothering me

00:17:29.100 | and I'm feeling highly irritable

00:17:30.540 | and everything is just distorting and troubling me,

00:17:33.680 | chances are we are not actively removing the meaning,

00:17:38.680 | the connectivity between life experiences

00:17:41.180 | as well as we could.

00:17:42.100 | And that almost always maps back to a deficit in REM sleep.

00:17:46.300 | So REM sleep seems to be where we uncouple

00:17:49.620 | the potential for emotionality between various experiences.

00:17:55.100 | And that brings us to the absolutely fundamental relationship

00:17:59.700 | and similarity of REM sleep

00:18:02.240 | to some of the clinical practices

00:18:04.820 | that have been designed to eliminate emotionality

00:18:07.400 | and help people move through trauma

00:18:09.620 | and other troubling experiences.

00:18:11.460 | Many of you perhaps have heard of trauma treatments

00:18:14.540 | such as EMDR, Eye Movement Desensitization Reprocessing,

00:18:19.540 | or ketamine treatment for trauma,

00:18:23.700 | something that recently became legal

00:18:25.680 | and is in fairly widespread clinical use.

00:18:28.420 | Interestingly enough, EMDR and ketamine

00:18:33.740 | at kind of a core level bear very similar features

00:18:38.740 | to REM sleep.

00:18:41.060 | So let's talk about EMDR first.

00:18:43.700 | EMDR, Eye Movement Desensitization Reprocessing

00:18:46.740 | is something that was developed by a psychologist,

00:18:49.020 | Francine Shapiro.

00:18:50.980 | She actually was in Palo Alto.

00:18:53.480 | And the story goes that she was walking,

00:18:57.960 | not so incidentally in the trees and forest behind Stanford,

00:19:03.560 | and she was recalling a troubling event in her own mind.

00:19:06.560 | So this would be from her own life.

00:19:08.480 | And she realized that as she was walking,

00:19:10.680 | the emotional load of that experience

00:19:12.680 | was not as intense or severe.

00:19:15.200 | She extrapolated from that experience

00:19:20.600 | of walking and not feeling as stressed

00:19:23.440 | about the stressful event

00:19:25.040 | to a practice that she put into work

00:19:27.840 | with her clients, with her patients,

00:19:30.120 | and that now has become fairly widespread.

00:19:32.640 | It's actually one of the few behavior treatments

00:19:36.240 | that are approved by the American Psychological Association

00:19:38.920 | for the Treatment of Trauma.

00:19:40.320 | What she had her clients and patients do

00:19:44.560 | was move their eyes from side to side

00:19:47.620 | while recounting some traumatic or troubling event.

00:19:50.960 | Why eye movements?

00:19:52.120 | Well, she never really said why eye movements,

00:19:54.760 | but soon I'll tell you why the decision

00:19:58.400 | to select these lateralized eye movements

00:20:00.840 | for the work in the clinic was the right one.

00:20:03.960 | So these eye movements, they look silly,

00:20:06.120 | but they basically involve sitting in a chair

00:20:08.800 | and moving one's eyes from side to side for 30, 60 seconds,

00:20:12.580 | then describing this challenging procedure.

00:20:15.880 | Now, as a vision scientist who also works on stress,

00:20:20.800 | when I first heard this, I thought it was crazy, frankly.

00:20:26.040 | People would ask me about EMDR,

00:20:27.720 | and I just thought, "That's crazy."

00:20:29.480 | I went and looked up some of the theories

00:20:31.040 | about why EMDR might work,

00:20:33.320 | and there were a bunch of theories.

00:20:35.800 | Oh, it mimics the eye movements during REM sleep.

00:20:38.680 | That was one.

00:20:39.640 | Turns out that's not true, and I'll explain why.

00:20:42.520 | The other one was, oh, it synchronizes the activity

00:20:45.180 | on the two sides of the brain.

00:20:46.920 | Well, sort of.

00:20:47.760 | I mean, when you look into both sides

00:20:49.800 | of the binocular visual field,

00:20:51.040 | you activate the visual cortex,

00:20:52.560 | but this whole idea of synchrony

00:20:54.960 | between the two sides of the brain

00:20:56.320 | is something that I think modern neuroscience

00:20:58.080 | is starting to, let's just say,

00:21:01.360 | gently or not so gently move away from,

00:21:04.600 | this whole right brain, left brain business.

00:21:08.320 | It turns out, however,

00:21:09.960 | that eye movements of the sort that I just did,

00:21:11.960 | and that Francine Shapiro took from this walk experience

00:21:14.860 | and brought to her clients in the clinic,

00:21:17.940 | are the sorts of eye movements that you generate

00:21:20.780 | whenever you're moving through space,

00:21:22.620 | when you are self-generating that movement.

00:21:24.960 | So not so much when you're driving a car,

00:21:27.280 | but certainly if you were riding a bicycle,

00:21:29.080 | or you were walking, or you were running,

00:21:31.120 | you don't realize it,

00:21:31.960 | but you have these reflexive subconscious eye movements

00:21:34.220 | that go from side to side,

00:21:36.040 | and they are associated with the motor system.

00:21:38.680 | So when you move forward, your eyes go like this.

00:21:41.520 | There've been a number of studies

00:21:42.680 | showing that these lateralized eye movements

00:21:44.640 | helped people move through or dissociate

00:21:48.720 | the emotional experience of particular traumas

00:21:51.000 | with those experiences,

00:21:52.080 | such that they could recall those experiences

00:21:54.540 | after the treatment and not feel stressed about them,

00:21:57.760 | or they didn't report them as traumatic any longer.

00:22:00.520 | Now, the success rate wasn't 100%,

00:22:02.440 | but they were statistically significant

00:22:04.040 | in a number of studies.

00:22:05.320 | In the last five years,

00:22:06.840 | there have been no fewer than five journals and papers

00:22:11.360 | showing that lateralized eye movements

00:22:13.540 | of the sort that I just did,

00:22:14.960 | and if you're just listening to this,

00:22:16.000 | it's just sweeping, moving the eyes from side to side

00:22:18.120 | with eyes open,

00:22:19.460 | that those eye movements, but not vertical eye movements,

00:22:22.800 | suppress the activity of the amygdala,

00:22:26.400 | which is this brain region

00:22:28.560 | that is involved in threat detection,

00:22:31.600 | stress, anxiety, and fear.

00:22:34.120 | There are some forms of fear

00:22:35.040 | that are not amygdala dependent,

00:22:36.360 | but the amygdala, it's not a fear center,

00:22:39.100 | but it is critical for the fear response.

00:22:43.400 | And for the experience of anxiety.

00:22:45.300 | So that's interesting.

00:22:46.220 | We've got a clinical tool now

00:22:49.200 | that indeed shows a lot of success

00:22:51.920 | in a good number of people,

00:22:53.660 | where eye movements from side to side

00:22:55.840 | are suppressing the amygdala,

00:22:57.200 | and the general theme is to use those eye movements

00:23:00.020 | to suppress the fear response,

00:23:01.960 | and then to recount or repeat the experience,

00:23:06.100 | and over time, uncouple the heavy emotional load,

00:23:10.080 | the sadness, the depression, the anxiety, the fear,

00:23:12.600 | from whatever it was that happened that was traumatic.

00:23:16.160 | This is important to understand

00:23:17.840 | because I'd love to be able to tell somebody

00:23:21.260 | who had a traumatic experience

00:23:22.560 | that they would forget that experience,

00:23:24.480 | but the truth is you never forget the traumatic experience.

00:23:27.500 | What you do is you remove the emotional load.

00:23:29.880 | Eventually, it really does lose its potency.

00:23:33.840 | The emotional potency is alleviated.

00:23:36.440 | Now, EMDR, I should just mention,

00:23:38.960 | tends to be most successful for single event

00:23:41.640 | or very specific kinds of trauma that happen over and over,

00:23:44.840 | as opposed to, say, an entire childhood

00:23:47.520 | or an entire divorce.

00:23:48.920 | They tend to be, it tends to be most effective

00:23:51.760 | for single event kinds of things, car crashes, et cetera,

00:23:55.440 | where people can really recall the events

00:23:57.800 | in quite a lot of detail.

00:23:59.440 | It's not for everybody, and it should be done,

00:24:01.760 | if it's going to be done for trauma,

00:24:03.280 | it should be done in a clinical setting

00:24:05.000 | with somebody who's certified to do this,

00:24:07.960 | but that bears a lot of resemblance to REM sleep, right?

00:24:11.040 | This experience in our sleep,

00:24:12.400 | where our eyes are moving, excuse me,

00:24:15.360 | although in a different way,

00:24:16.800 | but we don't have the chemical, epinephrine,

00:24:19.480 | in order to generate the fear response,

00:24:21.720 | and yet we're remembering the event

00:24:23.740 | from the previous day or days.

00:24:25.640 | And then now there's this chemical treatment

00:24:28.200 | with the drug ketamine,

00:24:29.920 | which also bears a lot of resemblance

00:24:32.500 | to the sorts of things that happen in REM sleep.

00:24:35.520 | Ketamine is a dissociative anesthetic.

00:24:39.120 | It is remarkably similar to the drug called PCP,

00:24:44.100 | which is certainly a hazardous drug for people to use.

00:24:49.100 | Ketamine and PCP both function to disrupt the activity

00:24:54.640 | of a particular receptor in the brain

00:24:57.200 | called the NMDA receptor, N-methyl-D-aspartate receptor.

00:25:02.200 | This is a receptor that's in the surface of neurons

00:25:05.800 | or on the surface of neurons

00:25:07.360 | for which most of the time it's not active.

00:25:11.220 | But when something very extreme happens,

00:25:14.880 | and there's a lot of activity in the neural pathway

00:25:17.440 | that impinges on that receptor,

00:25:19.520 | it opens and it allows the entry of molecules, ions,

00:25:24.520 | that trigger a cellular process

00:25:28.020 | that we call long-term potentiation.

00:25:30.520 | And long-term potentiation translates

00:25:32.720 | to a change in connectivity

00:25:34.920 | so that later you don't need that intense event

00:25:37.880 | for the neuron to become active again.

00:25:40.400 | Ketamine blocks this NMDA receptor.

00:25:43.640 | So how is ketamine being used?

00:25:45.700 | Ketamine is being used to prevent learning of emotions

00:25:49.760 | very soon after trauma.

00:25:51.520 | Ketamine is being stocked

00:25:52.720 | in a number of different emergency rooms

00:25:54.240 | where if people are brought in quickly,

00:25:56.660 | and these are hard to describe even,

00:25:58.840 | but a horrible experience of somebody seeing a loved one

00:26:02.520 | next to them killed in a car accident

00:26:04.200 | and they were driving that car.

00:26:06.280 | This isn't for everybody, certainly,

00:26:08.320 | and you need to talk to your physician,

00:26:09.920 | but ketamine is being used

00:26:11.680 | so they might infuse somebody with ketamine

00:26:13.880 | so that their emotion can still occur,

00:26:17.520 | but that the plasticity,

00:26:19.600 | the change in the wiring of their brain

00:26:22.240 | won't allow that intense emotion

00:26:24.720 | to be attached to the experience.

00:26:26.440 | Now, immediately you can imagine

00:26:27.760 | the sort of ethical implications of this, right?

00:26:30.240 | Because certain emotions need to be coupled to experiences,

00:26:33.760 | but in the clinical setting,

00:26:35.320 | the basis of ketamine-assisted therapies

00:26:38.440 | is really to remove emotion.

00:26:40.680 | Ketamine is about becoming dissociative

00:26:43.440 | or removed from the emotional component of the experience.

00:26:46.480 | So now we have ketamine,

00:26:48.280 | which chemically blocks plasticity

00:26:50.420 | and prevents the connection

00:26:52.420 | between an emotion and an experience.

00:26:54.800 | That's a pharmacologic intervention.

00:26:56.160 | We have EMDR, which is this eye movement thing

00:26:59.360 | that is designed to suppress the amygdala

00:27:01.560 | and is designed to remove emotionality

00:27:03.840 | while somebody recounts an experience.

00:27:05.920 | And we have REM sleep,

00:27:08.080 | where the chemical epinephrine

00:27:10.000 | that allows for signaling of intense emotion

00:27:14.200 | and the experience of a tense emotion

00:27:16.100 | in the brain and body is not allowed.

00:27:18.040 | And so we're starting to see a organizational logic,

00:27:21.780 | which is that a certain component of our sleeping life

00:27:24.920 | is acting like therapy.

00:27:26.880 | And that's really what REM sleep is about.

00:27:30.000 | So we should really think about REM sleep

00:27:33.180 | and slow-wave sleep as both critical.

00:27:35.440 | Slow-wave sleep for motor learning and detailed learning,

00:27:37.840 | REM sleep for attaching of emotions

00:27:39.880 | to particular experiences,

00:27:41.520 | and then for making sure that the emotions

00:27:45.360 | are not attached to the wrong experiences,

00:27:47.840 | and for unlearning emotional responses

00:27:50.420 | if they're too intense or severe.

00:27:52.680 | And this all speaks to the great importance

00:27:55.400 | of mastering one's sleep,

00:27:57.180 | something that we talked about

00:27:58.200 | in episode two of the podcast,

00:28:00.720 | and making sure that if life has disruptive events,

00:28:04.880 | either due to travel or stress

00:28:07.280 | or changes in school or food schedule,

00:28:11.240 | something that we talked about in episodes three and four,

00:28:13.700 | that one can still grab a hold and manage one's sleep life.

00:28:18.620 | Because fundamentally, the unlearning of emotions

00:28:22.600 | that are troubling to us

00:28:24.960 | is what allows us to move forward in life.

00:28:26.760 | And indeed, the REM deprivation studies

00:28:28.600 | show that people become hyper-emotional.

00:28:31.080 | They start to catastrophize.

00:28:32.880 | And it's no surprise, therefore,

00:28:35.680 | that sleep disturbances correlate

00:28:38.080 | with so many emotional and psychological disturbances.

00:28:42.120 | By now, it should just be obvious

00:28:44.040 | why that will be the case.

00:28:45.520 | I was in a discussion with a colleague of mine

00:28:48.520 | who's down in Australia, Dr. Sarah McKay.

00:28:50.560 | I've known her for two decades now

00:28:53.120 | from the time she was at Oxford.

00:28:55.520 | And Sarah studies, among other things,

00:28:57.800 | menopause in the brain.

00:28:59.200 | And she was saying that a lot of the emotional

00:29:02.560 | effects of menopause

00:29:05.280 | actually are not directly related to the hormones.

00:29:07.680 | There've been some really nice studies

00:29:09.000 | showing that the disruptions

00:29:10.560 | in temperature regulation in menopause

00:29:13.200 | map to changes in sleep regulation

00:29:16.600 | that then impact emotionality

00:29:19.080 | and an inability to correctly adjust

00:29:22.280 | the circuits related to emotionality.

00:29:24.440 | So sleep deprivation isn't just deprivation of energy.

00:29:29.440 | It's not just deprivation of immune function.

00:29:32.040 | It is deprivation of self-induced therapy

00:29:35.800 | every time we go to sleep.

00:29:37.440 | So these things like EMDR and ketamine therapies

00:29:40.880 | are in-clinic therapies,

00:29:43.000 | but REM sleep is the one that you're giving yourself

00:29:45.320 | every night when you go to sleep,

00:29:47.280 | which raises, I think, the other important question,

00:29:50.440 | which is how to get and how to know

00:29:52.760 | if you're getting the appropriate amount of REM sleep

00:29:54.700 | and slow-wave sleep.

00:29:55.720 | Turns out that for sake of learning new information,

00:29:59.380 | limiting the variation in the amount of your sleep

00:30:02.540 | is at least as important and perhaps more important

00:30:06.860 | than just getting more sleep overall.

00:30:09.340 | I find great relief personally

00:30:11.440 | in the fact that consistently getting,

00:30:13.600 | for me, about six hours or six and a half hours

00:30:16.960 | is going to be more beneficial

00:30:18.600 | than constantly striving for eight or nine

00:30:20.620 | and finding that some nights I'm getting five

00:30:22.420 | and sometimes I'm getting nine and varying around the mean.

00:30:25.200 | Now, ideally, you're getting the full complement

00:30:28.000 | of slow-wave sleep early in night

00:30:30.000 | and sleep toward morning, which is REM sleep,

00:30:32.280 | which brings us to how to get more REM sleep.

00:30:35.000 | Well, there are a couple of different ways,

00:30:37.200 | but here's how to not get more REM sleep, all right?

00:30:42.200 | First of all, drink a lot of fluid

00:30:45.000 | right before going to sleep.

00:30:46.320 | One of the reasons why we wake up

00:30:47.740 | in the middle of the night to use the bathroom

00:30:49.640 | is because when our bladder is full,

00:30:52.320 | there is a neural connection,

00:30:53.920 | literally a set of neurons and a nerve circuit

00:30:56.280 | that goes to the brainstem that wakes us up.

00:30:58.800 | So having a full bladder is one way to disrupt your sleep.

00:31:02.440 | The other one is tryptophan

00:31:03.760 | or anything that contains 5-HTP,

00:31:05.760 | which is serotonin or a precursor to serotonin.

00:31:09.560 | Serotonin is made from tryptophan.

00:31:11.280 | For some people, those supplements might work,

00:31:13.200 | but beware serotonin supplements

00:31:15.840 | could disrupt the timing of REM sleep and slow-wave sleep.

00:31:20.720 | Now, if you want to increase your slow-wave sleep,

00:31:24.360 | that's interesting.

00:31:25.480 | There are ways to do that.

00:31:26.840 | One of the most powerful ways to increase slow-wave sleep,

00:31:30.200 | the percentage of slow-wave sleep,

00:31:31.920 | apparently without any disruption

00:31:34.360 | to the other components of sleep and learning,

00:31:37.700 | is to engage in resistance exercise.

00:31:40.400 | It's pretty clear that resistance exercise

00:31:42.600 | triggers a number of metabolic and endocrine pathways

00:31:45.360 | that lend themselves to release of growth hormone,

00:31:48.440 | which happens early in the night.

00:31:50.680 | And resistance exercise, therefore,

00:31:53.080 | can induce a greater percentage of slow-wave sleep.

00:31:56.640 | It doesn't have to be done very close to going to bedtime.

00:31:59.400 | In fact, for some people,

00:32:00.720 | the exercise could be disruptive

00:32:02.080 | for reasons I've talked about in previous episodes.

00:32:04.680 | But resistance exercise, unlike aerobic exercise,

00:32:07.920 | does seem to increase the amount of slow-wave sleep,

00:32:10.240 | which, as we know, is involved in motor learning

00:32:13.480 | and the acquisition of fine detailed information,

00:32:16.280 | not general rules

00:32:17.480 | or the emotional components of experiences.

00:32:20.880 | Alcohol.

00:32:21.880 | Alcohol and marijuana are well-known to induce states

00:32:25.080 | that are pseudo-sleep-like,

00:32:27.300 | especially when people fall asleep

00:32:29.640 | after having consumed alcohol or THC,

00:32:32.760 | the active component,

00:32:34.160 | one of the active components in marijuana.

00:32:37.000 | Alcohol, THC, and most things like them,

00:32:42.000 | meaning things that increase serotonin or GABA,

00:32:47.040 | are going to disrupt the pattern of sleep.

00:32:49.080 | They're going to disrupt the depth.

00:32:50.280 | They're going to disrupt the overall sequencing

00:32:52.560 | of more slow-wave sleep early in the night

00:32:54.200 | and more REM sleep later in the night.

00:32:55.880 | That's just the reality.

00:32:57.800 | Now, of course, if that's what you need in order to sleep,

00:33:00.860 | and that's within your protocol, as I've said here before,

00:33:03.020 | I'm not suggesting people take anything.

00:33:04.320 | I'm not a medical doctor.

00:33:05.760 | I'm not a cop.

00:33:06.580 | So I'm not trying to regulate anyone's behavior.

00:33:09.460 | I'm just telling you what the literature says.

00:33:12.600 | Today, we've been in a deep dive of sleep and dreaming,

00:33:17.600 | learning and unlearning.

00:33:19.640 | And I just want to recap a few of the highlights

00:33:22.000 | and important points.

00:33:24.200 | A lot more slow-wave sleep and less REM early in the night.

00:33:27.300 | More REM and less slow-wave sleep later in the night.

00:33:30.840 | REM sleep is associated with intense experiences

00:33:34.720 | without this chemical, epinephrine,

00:33:36.800 | that allows us the anxiety or fear,

00:33:39.480 | and almost certainly has an important role

00:33:41.940 | in uncoupling of emotion from experiences,

00:33:45.440 | kind of self-induced therapy that we go into each night.

00:33:48.920 | That bears striking resemblance to things like EMDR

00:33:52.000 | and ketamine therapies and so forth.

00:33:54.520 | Slow-wave sleep is critical, however.

00:33:57.660 | It's critical mostly for motor learning

00:33:59.520 | and the learning of specific details.

00:34:01.600 | So REM is kind of emotions and general themes and meaning,

00:34:06.120 | and slow-wave sleep, motor learning and details.

00:34:09.640 | I personally find it fascinating that consistency of sleep,

00:34:14.300 | meaning getting six hours every night

00:34:16.860 | is better than getting 10 one night,

00:34:19.140 | eight the next, five the next, four the next.

00:34:21.560 | I find that fascinating and I think I also like it

00:34:25.120 | because it's something I can control better

00:34:26.860 | than just trying to sleep more,

00:34:28.040 | which I think I'm not alone in agreeing

00:34:30.140 | that that's just hard for a lot of people to do.

00:34:32.420 | Thank you for joining me in this journey

00:34:34.860 | of the nervous system and biology

00:34:36.920 | and trying to understand the mechanisms

00:34:39.420 | that make us who we are and how we function

00:34:41.620 | in sleep and in wakefulness.

00:34:43.940 | It's really an incredible landscape to consider,

00:34:47.020 | and I hope that you're getting a lot out of the information.

00:34:49.780 | As always, thank you for your interest in science.

00:34:52.500 | [upbeat music]

00:34:55.080 | (upbeat music)

Understand and Use Dreams to Learn and Forget | Huberman Lab Essentials

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