The following is a conversation with Matt Walker,

sleep scientist, professor of neuroscience

and psychology at Berkeley, author of Why We Sleep

and The Host of a new podcast

called The Matt Walker Podcast.

It's 10 minute episodes a couple of times a month

covering sleep and other health and science topics.

I love it and recommend it highly.

It's up there with the greats

like the Huberman Lab podcast with Andrew Huberman.

And I think Davis and Claire is putting out

an audio series soon too.

I can't wait to listen to it.

I'm really excited by the future of science

in the podcasting world.

To support this podcast, please check out our sponsors,

Stamps.com, Squarespace, Athletic Greens,

BetterHelp and On It.

There are links are in the description.

As a side note, let me say that to me,

a healthy life is one in which you fall in love

with the world around you, with ideas, with people,

with small goals and big goals, no matter how difficult,

with dreams you hold onto and chase for years.

Life should be lived fully.

That to me is the priority.

That to me is a healthy life.

Second to that is the understanding

and the utilization of the best available science

on diet, exercise, supplements, sleep

and other lifestyle choices.

To me, science in the realm of health is a guide

for we should try not the absolute truth

of how to live life.

The goal is to learn to listen to your body

and figure out what works best for you.

All that said, a good night's sleep can be a great tool

in making life awesome and productive.

And Matt is a great advocate of the how

and the why of sleep.

We agree on some things and disagree on others,

but he's a great human being, a great scientist

and is a recently a friend,

with whom I enjoy having these wide ranging conversations.

This is the Lex Friedman podcast

and here is my conversation with Matt Walker.

You should try these shades on and see what you look like.

So they are now your shades and that's not the question.

It's the same thing as Putin took the Super Bowl ring

and it's now his ring.

Yeah, one wonders if he was offered it, but they are yours.

When did you first fall in love

with the dream of understanding sleep?

Like where did the fascination with sleep begin?

So back in the United Kingdom,

you can sort of start doing medicine at age to 18

and it's a five year program.

And I was at the Queen's Medical Center in the UK

and I remember just being fascinated

by states of consciousness and particularly anesthesia.

I was thinking, isn't that within seconds

I can take a perfectly conscious human being

and I can remove all existence of the mentality

and their awareness within seconds.

And that stunned me.

So I started to get really interested in conscious states.

I even started to read a lot about hypnosis

and all of these things, hypnosis,

even sleep and dreams at the time,

they were very esoteric.

It was sort of charlatan science at that stage.

And I think almost all of my colleagues

and I are accidental sleep researchers.

No one as I recall in the classroom

when you're sort of five years old and the teacher says,

what would you like to be when you grow up?

No one's putting their hand up and saying,

I would love to be a sleep researcher.

And so when I was doing my PhD,

I was trying to identify different forms of dementia

very early on in the course.

And I was using electrical brainwave recordings to do that.

And I was failing miserably.

It was a disaster, just no result after no result.

And I used to go home to the doctor's residence

with this sort of little igloo of journals

that at the weekend I would sort of sit in

and read and which I'm now thinking,

do I really want to admit this?

Because it sounds like I had no social life,

which I didn't, I was social leper.

But and I started to realize that some parts of the brain

were sleep related areas.

And some dementias were eating away

those sleep related areas.

Other dementias would leave them untouched.

And I thought, well, I'm doing this all wrong.

I'm measuring my patients while they're awake.

Instead I should be measuring them

while they're asleep.

Started doing that, got some amazing results.

And then I wanted to ask the question,

is that sleep disruption

that my patients are experiencing

as they go into dementia?

Maybe it's not a symptom of the dementia.

I wonder if it's a cause of the dementia.

And at that point, which was golf golf 20 years ago,

no one could answer a very simple fundamental question.

Why do we sleep?

And I at the time didn't realize

that some of the most brilliant minds

in scientific history had tried to answer that question

and failed.

And at that point, I just thought, well,

I'm going to go and do a couple of years of sleep research

and I'll figure out why we sleep.

And then I'll come back to my patients

in this question of dementia.

And as I said, that was 20 years ago.

And what I realized is that hard questions

care very little about who asks them.

They will meter out their lessons of difficulty all the same.

And I was schooled in the difficulty of the question,

why do we sleep?

But in truth, 20 years later,

we've had to upend the question

rather than saying, why do we sleep?

And by the way, the answer then was

that we sleep to cure sleepiness.

Which is like saying, we eat to cure hunger.

That tells you nothing about the physiological benefits

of food, same with sleep.

Now we've actually have to ask the question,

is there any physiological system in the body

or any major operation of the mind

that isn't wonderfully enhanced when we get sleep

or demonstrably impaired when we don't get enough?

And so far, for the most part, the answer seems to be no.

So far, the answer seems to be no.

So why does the body and the mind crave sleep then?

Why do we sleep?

How can we begin to answer that question then?

So I think one of the ways that I think about this all,

one of the answers that came to me is the following.

The reason that we implode so quickly

and so thoroughly with insufficient sleep

is because human beings seem to be one of the few species

that will deliberately deprive themselves of sleep

for no apparent good reason, biological.

And what that led me then to was the following.

Mother nature as a consequence.

So no other species does what we do in that context.

There are a few species that do undergo sleep deprivation,

but for very obvious, clear biological reasons.

One is when they're in a condition of severe starvation.

The second is when they're caring for their newborn.

So for example, killer whales will often deprive themselves.

The female will go away from the pod, give birth,

and then bring the calf back.

And during that time,

the mother will undergo sleep deprivation.

And then the third one is during migration

when birds are flying trans oceanographic to 3000 miles.

But for the most part,

it's never seen in the animal kingdom,

which brings me back to the point.

Therefore, mother nature in the course of evolution

has never had to face the challenge

of this thing called sleep deprivation.

And therefore she has never created a safety net in place

to circumnavigate this common influence.

And there is a good example where we have,

which is called the adipose cell, the fat cell.

Because during our evolutionary past,

we had famine and we had feast.

And mother nature came up with a very clever recipe,

which is how can I store caloric credit

so that I can spend it when I go into debt?

And the fat cell was born, brilliant idea.

Where is the fat cell for sleep?

Where is that sort of banking chip for sleep?

And unfortunately, we don't seem to have one

because she's never had to face that challenge.

So even if there's not some kind of physics

fundamental need for sleep

that physiologically or psychologically,

the fact is most organisms are built such that they need it.

And then mother nature never built an extra mechanism

for sleep deprivation.

So it's interesting that why we sleep

by not have a good answer,

but we need to sleep to be healthy is nevertheless true.

Yeah, and we have many answers right now.

In some ways, the question of why we sleep

was the wrong question too.

It's what are the pluripotent many reasons we sleep?

We don't just sleep for one reason

because from an evolutionary perspective,

it is the most idiotic thing that you could imagine.

When you're sleeping, you're not finding a mate,

you're not reproducing, you're not caring for your young,

you're not foraging for food.

And worse still, you're vulnerable to predation.

So on any one of those grounds,

especially as a collective,

sleep should have been strongly selected

against in the course of evolution.

But in every species that we've studied carefully to date,

sleep is present.

So it is important.

So like you're right.

I think I've heard arguments from an evolutionary biology

perspective that sleep is actually advantageous.

Maybe like some kind of predator, prey relationships.

But you're saying, and actually makes way more sense

what you're saying is it should have been selected against.

Like why close your eyes?

Yeah, why?

Because there was an energy conservation hypothesis for a while,

which is that we need to essentially go into low battery mode,

power down because it's unsustainable.

But in fact, that actually has been blasted out the water

because sleep is an incredibly active process.

In fact, the difference between you just lying on the couch

but remaining conscious versus you lying on the couch

and falling asleep, it's only a savings of about 140,

150 calories.

In other words, you just go out and club another baby seal

or whatever it was and you wouldn't worry.

So it has to be much more to it than energy conservation,

much more to it than sharing ecosystem space and time,

much more to it than simply predator prey relationships.

If sleep really did, and looking back,

even very old evolutionary organisms

like earthworms, millions of years old,

they have periods where they're active

and periods where they're passively asleep.

It's called lethargicus.

And so what that in some way suggested to me

was sleep evolved with life itself on this planet.

And then it has fought its way through heroically

every step along the evolutionary pathway,

which then leads to the sort of famous sleep statement

from a researcher that if sleep doesn't serve

an absolutely vital function or functions,

then it's the biggest mistake the evolutionary process

has ever made.

And we've now realized Mother Nature

didn't make a spectacular blender with sleep.

You've mentioned an idea of conscious states.

Do you think of sleep as a fundamentally different

conscious state than awakeness?

And how many conscious states are there

sort of when you're into it, your understanding

of what the mind can do?

Do you think awake state, sleep state,

or is there some kind of continuum?

There's a complicated state transition diagram.

Like how do you think about this whole space?

I think about it as a state space diagram.

And I think it's probably more of a continuum

than we have believed it to be or suggested it to be.

So we used to think absent of anesthesia

that there were already three main states of consciousness

that was being awake, being in non rapid eye movement sleep

or non dream sleep, and then being in rapid eye movement

sleep or dream sleep.

And those were the three states within which your brain

could percolate and be conscious.

Conscious during non REM sleep is maybe a stretch to say,

but I still believe there is plenty of consciousness there.

I don't believe that though anymore.

And the reason is because we can have daydreams

and we are in a very different wakeful state

in those daydreams than we are when we are, as we are now,

together present and extraceptively focused

rather than intraceptively focused.

And then we also know that as you

are sort of progressing into those different stages of sleep

during non REM sleep, you can also still dream.

It depends on your definition of dreaming,

but we seem to have some degree of dreaming

in almost all stages of sleep.

We've also then found that when you are sleep deprived,

there are even individual brain cells will fall asleep.

Despite the animal being, you know,

behaviorally from best we can tell awake,

individual brain cells and clusters of brain cells

will go into a sleep like state.

And humans do this too, when we are sleep deprived,

we have what are called microsleeps,

where the eyelid will partially close

and the brain essentially falls lapses

into a state of sleep,

but behaviorally you seem to be awake

and the danger here is road traffic accidents.

So these are what we call these sort of microsleep events

at the wheel.

Now, if you're traveling at 65 miles an hour

in a two ton vehicle, you know,

it takes probably around one second

to drift from one lane to the next

and it takes two seconds to go completely off the road.

So if you have one of these microsleeps at the wheel,

you know, it could be the last microsleep

that you ever have, but I don't now see it as a set of,

you know, very binary distinct, you know,

step function states, it's not a one or a zero.

I see it more of a, as a continuum.

Yeah.

So I've for five, six years at MIT

really focused on this human side of driving question.

And one of the big concerns is the microsleeps,

drowsiness, these kinds of ideas.

And one of the open questions was,

is it possible through computer vision to detect

or any kind of sensors?

The nice thing about computer vision

is you don't have to have direct contact to the person.

Is it possible to detect increases in drowsiness?

Is it possible to detect these kinds of microsleeps

or actually just sleep in general?

Among other things, like distraction,

these are all words that have so many meanings

and so many debates, like attention is a whole nother one,

just because you're looking at something

doesn't mean you're loading in the information.

Just because you're looking away

doesn't mean your peripheral vision can't pick up

the important information.

There's so many complicated vision science things there.

So I wonder if you could say something to,

they say the eyes are the windows to the soul.

Do you think the eyes can reveal something

about sleepiness through computer vision,

through just looking at the video of the face.

And Andrew Huberman and I, your friend,

have talked about this.

So we'd love to work on this together.

You should do.

It's a fascinating problem,

but drowsiness is a tricky one.

So there's what kind of information?

There's blinking and there's eye movement.

And those are the ones that can be picked up

with computer vision.

Do you think those are signals that can be used

to say something about where we are in this continuum?

Yeah, I do.

And I think there are a number of other features too.

I think aperture of eye,

so in other words, partial closures, full closures,

duration of those closures,

duration of those partial closures of the eyelid.

I think there may be some information in the pupil as well,

because as we're transitioning between those states,

there are changes in what's called

the automatic nervous system,

or technically it's called the autonomic nervous system,

part of which will control your pupillary size.

So I actually think that there is probably

a wealth of information.

When you combine that,

probably with aspects of steering angle, steering maneuver.

And if you can sense the pressure on the pedals as well,

my guess is that there is some combinatorial feature

that creates a phenotype of you are starting to fall asleep

and as the autonomous controls develop,

it's time for them to kick in.

Some manufacturers, auto manufacturers,

sort of have something beta version,

or maybe an alpha version of this,

already starting to come online

where they have a little camera in the wheel

that I think tries to look at some features.

Almost everybody doing this and it's very alpha.

So the thing that you currently have

and some people have that in their car,

there's a coffee cup or something that comes up

that you might be sleepy.

The primary signal that they're comfortable using

is steering wheel reversals.

So basically using your interaction with the steering wheel

and how much you're interacting with it

as a sign of sleepiness.

So if you have to constantly correct the car,

that's a sign of you starting to drift into microsleep.

I think that's a very, very crude signal.

It's probably a powerful one.

There's a whole nother component to this,

which is it seems like it's so driver and subject dependent.

How our behavior changes as we get sleepy and drowsy

seems to be different in complicated, fascinating ways

where you can't just use one signal.

It's kind of like what you're saying.

There has to be a lot of different signals

that you should then be able to combine.

The hope is the search is for universal signals

that are pretty damn good for 90% of people.

But I don't think we need to take necessarily

quite that approach.

I think what we could do in some clever fashion

is using the individual.

So what you and I are perhaps suggesting here

is that there is an array of features that we know

provide information that is sensitive

to whether or not you're falling asleep at the wheel.

Some of those, let's say that there are 10 of them.

For me, seven of them are the cardinal features.

For you, however, six of them,

and they're not all the same sort of overlapping,

are those for you.

I think what we need is algorithms

that can firstly understand when you are well slept.

So let's say that people have sleep trackers at night

and then your car integrates that information.

And it understands when you are well slept.

And then you've got the data of the individual behavior

unique to that individual snowflake like

when they are well slept.

This is the signature of well rested driving.

Then you can look at deviations from that

and pattern match it with the sleep history

of that individual.

And then I don't need to find the sort of,

the one size fits all approach for 99% of the people.

I can create a very bespoke, tailor like set of features

of a Savile Row suit of sleepiness features.

That would be my,

if you want to ask me about moonshots and crazy ideas,

that's where I go.

But to start with, I think your approach is a great one.

Let's find something that covers 99% of the people.

Because the worrying thing about microsleeps, of course,

unlike drugs or alcohol,

which certainly is a terrible thing

to be behind the wheel.

With those, often you react too late.

And that's the reason you get into an accident.

When you fall asleep behind the wheel,

you don't react at all.

At that point, there is a two ton missile

driving down the street and no one's in control.

That's why those accidents can often be more dangerous.

Yeah, and the fascinating thing is,

in the case of semi autonomous vehicles

like Tesla autopilot,

this is where I've had disagreements with Mr. Elon Musk.

And the human factors community,

which is this community that one of the big things they study

is human supervision over automation.

So you have like pilots supervising an airplane

that's mostly flying autonomously.

The question is, when we're actually doing the driving,

how do microsleeps are general?

How does drowsiness progress?

And how does it affect our driving?

That question becomes more fascinating,

more complicated when your task is not driving,

but supervising the driving.

So your task is to take over when stuff goes wrong.

And that is complicated,

but the basic conclusions from many decades

is that humans are really crappy at supervising

because they get drowsy and lose vigilance much, much faster.

The really surprising thing with Tesla autopilot,

it was surprising to me,

surprising to the human factors community,

and in fact, they still argue with me about it,

is it seems that humans in Teslas with autopilot

and other similar systems are not becoming less vigilant,

at least with the studies we've done.

So there's something about the urgency of driving.

I can't, I'm not sure the why,

but there's something about the risk.

I think the fact that you might die

is still keeping people awake.

The question is, as Tesla autopilot

or similar systems get better and better and better,

how does that affect increasing drowsiness?

And that's when you need to have,

that's where the big disagreement was,

you need to have driver sensing,

meaning driver facing camera that tracks

some kind of information about the face

that can tell you drowsiness.

So you can tell the car if you're drowsy

so that the car can be like,

you should be probably driving or pull to the side.

Right, or I need to do some of the heavy lifting here.

Yeah, so there needs to be that dance

of interaction of human and machine,

but currently it's mostly steering wheel based.

So, this idea that your hands should be on the steering wheel,

that's a sign that you're paying attention

is an outdated and a very crude metric.

I agree, yeah.

I think there are far more sophisticated ways

that we can solve that problem if we invest.

Can I ask you a big philosophical question

before we get into fun details?

On the topic of conscious states,

how fundamental do you think is consciousness

to the human mind?

I ask this from almost like a robotics perspective.

So in your study of sleep,

do you think the hard question of consciousness,

that it feels like something to be us,

is that like a nice little feature,

like a quirk of our mind,

or is it some how fundamental?

Because sleep feels like we take a step out

of that consciousness a little bit.

So from all your study of sleep,

do you think consciousness is deeply part of who we are,

or is it just a nice trick?

I think it's a deeply embedded feature

that I can imagine has a whole panoply of biological benefits.

But to your point about sleep,

what is interesting if you do a lot of dream research

and we've done some, it's very, very rare at all,

in fact, for you to end up becoming someone

other than who you are in your dreams.

Now, you can have third person perspective dreams

where you can see yourself in the dream

as if you've risen above your physical being.

But for the most part, it's very rare

that we lose our sense of conscious self.

And maybe I'm sort of doing a sleight of hand

because it's really what I'm saying is it's very rare

that we lose our sense of who we are in dreams.

We never do.

Now, that's not to suggest that dreams aren't utterly bizarre.

And I mean, when you slept last night,

which I know may have been perhaps a little less than me,

but when you went into dreaming,

you became flagrantly psychotic

and there are five essentially good reasons.

Firstly, you started to see things which were not there.

So you were hallucinating.

Second, you believe things that couldn't possibly be true.

So you were delusional.

Third, you became confused about time and place and person.

So you're suffering from what we would call disorientation.

Fourth, you have wildly fluctuating emotions,

something that psychiatrists will call being affectively labile.

And then how wonderful you woke up this morning

and you forgot most if not all of that dream experience.

So you're suffering from amnesia.

If you had to experience any one of those five things

while you were awake,

you would probably be seeking psychological help.

But so I placed that as a backdrop

against your astute question

because despite all of that psychosis,

there is still a present self nested at the heart of it,

meaning that I think it's very difficult for us

to abandon our conscious sense of self.

And if it's that hard,

the old adage in some ways

that you can't outrun your shadow,

but here it's more of a philosophical question

which is about the conscious mind

and what the state of consciousness actually means

in a human being.

So I think that that to me, you become so dislocated

from so many other rational ways of waking consciousness.

But one thing that won't go away,

that won't get perturbed or sort of, you know,

manacled, is this your sense of conscious self?

Yeah, that's a strong sign that consciousness

is fundamental to the human mind.

Or we're just creatures of habit

who got used to having consciousness.

Maybe it just takes a lot of either chemical substances

or a lot of like mental work to escape that.

I mean, it's like trying to launch a rocket.

You know, the energy that has to be put in

to create escape velocity

from the gravitational pull of this thing

called planet Earth is immense.

Well, the same thing is true

for us to abandon our sense of conscious self.

Self, the amount of biological amount of substances,

the amount of wacky stuff that you have to do

to truly get escape velocity from your conscious self.

What does that tell us about then

the fundamental state of our conscious self?

Yeah, it also probably says that it's quite useful

to have consciousness for survival

and for just operation in this world.

And perhaps for intelligence.

I'm one of the, on the AI side,

people that think that intelligence requires consciousness.

So like high levels of general intelligence

requires consciousness.

Most people in the AI field think like consciousness

and intelligence are fundamentally different.

You could build a computer that's super intelligent.

It doesn't have to be conscious.

I think that if you define super intelligence

by being good at chess, yes.

But if you define super intelligence

as being able to operate in this living world

of humans and be able to perform

all kinds of different tasks, consciousness,

it seems to be some all fundamental

to richly integrate yourself into the human experience

into society.

It feels like you have to be a conscious being.

But then we don't even know what consciousness is.

And we certainly don't know how to engineer it

in our machines.

I love the fact that there are still questions

that are so embryonic

because I suspect it's the same with you.

Answers to me are simply ways to get to more questions.

It's questions where, questions turn me on, answers less so.

And I love the fact that we are still embryonic

in our sense of arguing about

even what the definition of consciousness is.

But I also find it fascinating.

I think it's thoroughly delightful

to absorb yourself in the thought.

Think about the brain and we can move back

across the complexity of phylogeny

from humans to mammals to birds to reptiles, amphibians, fish.

You can bacteria, whatever you want.

And you can go through this and say,

okay, where is the hard line

of what we would define as consciousness?

And I'm sure it's got something to do

with the complexity of the neural system.

Of that, I'm fairly certain.

But to me, it's always been fascinating.

So what is it then?

Is it that I just keep adding neurons to a Petri dish

and I just keep adding them and adding them and adding them.

At some point when I hit a critical mass

of interconnected neurons,

that is the mass of the interconnected human brain,

then bingo.

All of a sudden it kicks into gear

and we have consciousness.

Like a phase shift, phase transition of some kind.

Correct, yeah.

But there is something about the complexity

of the nervous system that I think is fundamental

to consciousness and the reason I bring that up

is because when we're trying to then think

about creating it in an artificial way,

does that inform us as to the complexity

that we should be looking at in terms of development?

I also think that it's a missed opportunity

in the sort of digital space

for us to try to recreate human consciousness.

We've already got human consciousness.

What if we were to think about

creating some other form of,

why do we have to think that the ultimate

in the creation of an artificial intelligence

is the replication of a human state of consciousness?

Can we not think outside of our own consciousness

and believe that there is something even more incredible

or more complimentary, more orthogonal?

Mm hmm.

So I'm sometimes perplexed

that people are trying to mimic human consciousness

rather than think about creating something that's different.

So yeah, I think of human consciousness

or consciousness in general as this magic

superpower that allows us to deeply experience the world.

And just as you're saying,

I don't think that superpower has to take

the exact flavor as humans have.

That's my love for robots.

I would love to add the ability to robots

that can experience the world and other humans deeply.

I'm humbled by the fact that that idea

does not necessarily need to look anything like

how humans experience the world.

But there's a dance of human to robot connection,

the same way human to dog or human to cat connection.

There's a magic there to that interaction.

And I'm not sure how to create that magic,

but it's a worthy effort.

I also love just exactly as you said,

on the question of consciousness

or engineering consciousness,

the fun thing about this problem

is it seems obvious to me that 100 years from now,

no matter what we do today,

people who are still here will laugh

at how silly our notions were.

So it's almost impossible for me to imagine

that we will truly solve this problem fully in my lifetime.

And more than that, everything we'll do

will be silly 100 years from now.

But that makes it fun to me

because it's like you have the full freedom

to not even be right, just to try, just to try as freedom.

And that's how I see it. Get me that T shirt, please.

I love that.

So, and, you know, human robot interaction is fascinating

because it's like watching dancing.

I've been dancing tango recently.

And just, it's like, there is no goal.

The goal is to create something magical.

And whether consciousness or emotion

or elegance of movement, all of those things

aid in the creation of the magic.

And it's a free, it's an art form to explore

how to make that, how to create that

in a way that's compelling.

Yeah, I love the line in Sense of a Woman with Al Pacino

where he's speaking about the tango

and he said, really, it's just freedom

that if you get tangled up, you just keep tangoing on.

I still to this day, I think first or second time

I talked to Joe Rogan on his podcast,

I said, we got into this heated argument

about whether Sense of a Woman is a better movie

than John Wick.

Because it's one of my favorite movies for many reasons.

One is Sense of a Woman.

Sense of a Woman.

Partially.

I didn't know that, by the way.

It was just, you just,

Yeah, I didn't know if you would actually know of the movie.

Awesome, awesome.

Yeah, yeah, I said, I love the tango scene.

I love Al Pacino's performance.

It's a wonderful movie.

Then Joe was saying, John Wick is better.

So we to this day argue about this.

I think it depends on what conscious state you're in

that you would be ready and receptive to.

But Sense of a Woman, I think it has one of the best monologues

at the end of the movie that has ever been written

or at least performed.

When Al Pacino defends the younger.

Yeah, I often think about that.

There's been times in my life,

I don't know about you,

where I wish I had an Al Pacino in my life.

Where integrity is really important in this life.

It is.

And sometimes you find yourself in places

where there's pressure to sacrifice that integrity.

And you want, what is it?

Lieutenant Colonel or whatever he was to come in on your side

and scream at everyone and say,

what the hell are we doing here?

Being, you know, unfortunately,

British instead of having that slightly awkward,

sort of huge grand gene,

it's very at the opposite end of the spectrum

of the remarkable feat of Al Pacino at the end of that scene.

But, and yeah, integrity is,

it's a challenging thing and I value it much.

And I think it can take 20 years to build a reputation

in two minutes to lose it.

And there is nothing more that I value than that integrity.

And, you know, if I'm ever wrong about anything,

I truly don't want to be wrong for any longer

than I have to be.

You know, that's what being in some ways a scientist is.

You're just driven by truth.

And the irony relative to something like mathematics

is that in science, you never find truth.

What all you do in science

is you discount the things that are likely to be untrue,

leaving only the possibility of what could be true.

But in math, you know, when you create, you know, a proof,

it's a proof for, you know, from that point forward,

there is truth in mathematics.

And I think there's a beauty in that.

But I kind of like the messiness of science

because again, to me, it's less about the truth of the answer

and it is more about the pursuit of questions.

But their integrity becomes more and more important

and it becomes more difficult.

There's a lot of pressure,

it's just like in the rest of the world,

but there's a lot of pressures on a scientist.

One is like funding sources.

I've noticed this that, you know, money affects

everyone's mind, I think.

I've been always somebody that I believe money can't,

you can't buy my opinion.

I don't care how much money, billions or trillions.

The, but that pressure is there

and you have to be very cognizant of it

and make sure that your opinion is not defined

by the funding sources.

And then the other is just your own success of, you know,

for a couple of decades publishing an idea

and then realizing at some point

that that idea was wrong all along.

And that's a tough thing for people to do.

But that's also integrity, is to walk away,

is to say that you were wrong.

That doesn't have to be in some big dramatic way.

It could be in a bunch of tiny ways along the way, right?

Like reconfigure your intuition

about a particular problem.

That's, and all of that is integrity.

When everybody in the room believes a certain thing,

everybody in the community believes a certain thing

to be able to still be open minded in the face of that.

Yeah, and I think it comes down

in some ways to the issue of ego,

that you bond your correctness or your rightness,

your scientific theory with your sense of ego.

You know, I've never found it that difficult

to let go of theories in the face of counter evidence,

in part because I have such low self esteem.

Well, I kind of like that.

I always liked that combination.

I have the same, I'm like very self critical,

imposter syndrome, all those things,

putting yourself below the podium,

but at the same time having the ego

that drives the ambition to work your ass off.

Like some kind of weird drive,

maybe like drive to be better.

Like thinking yourself is not that great

and always driving to be better.

And then at the same time,

because that can be paralyzing and exhausting and so on,

at the same time just being grateful to be alive.

But in the sciences, in the actual effort,

never be satisfied, never think of yourself highly.

That seems to be a nice combination.

I very much hope that that is part of who I am.

And I remain very quietly motivated and driven.

And I, like you, love the idea of perfection

and I know I will never achieve it,

but I will never stop trying to.

So similar to you, which sounds weird

because there's all these videos of me on the internet.

So I think I just naturally lean into the things

I'm afraid of and I'm uncomfortable doing.

Like I'm very afraid of talking to people

and just even before talking to you today,

just a lot of anxiety and all those kinds of things.

How about talking to me?

Yeah, yeah.

Oh, like nervousness, fear in some cases,

self doubt and all those kinds of things.

But I do it anyway.

So the reason I bring that up is you've launched a podcast.

I have. Allow me to say,

I think you're a great science communicator.

So this challenge of being afraid

or cautious of being in the public eye

and yet having a longing to communicate

some of the things you're excited about

in the space of sleep and beyond.

What's your vision with this project?

With this project, I think firstly to that question,

like you, I am always more afraid of not trying and trying.

Yeah, that to me frightens me more.

But with the podcast, I think really,

I have two very simple goals.

I want to try and democratize the science of sleep.

And in doing so, my goal would be to try

and reunite humanity with the sleep

that it is so desperately bereft of.

And if I can do that through a number of different means,

the podcast is a little bit different than this format.

It's going to be short form monologues from yours truly.

That will last usually less than just 10 minutes.

And I see it as simply a little slice of sleep goodness

that can accompany your waking day.

It's hard to know what is the right way

to do science communication.

Like your friend, mine, Andrew Huberman is does,

he's an incredible human being.

Oh gosh.

So he does like two hours of,

I wonder how many takes he does.

I don't know, but it looks like he doesn't do any.

Yeah, I suspect he's that magnificent of a human being.

When I talk to him in person,

he always generates intelligent words,

well cited nonstop for hours.

So I don't...

He's a Gatlin gun of information and it's pristine.

And passion and all those kinds of things.

So that's an interesting medium.

I wouldn't have, it's funny

because I wouldn't have done it the way he's doing it.

I wouldn't advise him to do it the way he's doing it.

Cause I thought there's no way you could do what you're doing.

Cause it's a lot of work,

but he is like doing an incredible job of it.

I just think it's the same with like Dan Carlin

in hardcore history.

I thought that the way Andrew is doing it

would crush him the way it crushes Dan Carlin.

So Dan has so much pressure on him to do a good job

that he ends up publishing like two episodes a year.

So that pressure can be paralyzing,

the pressure of like putting out like

strong scientific statements that that can be overwhelming.

Now Andrew seems to be just plowing through anyway.

If there's mistakes, he'll,

he'll say there's corrections and so on.

I just, I wonder,

I actually haven't talked too much about it like psychologically.

How difficult is it to put yourself out there

for an hour to a week of just nonstop dropping knowledge.

Any one sentence of which could be totally wrong.

It could be a mistake.

And there will be mistakes, you know?

And I, you know, in the first edition of my book,

there were errors that, you know,

we corrected in the second edition too,

but there will be probabilistically, you know,

if you've got, you know, 10 facts per page of a book

and you've got 350 pages,

odds are it's probably not going to be

utter perfection out the gate.

And it will be the same way for Andrew too.

But having the, the reverence of

a humble mind

and simply accepting the things that are wrong

and correcting them and doing the right thing.

I know that that's his mentality.

I do want to say that I'm just kind of honored to be,

it's like, it's a cool group of like scientific people

that I'm fortunate enough to now be interacting with.

It's you and Andrew and David Sinclair

has been thinking about throwing his hat in the ring.

Oh, I hope so.

It is another one of those very special people in the world.

So it's cool because podcasts are, it's cool.

It's a, it's such a powerful medium of communication.

It's much freer than more constrained

like publications and so on.

Or it's much more accessible and inspiring than like,

I don't know, conference presentations or lectures.

And so it's a really exciting medium to me.

And it's cool that there's this like group of people

that are becoming friends and putting stuff out there

and supporting each other.

So it's fun to also watch

how that's going to evolve in your case.

Cause it will wonder, it'll be too among.

Oh, Dival, I think is the answer to that.

Well, I mean, some of it is persistence

through the challenges that we've been talking about,

which is like,

I think I've got a lot to learn.

Yeah.

But I will persist.

Can I ask you some detailed stuff you mentioned?

Oh my goodness, go anywhere you wish with sleep.

So I'm a big fan of coffee and caffeine.

And I've been, especially in the last few days,

consuming a very large amount.

And I'm cognizant of the fact that

my body is affected by caffeine

different than the anecdotal information

that other people tell me.

I seem to be not at all affected by it.

It's almost,

it feels like more like a ritual

than it is a chemical boost to my performance.

Like I can drink several cups of coffee right before bed

and just knock out anyway.

I'm not sure if it's biological chemical

or it has to do with just the fact

that I'm consuming huge amounts of caffeine.

All that to say,

what do you think is the relationship

between coffee and sleep, caffeine and sleep?

If there's an interesting distinction there.

There is a distinction.

So I think the first thing to say,

which is going to sound strange coming from me

is drink coffee.

The health benefits associated with drinking coffee

are really quite well established now.

But I think that the counterpoint to that,

well firstly, the dose and the timing make the poison

and I'll perhaps come back to that in just a second.

But for coffee, it's actually not the caffeine.

So a lot of people have asked me

about this rightful paradox between the fact that sleep

provides all of these incredible health benefits

and then coffee, which can have a deleterious impact

on your sleep, has a whole collection of health benefits.

Many of them, Venn diagram overlapping with those

that sleep provides, how on earth can you reconcile those two?

And the answer is that, well, the answer is very simple.

The answer is very simple, it's called antioxidants.

That it turns out that for most people in Western civilization

because of diet not being quite what it should be,

the major source through which they obtain antioxidants

is the coffee bean.

So the humble coffee bean has now been asked to carry

the astronomical weight of serving up the large majority

of people's antioxidant needs.

And you can see this if, for example,

you look at the health benefits of decaffeinated coffee,

it has a whole constellation

of really great health benefits too.

So it's not the caffeine, and that's why I liked

what you said, this sort of separation of church

and state between coffee and caffeine.

It's not the caffeine, it's the coffee bean itself

that provides those health benefits.

But coming back to how it impacts sleep,

it impacts sleeping probably at least three different ways.

The first is that for most people,

caffeine can make it obviously a little harder

to fall asleep, caffeine can make it harder to stay asleep.

But let's say that you are one of those individuals

and I think you are, and you can say,

look, I can have three or four espressos with dinner

and I fall asleep just fine,

and I stay asleep soundly across the night,

so there's no problem.

The downside there is that even if that is true,

the amount of deep sleep that you get

will not be as deep, and so you will actually lose

somewhere between 10 to 30% of your deep sleep

if you drink caffeine in the evening.

So to give you some context to drop your deep sleep

by let's say 20%, I'd probably have to age you by 15 years,

or you could do it every night with a cup of coffee.

I think the fourth component that is perhaps less well

understood about coffee is its timing,

and that's why I was saying the timing and the dose

make the poison, the dose, by the way,

once you get past about three cups of coffee a day,

the health benefits actually start to turn down

in the opposite direction.

So there is a U shaped function,

it's sort of the Goldilocks syndrome,

not too little, not too much, just the right amount.

The second component is the timing though.

Caffeine has half life of about five to six hours,

meaning that after five to six hours,

50% of that on average for the average adult

is still in the system,

which means that it has a quarter life of 10 to 12 hours.

So in other words, if you have a coffee at noon,

a quarter of that caffeine is still circulating

in your brain at midnight.

So having a cup of coffee at noon,

one could argue is the equivalent

of tucking yourself into bed at midnight,

and before you turn the light out,

you swig a quarter of a cup of coffee.

But that doesn't still answer your question

as to why are you so immune?

So I'm someone who is actually unfortunately

very sensitive to caffeine.

And if I have, you know, even two cups of coffee

in the morning, I don't sleep as well that night.

And I find it miserable because I love the smell of coffee,

I love the routine, I love the ritual.

I think I would love to be invested in it.

It's just terrible for my sleep.

So I switched to decaf.

There is a difference from one individual to the next,

and it's controlled by a set of liver enzymes

called cytochrome P450 enzymes.

And there is a particular gene

that if you have a different sort of version of this gene,

it's called CYP1A2.

That gene will determine the speed

of the clearance of caffeine from your system.

Some people will have a version of that gene

that is very effective and efficient

at clearing that caffeine.

And so their half life could be as short as two hours

rather than five to six hours.

Other people, hands up Matt Walker,

have a version of that gene

that is not very effective at clearing out the caffeine.

And therefore their half life sort of sensitivity

could be somewhere between, you know, eight to nine hours.

So we understand that there are individual differences,

but overall I guess the top line here is drink coffee

and understand that it's not the caffeine,

it's the coffee that's the benefit

and the dose makes the poison.

Is there some aspect to it that it's like a muscle

in terms of all the combination of letters

and numbers that you just said?

Is there some aspect that if I can improve

the quarter life, the half life,

I could decrease that number if I just practice.

Like I drink a lot of coffee, it's just like habit,

it alters how your body's able to get rid of the caffeine.

Not how the body is able to get rid of the caffeine,

but it does alter how sensitive the body is to the caffeine.

And it's not at the level of the enzyme degrading the caffeine,

it's at the level of the receptors

that caffeine will act upon.

Now it turns out that those are called adenosine receptors

and maybe we can speak about what adenosine is

and sleep pressure and all of that good stuff.

But as you start to drink more and more coffee,

the body tries to fight back

and it happens with many different drugs by the way

and it's called tolerance.

And so one of the ways that your body becomes tolerant

to a drug is that the receptors that the drug is binding to,

these sort of welcome sites,

these sort of picture mitts, as it were,

that receive the drug,

those start to get taken away from the surface of the cell.

And it's what we call receptor internalization.

So the cell starts to think, gee whiz,

there's a lot of stimulation going on, this is too much.

So I'm just going to,

when normally I would coat my cell with,

let's just say five of these receptors for argument's sake,

things are going a little bit too ballistic right now,

I'm going to take away at least two of those receptors

and downscale it to just having three of those.

And now you need two cups of coffee to get the same effect

that one cup of coffee got you before.

And that's why then when you go cold turkey on coffee,

all of a sudden the system has equilibrated itself

to expecting X amount of stimulation.

And now all of that stimulation is gone.

So it's now got too few receptors

and you have a caffeine withdrawal syndrome.

And that's why, for example, with drugs of abuse,

things like heroin, when people go into abstinence,

as they're sort of moving into their addiction,

they will build up a progressive tolerance to that drug.

So they need to take more of it to get the same high.

But then if they go cold turkey for some period of time,

the system goes back to being more sensitive again.

It starts to repopulate the surface of the cell

with these receptors.

But now when they reuse and they fall off the wagon,

if they go back to the same dose

that they were using before 10 weeks ago

or three months ago,

that dose can kill them, they can have an overdose.

Even though they were using the same amount

at those two different times,

the difference is that it's not the dose of the drug,

it's the sensitivity of the system.

And that's the same thing that we see with caffeine.

In terms of training the muscle, as it were,

is the system becomes less sensitive, can calibrate.

Is there a time, the number of hours before bed,

that's a safe bet to most people to recommend,

you shouldn't drink caffeine this many hours?

Like, is there an average half life

that you should be aiming at?

Or is this advice kind of impossible

because there's so much variability?

There is a huge variability.

And I think everyone themselves,

to a degree knows it,

although I'll put a caveat on that too,

because it's a slightly dangerous point.

So the recommendation for the average adult

and who, where is the average adult in society?

There is no such thing.

But for the average adult,

it would be probably cutting yourself off

maybe 10 hours before.

So assuming a normative bedtime in society,

I would say try to stop drinking caffeine before 2 p.m.

and just keep an eye out.

And if you're struggling with sleep,

dial down the caffeine and see if it makes a difference.

Can I ask you about sleep and learning?

So how does sleep affect learning?

Sleep before learning, sleep after learning,

which are both fascinating kind of dynamics

of the mind's interaction with this extra conscious state.

Yeah, sleep is profoundly and very intimately related

to your memory systems and your informational systems.

The first is you just mentioned is that sleep before learning

will essentially prepare your brain

almost like a dry sponge,

ready to sort of initially soak up new information.

In other words, you need sleep before learning

to effectively imprint information into the brain

to lay down fresh memory traces.

And without sleep, the memory circuits of the brain,

and we know we've studied these memory circuits,

will essentially become waterlogged,

as it were for the sponge analogy,

and you can't absorb the information as effectively.

So you need sleep before learning,

but you also need sleep, unfortunately, after learning too,

to then take those freshly minted memories

and effectively hit the save button on them,

but it's nowhere near as quick as a digital system.

It takes hours because it's a physical biological change

that happens at the level of brain cells.

But sleep after learning will cement and solidify

that new memory into the neural architecture of the brain,

therefore making it less likely to be forgotten.

So I often think of sleep in that way as,

it's almost sort of future proofing information in your way.

Well, it means that it gives it a higher degree of assurance

to be remembered in the future,

rather than go through the sort of degradation

that we think of as forgetting.

So the brain has, in some ways, by default, there is forget.

And actually, I would love to,

I was going to say sleep is relevant for memory

in three different ways,

but I'm going to amend that and say there's four different ways,

which is learning, maintaining, memorizing,

abstraction, assimilation, association, then forgetting,

which the last one sounds oxymoronic

based on the form of three, but I'll see if I can explain.

So sleep after learning then sort of sets that information

like amber in solidification.

The third benefit, however, is that sleep we've learned

more recently is much more intelligent

than we ever gave it credit for.

Sleep doesn't simply just take individual memories

and strengthen them.

Sleep will then intelligently integrate and crosslink

and associate that information together.

And it's almost like informational alchemy

so that you wake up the next morning

with a revised, mind wide web of associations.

And that's probably the reason that you've never been told

to stay awake on a problem.

And in every language that I've inquired about that phrase

or something very similar seems to exist,

which means to me that this creative associative benefit

of sleep transcends cultural boundaries.

It is a common experience across humanity.

Now I should note that I think the French translation

of that is much closer to you.

I think you sleep with a problem, whereas the British,

you sleep on a problem.

The French, you sleep with a problem.

I think it says so much about the romantic difference

between the British and the French, but let's not go there.

That's brilliant.

So such a subtle, but such a fundamental difference.

Yeah, gorgeous.

Yeah, goodness me.

Sleep with the problem.

Yes, exactly.

It's right along on the French.

So, and we can sort of double click on any one of these

and go into detail, but the fourth,

I became really enchanted by about eight years ago

in our research, which was this idea of forgetting.

And I started to think that forgetting may be the price

that we pay for remembering.

And in that sense, there is an enormous benefit

to letting go.

And you may be thinking, that sounds ridiculous.

I don't want to forget.

In fact, my biggest problem is I keep forgetting things,

but the brain will we believe has a finite storage capacity.

We can't prove it yet, but my suspicion is

that that's probably true.

It doesn't have an infinite storage capacity.

It has constraints.

If that's the case, we can't simply go through life

being constantly informational aggregators,

unless we are programmed to say,

we've got a hard drive space of about 85 to 90 years

and we're good and we can do that.

Maybe that's true.

I don't think that's true.

I think forgetting is an incredibly good and useful thing.

So for example, it's not beneficial

from an evolutionary perspective for me to remember

where I parked my car three years ago.

So it's important that I can remember today's parking spot,

but I don't want to have the junk DNA

from a memory perspective of where I parked my car

two years ago.

Now, I actually have in some ways a problem with forgetting.

I'm, and again, I'm not trying to sort of be laudatory,

but I tend not to forget too many things.

And I don't think that that's a good thing.

And there was a wonderful neurologist, Luria,

who wrote a book called The Mind of the Pneumonocyst.

And it was a brilliant book,

both because it was written exquisitely,

but he was studying these sort of memory savants

who basically could remember everything that he gave them.

And he tried to find a chink in their armor.

And the first half of the book is essentially about him

seeing how far he can push them before they fail.

And he never found that place.

He could never find a place where they stopped remembering.

And then in his brilliance,

he turned the question on its head.

He said, not what is the benefit of constantly remembering,

but instead what is the detriment to never forgetting?

And when you start to realize his descriptions

of those individuals,

it's probably a life that you would not want.

But it's as fascinating both from a human perspective,

but also AI perspective.

There's a big challenge in the machine learning community

of how to build systems that are able to remember

for prolonged periods of time,

lifelong continuous learning.

So where you build up information over time.

So memory is one of the biggest open problems

in AI and machine learning.

But at the same time,

the right way to formulate memory is actually forgetting

because you have to be exceptionally selective

at which kind of stuff you remember.

And that's where the step of a simulation integration

that you're referring to is really important.

I mean, we forget most of the things.

And the question is exactly the cost of forgetting

at the very edge of stuff that could be important

or could not be.

How do we remember or not those things?

Like for example, I've, you know, doing a podcast,

I've become cognizant of one feature of my forgetting

that's been problematic,

which is I forget names and titles of books and so on.

So when I read, I remember ideas.

I remember quotes.

I remember statements and like,

that's the space in which I'm thinking.

But when you communicate to others,

you have to say this person in this book said that.

So it's the same thing with like Andrew Huberman

is masterful at this.

It's this important academia,

remembering the authors of a paper

and the title of the paper as part of remembering the idea.

And I've been feeling the cost of not being able

to naturally remember those things.

And so that's something I need to sort of work on.

But that's an example with faces.

Yes, very good at faces.

But not good with names.

So I am exactly like you.

And there is, you know, an understanding of that

in the brain too.

We understand that there is partitioning of those

in terms of the territory of the brain

that takes care of faces and facts and places

and that they can be separate.

So I will never forget a face.

But, you know, and as I said, I usually forget very little.

But for some reason, names are a struggle.

I think in some ways

because I'm probably just a slightly anxious person.

So when you first meet someone,

which is usually the time when a name is introduced,

you know, you were saying you were sort of anxious

maybe about sort of sitting down with me.

But I find that a little bit, you know, activating.

And so it's not as though there's anything wrong with my memory.

It's just the emotional state I'm in

when I'm first meeting someone.

You know, it's a little bit, it's hoping.

But I will never forget the face.

But I completely relate to that

because I almost don't hear people's names

when they tell me because I'm so anxious.

Yeah, yeah.

But I think there's certain quirks of social interaction

that show that you care about the person,

that you remember that person,

that they matter to you, they had an impact on you.

And one of the ways to show that is you remember their name.

And, but that's a quirk to me because there's,

a lot of people I meet have a deep impact on me.

But they, I can't communicate that unless I know their name,

unless I know some of the details that,

that we humans seem to use to communicate

that we remember each other.

What I remember well is the feeling we shared,

is the experience we shared.

What I don't remember well is the detailed labels

of those experiences.

And I need to certainly work on that.

I don't know.

I think it's, you know, just allowing yourself to be an eight

and who you are is also a beautiful thing too.

I'm not suggesting it's not important

to try and better oneself and,

but I also sometimes worry about the misery

that that puts us in.

But like you, I will, I do struggle with them,

but I know for the first time when we met in the lobby,

I know exactly what you look like.

I know that you were wearing headphones.

I know the shape and the size of those headphones.

You didn't have your black jacket on.

I know exactly what the weave of your shirt looked like.

I know what your shoes look like.

And I knew exactly the height of your,

the end of your pants from the top of your shoes.

And so those things I don't forget, you know,

and I can remember when people,

I met people, you know, two years ago

and I'll say, oh, yes, we met there.

And I remember you had those fantastic, you know, boots on.

I thought they were pretty great pair of boots, you know,

and they're like, how do you,

I didn't even remember what I was wearing that day.

It's fascinating.

Yeah, I'm the exact the same way,

but you can't, until we have neural link

or something like that,

we can't communicate that you remember all those things.

I know that's what I want to see.

You have to be able to use tricks

of human communication for that.

But so that, I mean, that's the,

it ultimately is a trick of like,

which to remember, which to forget.

Right.

And the forgetting is so, it's so fascinating to say this.

I mean, it seems to be deeply connected

to that assimilation process.

So forgetting, you try to fit all the new stuff

into this big web of the old stuff

and the things that don't fit, you throw out.

I think the assimilation,

the way I've been thinking about it with sleep,

and it's particularly sort of dream sleep

that we think can help with this assimilation,

is that during wake,

we have one version of associative processing.

And what I mean by that is we see

the most obvious connections.

So I think of wakefulness as a Google search gone right.

Whereas I see dream sleep as doing something very different.

I think dream sleep is a little bit

like group therapy for memories,

that everyone gets a name badge,

and sleep gathers in all of the individual pieces of the day.

And it sort of starts to get you to forces you, in fact,

to speak to the people, not at the front of the room,

that you think you've got the most obvious connection with,

but to speak with the people all the way

at the back of the room, that at first you think,

I've got no connection to sleep.

You think I've got no obvious connection with them at all.

But once you get chatting with them,

you learn that you do have

a very distant, non obvious connection,

but it's still a connection non the same.

And it's almost as though you're doing a Google search

where I input Lex Friedman,

and it doesn't take me to the first page of your home site.

It takes me to page 20,

which is about some field hockey game at Utah.

It turns out that there actually is a link if I look at it.

It's a distant, non obvious one.

And to me, I find that exciting

because when you fuse things together

that shouldn't normally go together,

but when they do, they cause marked advances

in evolutionary fitness,

it sounds like the biological basis of creativity.

And that's exactly what I think dream sleep

and the algorithm of dream sleep is designed to do.

It's not a Boolean like system

where you have the sort of assumptions of true and false.

Maybe it's more fuzzy logic system.

And I think REM sleep is a perfect environment

within which we do, it's almost like memory pinball.

You get the information that you've learned during the day

and then you pull the lever back

and you shoot it up into the attic of your brain.

This cortex filled with all of your past historical knowledge

and you start to bounce it around

and see where one of those things lights up

and you build a new connection there

and you build another one there too.

You're developing schemas.

And so in that way, I think you could argue,

we dream, therefore we are.

Yeah, so in terms of this line between learning

and thinking through a new thing

that seems to be deeply connected,

there's this legendary engineer named Jim Keller

who keeps yelling at me about this.

He says it's very effective.

He likes to, for difficult problems before bed,

think about that difficult problem.

We're not talking about like drama, work

or all that kind of stuff.

No, like a scientific for him engineering problem.

He likes to like intensely think about it

and to prime his mind before sleep and then go to sleep.

And then he finds that the next day,

he's able to think much clearer

and there's new ideas that come, but also just,

I guess it's more well integrated.

And sometimes during the process of like,

he's able to like wake up and like seeing new insights.

That's right.

If he's deeply sort of aggressively thinking through a problem.

And there's many scientific demonstrations of this.

The Mendelea with a periodic table of elements,

you know, he was trying for months to understand.

I mean, talk about a ecumenical problem of epic proportions.

Here's your question today.

You have to understand how all of the known elements

in the universe fit together in a logical way.

Good luck, take care.

It was non trivial at the time.

And he would try and try.

He was so obsessed with it.

He created playing cards with all of the different elements on.

And then he would go on these long train journeys around Europe

and he would just sort of deal these cards in front of them

and he would shuffle them shuffling and shuffling

and he would just try to see if he could find what the answer was.

And then so the story goes, you know, he fell asleep

and he had a dream.

And in that dream, you know, all of these elements

started to dance and play around

and they snapped into a logical grid, you know,

atomic weights, et cetera, et cetera.

And it wasn't his waking brain that solved the problem.

It was his sleeping brain that solved the impenetrable problem

that his waking brain could not.

And there's been, you know, even in the arts and in music

some wonderful dreams.

You know, Frankenstein, Mary Shelley's epic Gothic novel

came to her in a dream at Lord Byron's home.

And then we've got, you know, Paul McCartney.

Yesterday the song came to him in a dream.

He was filming, gosh, what was the movie?

I don't recall it.

I should be shot because I'm from Liverpool myself.

But he was on Wimpoll Street in London and filming

and he came up with that song, the melody in his sleep

not to be outdone by the Beatles

and by the way, Let It Be also came from a dream

that McCartney had.

People usually give it, you know, religious overtones.

You know, Mother Mary comes to me speaking words of wisdom,

Let It Be.

If you've ever asked who Mother Mary is,

it's not, you know, the biblical content.

It's his mother.

It's Mary McCartney.

And she came to him in a dream and gifted him the song.

But the best story I've heard is not to be outdone

by the Beatles, the Stones.

Keith Richards, who I think once was suggested it.

Who was it?

It was a comedian who was saying that in an interview

with Rolling Stone, Keith Richards suggested or inferred

that young kids should not do drugs.

And they said, well, look, young kids can't do drugs

because you've done all of the drugs.

But Keith Richards described he would always go to bed

with his guitar and a tape recorder.

And then probably he would have a whole set of other things

in the bed with him and who knows how many other people.

But anyway, and then he said in his autobiography,

and I'm paraphrasing here, but one morning I woke up

and I realized that the tape had recorded all the way to the end.

So I rewound the tape and I hit play.

And there in some kind of ghostly form

were the opening chords to satisfaction.

The most famous successful Rolling Stone song of all time.

Yeah.

Followed by then 43 minutes of snoring.

That's awesome.

But that riff came to him when one of the most famous riffs

in all of rock and roll came to him

by way of a dream inspired insight.

So I think there is too many of those anecdotes.

And we've now got the science.

I don't rely on anecdotes as science.

We've now done the studies in the laboratory

and we can reliably demonstrate that sleep inspires creativity

inspires problem solving capacity.

Well, the interesting thing is is it possible

to some of the ideas that you talk about

to turn them into a protocol that could be practiced rigorously.

So what Jim Keller espouses is saying

not just the fact that sleep helps you increase the creativity