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Speaker 1

00:00

The following is a conversation with David Eagleman, a neuroscientist and 1 of the great science communicators of our time, exploring the beauty and mystery of the human brain. He's an author of a lot of amazing books about the human mind, and his new 1 called LiveWired. LiveWired is a work of 10 years on a topic that is fascinating to me, which is neuroplasticity or the malleability of the human brain. Quick summary of the sponsors, Athletic Greens, BetterHelp, and Cash App.

Speaker 1

00:32

Click the sponsor links in the description to get a discount and to support this podcast. As a side note, let me say that the adaptability of the human mind at the biological, chemical, cognitive, psychological, and even sociological levels is the very thing that captivated me many years ago when I first began to wonder how we might engineer something like it in the machine. The open question today in the 21st century is what are the limits of this adaptability? As new, smarter and smarter devices and AI systems come to life, or as better and better brain-computer interfaces are engineered, will our brain be able to adapt, to catch up, to excel?

Speaker 1

01:16

I personally believe yes, that we're far from reaching the limitation of the human mind and the human brain, just as we are far from reaching the limitations of our computational systems. If you enjoy this thing, subscribe on YouTube, review it with 5 Stars and Apple Podcast, follow on Spotify, support on Patreon, or connect with me on Twitter at Lex Friedman. As usual, I'll do a few minutes of ads now and no ads in the middle. I try to make these interesting, but I give you timestamps so you can skip.

Speaker 1

01:47

But please do check out the sponsors by clicking the links in the description. It's the best way to support this podcast. This show is brought to you by Athletic Greens, the all-in-one daily drink to support better health and peak performance. Even with a balanced diet, it's difficult to cover all of your nutritional bases.

Speaker 1

02:06

That's where athletic greens will help. Their daily drink is like nutritional insurance for your body as delivered straight to your door. As you may know, I fast often, sometimes intermittent fasting for 16 hours, sometimes 24 hours, dinner to dinner, sometimes more. I break the fast with Athletic Greens.

Speaker 1

02:26

It's delicious, refreshing, just makes me feel good. I think it's like 50 calories, less than a gram of sugar, but has a ton of nutrients to make sure my body has what it needs despite what I'm eating. Go to athleticgreens.com slash lex to claim a special offer of a free vitamin D3K2 for a year. If you listen to the Joe Rogan experience, you might have listened to him rant about how awesome vitamin D is for your immune system.

Speaker 1

02:56

So there you have it. So click the athleticgreens.com slash Lex in the description to get the free stuff and to support this podcast. This show is sponsored by BetterHelp, spelled H-E-L-P, help. Check it out at betterhelp.com slash Lex.

Speaker 1

03:14

They figure out what you need, match you with a licensed professional therapist in under 48 hours. It's not a crisis line, it's not self-help, it's professional counseling done securely online. I'm a bit from the David Goggins line of creatures and so have some demons to contend with, usually on long runs or all nights full of self-doubt. I think suffering is essential for creation, but you can suffer beautifully, in a way that doesn't destroy you.

Speaker 1

03:41

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Speaker 1

03:58

Check it out at betterhelp.com slash Lex. This show is presented by Cash App, the number 1 finance app in the App Store. When you get it, use code LEXPODCAST. Cash App lets you send money to friends, buy Bitcoin, and invest in the stock market with as little as $1.

Speaker 1

04:14

Since Cash App allows you to buy Bitcoin, let me mention that cryptocurrency in the context of the history of money is fascinating. I recommend Ascent of Money as a great book on this history. Davidson credits on ledgers started around 30,000 years ago and the first decentralized cryptocurrency released just over 10 years ago. So given that history, cryptocurrency is still very much in its early days of development, but it's still aiming to, and just might, redefine the nature of money.

Speaker 1

04:45

So again, if you get Cash App from the App Store or Google Play and use code LEXPODCAST, you get $10 and Cash App will also donate $10 to FIRST, an organization that is helping to advance robotics and STEM education for young people around the world. And now, here's my conversation with David Eagleman. You have a new book coming out on the changing brain. Can you give a high level overview of the book?

Speaker 1

05:13

It's called LiveWired, by the way.

Speaker 2

05:14

Yeah, The thing is we typically think about the brain in terms of the metaphors we already have, like hardware and software. That's how we build all our stuff. But what's happening in the brain is fundamentally so different.

Speaker 2

05:26

So I coined this new term liveware, which is a system that's constantly reconfiguring itself physically as it learns and adapts to the world around it. It's physically changing.

Speaker 3

05:38

So it's a liveware, meaning like hardware, but changing.

Speaker 2

05:43

Yeah, exactly. Well, the hardware and the software layers are blended. And so, you know, typically engineers are praised for their efficiency and making something really clean and clear, like, okay, here's the hardware layer, then I'm gonna run software on top of it.

Speaker 2

05:57

And there's all sorts of universality that you get out of a piece of hardware like that that's useful. But what the brain is doing is completely different. And I am so excited about where this is all going because I feel like this is where our engineering will go. So currently we build all our devices a particular way, but I can't tear half the circuitry out of your cell phone and expect it to still function.

Speaker 2

06:23

But you can do that with the brain. So just as an example, kids who are under about 7 years old can get 1 half of their brain removed. It's called a hemispherectomy. And they're fine.

Speaker 2

06:36

They have a slight limp on the other side of their body, but they can function just fine that way. And this is generally true. Sometimes children are born without a hemisphere. And their visual system rewires so that everything is on the single remaining hemisphere.

Speaker 2

06:53

What thousands of cases like this teach us is that it's a very malleable system that is simply trying to accomplish the tasks in front of it by rewiring itself with the available real estate.

Speaker 3

07:06

How much of that is a quirk or a feature of evolution? Like how hard is it to engineer? Because evolution took a lot of work.

Speaker 3

07:15

Trillions of organisms had to die to create this thing we have in our skull. Because you said you kind of look forward to the idea that we might be engineering our systems like this in the future, like creating live wire systems. How hard do you think is it to create systems like that?

Speaker 2

07:33

Great question. It has proven itself to be a difficult challenge. What I mean by that is even though it's taken evolution a really long time to get where it is now, all we have to do now is peek at the blueprints.

Speaker 2

07:47

It's just 3 pounds, this organ, and we just figure out how to do it. But that's the part that I mean is a difficult challenge because there are tens of thousands of neuroscientists. We're all poking and prodding and trying to figure this out, but it's an extremely complicated system. But it's only going to be complicated until we figure out the general principles.

Speaker 2

08:05

Exactly like if you, you know, had a magic camera and you could look inside the nucleus of a cell and you'd see hundreds of thousands of things moving around or whatever. And then, you know, it takes Crick and Watts and say, oh, you know, you're just trying to maintain the order of the base pairs and all the rest is details. Then it simplifies it and we come to understand something. That was my goal in LiveWire, which I've written over 10 years, by the way, is to try to distill things down to the principles of what plastic systems are trying to accomplish.

Speaker 3

08:34

But to even just linger, you said it's possible to be born with just 1 hemisphere and you still are able to function. First of all, just to pause on that, I mean, That's amazing. I don't know if people quite, I mean, you kind of hear things here and there.

Speaker 3

08:51

This is why I'm kind of, I'm really excited about your book is I don't know if there's definitive sort of popular sources to think about this stuff. I mean, there's a lot of, I think from my perspective, what I heard is there's like been debates over decades about how much neuroplasticity there is in the brain and so on, and people have learned a lot of things and now it's converging towards people that are understanding this much more in Europe, much more plastic than people realize. But just like linger on that topic, like how malleable is the hardware of the human brain? Maybe you said children at each stage of life.

Speaker 2

09:32

Yeah, so here's the whole thing. I think part of the confusion about plasticity has been that there are studies at all sorts of different ages, and then people might read that from a distance and they think, oh, well, Fred didn't recover when half his brain was taken out. And so clearly you're not plastic, but then you do it with a child and they are plastic.

Speaker 2

09:52

And so part of my goal here was to pull together the tens of thousands of papers on this, both from clinical work and from, you know, all the way down to the molecular and understand what are the principles here. The principles are that plasticity diminishes, that's no surprise. By the way, we should just define plasticity, it's the ability of a system to mold into a new shape and then hold that shape. That's why we make things that we call plastic because they are moldable and they can hold that new shape like a plastic toy or something.

Speaker 3

10:25

And so maybe we use, maybe we'll use a lot of terms that are synonymous. So something is plastic, something is malleable, changing, live wire, the name of the book is like.

Speaker 2

10:38

So I'll tell you, exactly right, but I'll tell you why I chose live wire instead of plasticity. So I use the term plasticity in the book, but sparingly. Because that was a term coined by William James over a hundred years ago.

Speaker 2

10:52

And he was of course very impressed with plastic manufacturing, that you could mold something in shape and then it holds that. But that's not what's actually happening in the brain. It's constantly rewiring your entire life. You never hit an end point.

Speaker 2

11:06

The whole point is for it to keep changing. So even in the few minutes of conversation that we've been having, your brain is changing, my brain is changing. Next time I see your face, I will remember, oh yeah, like that time Lex and I sat together and we did these things.

Speaker 3

11:21

I wonder if your brain will have a Lex thing going on for the next few months. Like it'll stay there until you get rid of it. Because it was useful for now.

Speaker 2

11:29

Yeah, no, I'll probably never get rid of it. Let's say for some circumstance, you and I don't see each other for the next 35 years. When I run into you, I'll be like, oh yeah.

Speaker 3

11:36

That looks familiar.

Speaker 2

11:37

Yeah, yeah. And we sat down for a podcast back when there were podcasts. Exactly.

Speaker 3

11:42

Back when we lived outside virtual reality. Exactly. So you chose live wire to mold

Speaker 2

11:49

plastic. Exactly, because plastic implies, I mean, it's the term that's used in the field and so that's why we need to use it still for a while. But yeah, it implies something gets molded into shape and then holds that shape forever. But in fact, the whole system is completely changing.

Speaker 3

12:03

Then back to how malleable is the human brain at each stage of life. So what, just at a high level, is it malleable?

Speaker 2

12:13

So yes, and plasticity diminishes. But 1 of the things that I felt like I was able to put together for myself after reading thousands of papers on this issue is that different parts of the brain have different plasticity windows. So for example, with the visual cortex, that cements itself into place pretty quickly over the course of a few years.

Speaker 2

12:37

And I argue that's because of the stability of the data. In other words, what you're getting in from the world, you've got a certain number of angles, colors, shapes. You know, it's essentially the world is visually stable. So that hardens around that data.

Speaker 2

12:52

As opposed to, let's say the somatosensory cortex, which is the part that's taking information from your body or the motor cortex right next to it, which is what drives your body. The fact is bodies are always changing. You get taller over time, you get fatter, thinner over time. You might break a leg and have to limp for a while, stuff like that.

Speaker 2

13:08

So because the data there is always changing, and by the way, you might get on a bicycle, you might get on a surfboard, things like that. Because the data is always changing, that stays more malleable. And when you look through the brain, you find that it appears to be this, how stable the data is determines how fast something hardens into place. But the point is different parts of the brain harden into place at different times.

Speaker 3

13:31

Do you think it's possible that depending on how much data you get on a different sensors, that it stays more malleable longer? So like, you know, if you look at different cultures that experience, Like if you keep your eyes closed, or maybe you're blind, I don't know, but let's say you keep your eyes closed for your entire life, then the visual cortex might be much less malleable. The reason I bring that up is like, maybe we'll talk about brain-computer interfaces a little bit down the line, but, you know, like, is this, is the malleability a genetic thing or is it more about the data, like you said, that comes in?

Speaker 2

14:14

Ah, so the Malleability itself is a genetic thing. The big trick that mother nature discovered with humans is make a system that's really flexible as opposed to most other creatures to different degrees. So if you take an alligator, It's born, its brain does the same thing every generation.

Speaker 2

14:34

If you compare an alligator 100,000 years ago to an alligator now, they're essentially the same. We, on the other hand, as humans, drop into a world with a half-baked brain and what we require is to absorb the culture around us and the language and the beliefs and the customs and so on. That's what Mother Nature has done with us. And it's been a tremendously successful trick we've taken over the whole planet as a result of this.

Speaker 3

14:59

So that's an interesting point. I mean, just to linger on it, that I mean this is a nice feature, like if you were to design a thing to survive in this world, do you put it at age 0, already equipped to deal with the world in a like hard-coded way, or do you put it, do you make it malleable and just throw it in, take the risk that you're maybe going to die, but you're going to learn a lot in the process, and if you don't die, you'll learn a hell of a lot to be able to survive in the environment.

Speaker 2

15:29

So this is the experiment that Mother Nature ran, and it turns out that, for better or worse, we've won. I mean, we put other animals into zoos and we, yeah.

Speaker 3

15:38

That's right. AI might do better.

Speaker 2

15:39

Okay, fair enough. That's true. And maybe what the trick Mother Nature did is just the stepping stone to AI.

Speaker 3

15:46

So that's a beautiful feature of the human brain, that it's malleable, but let's, on the topic of mother nature, what do we start with? Like how blank is the slate?

Speaker 2

15:58

Ah, so it's not actually a blank slate. What it's, terrific engineering that's set up in there, but much of that engineering has to do with, okay, just make sure that things get to the right place. For example, like the fibers from the eyes getting to the visual cortex or all this very complicated machinery in the ear getting to the auditory cortex and so on.

Speaker 2

16:17

So things, first of all, there's that. And then what we also come equipped with is the ability to absorb language and culture and beliefs and so on. So you're already set up for that. So no matter what you're exposed to, you will absorb some sort of language.

Speaker 2

16:32

That's the trick is how do you engineer something just enough that it's then a sponge that's ready to take in and fill in the blanks?

Speaker 3

16:39

How much of the malleability is hardware? How much is software? Is that useful at all in the brain?

Speaker 3

16:45

So like, what are we talking about? So there's like, there's neurons, there's synapses, and all kinds of different synapses, and there's chemical communication, like electrical signals, and there's chemical communication from the synapses. What, I would say, the software would be the timing and the nature of the electrical signals, I guess, and the hardware would be the actual synapses.

Speaker 2

17:14

So here's the thing. This is why I really, if we can, I wanna get away from the hardware and software metaphor because what happens is as activity passes through the system, it changes things? Now, the thing that computer engineers are really used to thinking about is synapses, where 2 neurons connect.

Speaker 2

17:31

Of course, each neuron connects with 10,000 of its neighbors. But at a point where they connect, what we're all used to thinking about is the changing of the strength of that connection, the synaptic weight. But in fact, everything is changing. The receptor distribution inside that neuron so that you're more or less sensitive to the neurotransmitter, then the structure of the neuron itself and what's happening there, all the way down to biochemical cascades inside the cell, all the way down to the nucleus, And for example, the epigenome, which is the, you know, these little proteins that are attached to the DNA that cause conformational changes that cause more genes to be expressed or repressed, all of these things are plastic.

Speaker 2

18:15

The reason that most people only talk about the synaptic weights is because that's really all we can measure well. And all this other stuff is really, really hard to see with our current technology. So essentially that just gets ignored. But in fact, the system is plastic at all these different levels.

Speaker 2

18:30

And my way of thinking about this is an analogy to pace layers. So pace layers is a concept that Stuart Brand suggested about how to think about cities. So you have fashion, which changes rapidly in cities. You have governance, which changes more slowly.

Speaker 2

18:52

You have the structure, the buildings of a city, which changes more slowly, all the way down to nature. You've got all these different layers of things that are changing at different paces, at different speeds. I've taken that idea and mapped it onto the brain, which is to say you have some biochemical cascades that are just changing really rapidly when something happens, all the way down to things that are more and more cemented in there. And this is actually, this actually allows us to understand a lot about particular kinds of things that happen.

Speaker 2

19:21

For example, 1 of the oldest, probably the oldest rule in neurology is called Ribo's Law, which is that older memories are more stable than newer memories. So when you get old and demented, you'll be able to remember things from your young life. Maybe you'll remember this podcast, but you won't remember what you did a month ago or a year ago. And this is a very weird structure, right?

Speaker 2

19:43

No other system works this way, where older memories are more stable than newer memories. But it's because through time, things get more and more cemented into deeper layers of the system. And so this is, I think, the way we have to think about the brain, not as, okay, you've got neurons, you've got synaptic weights and that's it.

Speaker 3

20:05

So yeah, so the idea of liveware and livewired, is that it's like a, it's a gradual, yeah, it's a gradual spectrum between software and hardware. And so the metaphors completely doesn't make sense. Cause like when you talk about software and hardware, it's really hard lines.

Speaker 3

20:26

I mean, of course software is unlike hard, but even hardware, but like, so there's 2 groups, but in the software world, there's levels of abstractions, right? There's the operating system, there's machine code, and then it gets higher and higher levels. But somehow that's actually fundamentally different than the layers of abstractions in the hardware. But in the brain, it's all like the same.

Speaker 3

20:53

And I love the city metaphor. I mean, yeah, it's kind of mind-blowing because it's hard to know what to think about that. Like if I were to ask the question, this is an important question for machine learning, is how does the brain learn? So essentially you're saying that, I mean it just learns on all of these different levels at all different paces.

Speaker 2

21:19

Exactly right. And as a result, what happens is as you practice something, you get good at something, you're physically changing the circuitry, you're adapting your brain around the thing that is relevant to you. So let's say you take up, do you know how to surf?

Speaker 3

21:34

No. Okay, great,

Speaker 2

21:35

so let's say you take up surfing. Yeah. Now at this age, what happens is, you know, you'll be terrible at first, you don't know how to operate your body, you don't know how to read the waves, things like that.

Speaker 2

21:44

And through time, you get better and better. What you're doing is you're burning that into the actual circuitry of your brain. You're of course conscious when you're first doing it, you're thinking about, okay, where am I doing? What's my body weight?

Speaker 2

21:53

But eventually when you become a pro at it, you are not conscious of it at all. In fact, you can't even unpack what it is that you did. Think about riding a bicycle. You can't describe how you're doing it.

Speaker 2

22:04

You're just doing it. You're changing your balance when you come, you know, you do this to go to a stop and stuff. So this is what we're constantly doing, is actually shaping our own circuitry based on what is relevant for us. Survival, of course, being the top thing that's relevant.

Speaker 2

22:18

But interestingly, especially with humans, we have these particular goals in our lives, computer science, neuroscience, whatever. And so we actually shape our circuitry around that.

Speaker 3

22:28

I mean, you mentioned this gets slower and slower with age, but is there, like I've, I think I've read and spoken offline, even on this podcast with a developmental neurobiologist, I guess would be the right terminology, is like looking at the very early, like from embryonic stem cells to the creation of the brain. And like, that's like, what? That's mind blowing how much stuff happens there.

Speaker 3

22:55

So it's very malleable at that stage.

Speaker 2

22:59

And then, but after that, at which point does it stop being malleable? So that's the interesting thing, is that it remains malleable your whole life. So even when you're an old person, you'll be able to remember new faces and names, you'll be able to learn new sorts of tasks, and thank goodness, because the world is changing rapidly in terms of technology and so on.

Speaker 2

23:19

I just sent my mother an Alexa and she, you know, figured out how to go in the settings and do the thing. And I was really impressed by that, that she was able to do it. So there are parts of the brain that remain malleable their whole life. The interesting part is that really your goal is to make an internal model of the world.

Speaker 2

23:36

Your goal is to say, okay, the brain is trapped in silence and darkness, and it's trying to understand how the world works out there, right?

Speaker 3

23:45

I love that image. Yeah, I guess it is. Yeah.

Speaker 3

23:49

You forget, it's like this lonely thing is sitting in its own container and trying to actually throw a few sensors, figure out what the hell's going on.

Speaker 2

23:58

You know what I sometimes think about is that movie The Martian with Matt Damon. The, I mean it was written in a book of course, but the movie poster shows Matt Damon all alone on the red planet. And I think, God, that's actually what it's like to be inside your head and my head and anybody's head is that you're essentially on your own planet in there.

Speaker 2

24:20

And I'm essentially on my own planet. And everyone's got their own world where you've absorbed all of your experiences up to this moment in your life that have made you exactly who you are. And Same for me and everyone. And we've got this very thin bandwidth of communication.

Speaker 2

24:36

And I'll say something like, oh, yeah, that tastes just like peaches. And you'll say, oh, I know what you mean. But the experience, of course, might be vastly different for us. But anyway, yes, so the brain is trapped in silence and darkness, each 1 of us, and what it's trying to do, this is the important part, it's trying to make an internal model of what's going on out there, as in how do I function in the world?

Speaker 2

24:59

How do I interact with other people? Do I say something nice and polite? Do I say something aggressive and mean? All these things that it's putting together about the world.

Speaker 2

25:08

And I think what happens when people get older and older, it may not be that plasticity is diminishing. It may be that their internal model essentially has set itself up in a way where it says, okay, I've pretty much got a really good understanding of the world now, and I don't really need to change. Right, so when much older people find themselves in a situation where they need to change, they can actually, or are able to do it. It's just that I think this notion that we all have that plasticity diminishes as we grow older is in part because the motivation isn't there.

Speaker 2

25:41

But if you were 80 and you get fired from your job and suddenly had to figure out how to program a WordPress site or something, you'd figure it out.

Speaker 3

25:48

Got it. So the capability, the possibility of change is there.

Speaker 2

25:53

But

Speaker 3

25:53

let me ask the highest challenge, the interesting challenge to this plasticity, to this liveware system. If we could talk about brain-computer interfaces and Neuralink, what are your thoughts about the efforts of Elon Musk, Neuralink, BCI in general in this regard, which is adding a machine, a computer, the capability of a computer to communicate with the brain and the brain to communicate with a computer at the very basic applications and then like the futuristic kind of thoughts.

Speaker 2

26:28

Yeah. First of all, it's terrific that people are jumping into doing that because it's clearly the future. The interesting part is our brains have pretty good methods of interacting with technology. So maybe it's your fat thumbs on a cell phone or something, or maybe it's watching a YouTube video and getting into your eye that way.

Speaker 2

26:45

But we have pretty rapid ways of communicating with technology and getting data. So if you actually crack open the skull and go into the inner sanctum of the brain, you might be able to get a little bit faster, but I'll tell you, I'm not so sanguine on the future of that as a business, and I'll tell you why. It's because there are various ways of getting data in and out, and an open-head surgery is a big deal. Neurosurgeons don't want to do it because there's always risk of death and infection on the table.

Speaker 2

27:19

And also, it's not clear how many people would say, I'm going to volunteer to get something in my head so that I can text faster, you know, 20% faster. So I think it's, you know, mother nature surrounds the brain with this armored, you know, bunker of the skull because it's a very delicate material. And there's an expression in neurosurgery about the brain is, you know, the person is never the same after you open up their skull. Now, whether or not that's true or whatever, who cares?

Speaker 2

27:51

But it's a big deal to do an open-head surgery. So what I'm interested in is how can we get information in and out of the brain without having to crack the skull open?

Speaker 3

28:00

Got it, Without messing with the biological part, like directly connecting or messing with the intricate biological thing that we got going on and it seems to be working.

Speaker 2

28:11

Yeah, exactly. And by the way, where Neuralink is going, which is wonderful, is going to be in patient cases. It really matters for all kinds of surgeries that a person needs, whether for Parkinson's or epilepsy or whatever.

Speaker 2

28:23

It's a terrific new technology for essentially sewing electrodes in there and getting more, higher density of electrodes, so That's great. I just don't think as far as the future of BCI goes, I don't suspect that people will go in and say, yeah, drill a hole in my head and do that.

Speaker 3

28:40

Well, it's interesting, because I think there's a similar intuition, but say in the world of autonomous vehicles, that folks know how hard it is, and it seems damn impossible. The similar intuition about, I'm sticking on the Elon Musk thing, is just a good, easy example. Similar intuition about colonizing Mars, it like, if you really think about it, it seems extremely difficult and almost, I mean, just technically difficult to a degree where you want to ask, is it really worth doing, worth trying?

Speaker 3

29:14

And then the same is applied with BCI. But the thing about the future is it's hard to predict. So the exciting thing to me with, so once it does, once if successful it's able to help patients, it may be able to discover something very surprising about our ability to directly communicate with the brain. So exactly what you're interested in is figuring out how to play with this malleable brain, but like help assist it somehow.

Speaker 3

29:49

I mean, it's such a compelling notion to me that we're now working on all these exciting machine learning systems that are able to learn, you know, from data. And then if we can have this other brain that's a learning system, that's live wired on the human side and then them to be able to communicate, it's like a self-play mechanism was able to beat the world champion at Go. So they can play with each other, the computer and the brain, like when you sleep. I mean, there's a lot of futuristic kind of things that it's just exciting possibilities.

Speaker 3

30:27

But I hear you, we understand so little about the actual intricacies of the communication of the brain, that it's hard to find the common language.

Speaker 2

30:38

Well, interestingly, the technologies that have been built don't actually require the perfect common language. So for example, hundreds of thousands of people are walking around with artificial ears and artificial eyes, meaning cochlear implants or retinal implants. So this is, you take a essentially digital microphone, you slip an electrode strip into the inner ear and people can learn how to hear that way.

Speaker 2

31:05

Or you take an electrode grid and you plug it into the retina at the back of the eye and people can learn how to see that way. The interesting part is those devices don't speak exactly the natural biological language. They speak the dialect of Silicon Valley. And it turns out that as recently as about 25 years ago, a lot of people thought this was never going to work.

Speaker 2

31:26

They thought it wasn't going to work for that reason, but the brain figures it out. It's really good at saying, okay, look, there's some correlation between what I can touch and feel and hear and so on, and the data that's coming in, or between, you know, I clap my hands and I have signals coming in there, and it figures out how to speak any language.

Speaker 3

31:44

Oh, that's fascinating. So like, no matter if it's Neuralink, so directly communicating with the brain, or it's a smartphone, or Google Glass, or the brain figures out the efficient way of communication. Well, exactly, exactly.

Speaker 3

32:00

And

Speaker 2

32:01

what I propose is the potato head theory of evolution, which is that all our eyes and nose and mouth and ears and fingertips, all this stuff is just plug and play. And the brain can figure out what to do with the data that comes in. And part of the reason that I think this is right, and I care so deeply about this, is when you look across the animal kingdom, you find all kinds of weird peripheral devices plugged in, and the brain figures out what to do with the data.

Speaker 2

32:25

And I don't believe that Mother Nature has to reinvent the principles of brain operation each time, to say, oh, now I'm gonna have heat pits to detect infrared. Now I'm gonna have something to detect, you know, electro receptors on the body. Now I'm gonna detect something to pick up the magnetic field of the earth with cryptochromes in the eye and so on. Instead, the brain says, oh, I got it.

Speaker 2

32:45

There's data coming in. Is that useful? Can I do something with it? Oh, great, I'm gonna mold myself around the data that's coming in.

Speaker 3

32:52

It's kind of fascinating to think that we think of smartphones and all this new technology as novel. It's totally novel as outside of what evolution ever intended or like what nature ever intended. It's fascinating to think that like the entirety of the process of evolution is perfectly fine and ready for the smartphone and the internet.

Speaker 3

33:14

Like it's ready, it's ready to be malleable to that. And whatever comes to cyborgs, to virtual reality, we kind of think like, this is, you know, there's all these like books written about natural, what's natural, and we're like destroying our natural selves by like embracing all this technology. It's kind of, you know, probably not giving the brain enough credit. Like this thing is just fine with new tech.

Speaker 2

33:40

Oh, exactly. It wraps itself around. And by the way, wait till you have kids.

Speaker 2

33:43

You'll see the ease with which they pick up on stuff. And as Kevin Kelly said, technology is what gets invented after you're born. But the stuff that already exists when you're born, that's not even tech, that's just background furniture. Like the fact that the iPad exists for my son and daughter, like that's just background furniture.

Speaker 2

34:02

So yeah, it's because we have this incredibly malleable system, it just absorbs whatever is going on in the world and learns what to do with it.

Speaker 3

34:11

So do you think, just to linger for a little bit more, do you think it's possible to co-adjust? Like, what kind of, you know, for the machine to adjust to the brain, for the brain to adjust to the machine. I guess that's what's already happening.

Speaker 2

34:30

Sure, that is what's happening. So for example, when when you put electrodes in the motor cortex to control a robotic arm for somebody who's paralyzed, the engineers do a lot of work to figure out, okay, what can we do with the algorithm here so that we can detect what's going on from these cells and figure out how to best program the robotic arm to move given the data that we're measuring from these cells. But also, the brain is learning too.

Speaker 2

34:54

So, you know, the paralyzed woman says, wait, I'm trying to grab this thing. And by the way, it's all about relevance. So if there's a piece of food there and she's hungry, she'll figure out how to get this food into her mouth with the robotic arm, because that is what matters.

Speaker 3

35:13

Well, that's, okay, First of all, that paints a really promising and beautiful, for some reason, really optimistic picture that our brain is able to adjust to so much. That so many things happened this year, 2020, that you think like, how are we ever going to deal with it? And it's somehow encouraging and inspiring that like we're going to be okay.

Speaker 2

35:40

Well, that's right. I actually think, so 2020 has been an awful year for almost everybody in many ways, But the 1 silver lining has to do with brain plasticity, which is to say, we've all been on our gerbil wheels, we've all been in our routines. And as I mentioned, our internal models are all about how do you maximally succeed?

Speaker 2

36:02

How do you optimize your operation in this circumstance where you are, right? And then all of a sudden, bang, 2020 comes, we're completely off our wheels. We're having to create new things all the time and figure out how to do it. And that is terrific for brain plasticity because, and we know this because there are very large studies on older people who stay cognitively active their whole lives.

Speaker 2

36:28

Some fraction of them have Alzheimer's disease physically, but nobody knows that when they're alive. Even though their brain is getting chewed up with the ravages of Alzheimer's, cognitively they're doing just fine. Why? It's because they're challenged all the time.

Speaker 2

36:43

They've got all these new things going on, all this novelty, all these responsibilities, chores, social life, all these things happening. And as a result, they're constantly building new roadways, even as parts degrade. And that's the only good news is that we are in a situation where suddenly we can't just operate like automata anymore. We have to think of completely new ways to do things.

Speaker 2

37:05

And that's wonderful.

Speaker 3

37:07

I don't know why this question popped into my head. It's quite absurd, but are we going to be okay? Yeah.

Speaker 3

37:17

You said this is the promising silver lining just from your own, because you've written about this and thought about this outside of maybe even the plasticity of the brain, but just this whole pandemic kind of changed the way it knocked us out of this hamster wheel like that, of habit, a lot of people had to reinvent themselves. Unfortunately, and I have a lot of friends who either are ready or are going to lose their business, you know, is basically, it's taking the dreams that people have had and said like, said this dream, this particular dream you've had will no longer be possible. So you have to find something new. What are your, are we gonna be okay?

Speaker 2

38:05

Yeah, we'll be okay in the sense that, I mean, it's gonna be a rough time for many or most people, but in the sense that it is sometimes useful to find that what you thought was your dream was not the thing that you're going to do. This is obviously the plot in lots of Hollywood movies that someone says, I'm gonna do this, and then that gets foiled and they end up doing something better. But this is true in life.

Speaker 2

38:32

I mean, in general, even though we plan our lives as best we can, it's predicated on our notion of, okay, given everything that's around me, this is what's possible for me next. But it takes 2020 to knock you off that where you think, oh, well, actually, maybe there's something I can be doing that's bigger, that's better.

Speaker 3

38:54

Yeah, you know, for me, 1 exciting thing, and I just talked to Grant Sanderson, I don't know if you know who he is, it's a 3 blue, 1 brown, it's a YouTube channel. He does, he's a, if you see it, you would recognize it. He's like a really famous math guy and he's a math educator and he does these incredible, beautiful videos.

Speaker 3

39:15

And now I see sort of at MIT, folks are struggling to try to figure out, if we do teach remotely, how do we do it effectively? So you have these world-class researchers and professors trying to figure out how to put content online that teaches people. And to me, a possible future of that is, Nobel prize winning faculty become YouTubers. Like that to me is so exciting.