← Lex Fridman

David Eagleman: Neuroplasticity and the Livewired Brain

第119期2020-08-26English

嘉宾:David Eagleman

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§01Transcript · 00:00–09:28

00:00The following is a conversation with David Eagleman,

00:02a neuroscientist and one of the great science communicators

00:06of our time, exploring the beauty and mystery

00:09of the human brain.

00:10He's an author of a lot of amazing books

00:13about the human mind, and his new one called Livewired.

00:18Livewired is a work of 10 years on a topic

00:21that is fascinating to me, which is neuroplasticity

00:24or the malleability of the human brain.

00:27Quick summary of the sponsors.

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00:37As a side note, let me say that the adaptability

00:41of the human mind at the biological, chemical,

00:44cognitive, psychological, and even sociological levels

00:48is the very thing that captivated me many years ago

00:51when I first began to wonder how would my engineer

00:54something like it in the machine.

00:57The open question today in the 21st century

01:00is what are the limits of this adaptability?

01:03As new, smarter and smarter devices and AI systems

01:07come to life, or as better and better brain computer

01:10interfaces are engineered, will our brain be able to adapt,

01:13to catch up, to excel?

01:16I personally believe yes, that we're far from reaching

01:19the limitation of the human mind and the human brain,

01:23just as we are far from reaching the limitations

01:26of our computational systems.

01:28If you enjoy this thing, subscribe on YouTube,

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01:33follow on Spotify, support on Patreon,

01:36or connect with me on Twitter at Lex Friedman.

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05:00And now here's my conversation with David Eagleman.

05:05You have a new book coming out on the changing brain.

05:10Can you give a high level overview of the book?

05:13It's called Livewired by the way.

05:14Yeah, the thing is we typically think about the brain

05:17in terms of the metaphors we already have,

05:19like hardware and software, that's how we build

05:21all our stuff, but what's happening in the brain

05:24is fundamentally so different.

05:26So I coined this new term liveware,

05:29which is a system that's constantly reconfiguring itself

05:32physically as it learns and adapts to the world around it.

05:37It's physically changing.

05:38So it's liveware meaning like hardware but changing.

05:43Yeah, exactly.

05:44Well, the hardware and the software layers are blended

05:47and so typically engineers are praised for their efficiency

05:53and making something really clean and clear,

05:55like, okay, here's the hardware layer,

05:56then I'm gonna run software on top of it.

05:57And there's all sorts of universality that you get out

06:00of a piece of hardware like that that's useful.

06:02But what the brain is doing is completely different.

06:05And I am so excited about where this is all going

06:08because I feel like this is where our engineering will go.

06:13So currently we build all our devices a particular way,

06:17but I can't tear half the circuitry out of your cell phone

06:20and expect it to still function.

06:22But you can do that with the brain.

06:26So just as an example, kids who are under

06:29about seven years old can get one half of their brain

06:32removed, it's called a hemispherectomy, and they're fine.

06:35They have a slight limp on the other side of their body,

06:37but they can function just fine that way.

06:40And this is generally true.

06:42You know, sometimes children are born without a hemisphere

06:45and their visual system rewires so that everything is

06:48on the single remaining hemisphere.

06:52What thousands of cases like this teach us

06:55is that it's a very malleable system that is simply trying

06:59to accomplish the tasks in front of it by rewiring itself

07:04with the available real estate.

07:06How much of that is a quirk or a feature of evolution?

07:09Like, how hard is it to engineer?

07:11Because evolution took a lot of work.

07:14Trillions of organisms had to die for it to create

07:18this thing we have in our skull.

07:21Like, because you said you kind of look forward to the idea

07:24that we might be engineering our systems like this

07:27in the future, like creating liveware systems.

07:30How hard do you think is it to create systems like that?

07:33Great question.

07:34It has proven itself to be a difficult challenge.

07:37What I mean by that is even though it's taken evolution

07:40a really long time to get where it is now,

07:44all we have to do now is peek at the blueprints.

07:47It's just three pounds, this organ,

07:49and we just figure out how to do it.

07:50But that's the part that I mean is a difficult challenge

07:52because there are tens of thousands of neuroscientists,

07:57we're all poking and prodding and trying to figure this out,

07:59but it's an extremely complicated system.

08:00But it's only gonna be complicated until we figure out

08:03the general principles.

08:05Exactly like if you had a magic camera

08:09you could look inside the nucleus of a cell

08:10and you'd see hundreds of thousands of things

08:13moving around or whatever,

08:14and then it takes Crick and Watson to say,

08:16oh, you know what, you're just trying to maintain

08:17the order of the base pairs and all the rest is details.

08:20Then it simplifies it and we come to understand something.

08:23That was my goal in LiveWire,

08:25which I've written over 10 years, by the way,

08:26is to try to distill things down to the principles

08:29of what plastic systems are trying to accomplish.

08:34But to even just linger, you said,

08:36it's possible to be born with just one hemisphere

08:38and you still are able to function.

08:41First of all, just to pause on that,

08:43I mean, that's kind of, that's amazing.

08:47I don't know if people quite,

08:50I mean, you kind of hear things here and there.

08:51This is why I'm kind of, I'm really excited about your book

08:54is I don't know if there's definitive sort of popular sources

09:00to think about this stuff.

09:01I mean, there's a lot of, I think from my perspective,

09:05what I heard is there's like been debates over decades

09:07about how much neuroplasticity there is in the brain

09:12and so on, and people have learned a lot of things

09:14and now it's converging towards people

09:16that are understanding there's much more plastic

09:20than people realize.

09:21But just like linger on that topic,

09:23like how malleable is the hardware of the human brain?

§02Transcript · 09:28–17:49

09:28Maybe you said children at each stage of life.

09:32Yeah, so here's the whole thing.

09:33I think part of the confusion about plasticity

09:36has been that there are studies

09:38at all sorts of different ages,

09:40and then people might read that from a distance

09:42and they think, oh, well, Fred didn't recover

09:45when half his brain was taken out

09:47and so clearly you're not plastic,

09:49but then you do it with a child and they are plastic.

09:52And so part of my goal here was to pull together

09:56the tens of thousands of papers on this,

09:59both from clinical work and from all the way down

10:02to the molecular and understand

10:04what are the principles here?

10:04The principles are that plasticity diminishes,

10:08that's no surprise.

10:09By the way, maybe I should just define plasticity.

10:11It's the ability of a system to mold into a new shape

10:14and then hold that shape.

10:16That's why we make things that we call plastic

10:20because they are moldable and they can hold that new shape,

10:23like a plastic toy or something.

10:25And so maybe we'll use a lot of terms that are synonymous.

10:29So something is plastic, something is malleable,

10:34changing, live wire, the name of the book is like synonyms.

10:38So I'll tell you, exactly right,

10:39but I'll tell you why I chose live wire

10:41instead of plasticity.

10:42So I use the term plasticity in the book, but sparingly,

10:47because that was a term coined by William James

10:51over a hundred years ago and he was, of course,

10:53very impressed with plastic manufacturing

10:55that you could mold something into shape

10:57and then it holds that.

10:58But that's not what's actually happening in the brain.

11:01It's constantly rewiring your entire life.

11:03You never hit an end point.

11:06The whole point is for it to keep changing.

11:08So even in the few minutes of conversation

11:11that we've been having, your brain is changing,

11:12my brain is changing.

11:15Next time I see your face, I will remember,

11:18oh yeah, like that time Lex and I sat together

11:19and we did these things.

11:21I wonder if your brain will have like a Lex thing

11:24going on for the next few months.

11:25Like it'll stay there until you get rid of it

11:27because it was useful for now.

11:29Yeah, no, I'll probably never get rid of it.

11:30Let's say for some circumstance,

11:32you and I don't see each other for the next 35 years.

11:34When I run into you, I'll be like, oh yeah.

11:36That looks familiar.

11:37Yeah, yeah, we sat down for a podcast

11:40back when there were podcasts.

11:42Exactly.

11:43Back when we lived outside virtual reality.

11:46Exactly.

11:47So you chose live wire to mold a plastic.

11:50Exactly, because plastic implies,

11:52I mean, it's the term that's used in the field

11:54and so that's why we need to use it still for a while.

11:57But yeah, it implies something gets molded into shape

11:59and then holds that shape forever.

12:00But in fact, the whole system is completely changing.

12:03Then back to how malleable is the human brain

12:07at each stage of life.

12:08So what, just at a high level, is it malleable?

12:13So yes, and plasticity diminishes.

12:17But one of the things that I felt like

12:19I was able to put together for myself

12:21after reading thousands of papers on this issue

12:23is that different parts of the brain

12:26have different plasticity windows.

12:30So for example, with the visual cortex,

12:33that cements itself into place pretty quickly

12:35over the course of a few years.

12:37And I argue that's because of the stability of the data.

12:41In other words, what you're getting in from the world,

12:43you've got a certain number of angles, colors, shapes.

12:47It's essentially the world is visually stable.

12:49So that hardens around that data.

12:52As opposed to, let's say, the somatosensory cortex,

12:55which is the part that's taking information

12:56from your body, or the motor cortex right next to it,

12:58which is what drives your body.

13:00The fact is, bodies are always changing.

13:01You get taller over time, you get fatter, thinner,

13:05over time, you might break a leg

13:06and have to limp for a while, stuff like that.

13:08So because the data there is always changing,

13:11by the way, you might get on a bicycle,

13:12you might get on a surfboard, things like that.

13:15Because the data is always changing,

13:16that stays more malleable.

13:19And when you look through the brain,

13:20you find that it appears to be this,

13:23how stable the data is determines how fast

13:26something hardens into place.

13:28But the point is, different parts of the brain

13:30harden into place at different times.

13:31Do you think it's possible that,

13:35depending on how much data you get on different sensors,

13:38that it stays more malleable longer?

13:41So like, if you look at different cultures

13:44that experience, like if you keep your eyes closed,

13:47or maybe you're blind, I don't know,

13:48but let's say you keep your eyes closed

13:51for your entire life, then the visual cortex

13:55might be much less malleable.

13:58The reason I bring that up is like,

14:01well maybe we'll talk about brain computer interfaces

14:03a little bit down the line, but is this,

14:08is the malleability a genetic thing,

14:11or is it more about the data, like you said, that comes in?

14:14Ah, so the malleability itself is a genetic thing.

14:17The big trick that Mother Nature discovered with humans

14:20is make a system that's really flexible,

14:24as opposed to most other creatures to different degrees.

14:28So if you take an alligator, it's born,

14:31its brain does the same thing every generation.

14:34If you compare an alligator 100,000 years ago

14:36to an alligator now, they're essentially the same.

14:39We, on the other hand, as humans,

14:41drop into a world with a half baked brain,

14:44and what we require is to absorb the culture around us,

14:48and the language, and the beliefs, and the customs,

14:50and so on, that's what Mother Nature has done with us,

14:55and it's been a tremendously successful trick

14:57we've taken over the whole planet as a result of this.

15:00So that's an interesting point,

15:01I mean, just to link on it, that,

15:03I mean, this is a nice feature,

15:05like if you were to design a thing

15:07to survive in this world, do you put it at age zero

15:11already equipped to deal with the world

15:14in a hard coded way, or do you put it,

15:17do you make it malleable and just throw it in,

15:19take the risk that you're maybe going to die,

15:23but you're going to learn a lot in the process,

15:25and if you don't die, you'll learn a hell of a lot

15:27to be able to survive in the environment.

15:29So this is the experiment that Mother Nature ran,

15:31and it turns out that, for better or worse, we've won.

15:34I mean, yeah, we put other animals in the zoos,

15:37and we, yeah, that's right.

15:38AI might do better.

15:39Okay, fair enough, that's true.

15:41And maybe what the trick Mother Nature did

15:43is just the stepping stone to AI, but.

15:46So that's a beautiful feature of the human brain,

15:50that it's malleable, but let's,

15:52on the topic of Mother Nature, what do we start with?

15:56Like, how blank is the slate?

15:58Ah, so it's not actually a blank slate.

16:01What it's, it's terrific engineering that's set up in there,

16:05but much of that engineering has to do with,

16:07okay, just make sure that things get to the right place.

16:10For example, like the fibers from the eyes

16:12getting to the visual cortex,

16:13or all this very complicated machinery in the ear

16:15getting to the auditory cortex, and so on.

16:17So things, first of all, there's that.

16:19And then what we also come equipped with

16:21is the ability to absorb language

16:24and culture and beliefs, and so on.

16:27So you're already set up for that.

16:28So no matter what you're exposed to,

16:30you will absorb some sort of language.

16:32That's the trick, is how do you engineer something

16:34just enough that it's then a sponge

16:37that's ready to take in and fill in the blanks?

16:40How much of the malleability is hardware?

16:42How much is software?

16:43Is that useful at all in the brain?

16:45So what are we talking about?

16:46So there's neurons, there's synapses,

16:52and all kinds of different synapses,

16:54and there's chemical communication,

16:55like electrical signals,

16:57and there's chemical communication from the synapses.

17:04I would say the software would be the timing

17:09and the nature of the electrical signals, I guess,

17:11and the hardware would be the actual synapses.

17:14So here's the thing, this is why I really, if we can,

17:16I wanna get away from the hardware and software metaphor

17:19because what happens is,

17:21as activity passes through the system, it changes things.

17:25Now, the thing that computer engineers

17:27are really used to thinking about is synapses,

17:30where two neurons connect.

17:31Of course, each neuron connects with 10,000 of its neighbors,

17:33but at a point where they connect,

17:36what we're all used to thinking about

17:37is the changing of the strength of that connection,

17:40the synaptic weight.

17:42But in fact, everything is changing.

17:44The receptor distribution inside that neuron

17:47so that you're more or less sensitive

§03Transcript · 17:49–25:53

17:49to the neurotransmitter,

17:50then the structure of the neuron itself

17:53and what's happening there,

17:54all the way down to biochemical cascades inside the cell,

17:57all the way down to the nucleus,

17:59and for example, the epigenome,

18:00which is these little proteins that are attached to the DNA

18:05that cause conformational changes,

18:07that cause more genes to be expressed or repressed.

18:11All of these things are plastic.

18:13The reason that most people only talk

18:15about the synaptic weights

18:17is because that's really all we can measure well.

18:20And all this other stuff is really, really hard to see

18:22with our current technology.

18:23So essentially, that just gets ignored.

18:25But in fact, the system is plastic

18:27at all these different levels.

18:28And my way of thinking about this

18:33is an analogy to pace layers.

18:37So pace layers is a concept that Stewart Brand

18:40suggested about how to think about cities.

18:43So you have fashion, which changes rapidly in cities.

18:46You have governance, which changes more slowly.

18:52You have the structure, the buildings of a city,

18:54which changes more slowly, all the way down to nature.

18:57You've got all these different layers of things

18:59that are changing at different paces, at different speeds.

19:02I've taken that idea and mapped it onto the brain,

19:05which is to say you have some biochemical cascades

19:08that are just changing really rapidly

19:10when something happens, all the way down to things

19:11that are more and more cemented in there.

19:14And this actually allows us to understand a lot

19:19about particular kinds of things that happen.

19:20For example, one of the oldest,

19:22probably the oldest rule in neurology

19:24is called Ribot's Law, which is that older memories

19:27are more stable than newer memories.

19:29So when you get old and demented,

19:32you'll be able to remember things from your young life.

19:36Maybe you'll remember this podcast,

19:37but you won't remember what you did

19:39a month ago or a year ago.

19:41And this is a very weird structure, right?

19:43No other system works this way,

19:44where older memories are more stable than newer memories.

19:48But it's because through time,

19:52things get more and more cemented

19:53into deeper layers of the system.

19:56And so this is, I think, the way we have to think

19:59about the brain, not as, okay, you've got neurons,

20:03you've got synaptic weights, and that's it.

20:04So, yeah, so the idea of LiveWare and LiveWired

20:08is that it's like a, it's a gradual, yeah,

20:14it's a gradual spectrum between software and hardware.

20:18And so the metaphors completely doesn't make sense.

20:22Cause like when you talk about software and hardware,

20:24it's really hard lines.

20:26I mean, of course, software is unlike hard,

20:31but even hardware, but like, so there's two groups,

20:36but in the software world,

20:37there's levels of abstractions, right?

20:39There's the operating system, there's machine code,

20:42and then it gets higher and higher levels.

20:44But somehow that's actually fundamentally different

20:46than the layers of abstractions in the hardware.

20:50But in the brain, it's all like the same.

20:53And I love the city, the city metaphor.

20:55I mean, yeah, it's kind of mind blowing

20:57cause it's hard to know what to think about that.

21:01Like if I were to ask the question,

21:04this is an important question for machine learning is,

21:07how does the brain learn?

21:09So essentially you're saying that,

21:13I mean, it just learns on all of these different levels

21:17at all different paces.

21:19Exactly right.

21:19And as a result, what happens is

21:21as you practice something, you get good at something,

21:24you're physically changing the circuitry,

21:26you're adapting your brain around the thing

21:30that is relevant to you.

21:31So let's say you take up, do you know how to surf?

21:34Nope.

21:35Okay, great.

21:36So let's say you take up surfing now at this age.

21:39What happens is you'll be terrible at first,

21:41you don't know how to operate your body,

21:42you don't know how to read the waves, things like that.

21:43And through time you get better and better.

21:45What you're doing is you're burning that

21:46into the actual circuitry of your brain.

21:48You're of course conscious when you're first doing it,

21:50you're thinking about, okay, where am I doing?

21:52What's my body weight?

21:53But eventually when you become a pro at it,

21:55you are not conscious of it at all.

21:57In fact, you can't even unpack what it is that you did.

22:00Think about riding a bicycle.

22:01You can't describe how you're doing it,

22:04you're just doing it, you're changing your balance

22:05when you come, you know, you do this to go to a stop.

22:08So this is what we're constantly doing

22:10is actually shaping our own circuitry

22:14based on what is relevant for us.

22:16Survival, of course, being the top thing that's relevant.

22:18But interestingly, especially with humans,

22:21we have these particular goals in our lives,

22:23computer science, neuroscience, whatever.

22:25And so we actually shape our circuitry around that.

22:28I mean, you mentioned this gets slower and slower with age,

22:31but is there, like I think I've read and spoken offline,

22:36even on this podcast with a developmental neurobiologist,

22:41I guess would be the right terminology,

22:43is like looking at the very early,

22:45like from embryonic stem cells to the creation of the brain.

22:50And like, that's mind blowing how much stuff happens there.

22:55So it's very malleable at that stage.

22:59And then, but after that,

23:01at which point does it stop being malleable?

23:04So that's the interesting thing

23:06is that it remains malleable your whole life.

23:08So even when you're an old person,

23:10you'll be able to remember new faces and names,

23:13you'll be able to learn new sorts of tasks.

23:15And thank goodness,

23:16cause the world is changing rapidly

23:17in terms of technology and so on.

23:19I just sent my mother an Alexa

23:21and she figured out how to go on the settings

23:23and do the thing.

23:24And I was really impressed that she was able to do it.

23:26So there are parts of the brain

23:28that remain malleable their whole life.

23:30The interesting part is that really your goal

23:34is to make an internal model of the world.

23:36Your goal is to say, okay,

23:39the brain is trapped in silence and darkness,

23:42and it's trying to understand

23:43how the world works out there, right?

23:46I love that image.

23:47Yeah, I guess it is.

23:48Yeah.

23:49You forget, it's like this lonely thing

23:53is sitting in its own container

23:54and trying to actually throw a few sensors,

23:57figure out what the hell's going on.

23:58You know what I sometimes think about

23:59is that movie, The Martian with Matt Damon,

24:03the, I mean, it was written in a book, of course,

24:05but the movie poster shows Matt Damon

24:08all alone on the red planet.

24:09And I think, God, that's actually what it's like

24:12to be inside your head and my head and anybody's head

24:16is that you're essentially on your own planet in there.

24:20And I'm essentially on my own planet.

24:21And everyone's got their own world

24:24where you've absorbed all of your experiences

24:26up to this moment in your life

24:28that have made you exactly who you are

24:29and same for me and everyone.

24:31And we've got this very thin bandwidth of communication.

24:36And I'll say something like,

24:38oh yeah, that tastes just like peaches.

24:40And you'll say, oh, I know what you mean.

24:42But the experience, of course,

24:44might be vastly different for us.

24:47But anyway, yes.

24:48So the brain is trapped in silence and darkness,

24:50each one of us, and what it's trying to do,

24:53this is the important part,

24:54it's trying to make an internal model

24:55of what's going on out there,

24:56as in how do I function in the world?

24:58How do I interact with other people?

25:00Do I say something nice and polite?

25:02Do I say something aggressive and mean?

25:04Do I, you know, all these things

25:05that it's putting together about the world.

25:08And I think what happens when people get older and older,

25:12it may not be that plasticity is diminishing.

25:15It may be that their internal model essentially

25:18has set itself up in a way where it says,

25:20okay, I've pretty much got

25:21a really good understanding of the world now,

25:22and I don't really need to change, right?

25:25So when much older people find themselves

25:28in a situation where they need to change,

25:30they can actually are able to do it.

25:33It's just that I think this notion

25:34that we all have that plasticity diminishes

25:36as we grow older is in part

25:38because the motivation isn't there.

25:41But if you were 80 and you get fired from your job

25:44and suddenly had to figure out

25:45how to program a WordPress site or something,

25:47you'd figure it out.

25:48Got it.

25:49So the capability, the possibility of change is there.

§04Transcript · 25:53–34:31

25:53But then that's the highest challenge,

25:57the interesting challenge to this plasticity,

26:00to this liveware system.

26:03If we could talk about brain computer interfaces

26:06and Neuralink, what are your thoughts

26:09about the efforts of Elon Musk, Neuralink, BCI in general

26:13in this regard, which is adding a machine,

26:18a computer, the capability of a computer

26:21to communicate with the brain

26:22and the brain to communicate with a computer

26:24at the very basic applications

26:26and then like the futuristic kind of thoughts.

26:28Yeah, first of all, it's terrific

26:30that people are jumping in and doing that

26:32because it's clearly the future.

26:34The interesting part is our brains have pretty good methods

26:37of interacting with technology.

26:38So maybe it's your fat thumbs on a cell phone or something,

26:41but, or maybe it's watching a YouTube video

26:44and getting into your eye that way.

26:45But we have pretty rapid ways of communicating

26:48with technology and getting data.

26:49So if you actually crack open the skull

26:52and go into the inner sanctum of the brain,

26:56you might be able to get a little bit faster,

26:58but I'll tell you, I'm not so sanguine

27:03on the future of that as a business.

27:06And I'll tell you why.

27:07It's because there are various ways

27:10of getting data in and out

27:11and an open head surgery is a big deal.

27:14Neurosurgeons don't wanna do it

27:16because there's always risk of death

27:18and infection on the table.

27:19And also it's not clear how many people would say,

27:23I'm gonna volunteer to get something in my head

27:26so that I can text faster, 20% faster.

27:29So I think it's, mother nature surrounds the brain

27:33with this armored bunker of the skull

27:37because it's a very delicate material.

27:39And there's an expression in neurosurgery

27:44about the brain is,

27:46the person is never the same after you open up their skull.

27:49Now, whether or not that's true or whatever, who cares?

27:51But it's a big deal to do an open head surgery.

27:54So what I'm interested in is how can we get information

27:57in and out of the brain

27:58without having to crack the skull open?

28:00Without messing with the biological part,

28:03directly connecting or messing

28:06with the intricate biological thing that we got going on

28:10and it seems to be working.

28:11Yeah, exactly.

28:12And by the way, where Neuralink is going,

28:15which is wonderful, is going to be in patient cases.

28:18It really matters for all kinds of surgeries

28:20that a person needs,

28:21whether for Parkinson's or epilepsy or whatever.

28:24It's a terrific new technology

28:25for essentially sewing electrodes in there

28:27and getting more higher density of electrodes.

28:30So that's great.

28:30I just don't think as far as the future of BCI goes,

28:34I don't suspect that people will go in and say,

28:38yeah, drill a hole in my head and do this.

28:40Well, it's interesting

28:41because I think there's a similar intuition

28:44but say in the world of autonomous vehicles

28:46that folks know how hard it is

28:49and it seems damn impossible.

28:51The similar intuition about,

28:52I'm sticking on the Elon Musk thing

28:54is just a good, easy example.

28:57Similar intuition about colonizing Mars,

28:59it like, if you really think about it,

29:01it seems extremely difficult.

29:04And almost, I mean, just technically difficult

29:08to a degree where you wanna ask,

29:12is it really worth doing, worth trying?

29:14And then the same is applied with BCI.

29:17But the thing about the future

29:21is it's hard to predict.

29:23So the exciting thing to me with,

29:26so once it does, once if successful,

29:29it's able to help patients,

29:31it may be able to discover something very surprising

29:36of our ability to directly communicate with the brain.

29:39So exactly what you're interested in is figuring out

29:42how to play with this malleable brain,

29:46but like help assist it somehow.

29:49I mean, it's such a compelling notion to me

29:52that we're now working on

29:53all these exciting machine learning systems

29:55that are able to learn from data.

29:59And then if we can have this other brain

30:04that's a learning system,

30:05that's live wired on the human side

30:09and them to be able to communicate,

30:11it's like a self play mechanism

30:14was able to beat the world champion at Go.

30:17So they can play with each other,

30:19the computer and the brain, like when you sleep.

30:22I mean, there's a lot of futuristic kind of things

30:24that it's just exciting possibilities,

30:27but I hear you, we understand so little

30:30about the actual intricacies of the communication

30:34of the brain that it's hard to find the common language.

30:38Well, interestingly, the technologies that have been built

30:45don't actually require the perfect common language.

30:48So for example, hundreds of thousands of people

30:51are walking around with artificial ears

30:52and artificial eyes,

30:53meaning cochlear implants or retinal implants.

30:56So this is, you take a essentially digital microphone,

31:00you slip an electrode strip into the inner ear

31:03and people can learn how to hear that way,

31:05or you take an electrode grid

31:06and you plug it into the retina at the back of the eye

31:09and people can learn how to see that way.

31:11The interesting part is those devices

31:13don't speak exactly the natural biological language,

31:17they speak the dialect of Silicon Valley.

31:19And it turns out that as recently as about 25 years ago,

31:24a lot of people thought this was never gonna work.

31:26They thought it wasn't gonna work for that reason,

31:28but the brain figures it out.

31:30It's really good at saying, okay, look,

31:32there's some correlation between what I can touch

31:34and feel and hear and so on,

31:35and the data that's coming in,

31:37or between I clap my hands and I have signals coming in there

31:41and it figures out how to speak any language.

31:44Oh, that's fascinating.

31:45So like no matter if it's Neuralink,

31:50so directly communicating with the brain,

31:51or it's a smartphone or Google Glass,

31:54or the brain figures out the efficient way of communication.

31:58Well, exactly, exactly.

32:00And what I propose is the potato head theory of evolution,

32:03which is that all our eyes and nose and mouth and ears

32:08and fingertips, all this stuff is just plug and play.

32:10And the brain can figure out

32:12what to do with the data that comes in.

32:14And part of the reason that I think this is right,

32:17and I care so deeply about this,

32:18is when you look across the animal kingdom,

32:20you find all kinds of weird peripheral devices plugged in,

32:23and the brain figures out what to do with the data.

32:25And I don't believe that Mother Nature

32:27has to reinvent the principles of brain operation each time

32:32to say, oh, now I'm gonna have heat pits

32:33to detect infrared.

32:34Now I'm gonna have something

32:36to detect electroreceptors on the body.

32:39Now I'm gonna detect something

32:40to pick up the magnetic field of the earth

32:42with cryptochromes in the eye.

32:43And so instead the brain says, oh, I got it.

32:45There's data coming in.

32:47Is that useful?

32:48Can I do something with it?

32:48Oh, great, I'm gonna mold myself

32:50around the data that's coming in.

32:52It's kind of fascinating to think that,

32:55we think of smartphones

32:56and all this new technology as novel.

32:58It's totally novel as outside of what evolution

33:02ever intended or like what nature ever intended.

33:05It's fascinating to think that like the entirety

33:08of the process of evolution is perfectly fine

33:10and ready for the smartphone and the internet.

33:14Like it's ready.

33:15It's ready to be valuable to that.

33:17And whatever comes to cyborgs, to virtual reality,

33:21we kind of think like, this is, you know,

33:23there's all these like books written about what's natural

33:27and we're like destroying our natural cells

33:29by like embracing all this technology.

33:32It's kind of, you know,

33:34probably not giving the brain enough credit.

33:36Like this thing is just fine with new tech.

33:40Oh, exactly, it wraps itself around.

33:41And by the way, wait till you have kids.

33:43You'll see the ease with which they pick up on stuff.

33:46And as Kevin Kelly said,

33:50technology is what gets invented after you're born.

33:54But the stuff that already exists when you're born,

33:56that's not even tech, that's just background furniture.

33:58Like the fact that the iPad exists for my son and daughter,

34:00like that's just background furniture.

34:02So, yeah, it's because we have

34:06this incredibly malleable system,

34:08that just absorbs whatever is going on in the world

34:10and learns what to do with it.

34:11So do you think, just to linger for a little bit more,

34:15do you think it's possible to co adjust?

34:22Like we're kind of, you know,

34:25for the machine to adjust to the brain,

34:27for the brain to adjust to the machine.

34:29I guess that's what's already happening.

§05Transcript · 34:31–43:40

34:31Sure, that is what's happening.

34:32So for example, when you put electrodes

34:34in the motor cortex to control a robotic arm

34:37for somebody who's paralyzed,

34:39the engineers do a lot of work to figure out,

34:41okay, what can we do with the algorithm here

34:42so that we can detect what's going on from these cells

34:45and figure out how to best program the robotic arm to move

34:49given the data that we're measuring from these cells.

34:51But also the brain is learning too.

34:54So, you know, the paralyzed woman says,

34:57wait, I'm trying to grab this thing.

34:58And by the way, it's all about relevance.

35:00So if there's a piece of food there and she's hungry,

35:04she'll figure out how to get this food into her mouth

35:08with the robotic arm because that is what matters.

35:13Well, that's, okay, first of all,

35:15that paints a really promising and beautiful,

35:17for some reason, really optimistic picture

35:20that, you know, our brain is able to adjust to so much.

35:26You know, so many things happened this year, 2020,

35:29that you think like, how are we ever going to deal with it?

35:32And it's somehow encouraging

35:35and inspiring that like we're going to be okay.

35:41Well, that's right.

35:41I actually think, so 2020 has been an awful year

35:45for almost everybody in many ways,

35:46but the one silver lining has to do with brain plasticity,

35:50which is to say we've all been on our, you know,

35:54on our gerbil wheels, we've all been in our routines.

35:56And, you know, as I mentioned,

35:58our internal models are all about

36:00how do you maximally succeed?

36:02How do you optimize your operation

36:04in this circumstance where you are, right?

36:07And then all of a sudden, bang, 2020 comes,

36:09we're completely off our wheels.

36:10We're having to create new things all the time

36:14and figure out how to do it.

36:15And that is terrific for brain plasticity because,

36:18and we know this because there are very large studies

36:23on older people who stay cognitively active

36:26their whole lives.

36:28Some fraction of them have Alzheimer's disease

36:31physically, but nobody knows that when they're alive.

36:34Even though their brain is getting chewed up

36:36with the ravages of Alzheimer's,

36:38cognitively they're doing just fine.

36:40Why?

36:40It's because they're challenged all the time.

36:44They've got all these new things going on,

36:45all this novelty, all these responsibilities,

36:47chores, social life, all these things happening.

36:49And as a result, they're constantly building new roadways,

36:52even as parts degrade.

36:54And that's the only good news is that

36:57we are in a situation where suddenly

36:59we can't just operate like automata anymore.

37:02We have to think of completely new ways to do things.

37:05And that's wonderful.

37:07I don't know why this question popped into my head.

37:11It's quite absurd, but are we gonna be okay?

37:16Yeah.

37:17You said this is the promising silver lining

37:19just from your own,

37:20cause you've written about this and thought about this

37:22outside of maybe even the plasticity of the brain,

37:25but just this whole pandemic kind of changed the way

37:29it knocked us out of this hamster wheel like that of habit.

37:35A lot of people had to reinvent themselves.

37:39Unfortunately, and I have a lot of friends

37:42who either already or are going to lose their business,

37:48is basically it's taking the dreams that people have had

37:52and said this dream, this particular dream you've had

37:58will no longer be possible.

38:00So you have to find something new.

38:02What are your, are we gonna be okay?

38:06Yeah, we'll be okay in the sense that,

38:08I mean, it's gonna be a rough time

38:09for many or most people,

38:11but in the sense that it is sometimes useful

38:18to find that what you thought was your dream

38:20was not the thing that you're going to do.

38:24This is obviously the plot in lots of Hollywood movies

38:26that someone says, I'm gonna do this,

38:27and then that gets foiled

38:29and they end up doing something better.

38:31But this is true in life.

38:32I mean, in general, even though we plan our lives

38:38as best we can, it's predicated on our notion of,

38:42okay, given everything that's around me,

38:43this is what's possible for me next.

38:47But it takes 2020 to knock you off that

38:49where you think, oh, well, actually,

38:50maybe there's something I can be doing

38:52that's bigger, that's better.

38:54Yeah, you know, for me, one exciting thing,

38:56and I just talked to Grant Sanderson.

38:59I don't know if you know who he is.

39:00He's a 3Blue1Brown, it's a YouTube channel.

39:03He does, he's a, if you see it, you would recognize it.

39:08He's like a really famous math guy,

39:11and he's a math educator,

39:12and he does these incredible, beautiful videos.

39:15And now I see sort of at MIT,

39:17folks are struggling to try to figure out,

39:19you know, if we do teach remotely,

39:21how do we do it effectively?

39:23So you have these world class researchers

39:27and professors trying to figure out

39:30how to put content online that teaches people.

39:33And to me, a possible future of that is,

39:37you know, Nobel Prize winning faculty become YouTubers.

39:42Like that to me is so exciting, like what Grant said,

39:47which is like the possibility of creating canonical videos

39:52on the thing you're a world expert in.

39:55You know, there's so many topics.

39:56It just, the world doesn't, you know, there's faculty.

40:00I mentioned Russ Tedrick.

40:02There's all these people in robotics

40:04that are experts in a particular beautiful field

40:07on which there's only just papers.

40:09There's no popular book.

40:12There's no clean canonical video

40:16showing the beauty of a subject.

40:18And one possibility is they try to create that

40:22and share it with the world.

40:25This is the beautiful thing.

40:26This of course has been happening for a while already.

40:28I mean, for example, when I go and I give book talks,

40:31often what'll happen is some 13 year old

40:33will come up to me afterwards and say something,

40:35and I'll say, my God, that was so smart.

40:37Like, how did you know that?

40:38And they'll say, oh, I saw it on a Ted talk.

40:40Well, what an amazing opportunity.

40:42Here you got the best person in the world on subject X

40:46giving a 15 minute talk as beautifully as he or she can.

40:51And the 13 year old just grows up with that.

40:53That's just the mother's milk, right?

40:55As opposed to when we grew up,

40:57you know, I had whatever homeroom teacher I had

41:00and, you know, whatever classmates I had.

41:03And hopefully that person knew what he or she was teaching

41:06and often didn't and, you know, just made things up.

41:08So the opportunity that has become extraordinary

41:12to get the best of the world.

41:14And the reason this matters, of course,

41:15is because obviously, back to plasticity,

41:18the way that we, the way our brain gets molded

41:22is by absorbing everything from the world,

41:24all of the knowledge and the data and so on that it can get,

41:28and then springboarding off of that.

41:33And we're in a very lucky time now

41:34because we grew up with a lot of just in case learning.

41:40So, you know, just in case you ever need to know

41:42these dates in Mongolian history, here they are.

41:44But what kids are grown up with now, like my kids,

41:47is tons of just in time learning.

41:48So as soon as they're curious about something,

41:50they ask Alexa, they ask Google Home,

41:51they get the answer right there

41:53in the context of their curiosity.

41:54The reason this matters is because for plasticity to happen,

41:59you need to care, you need to be curious about something.

42:02And this is something, by the way,

42:03that the ancient Romans had noted.

42:06They had outlined seven different levels of learning

42:08and the highest level is when you're curious about a topic.

42:10But anyway, so kids now are getting tons

42:13of just in time learning, and as a result,

42:15they're gonna be so much smarter than we are.

42:18They're just, and we can already see that.

42:19I mean, my boy is eight years old, my girl is five.

42:22But I mean, the things that he knows are amazing

42:25because it's not just him having to do

42:27the rote memorization stuff that we did.

42:29Yeah, it's just fascinating what the brain,

42:32what young brains look like now

42:33because of all those TED Talks just loaded in there.

42:36And there's also, I mean, a lot of people, right,

42:39kind of, there's a sense that our attention span

42:42is growing shorter, but it's complicated

42:46because for example, most people, majority of people,

42:50it's the 80 plus percent of people listen

42:53to the entirety of these things,

42:54two, three hours for the podcast,

42:56long form podcasts are becoming more and more popular.

43:00So like that's, it's all really giant complicated mess.

43:04And the point is that the brain is able to adjust to it

43:07and somehow like form a worldview

43:11within this new medium of like information that we have.

43:17You have like these short tweets

43:19and you have these three, four hour podcasts

43:22and you have Netflix movie.

43:24I mean, it's just, it's adjusting to the entirety

43:27and just absorbing it and taking it all in

43:30and then pops up COVID that forces us all to be home

43:34and it all just adjusts and figures it out.

43:39Yeah, yeah, exactly.

§06Transcript · 43:40–52:20

43:40It's fascinating.

43:41Been talking about the brain

43:43as if it's something separate from the human

43:48that carries it a little bit.

43:50Like whenever you talk about the brain,

43:52it's easy to forget that that's like, that's us.

43:55Like how much do you,

43:59how much is the whole thing like predetermined?

44:04Like how much is it already encoded in there?

44:08And how much is it the, what's the hit?

44:17The actions, the decisions, the judgments, the...

44:22You mean like who you are?

44:23Who you are.

44:24Oh, yeah, yeah, okay, great question.

44:25Right, so there used to be a big debate

44:27about nature versus nurture.

44:28And we now know that it's always both.

44:31You can't even separate them

44:32because you come to the table with a certain amount of nature

44:35for example, your whole genome and so on.

44:37The experiences you have in the womb,

44:39like whether your mother is smoking or drinking,

44:41things like that, whether she's stressed, so on.

44:43Those all influence how you're gonna pop out of the womb.

44:47From there, everything is an interaction

44:50between all of your experiences and the nature.

44:55What I mean is, I think of it like a space time cone

44:59where you have, you drop into the world

45:01and depending on the experience that you have,

45:03you might go off in this direction

45:04or that direction or in that direction

45:05because there's interaction on the way.

45:08Your experiences determine what happens

45:11with the expression of your genes.

45:12So some genes get repressed, some get expressed and so on.

45:15And you actually become a different person

45:17based on your experiences.

45:18There's a whole field called epigenomics,

45:21which is, or epigenetics I should say,

45:24which is about the epigenome.

45:26And that is the layer that sits on top of the DNA

45:30and causes the genes to express differently.

45:32That is directly related to the experiences that you have.

45:35So if, just as an example, they take rat pups

45:38and one group is placed away from their parents

45:41and the other group is groomed and licked

45:43and taken good care of,

45:44that changes their gene expression

45:46for the rest of their life.

45:46They go off in different directions

45:48in this space time cone.

45:50So yeah, this is of course why it matters

45:55that we take care of children and pour money

45:58into things like education and good childcare

46:00and so on for children broadly,

46:04because these formative years matter so much.

46:08So is there a free will?

46:11This is a great question.

46:13I apologize for the absurd high level

46:16philosophical questions.

46:17No, no, these are my favorite kind of questions.

46:19Here's the thing, here's the thing.

46:20We don't know.

46:21If you ask most neuroscientists,

46:23they'll say that we can't really think

46:26of how you would get free will in there

46:28because as far as we can tell, it's a machine.

46:30It's a very complicated machine.

46:33Enormously sophisticated, 86 billion neurons,

46:36about the same number of glial cells.

46:38Each of these things is as complicated

46:40as the city of San Francisco.

46:41Each neuron in your head has the entire human genome in it.

46:43It's expressing millions of gene products.

46:47These are incredibly complicated biochemical cascades.

46:50Each one is connected to 10,000 of its neighbors,

46:51which means you have like half a quadrillion connections

46:54in the brain.

46:55So it's incredibly complicated thing,

46:58but it is fundamentally appears to just be a machine.

47:02And therefore, if there's nothing in it

47:04that's not being driven by something else,

47:07then it seems it's hard to understand

47:10where free will would come from.

47:12So that's the camp that pretty much all of us fall into,

47:14but I will say, our science is still quite young.

47:18And I'm a fan of the history of science,

47:20and the thing that always strikes me as interesting

47:22is when you look back at any moment in science,

47:26everybody believes something is true,

47:28and they simply didn't know about

47:31what Einstein revealed or whatever.

47:33And so who knows?

47:35And they all feel like that we've,

47:37at any moment in history,

47:38they all feel like we've converged to the final answer.

47:40Exactly, exactly.

47:41Like all the pieces of the puzzle are there.

47:43And I think that's a funny illusion

47:45that's worth getting rid of.

47:47And in fact, this is what drives good science

47:49is recognizing that we don't have most of the puzzle pieces.

47:52So as far as the free will question goes, I don't know.

47:55At the moment, it seems, wow,

47:57it'd be really impossible to figure out

47:58how something else could fit in there,

48:00but 100 years from now,

48:02our textbooks might be very different than they are now.

48:05I mean, could I ask you to speculate

48:07where do you think free will could be squeezed into there?

48:11Like, what's that even,

48:14is it possible that our brain just creates

48:16kinds of illusions that are useful for us?

48:19Or like what, where could it possibly be squeezed in?

48:24Well, let me give a speculation answer

48:27to your very nice question,

48:28but don't, and the listeners of this podcast,

48:32don't quote me on this.

48:33Yeah, exactly.

48:33I'm not saying this is what I believe to be true,

48:35but let me just give an example.

48:36I give this at the end of my book, Incognito.

48:38So the whole book of Incognito is about,

48:41all the what's happening in the brain.

48:42And essentially I'm saying, look,

48:44here's all the reasons to think

48:45that free will probably does not exist.

48:47But at the very end, I say, look,

48:50imagine that you are,

48:53imagine that you're a Kalahari Bushman

48:56and you find a radio in the sand

48:58and you've never seen anything like this.

49:01And you look at this radio and you realize

49:04that when you turn this knob, you hear voices coming from,

49:07there are voices coming from it.

49:08So being a radio materialist,

49:11you try to figure out like, how does this thing operate?

49:14So you take off the back cover

49:15and you realize there's all these wires.

49:16And when you take out some wires,

49:19the voices get garbled or stop or whatever.

49:22And so what you end up developing is a whole theory

49:24about how this connection, this pattern of wires

49:26gives rise to voices.

49:29But it would never strike you that in distant cities,

49:31there's a radio tower and there's invisible stuff beaming.

49:34And that's actually the origin of the voices.

49:36And this is just necessary for it.

49:38So I mentioned this just as a speculation,

49:42say, look, how would we know,

49:44what we know about the brain for absolutely certain

49:46is that when you damage pieces and parts of it,

49:48things get jumbled up.

49:50But how would you know if there's something else going on

49:52that we can't see like electromagnetic radiation

49:55that is what's actually generating this?

49:58Yeah, you paint a beautiful example

50:01of how totally,

50:06because we don't know most of how our universe works,

50:10how totally off base we might be with our science until,

50:14I mean, yeah, I mean, that's inspiring, that's beautiful.

50:19It's kind of terrifying, it's humbling.

50:21It's all of the above.

50:23And the important part just to recognize

50:26is that of course we're in the position

50:28of having massive unknowns.

50:31And we have of course the known unknowns

50:36and that's all the things we're pursuing in our labs

50:38and trying to figure out that,

50:39but there's this whole space of unknown unknowns.

50:41Things we haven't even realized we haven't asked yet.

50:44Let me kind of ask a weird, maybe a difficult question,

50:47part that has to do with,

50:50I've been recently reading a lot about World War II.

50:54I'm currently reading a book I recommend for people,

50:56which as a Jew has been difficult to read,

51:00but the rise and fall of the Third Reich.

51:04So let me just ask about like the nature of genius,

51:08the nature of evil.

51:10If we look at somebody like Einstein,

51:14we look at Hitler, Stalin, modern day Jeffrey Epstein,

51:19just folks who through their life have done with Einstein

51:24and works of genius and with the others I mentioned

51:27have done evil on this world.

51:30What do we think about that in a livewired brain?

51:34Like how do we think about these extreme people?

51:39Here's what I'd say.

51:41This is a very big and difficult question,

51:43but what I would say briefly on it is,

51:47first of all, I saw a cover of Time Magazine some years ago

51:51and it was a big sagittal slice of the brain

51:55and it said something like, what makes us good and evil?

51:59And there was a little spot pointing to it

52:00and there was a picture of Gandhi

52:01and there was a little spot that was pointing to Hitler.

52:03And these Time Magazine covers always make me mad

52:05because it's so goofy to think that we're gonna find

52:08some spot in the brain or something.

52:10Instead, the interesting part is because we're livewired,

52:16we are all about the world and the culture around us.

§07Transcript · 52:20–1:00:51

52:20So somebody like Adolf Hitler got all this positive feedback

52:25about what was going on and the crazier and crazier

52:28the ideas he had and he's like, let's set up death camps

52:31and murder a bunch of people and so on.

52:34Somehow he was getting positive feedback from that

52:37and all these other people, they're all spun each other up.

52:40And you look at anything like, I mean, look at the cultural

52:45revolution in China or the Russian revolution

52:51or things like this where you look at these things,

52:52my God, how do people all behave like this?

52:55But it's easy to see groups of people spinning themselves up

52:58in particular ways where they all say,

53:00well, would I have thought this was right

53:03in a different circumstance?

53:04I don't know, but Fred thinks it's right

53:05and Steve thinks it's right,

53:06everyone around me seems to think it's right.

53:08And so part of the maybe downside of having a livewired brain

53:13is that you can get crowds of people doing things as a group.

53:17So it's interesting to, we would pinpoint Hitler

53:20as saying that's the evil guy.

53:21But in a sense, I think it was Tolstoy who said

53:24the king becomes slave to the people.

53:30In other words, Hitler was just a representation

53:34of whatever was going on with that huge crowd

53:37that he was surrounded with.

53:39So I only bring that up to say that it's very difficult

53:45to say what it is about this person's brain

53:48or that person's brain.

53:49He obviously got feedback for what he was doing.

53:51The other thing, by the way,

53:52about what we often think of as being evil in society

53:57is my lab recently published some work

54:01on in groups and out groups,

54:04which is a very important part of this puzzle.

54:08So it turns out that we are very engineered

54:13to care about in groups versus out groups.

54:16And this seems to be like a really fundamental thing.

54:18So we did this experiment in my lab

54:20where we brought people and we stick them in the scanner.

54:23And we, I don't know if you noticed,

54:25but we show them on the screen six hands

54:30and the computer goes around randomly picks a hand.

54:33And then you see that hand gets stabbed

54:34with a syringe needle.

54:36So you actually see a syringe needle enter the hand

54:38and come out.

54:39And it's really, what that does is that triggers

54:42parts of the pain matrix,

54:44this areas in your brain that are involved

54:46in feeling physical pain.

54:47Now, the interesting thing is it's not your hand

54:48that was stabbed.

54:49So what you're seeing is empathy.

54:51This is you seeing someone else's hand gets stabbed.

54:54You feel like, oh God, this is awful, right?

54:56Okay.

54:57We contrast that by the way,

54:58with somebody's hand getting poked as a Q tip,

55:00which is, you know, looks visually the same,

55:02but you don't have that same level of response.

55:06Now what we do is we label each hand with a one word label,

55:10Christian, Jewish, Muslim, atheist, Scientologist, Hindu.

55:14And now the computer goes around, picks a hand,

55:16stabs the hand.

55:17And the question is, how much does your brain care

55:21about all the people in your out group

55:23versus the one label that happens to match you?

55:26And it turns out for everybody across all religions,

55:29they care much more about their in group

55:31than their out group.

55:31And when I say they care, what I mean is

55:33you get a bigger response from their brain.

55:35Everything's the same.

55:36It's the same hands.

55:38It's just a one word label.

55:40You care much more about your in group than your out group.

55:42And I wish this weren't true, but this is how humans are.

55:45I wonder how fundamental that is,

55:47or if it's the emergent thing about culture.

55:53Like if we lived alone with like,

55:55if it's genetically built into the brain,

55:57like this longing for tribe.

56:00So I'll tell you, we addressed that.

56:02So here's what we did.

56:03There are two, actually there are two other things

56:06we did as part of this study

56:07that I think matter for this point.

56:09One is, so okay, so we show that you have

56:11a much bigger response.

56:13And by the way, this is not a cognitive thing.

56:14This is a very low level basic response

56:17to seeing pain in somebody, okay.

56:19Great study by the way.

56:20Thanks, thanks, thanks.

56:21What we did next is we next have it where we say,

56:24okay, the year is 2025 and these three religions

56:28are now in a war against these three religions.

56:30And it's all randomized, right?

56:31But what you see is your thing and you have two allies now

56:34against these others.

56:37And now it happens over the course of many trials,

56:38you see everybody gets stabbed at different times.

56:41And the question is, do you care more about your allies?

56:43And the answer is yes.

56:44Suddenly people who a moment ago,

56:45you didn't really care when they got stabbed.

56:47Now, simply with this one word thing

56:49that they're now your allies, you care more about them.

56:52But then what I wanted to do was look at

56:55how ingrained is this or how arbitrary is it?

56:57So we brought new participants in and we said,

57:01here's a coin, toss the coin.

57:02If it's heads, you're an Augustinian.

57:04If it's a tails, you're a Justinian.

57:06These are totally made up.

57:08Okay, so they toss it, they get whatever.

57:10We give them a band that says Augustinian on it,

57:13whatever tribe they're in now, and they get in the scanner

57:16and they see a thing on the screen that says

57:18the Augustinians and Justinians are two warring tribes.

57:21Then you see a bunch of hands,

57:22some are labeled Augustinians, some are Justinian.

57:24And now you care more about whichever team you're on

57:27than the other team, even though it's totally arbitrary

57:29and you know it's arbitrary

57:30because you're the one who tossed the coin.

57:32So it's a state that's very easy to find ourselves in.

57:36In other words, just before walking in the door,

57:39they'd never even heard of Augustinian versus Justinian

57:41and now their brain is representing it

57:43simply because they're told they're on this team.

57:46You know, now I did my own personal study of this.

57:49So once you're an Augustinian, that tends to be sticky

57:55because I've been a Packers fan,

57:57grew to be a Packers fan my whole life.

57:59Now when I'm in Boston with like the Patriots,

58:03it's been tough going for my livewired brain

58:05to switch to the Patriots.

58:07So once you become, it's as interesting,

58:10once the tribe is sticky.

58:12Yeah, I'll admit that's true.

58:14That's it, you know.

58:15You know, we never tried that about saying,

58:16okay, now you're a Justinian and you were an Augustinian.

58:19We never saw how sticky it is.

58:21But there are studies of this,

58:24of monkey troops on some island.

58:30And what happens is they look at the way monkeys behave

58:33when they're part of this tribe

58:34and how they treat members of the other tribe of monkeys.

58:37And then what they do, I've forgotten how they do that,

58:39exactly, but they end up switching a monkey

58:42so he ends up in the other troop.

58:43And very quickly they end up becoming a part

58:45of that other troop and hating and behaving badly

58:48towards the original troop.

58:50These are fascinating studies, by the way.

58:52This is beautiful.

58:55In your book, you have a good light bulb joke.

59:01How many psychiatrists does it take to change a light bulb?

59:04Only one, but the light bulb has to want to change.

59:07Sorry.

59:09I'm a sucker for a good light bulb joke.

59:11Okay, so given, you know, I've been interested

59:15in psychiatry my whole life, just maybe tangentially.

59:19I've kind of early on dreamed to be a psychiatrist

59:22until I understood what it entails.

59:25But, you know, is there hope for psychiatry

59:31for somebody else to help this live, wired brain to adjust?

59:37Oh yeah, I mean, in the sense that,

59:40and this has to do with this issue

59:41about us being trapped on our own planet.

59:43Forget psychiatrists, just think of like

59:45when you're talking with a friend

59:47and you say, oh, I'm so upset about this.

59:48And your friend says, hey, just look at it this way.

59:53You know, all we have access to under normal circumstances

59:55is just the way we're seeing something.

59:57And so it's super helpful to have friends and communities

60:02and psychiatrists and so on to help things change that way.

60:05So that's how psychiatrists sort of helped us.

60:07But more importantly, the role that psychiatrists have played

60:10is that there's this sort of naive assumption

60:13that we all come to the table with,

60:15which is that everyone is fundamentally just like us.

60:18And when you're a kid, you believe this entirely,

60:21but as you get older and you start realizing,

60:22okay, there's something called schizophrenia

60:25and that's a real thing.

60:26And to be inside that person's head is totally different

60:29than what it is to be inside my head or their psychopathy.

60:32And to be inside the psychopath's head,

60:34he doesn't care about other people.

60:36He doesn't care about hurting other people.

60:37He's just doing what he needs to do to get what he needs.

60:40That's a different head.

60:42There's a million different things going on

60:45and it is different to be inside those heads.

60:48This is where the field of psychiatry comes in.

§08Transcript · 1:00:51–1:09:00

60:51Now, I think it's an interesting question

60:53about the degree to which neuroscience is leaking into

60:57and taking over psychiatry

60:58and what the landscape will look like 50 years from now.

61:00It may be that psychiatry as a profession changes a lot

61:05or maybe goes away entirely,

61:07and neuroscience will essentially be able

61:09to take over some of these functions,

61:10but it has been extremely useful to understand

61:14the differences between how people behave and why

61:18and what you can tell about what's going on

61:19inside their brain just based on observation

61:22of their behavior.

61:25This might be years ago, but I'm not sure.

61:28There's an Atlantic article you've written

61:32about moving away from a distinction

61:34between neurological disorders,

61:36quote unquote, brain problems,

61:39and psychiatric disorders or quote unquote, mind problems.

61:43So on that topic, how do you think about this gray area?

61:47Yeah, this is exactly the evolution that things are going

61:50is there was psychiatry and then there were guys and gals

61:54in labs poking cells and so on.

61:55Those were the neuroscientists.

61:57But yeah, I think these are moving together

61:58for exactly the reason you just cited.

62:00And where this matters a lot,

62:02the Atlantic article that I wrote

62:04was called The Brain on Trial,

62:06where this matters a lot is the legal system

62:09because the way we run our legal system now,

62:12and this is true everywhere in the world,

62:13is someone shows up in front of the judge's bench,

62:17or let's say there's five people

62:18in front of the judge's bench,

62:20and they've all committed the same crime.

62:21What we do, because we feel like, hey, this is fair,

62:23is we say, all right, you're gonna get the same sentence.

62:25You'll all get three years in prison or whatever it is.

62:27But in fact, brains can be so different.

62:29This guy's got schizophrenia, this guy's a psychopath,

62:31this guy's tweaked down on drugs, and so on and so on,

62:33that it actually doesn't make sense to keep doing that.

62:37And what we do in this country more than anywhere

62:41in the world is we imagine that incarceration

62:44is a one size fits all solution.

62:45And you may know we have the,

62:47America has the highest incarceration rate

62:49in the whole world in terms of the percentage

62:50of our population we put behind bars.

62:52So there's a much more refined thing we can do

62:56as neuroscience comes in and changes,

62:59and has the opportunity to change the legal system.

63:01Which is to say, this doesn't let anybody off the hook.

63:03It doesn't say, oh, it's not your fault, and so on.

63:06But what it does is it changes the equation

63:09so it's not about, hey, how blameworthy are you?

63:12But instead is about, hey, what do we do from here?

63:15What's the best thing to do from here?

63:16So if you take somebody with schizophrenia

63:17and you have them break rocks in the hot summer sun

63:21in a chain gang, that doesn't help their schizophrenia.

63:24That doesn't fix the problem.

63:25If you take somebody with a drug addiction

63:28who's in jail for being caught with two ounces

63:30of some illegal substance, and you put them in prison,

63:34it doesn't actually fix the addiction.

63:36It doesn't help anything.

63:38Happily, what neuroscience and psychiatry

63:40bring to the table is lots of really useful things

63:43you can do with schizophrenia, with drug addiction,

63:45things like this.

63:46And that's why, so I don't know if you guys

63:49better run a national law and profit

63:50called the Center for Science and Law.

63:52And it's all about this intersection

63:53of neuroscience and psychiatry.

63:55It's the intersection of neuroscience and legal system.

63:57And we're trying to implement changes

63:59in every county, in every state.

64:02I'll just, without going down that rabbit hole,

64:04I'll just say one of the very simplest things to do

64:07is to set up specialized court systems

64:09where you have a mental health court

64:12that has judges and juries with expertise

64:14in mental illness.

64:15Because if you go, by the way, to a regular court

64:17and the person says, or the defense lawyer says,

64:21this person has schizophrenia, most of the jury will say,

64:24man, I call bullshit on that.

64:25Why?

64:26Because they don't know about schizophrenia.

64:28They don't know what it's about.

64:30And it turns out people who know about schizophrenia

64:34feel very differently as a juror

64:35than someone who happens not to know anybody with

64:37schizophrenia, they think it's an excuse.

64:39So you have judges and juries with expertise

64:42in mental illness and they know the rehabilitative

64:44strategies that are available.

64:45That's one thing.

64:46Having a drug court where you have judges and juries

64:48with expertise in rehabilitative strategies

64:50and what can be done and so on.

64:51A specialized prostitution court and so on.

64:54All these different things.

64:55By the way, this is very easy for counties

64:57to implement this sort of thing.

64:59And this is, I think, where this matters

65:01to get neuroscience into public policy.

65:05What's the process of injecting expertise into this?

65:08Yeah, I'll tell you exactly what it is.

65:10A county needs to run out of money first.

65:12I've seen this happen over and over.

65:14So what happens is a county has a completely full jail

65:17and they say, you know what?

65:18We need to build another jail.

65:19And then they realize, God, we don't have any money.

65:21We can't afford this.

65:22We've got too many people in jail.

65:23And that's when they turn to,

65:25God, we need something smarter.

65:26And that's when they set up specialized court systems.

65:28Yeah.

65:30We're all function best when our back is against the wall.

65:34And that's what COVID is good for.

65:36It's because we've all had our routines

65:38and we are optimized for the things we do.

65:40And suddenly our backs are against the wall, all of us.

65:43Yeah, it's really, I mean,

65:44one of the exciting things about COVID.

65:47I mean, I'm a big believer in the possibility

65:51of what government can do for the people.

65:56And when it becomes too big of a bureaucracy,

65:59it starts functioning poorly, it starts wasting money.

66:02It's nice to, I mean, COVID reveals that nicely.

66:07And lessons to be learned about who gets elected

66:11and who goes into government.

66:14Hopefully this, hopefully this inspires talented

66:18and young people to go into government

66:20to revolutionize different aspects of it.

66:23Yeah, so that's the positive silver lining of COVID.

66:28I mean, I thought it'd be fun to ask you,

66:30I don't know if you're paying attention

66:31to the machine learning world and GPT3.

66:37So the GPT3 is this language model,

66:39this neural network that's able to,

66:41it has 175 billion parameters.

66:44So it's very large and it's trained

66:47in an unsupervised way on the internet.

66:51It just reads a lot of unstructured texts

66:55and it's able to generate some pretty impressive things.

66:59The human brain compared to that has about,

67:02you know, a thousand times more synapses.

67:05People get so upset when machine learning people

67:10compare the brain and we know synapses are different.

67:14It was very different, very different.

67:16But like, do you, what do you think about GPT3?

67:20Here's what I think, here's what I think, a few things.

67:22What GPT3 is doing is extremely impressive,

67:25but it's very different from what the brain does.

67:27So it's a good impersonator, but just as one example,

67:33everybody takes a passage that GPT3 has written

67:37and they say, wow, look at this, and it's pretty good, right?

67:40But it's already gone through a filtering process

67:42of humans looking at it and saying,

67:43okay, well that's crap, that's crap, okay.

67:45Oh, here's a sentence that's pretty cool.

67:47Now here's the thing, human creativity

67:49is about absorbing everything around it

67:51and remixing that and coming up with stuff.

67:53So in that sense, we're sort of like GPT3,

67:55you know, we're remixing what we've gotten in before.

67:59But we also know, we also have very good models

68:03of what it is to be another human.

68:04And so, you know, I don't know if you speak French

68:08or something, but I'm not gonna start speaking in French

68:09because then you'll say, wait, what are you doing?

68:11I don't understand it.

68:12Instead, everything coming out of my mouth

68:14is meant for your ears.

68:16I know what you'll understand.

68:18I know the vocabulary that you know and don't know.

68:20I know what parts you care about.

68:23That's a huge part of it.

68:25And so of all the possible sentences I could say,

68:29I'm navigating this thin bandwidth

68:31so that it's something useful for our conversation.

68:34Yeah, in real time, but also throughout your life.

68:36I mean, we're co evolving together.

68:39We're learning how to communicate together.

68:42Exactly, but this is what GPT3 does not do.

68:46All it's doing is saying, okay,

68:47I'm gonna take all these senses and remix stuff

68:49and pop some stuff out.

68:51But it doesn't know how to make it

68:52so that you, Lex, will feel like,

68:54oh yeah, that's exactly what I needed to hear.

68:56That's the next sentence that I needed to know about

68:59for something.

§09Transcript · 1:09:00–1:16:46

69:00Well, of course, it could be,

69:02all the impressive results we see.

69:04The question is, if you raise the number of parameters,

69:07whether it's going to be after some...

69:09It will not be.

69:11It will not be.

69:11Raising more parameters won't...

69:14Here's the thing.

69:15It's not that I don't think neural networks

69:16can't be like the human brain,

69:18because I suspect they will be at some point, 50 years.

69:20Who knows?

69:21But what we are missing in artificial neural networks

69:26is we've got this basic structure where you've got units

69:29and you've got synapses that are connected.

69:32And that's great.

69:33And it's done incredibly mind blowing, impressive things,

69:35but it's not doing the same algorithms as the human brain.

69:40So when I look at my children, as little kids,

69:43as infants, they can do things that no GPT3 can do.

69:47They can navigate a complex room.

69:50They can navigate social conversation with an adult.

69:54They can lie.

69:55They can do a million things.

69:58They are active thinkers in our world and doing things.

70:03And this, of course, I mean, look,

70:04we totally agree on how incredibly awesome

70:07artificial neural networks are right now,

70:09but we also know the things that they can't do well,

70:12like be generally intelligent,

70:14do all these different things.

70:16The reason about the world,

70:17efficiently learn, efficiently adapt.

70:19Exactly.

70:20But it's still the rate of improvement.

70:23It's, to me, it's possible that we'll be surprised.

70:28I agree, possible we'll be surprised.

70:30But what I would assert,

70:33and I'm glad I'm getting to say this on your podcast,

70:36we can look back at this in two years and 10 years,

70:38is that we've got to be much more sophisticated

70:41than units and synapses between them.

70:44Let me give you an example,

70:45and this is something I talk about in LiveWired,

70:47is despite the amazing impressiveness,

70:50mind blowing impressiveness,

70:52computers don't have some basic things,

70:54artificial neural networks don't have some basic things

70:56that we like caring about relevance, for example.

70:59So as humans, we are confronted

71:02with tons of data all the time,

71:03and we only encode particular things

71:05that are relevant to us.

71:07We have this very deep sense of relevance

71:10that I mentioned earlier is based on survival

71:11at the most basic level,

71:12but then all the things about my life and your life,

71:16what's relevant to you, that we encode.

71:19This is very useful.

71:20Computers at the moment don't have that.

71:21They don't even have a yen to survive

71:24and things like that.

71:24So we filled out a bunch of the junk we don't need.

71:27We're really good at efficiently

71:29zooming in on things we need.

71:32Again, could be argued, you know,

71:34let me put on my Freud hat.

71:35Maybe it's, I mean, that's our conscious mind.

71:42There's no reason that neural networks

71:44aren't doing the same kind of filtration.

71:46I mean, in the sense with GPT3 is doing,

71:48so there's a priming step.

71:50It's doing an essential kind of filtration

71:53when you ask it to generate tweets from,

71:58I don't know, from an Elon Musk or something like that.

72:00It's doing a filtration of it's throwing away

72:04all the parameters it doesn't need for this task.

72:06And it's figuring out how to do that successfully.

72:09And then ultimately it's not doing a very good job

72:12right now, but it's doing a lot better job

72:14than we expected.

72:15But it won't ever do a really good job.

72:17And I'll tell you why.

72:18I mean, so let's say we say,

72:20hey, produce an Elon Musk tweet.

72:21And we see like, oh, wow, it produced these three.

72:23That's great.

72:24But again, we're not seeing the 3000 produced

72:27that didn't really make any sense.

72:28It's because it has no idea what it is like to be a human.

72:32And all the things that you might want to say

72:34and all the reasons you wouldn't,

72:35like when you go to write a tweet,

72:37you might write something you think,

72:38ah, it's not gonna come off quite right

72:39in this modern political climate or whatever.

72:41Like, you know, you can change things.

72:43So.

72:44And it somehow boils down to fear of mortality

72:46and all of these human things at the end of the day,

72:49all contained with that tweeting experience.

72:52Well, interestingly, the fear of mortality

72:55is at the bottom of this,

72:56but you've got all these more things like,

72:58you know, oh, I want to,

73:01just in case the chairman of my department reads this,

73:03I want it to come off well there.

73:04Just in case my mom looks at this tweet,

73:05I want to make sure she, you know, and so on.

73:08So those are all the things that humans are able

73:10to sort of throw into the calculation.

73:13I mean.

73:14What it required, what it requires though,

73:16is having a model of your chairman,

73:18having a model of your mother,

73:19having a model of, you know,

73:22the person you want to go on a date with

73:24who might look at your tweet and so on.

73:26All these things are,

73:27you're running models of what it is like to be them.

73:30So in terms of the structure of the brain,

73:34again, this may be going into speculation land.

73:37I hope you go along with me.

73:39Yeah, of course.

73:39Yep.

73:40Is, okay, so the brain seems to be intelligent

73:45and our AI systems aren't very currently.

73:48So where do you think intelligence arises in the brain?

73:52Like what is it about the brain?

73:55So if you mean where location wise,

73:58it's no single spot.

73:59It would be equivalent to asking,

74:01I'm looking at New York city,

74:04where is the economy?

74:06The answer is you can't point to anywhere.

74:08The economy is all about the interaction

74:09of all of the pieces and parts of the city.

74:12And that's what, you know, intelligence,

74:14whatever we mean by that in the brain

74:15is interacting from everything going on at once.

74:18In terms of a structure.

74:19So we look humans are much smarter than fish,

74:23maybe not dolphins, but dolphins are mammals, right?

74:26I assert that what we mean by smarter

74:28has to do with live wiring.

74:30So what we mean when we say, oh, we're smart

74:32is, oh, we can figure out a new thing

74:33and figure out a new pathway to get where we need to go.

74:36And that's because fish are essentially coming to the table

74:39with, you know, okay, here's the hardware, go swim, mate.

74:43But we have the capacity to say,

74:46okay, look, I'm gonna absorb, oh, oh,

74:47but you know, I saw someone else do this thing

74:49and I read once that you could do this other thing

74:51and so on.

74:52So do you think there's, is there something,

74:54I know these are mysteries,

74:56but like architecturally speaking,

75:00what feature of the brain of the live wire aspect of it

75:06that is really useful for intelligence?

75:08So like, is it the ability of neurons to reconnect?

75:15Like, is there something,

75:16is there any lessons about the human brain

75:18you think might be inspiring for us

75:21to take into the artificial, into the machine learning world?

75:26Yeah, I'm actually just trying to write some up on this now

75:29called, you know, if you wanna build a robot,

75:31start with the stomach.

75:32And what I mean by that, what I mean by that is

75:35a robot has to care, it has to have hunger,

75:37it has to care about surviving, that kind of thing.

75:40Here's an example.

75:41So the penultimate chapter of my book,

75:44I titled The Wolf and the Mars Rover.

75:46And I just look at this simple comparison

75:48of you look at a wolf, it gets its leg caught in a trap.

75:52What does it do?

75:53It gnaws its leg off,

75:55and then it figures out how to walk on three legs.

75:58No problem.

75:59Now, the Mars Rover Curiosity got its front wheel stuck

76:02in some Martian soil, and it died.

76:05This project that cost billions of dollars died

76:09because it got its wheels.

76:09Wouldn't it be terrific if we could build a robot

76:12that chewed off its front wheel and figured out

76:15how to operate with a slightly different body plan?

76:17That's the kind of thing that we wanna be able to build.

76:21And to get there, what we need,

76:23the whole reason the wolf is able to do that

76:25is because its motor and somatosensory systems

76:27are live wired.

76:28So it says, oh, you know what?

76:29Turns out we've got a body plan that's different

76:31than what I thought a few minutes ago,

76:34but I have a yen to survive and I care about relevance,

76:38which in this case is getting to food,

76:40getting back to my pack and so on.

76:42So I'm just gonna figure out how to operate with this.

76:44Oh, whoops, that didn't work.

§10Transcript · 1:16:46–1:24:33

76:46Oh, okay, I'm kind of getting it to work.

76:48But the Mars Rover doesn't do that.

76:49It just says, oh geez, I was pre programmed.

76:51Four wheels, now I have three, I'm screwed.

76:53Yeah, you know, I don't know if you're familiar

76:55with a philosopher named Ernest Becker.

76:58He wrote a book called Denial of Death.

77:00And there's a few psychologists, Sheldon Solomon,

77:03I think I just spoke with him on his podcast

77:07who developed terror management theory,

77:09which is like Ernest Becker is a philosopher

77:12that basically said that fear of mortality

77:17is at the core of it.

77:18Yeah.

77:19And so I don't know if it sounds compelling as an idea

77:23that all of the civilization we've constructed

77:26is based on this, but it's.

77:29I'm familiar with his work.

77:30Here's what I think.

77:31I think that yes, fundamentally this desire to survive

77:35is at the core of it, I would agree with that.

77:37But how that expresses itself in your life

77:40ends up being very different.

77:41The reason you do what you do is, I mean,

77:45you could list the 100 reasons why you chose

77:47to write your tweet this way and that way.

77:49And it really has nothing to do with the survival part.

77:51It has to do with, you know, trying to impress fellow humans

77:53and surprise them and say something.

77:55Yeah, so many things built on top of each other,

77:56but it's fascinating to think

77:58that in artificial intelligence systems,

78:00we wanna be able to somehow engineer this drive

78:05for survival, for immortality.

78:08I mean, because as humans, we're not just about survival,

78:11we're aware of the fact that we're going to die,

78:14which is a very kind of, we're aware of like space time.

78:17Most people aren't, by the way.

78:18Aren't?

78:19Aren't.

78:20Confucius said, he said, each person has two lives.

78:25The second one begins when you realize

78:28that you have just one.

78:29Yeah.

78:30But most people, it takes a long time

78:31for most people to get there.

78:32I mean, you could argue this kind of Freudian thing,

78:34which Erzbecker argues is they actually figured it out

78:41early on and the terror they felt

78:44was like the reason it's been suppressed.

78:47And the reason most people, when I ask them

78:49about whether they're afraid of death,

78:50they basically say no.

78:53They basically say like, I'm afraid I won't get,

78:56like submit the paper before I die.

78:59Like they kind of see, they see death

79:01as a kind of a inconvenient deadline

79:04for a particular set of, like a book you're writing.

79:08As opposed to like, what the hell?

79:10This thing ends at any moment.

79:14Like most people, as I've encountered,

79:17do not meditate on the idea that like right now

79:20you could die.

79:21Like right now, like in the next five minutes,

79:26it could be all over and, you know, meditate on that idea.

79:29I think that somehow brings you closer

79:32to like the core of the motivations

79:36and the core of the human cognition condition.

79:40I think it might be the core, but like I said,

79:41it is not what drives us day to day.

79:43Yeah, there's so many things on top of it,

79:45but it is interesting.

79:46I mean, as the ancient poet said,

79:49death whispers at my ear, live for I come.

79:53So it's, it is certainly motivating

79:56when we think about that.

79:58Okay, I've got some deadline.

79:59I don't know exactly when it is,

80:00but I better make stuff happen.

80:02It is motivating, but I don't think,

80:04I mean, I know for just speaking for me personally,

80:06that's not what motivates me day to day.

80:08It's instead, oh, I want to get this, you know,

80:13program up and running before this,

80:14or I want to make sure my coauthor isn't mad at me

80:17because I haven't gotten this in,

80:18or I don't want to miss this grant deadline,

80:19or, you know, whatever the thing is.

80:21Yeah, it's too distant in a sense.

80:24Nevertheless, it is good to reconnect.

80:26But for the AI systems, none of that is there.

80:31Like a neural network does not fear its mortality.

80:34And that seems to be somehow

80:37fundamentally missing the point.

80:39I think that's missing the point,

80:40but I wonder, it's an interesting speculation

80:42about whether you can build an AI system

80:43that is much closer to being a human

80:45without the mortality and survival piece,

80:48but just the thing of relevance,

80:51just I care about this versus that.

80:52Right now, if you have a robot roll into the room,

80:54it's going to be frozen

80:55because it doesn't have any reason to go there versus there.

80:57It doesn't have any particular set of things

81:02about this is how I should navigate my next move

81:05because I want something.

81:07Yeah, the thing about humans

81:10is they seem to generate goals.

81:13They're like, you said livewired.

81:15I mean, it's very flexible in terms of the goals

81:19and creative in terms of the goals we generate

81:21when we enter a room.

81:23You show up to a party without a goal,

81:25usually, and then you figure it out along the way.

81:27Yes, but this goes back to the question about free will,

81:29which is when I walk into the party,

81:33if you rewound it 10,000 times,

81:35would I go and talk to that couple over there

81:37versus that person?

81:38Like, I might do this exact same thing every time

81:41because I've got some goal stack and I think,

81:44okay, well, at this party,

81:45I really want to meet these kind of people

81:47or I feel awkward or whatever my goals are.

81:51By the way, so there was something

81:52that I meant to mention earlier.

81:54If you don't mind going back,

81:56which is this, when we were talking about BCI.

81:59So I don't know if you know this,

82:00but what I'm spending 90% of my time doing now

82:02is running a company.

82:03Do you know about this?

82:04Yes, I wasn't sure what the company is involved in.

82:08Right, so. Can you talk about it?

82:09Yeah, yeah.

82:10So when it comes to the future of BCI,

82:15you can put stuff into the brain invasively,

82:18but my interest has been how you can get data streams

82:22into the brain noninvasively.

82:24So I run a company called Neosensory

82:26and what we build is this little wristband.

82:29We've built this in many different form factors.

82:30Oh, wow, that's it?

82:31Yeah, this is it.

82:32And it's got these vibratory motors in it.

82:35So these things, as I'm speaking, for example,

82:38it's capturing my voice and running algorithms

82:41and then turning that into patterns of vibration here.

82:44So people who are deaf, for example,

82:48learn to hear through their skin.

82:50So the information is getting up to their brain this way

82:54and they learn how to hear.

82:55So it turns out on day one, people are pretty good,

82:58like better than you'd expect at being able to say,

83:00oh, that's weird, was that a dog barking?

83:02Was that a baby crying?

83:03Was that a door knock, a doorbell?

83:04Like people are pretty good at it,

83:06but with time they get better and better

83:09and what it becomes is a new qualia.

83:12In other words, a new subjective internal experience.

83:15So on day one, they say, whoa, what was that?

83:18Oh, oh, that was the dog barking.

83:20But by three months later, they say,

83:23oh, there's a dog barking somewhere.

83:24Oh, there's the dog.

83:25That's fascinating.

83:26And by the way, that's exactly how you learn

83:27how to use your ears.

83:29So of course you don't remember this,

83:30but when you were an infant, all you have are

83:33your eardrum vibrating causes spikes to go down,

83:36your auditory nerves and impinging your auditory cortex.

83:40Your brain doesn't know what those mean automatically,

83:43but what happens is you learn how to hear

83:44by looking for correlations.

83:46You clap your hands as a baby,

83:48you look at your mother's mouth moving

83:50and that correlates with what's going on there.

83:53And eventually your brain says, all right,

83:54I'm just gonna summarize this as an internal experience,

83:57as a conscious experience.

83:59And that's exactly what happens here.

84:01The weird part is that you can feed data into the brain,

84:04not through the ears, but through any channel

84:06that gets there.

84:07As long as the information gets there,

84:08your brain figures out what to do with it.

84:10That's fascinating.

84:11Like expanding the set of sensors,

84:14it could be arbitrarily, yeah,

84:19it could expand arbitrarily, which is fascinating.

84:21Well, exactly.

84:22And by the way, the reason I use this skin,

84:24there's all kinds of cool stuff going on

84:26in the AR world with glasses.

84:28But the fact is your eyes are overtaxed

84:29and your ears are overtaxed

84:30and you need to be able to see and hear other stuff.

§11Transcript · 1:24:33–1:31:56

84:33But you're covered with the skin,

84:34which is this incredible computational material

84:38with which you can feed information.

84:39And we don't use our skin for much of anything nowadays.

84:42My joke in the lab is that I say,

84:44we don't call this the waste for nothing.

84:45Because originally we built this as the vest

84:47and you're passing in all this information that way.

84:51And what I'm doing here with the deaf community

84:56is what's called sensory substitution,

84:59where I'm capturing sound and I'm just replacing the ears

85:02with the skin and that works.

85:05One of the things I talk about LiveWire

85:07is sensory expansion.

85:09So what if you took something like your visual system,

85:11which picks up on a very thin slice

85:13of the electromagnetic spectrum,

85:15and you could see infrared or ultraviolet.

85:18So we've hooked that up, infrared and ultraviolet detectors,

85:21and I can feel what's going on.

85:22So just as an example, the first night I built the infrared,

85:25one of my engineers built it, the infrared detector,

85:27I was walking in the dark between two houses

85:29and suddenly I felt all this infrared radiation.

85:31I was like, where's that come from?

85:32And I just followed my wrist and I found an infrared camera,

85:35a night vision camera that was,

85:37but I immediately, oh, there's that thing there.

85:40Of course, I would have never seen it,

85:42but now it's just part of my reality.

85:45That's fascinating.

85:46Yeah, and then of course,

85:46what I'm really interested in is sensory addition.

85:49What if you could pick up on stuff

85:51that isn't even part of what we normally pick up on,

85:55like the magnetic field of the earth

85:57or Twitter or stock market or things like that.

86:00Or the, I don't know, some weird stuff

86:02like the moods of other people or something like that.

86:04Sure, now what you need is a way to measure this.

86:06So as long as there's a machine that can measure it,

86:08it's easy, it's trivial to feed this in here

86:09and you come to be, it comes to be part of your reality.

86:14It's like you have another sensor.

86:16And that kind of thing is without doing like,

86:19if you look in Neuralink,

86:20I forgot how you put it, but it was eloquent,

86:23without getting, cutting into the brain, basically.

86:26Yeah, exactly, exactly.

86:27So this costs, at the moment, $399.

86:30That's not gonna kill you.

86:32Yeah, it's not gonna kill you.

86:33You just put it on and when you're done, you take it off.

86:36Yeah, and so, and the name of the company, by the way,

86:39is Neosensory for new senses, because the whole idea is.

86:42Beautiful, that's.

86:43You can, as I said, you come to the table

86:45with certain plug and play devices and then that's it.

86:48Like I can pick up on this little bit

86:49of the electromagnetic radiation,

86:50you can pick up on this little frequency band

86:53for hearing and so on, but I'm stuck there

86:56and there's no reason we have to be stuck there.

86:57We can expand our umwelt by adding new senses, yeah.

87:01What's umwelt?

87:02Oh, I'm sorry, the umwelt is the slice of reality

87:05that you pick up on.

87:06So each animal has its own umwelt.

87:09Yeah, exactly.

87:10Nice.

87:11I'm sorry, I forgot to define it before.

87:12It's such an important concept, which is to say,

87:17for example, if you are a tick,

87:19you pick up on butyric gas, you pick up on odor

87:22and you pick up on temperature, that's it.

87:24That's how you construct your reality

87:25is with those two sensors.

87:26If you are a blind echolocating bat,

87:28you're picking up on air compression waves coming back,

87:31you know, echolocation.

87:32If you are the black ghost knife fish,

87:34you're picking up on changes in the electrical field

87:37around you with electroreception.

87:40That's how they swim around

87:41and tell there's a rock there and so on.

87:43But that's all they pick up on.

87:45That's their umwelt.

87:47That's the signals they get from the world

87:49from which to construct their reality.

87:51And they can be totally different umwelts.

87:53That's fantastic.

87:54And so our human umwelt is, you know,

87:57we've got little bits that we can pick up on.

87:59One of the things I like to do with my students

88:01is talk about, imagine that you are a bloodhound dog, right?

88:05You are a bloodhound dog with a huge snout

88:07with 200 million scent receptors in it.

88:09And your whole world is about smelling.

88:11You know, you've got slits in your nostrils,

88:13like big nose fulls of air and so on.

88:15Do you have a dog?

88:16Nope, used to.

88:17Used to, okay, right.

88:18So you know, you walk your dog around

88:19and your dog is smelling everything.

88:21The whole world is full of signals

88:22that you do not pick up on.

88:23And so imagine if you were that dog

88:25and you looked at your human master and thought,

88:26my God, what is it like to have

88:28the pitiful little nose of a human?

88:30How could you not know that there's a cat 100 yards away

88:32or that your friend was here six hours ago?

88:34And so the idea is because we're stuck in our own belt,

88:37because we have this little pitiful noses,

88:39we think, okay, well, yeah, we're seeing reality,

88:41but you can have very different sorts of realities

88:44depending on the peripheral plug and play devices

88:46you're equipped with.

88:47It's fascinating to think that like,

88:49if we're being honest, probably our own belt

88:52is, you know, some infinitely tiny percent

88:57of the possibilities of how you can sense,

89:01quote unquote, reality, even if you could,

89:04I mean, there's a guy named Donald Hoffman, yeah,

89:08who basically says we're really far away from reality

89:13in terms of our ability to sense anything.

89:15Like we're very, we're almost like we're floating out there

89:20that's almost like completely attached

89:22to the actual physical reality.

89:24It's fascinating that we can have extra senses

89:27that could help us get a little bit closer.

89:29Exactly, and by the way, this has been the fruits

89:33of science is realizing, like, for example,

89:36you know, you open your eyes

89:36and there's the world around you, right?

89:38But of course, depending on how you calculate it,

89:40it's less than a 10 trillionth of the electromagnetic

89:42spectrum that we call visible light.

89:45The reason I say it depends,

89:46because, you know, it's actually infinite

89:47in all directions presumably.

89:49Yeah, and so that's exactly that.

89:51And then science allows you to actually look

89:53into the rest of it.

89:54Exactly, so understanding how big the world is out there.

89:57And the same with the world of really small

89:59and the world of really large.

90:00Exactly.

90:01That's beyond our ability to sense.

90:03Exactly, and so the reason I think this kind of thing

90:04matters is because we now have an opportunity

90:07for the first time in human history to say,

90:10okay, well, I'm just gonna include other things

90:13in my own belt.

90:13So I'm gonna include infrared radiation

90:15and have a direct perceptual experience of that.

90:19And so I'm very, you know, I mean,

90:21so, you know, I've given up my lab

90:22and I run this company 90% of my time now.

90:25That's what I'm doing.

90:26I still teach at Stanford and I'm, you know,

90:27teaching courses and stuff like that.

90:29But this is like, this is your passion.

90:32The fire is on this.

90:35Yeah, I feel like this is the most important thing

90:37that's happening right now.

90:38I mean, obviously I think that,

90:40because that's what I'm devoting my time in my life to.

90:42But I mean, it's a brilliant set of ideas.

90:45It certainly is like, it's a step in a very vibrant future,

90:50I would say.

90:50Like the possibilities there are endless.

90:54Exactly.

90:55So if you ask what I think about Neuralink,

90:57I think it's amazing what those guys are doing

90:59and working on,

91:00but I think it's not practical for almost everybody.

91:02For example, for people who are deaf, they buy this

91:05and, you know, every day we're getting tons of emails

91:08and tweets and whatever from people saying, wow,

91:09I picked up on this and then I had no idea that was a,

91:12I didn't even know that was happening out there.

91:14And they're coming to hear, by the way,

91:16this is, you know, less than a 10 year old,

91:18by the way, this is less than a 10th of the price

91:20of a hearing aid and like 250 times less

91:23than a cochlear implant.

91:25That's amazing.

91:27People love hearing about what, you know,

91:30brilliant folks like yourself could recommend

91:33in terms of books.

91:35Of course, you're an author of many books.

91:36So I'll, in the introduction,

91:38mention all the books you've written.

91:40People should definitely read LiveWired.

91:42I've gotten a chance to read some of it and it's amazing.

91:44But is there three books, technical, fiction,

91:48philosophical that had an impact on you

91:52when you were younger or today and books,

§12Transcript · 1:31:56–1:39:52

91:56perhaps some of which you would want to recommend

91:59that others read?

92:01You know, as an undergraduate,

92:02I majored in British and American literature.

92:04That was my major because I love literature.

92:06I grew up with literature.

92:08My father had these extensive bookshelves.

92:10And so I grew up in the mountains in New Mexico.

92:13And so that was mostly why I spent my time was reading books.

92:16But, you know, I love, you know, Faulkner, Hemingway.

92:23I love many South American authors,

92:26Gabriel Garcia Marquez and Italo Calvino.

92:28I would actually recommend Invisible Cities.

92:29I just, I loved that book by Italo Calvino.

92:33Sorry, it's a book of fiction.

92:37Anthony Dorr wrote a book called

92:39All the Light We Cannot See,

92:41which actually was inspired by incognito,

92:44by exactly what we were talking about earlier

92:45about how you can only see a little bit of the,

92:48what we call visible light in the electromagnetic radiation.

92:51I wrote about this in incognito,

92:52and then he reviewed incognito for the Washington Post.

92:54Oh no, that's awesome.

92:56And then he wrote this book called,

92:57the book has nothing to do with that,

92:58but that's where the title comes from.

93:00All the Light We Cannot See

93:01is about the rest of the spectrum.

93:02But the, that's an absolutely gorgeous book.

93:08That's a book of fiction.

93:09Yeah, it's a book of fiction.

93:10What's it about?

93:12It takes place during World War II

93:14about these two young people,

93:15one of whom is blind and yeah.

93:18Anything else?

93:19So what, any, so you mentioned Hemingway?

93:21I mean.

93:22Old Man and the Sea, what's your favorite?

93:27Snow's a Kilimanjaro.

93:29Oh wow, okay.

93:30It's a collection of short stories that I love.

93:31As far as nonfiction goes,

93:33I grew up with Cosmos,

93:35both watching the PBS series and then reading the book,

93:38and that influenced me a huge amount in terms of what I do.

93:41I, from the time I was a kid,

93:42I felt like I want to be Carl Sagan.

93:44Like, I just, that's what I loved.

93:46And in the end, I just, you know,

93:47I studied space physics for a while as an undergrad,

93:50but then I, in my last semester,

93:53discovered neuroscience last semester,

93:55and I just thought, wow, I'm hooked on that.

93:57So the Carl Sagan of the brain.

94:01That was my aspiration.

94:02Is the aspiration.

94:03I mean, you're doing an incredible job of it.

94:07So you open the book live wide with a quote by Heidegger.

94:11Every man is born as many men and dies as a single one.

94:17Well, what do you mean, or what?

94:20I'll tell you what I meant by it.

94:21So he had his own reason why he was writing that,

94:23but I meant this in terms of brain plasticity,

94:25in terms of the library,

94:26which is this issue that I mentioned before

94:28about this, you know, this cone,

94:29the space time cone that we are in,

94:31which is that when you dropped into the world,

94:35you, Lex, had all this different potential.

94:37You could have been a great surfer

94:40or a great chess player or a,

94:42you could have been thousands of different men

94:45when you grew up,

94:46but what you did is things that were not your choice

94:49and your choice along the way.

94:50You know, you ended up navigating a particular path

94:52and now you're exactly who you are.

94:54You used to have lots of potential,

94:55but the day you die, you will be exactly Lex.

94:59You will be that one person, yeah.

95:01So on that, in that context,

95:03I mean, first of all, it's just a beautiful,

95:06it's a humbling picture, but it's a beautiful one

95:09because it's all the possible trajectories

95:12and you pick one and you walk down that road

95:14and it's the Robert Frost poem.

95:16But on that topic, let me ask the biggest

95:18and the most ridiculous question.

95:21So in this live, wide brain,

95:23when we choose all these different trajectories

95:25and end up with one, what's the meaning of it all?

95:27What's, is there a why here?

95:32What's the meaning of life?

95:34Yeah.

95:34David Engelman.

95:36That's it.

95:37I mean, this is the question that everyone has attacked

95:42from their own life or point of view,

95:45by which I mean, culturally,

95:47if you grew up in a religious society,

95:49you have one way of attacking that question.

95:51So if you grew up in a secular or scientific society,

95:53you have a different way of attacking that question.

95:55Obviously, I don't know, I abstain on that question.

95:59Yeah.

96:00I mean, I think one of the fundamental things,

96:03I guess, in that, in all those possible trajectories

96:06is you're always asking.

96:09I mean, that's the act of asking

96:11what the heck is this thing for,

96:14is equivalent to, or at least runs in parallel

96:18to all the choices that you're making.

96:20Cause it's kind of, that's the underlying question.

96:23Well, that's right.

96:24And by the way, you know,

96:25this is the interesting thing about human psychology.

96:27You know, we've got all these layers of things

96:29at which we can ask questions.

96:30And so if you keep asking yourself the question about,

96:33what is the optimal way for me to be spending my time?

96:36What should I be doing?

96:37What charity should I get involved with and so on?

96:39If you're asking those big questions

96:42that steers you appropriately,

96:44if you're the type of person who never asks,

96:46hey, is there something better I can be doing with my time,

96:48then presumably you won't optimize

96:51whatever it is that is important to you.

96:53So you've, I think just in your eyes, in your work,

96:58there's a passion that just is obvious and it's inspiring.

97:03It's contagious.

97:04What, if you were to give advice to us,

97:09a young person today,

97:10in the crazy chaos that we live today about life,

97:14about how to discover their passion,

97:20is there some words that you could give?

97:24First of all, I would say the main thing

97:26for a young person is stay adaptable.

97:29And this is back to this issue of why COVID

97:31is useful for us because it forces us off our tracks.

97:35The fact is the jobs that will exist 20 years from now,

97:39we don't even have names for it.

97:40We can't even imagine the jobs that are gonna exist.

97:42And so when young people that I know go into college

97:44and they say, hey, what should I major in and so on,

97:47college is and should be less and less vocational,

97:50as in, oh, I'm gonna learn how to do this

97:52and then I'm gonna do that the rest of my career.

97:54The world just isn't that way anymore

97:55with the exponential speed of things.

97:57So the important thing is learning how to learn,

98:00learning how to be livewired and adaptable.

98:03That's really key.

98:04And what I advise young people when I talk to them is,

98:09what you digest, that's what gives you the raw storehouse

98:13of things that you can remix and be creative with.

98:17And so eat broadly and widely.

98:21And obviously this is the wonderful thing

98:23about the internet world we live in now

98:24is you kind of can't help it.

98:25You're constantly, whoa.

98:27You go down some mole hole of Wikipedia

98:28and you think, oh, I didn't even realize that was a thing.

98:31I didn't know that existed.

98:32And so.

98:33Embrace that.

98:34Embrace that, yeah, exactly.

98:36And what I tell people is just always do a gut check

98:39about, okay, I'm reading this paper

98:41and yeah, I think that, but this paper, wow,

98:44that really, I really cared about that in some way.

98:47I tell them just to keep a real sniff out for that.

98:50And when you find those things, keep going down those paths.

98:54Yeah, don't be afraid.

98:55I mean, that's one of the challenges and the downsides

98:58of having so many beautiful options

99:00is that sometimes people are a little bit afraid

99:02to really commit, but that's very true.

99:05If there's something that just sparks your interest

99:09and passion, just run with it.

99:10I mean, that's, it goes back to the Haider quote.

99:14I mean, we only get this one life

99:16and that trajectory, it doesn't last forever.

99:20So just if something sparks your imagination,

99:23your passion is run with it.

99:24Yeah, exactly.

99:26I don't think there's a more beautiful way to end it.

99:29David, it's a huge honor to finally meet you.

99:32Your work is inspiring so many people.

99:34I've talked to so many people who are passionate

99:36about neuroscience, about the brain, even outside

99:39that read your book.

99:40So I hope you keep doing so.

99:43I think you're already there with Carl Sagan.

99:46I hope you continue growing.

99:48Yeah, it was an honor talking with you today.

99:50Thanks so much.

99:50Great, you too, Lex, wonderful.

§13Transcript · 1:39:53–1:41:23

99:53Thanks for listening to this conversation

99:54with David Eagleman, and thank you to our sponsors,

99:58Athletic Greens, BetterHelp, and Cash App.

100:01Click the sponsor links in the description

100:03to get a discount and to support this podcast.

100:07If you enjoy this thing, subscribe on YouTube,

100:09review it with Five Stars on Apple Podcast,

100:11follow on Spotify, support on Patreon,

100:14or connect with me on Twitter at Lex Friedman.

100:18And now let me leave you with some words

100:20from David Eagleman in his book,

100:21Some Forty Tales from the Afterlives.

100:25Imagine for a moment there were nothing but

100:28the product of billions of years of molecules

100:30coming together and ratcheting up through natural selection.

100:35There were composed only of highways of fluids

100:37and chemicals sliding along roadways

100:39within billions of dancing cells.

100:42The trillions of synaptic connections hum in parallel

100:46that this vast egg like fabric of micro thin circuitry

100:50runs algorithms undreamt of in modern science,

100:54and that these neural programs give rise to

100:56our decision making, loves, desires, fears, and aspirations.

101:02To me, understanding this would be a numinous experience,

101:07better than anything ever proposed in any holy text.

101:11Thank you for listening and hope to see you next time.

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