David Eagleman: Neuroplasticity and the Livewired Brain | Lex Fridman Podcast #119
the following is a conversation with david eagleman a neuroscientist and one of the great science communicators of our time exploring the beauty and mystery of the human brain he is an author a lot of amazing books about the human mind and his new one 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 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 would i 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 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 five star snapple podcast follow on spotify support on patreon and connect with me on twitter at lex friedman as usual i'll do a few minutes of as now and no ads in the middle i try to make these interesting but i give you timestamps so you can skip 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 your nutritional bases that's where athletic greens will help their daily drink is like nutritional 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history debits and 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 so again if you get cash out from the app store google play and use code lex podcast you get ten dollars and cash up will also donate ten dollars the 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 it's called live wired by the way 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 it's um so i coined this new term livewear which is a system that's constantly reconfiguring itself physically as it as it learns and adapts to the world around it it's physically changing so it's uh live wear meaning like as like hardware but changing yeah exactly well it's the hardware and the software layers are blended and so um 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 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 uh all our devices a particular way but you know i can't tear half the circuitry out of your cell phone and expect it to still function but you can do that with uh with the brain so just as an example kids who are under about seven years old can get one half of their brain removed it's called the hemispherectomy and and they're fine they have a slight limp on the other side of their body but um they can function just fine that way and uh and this is generally true you know sometimes children are born without a hemisphere and their visual system rewires so that everything is on the on the single remaining hemisphere 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 how much of that is uh is a quark or a feature of evolution like how how hard is it to engineer because evolution took a lot of work billion trillions of organisms had to die for to create this thing we have uh in our skull uh like because you said uh you kind of look forward to the idea that uh we might be engineering our systems like this in the future but creating live war systems how hard do you think is it to create systems like that great question it has proven itself to be a difficult challenge but what i mean by that is even though it's taken evolution a really long time to get where it is now um we all we have to do now is peek at the at the blueprints it's just three pounds this organ and and we just figure out how to do it but that's the part that i mean is a difficult challenge because you know uh there are tens of thousands of neuroscientists were 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 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 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 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 but to even just linger he said it's possible to be born with just one hemisphere and you still are able to function first of all just just to pause on that i mean that's kind of that's amazing that's that's uh i don't know if people quite i mean you kind of hear things here and there this is what i'm kind of i'm really excited about your book is i don't know if there's definitive uh sort of uh popular sources to think about the stuff i mean there's a lot of i think from my perspective what i've heard is there's like been debates over decades about how 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 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 and so um 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 you know it's the ability of a system to to mold into a new shape and then hold that shape that's why you know we make things that we call plastic um because they are moldable and they can hold that new shape like a plastic toy or something and so maybe we use maybe we'll use a lot of terms that are synonymous so something is plastic something is malleable uh changing livewire the name of the book is is like so i'll tell you exactly right but i'll tell you why i chose livewire instead of plasticity so i used the term plasticity in the book but um but sparingly because that was a term coined by william james over 100 years ago and 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 the whole point is for it to keep changing so even in the you know few minutes of conversation that we've been having your brain is changing my brain is changing um next time i see your face i will remember oh yeah like that time next time i sat together and we did these things and i wonder if your brain will have like a lex thing going on for the next few months like you'll stay there until you get rid of it because it was useful for now 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 that looks familiar yeah yeah and we yeah we sat down for a podcast back when there were podcasts yeah exactly back when we lived outside virtual reality yeah exactly so you chose livewire exactly 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 uh for a while but yeah it implies something gets molded in shape and then holds that shape forever but in fact the whole system is completely changing then then back to uh how malleable is the human brain at each stage of life so what just at a high level is it malleable so yes and plasticity diminishes but one 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 are 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 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 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 you might break a leg and have to limp for a while stuff like that so because the data there is always changing by the way you might get on a bicycle you might get a surfboard things like that um because that data is always changing that stays more malleable and when you look through the brain you find that it appears to be this you know 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 do you think it's possible that uh depending on how much data you get on different sensors that it stays more malleable longer so like you know if you look at different cultures of 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 uh it that then the visual cortex might be much less malleable the reason i bring that up is like you know well maybe we'll talk about brain computer interfaces a little bit and down the line but you know like is this uh is the malleability a genetic thing or is it more about the data like i said that comes in 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 a an alligator it's born its brain does the same thing every generation if you compare an alligator a hundred thousand years ago to an alligator now they're essentially the same um 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 so that's an interesting point i mean just to lingard 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 zero 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 so this is the experiment that mother nature ran and and it turns out that for better worse we've won i mean yeah we put other animals into the zoos and we yeah that's right yeah i might do better okay fair enough that's true and and maybe what the trick mother nature did is just the stepping stone to uh to ai but so it's that's 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 ah so it's not actually a blank slate what it's 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 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 you will absorb some sort of language 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 how much of the malleability is hardware how much software is that useful at all in the brain so like what what are we talking about so there's like there's neurons there's uh synapses and the all kinds of different synapses and there's chemical communication like electrical signals and there's chemical communication from this in the synapses uh 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 so here's the thing this is why i really if we can i want to 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 is synapses where two neurons connect of course each neuron connects with ten thousands of its neighbors but at a point where they connect um what we're all used to thinking about is the changing of the strength of that connection the 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 than the structure of the neuron itself and 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 um 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 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 but in fact the system is plastic at all these different levels and my my way of thinking about this is an analogy to paste layers so paste layers is a concept that stewart brand suggested about how to think about cities so you have fashion which changes rapidly in cities you have um governance which changes more slowly you have the structure the buildings of a city which changes more slowly all the way down to 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 and mapped it onto the brain which is to say you have some biochemical cascades 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 uh this actually allows us to understand a lot about particular kinds of things that happen for example one of the oldest probably the oldest rule in neurology is called ribose 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 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 no other system works this way where older memories are more stable than newer members but it's because through time things get more and more cemented into deeper layers of the system and um 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 so yeah so the idea of live where and live wired is it is that it's 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 because like when you talk about software and hardware it's really hard lines i mean of course software is unlike card but even hardware but like so there's two 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 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 i love the city the city metaphor i mean yeah it's kind of mind-blowing because it it's hard to know what to uh think about that like if i were to ask the question uh this is 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 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 you're adapting your brain around the thing that is relevant to you so let's say you take up um do you know how to surf no okay great so let's say you take up surfing yeah now at this age um what happens is you know you'll be terrible at first you know how to operate your body you know how to read the waves things like that 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 um 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 you can't describe how you're doing you're just doing you're changing your balance when you come you know you do this to go to a stop and so so um 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 the top thing that's relevant 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 i mean you mentioned this gets slower and slower with age but is there like i've i think i've uh read and spoken offline even on this podcast developmental neurobiologist i guess would be the right terminology is like looking at the very early like from from embryonic stem cells to like to the to the creation of the brain and like that's like what that's mind-blowing how much stuff happens there so it's very malleable at that stage uh it's and then but after that at which point does it stop being malleable so so that's the interesting thing is that it remains valuable 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 i just sent my mother and alexa and she you know figured out how to go on the settings and do the thing and i was really yeah i was really impressed by 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 your goal is to say okay the brain uh is trapped in silence and darkness and it's trying to understand how the world works out there right i love that image yeah i guess it is yeah you forget you forget it's like this this lonely thing is sitting in its own container and uh trying to actually throw a few sensors figure out what the what the hell's going on you know what i sometimes think about is um the that movie the martian with matt damon the um it was written in a book of course but the 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 and i'm essentially on my own planet everyone's got their own world where you've absorbed all of your experiences up to this moment in your life that made you exactly who you are and same for me and everyone and um and we've got this very thin bandwidth of communication 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 might be vastly different for us um but anyway yes so the brain is trapped in silence and darkness each one of us and what it's trying to do this is the important part is trying to make an internal model of what's going on out there as in how do i function in the world how do i how do i interact with other people do i say something nice and polite or do i say something aggressive and mean do i you know all these things that it's putting together about the world 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 old when when much older people find themselves in a situation where they need to change they can actually 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 um but if you were 80 and you got fired from your job and suddenly had to figure out how to program a wordpress site or something you'd figure it out got it so the the capability the possibility of changes is there but let me ask the the highest challenge the interesting challenge to this uh plasticity to this uh livewear system uh if we could talk about brain computer interfaces and neurolink 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 the computer at the very basic applications and then like the futuristic kind of thoughts yeah first of all it's terrific that people are jumping and doing that because it's clearly the 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 but um or maybe it's watching a youtube video getting into your eye that way 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 um you might be able to get a little bit faster but i'll tell you i i'm 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 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 um 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 but it's a big deal to do in 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 got it without messing with the biologicals the part like directly uh connecting or messing with the with the intricate biological thing that we got going on it seems to be working yeah exactly and by the way where neural link 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 it's a terrific new technology for essentially sowing 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 well it's interesting because uh 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 uh similar intuition about colonizing mars it like if you really think about it it seems extremely difficult and uh and almost i mean just technically difficult to the to a degree where you want to ask is it really worth doing worth trying and then the same the same is applied with bci but the thing about the future is it's hard to predict uh the the exciting thing to me with uh so once it does once if successful it's able to help patients it may be able to discover something uh very surprising about our ability to directly communicate with the brain so exactly what you're interested in is figuring out how to uh play with this malleable brain but like help assist it somehow 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 in when on the human side and them to be able to communicate it's like a self playing mechanism was able to beat the game the world champion 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 um exciting possibilities 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 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 know you take uh essentially digital microphone you slip an electrode strip into the inner ear and people can learn how to hear that way 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 and it turns out that as as recently as about 25 years ago a lot of people thought this was never going to work they thought it was 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 hearing and so on and the data that's coming in or between you know i clap my hands and i and i have signals coming in there and it figures out how to speak any language oh that's fascinating so like uh no matter you're no matter if it's neural link uh 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 and what i propose is the potato head theory of evolution which is which is um that all you know 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 day 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 and i don't believe that mother nature has to reinvent the principles of brain operation each time to say oh now i'm going to have heat pits to detect infrared now i'm going to have something to detect uh you know electro receptors on the body now i'm going to test 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 there's data coming in is that useful can do something with it oh great i'm gonna mold myself around the data that's coming in it's kind of fascinating to think that we think of smartphones and all this new technology is novel as 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 oh yeah and the internet like it's ready it's ready to be valuable 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 cells by like embracing all this technology it's kind of it's you know we're not probably not giving the brain enough credit like this this thing this thing is just fine with new tech oh exactly it wraps itself around by the way wait till you have kids you'll see the ease with which they pick up on stuff and yeah as kevin kelly said um 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 so um yeah it's um because we have this incredibly malleable system it just absorbs whatever is going on in the world and learns what to do with it so do you think just to linger for for a little bit more do you think it's possible to co-adjust like we're kind of uh you know for the machine to adjust to the brain for the brain to adjust the machine i guess that's what's already happening 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 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 well that's uh okay first of all that pain's really promising and beautiful for some reason really optimistic picture that you know our brain is able to to adjust to so much um you know so many things happen this year 2020 that you think like how we're ever going to deal with it and it's somehow encouraging and inspiring that like we're going to be okay well that's right i actually think so 2020 has been an awful year for almost everybody in many ways but the one silver lining has to do with brain plasticity which is to say we've all been on our you know on our gerbil wheels we've all been in our routines and and you know as i mentioned our internal models are all about how do you maximally succeed 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 where 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 um there are very large studies on older people who stay cognitively active their whole lives some 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 they're they're challenged all the time 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 and and that's the only good news is that we are in a situation where suddenly we can't just operate like automaton anymore we have to think of completely new ways to do things and that's wonderful i don't know why this question popped into my head it's quite absurd but uh are we going to be okay yeah you say 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 uh this whole pandemic kind of changed the way it knocked us out of this uh hamster wheel like that of habit a lot of people had had to reinvent themselves unfortunately and i have a lot of friends who either already or or are going to lose their business you know is basically it it's taking the dreams that people have had and said like said this this dream this particular dream you've had will no longer be possible you have to find something new what are your are we gonna be okay 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 was not the thing that you're going to do um this is obviously the plot in lots of hollywood movies that someone says i'm going to do this and then that gets foiled and they end up doing something better but this is true in life i mean um 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 could be doing that's bigger that's better yeah you know for me one exciting thing and i just talked to grant sanderson i don't know if you know who he is it's a three blue one 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 he's incredible beautiful videos and now i see sort of at mit folks are struggling to try to figure out you know if we do teach remotely how do we do it effectively so you have these um 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 you know nobel prize winning faculty become youtubers like like that that to me is so exciting uh like what grant said uh which is like the possibility of creating canonical videos on the thing you're a world expert in uh you know there's so many topics that just the world doesn't you know there's faculty i mentioned russ cedric there's all these people in robotics that are experts in a particular beautiful field on which there's only just papers there's there's no popular book there's no there's no clean canonical video showing the beauty of a subject and one possibility is uh they they try to create that and and share it with the world this is this is the beautiful thing this of course has been happening for a while already i mean for example when i go and i give book talks often what'll happen is some 13 year old will come up to me afterwards and say something and i'll say my god that was so small like how how did you know that yeah and they'll say oh i saw it on a ted talk well what an amazing opportunity here you got the the best person in the world on subject x giving a 15-minute talk as as beautifully as he or she can and the 13 year old just grows up with that that's just the mother's milk right yeah as opposed to when we grew up you know i had whatever homeroom teacher i had and uh you know whatever classmates i had and and hopefully that person knew what what he or she was teaching and often didn't and you know just made things up so the the opportunity now has become extraordinary to get the best of the world and the reason this matters of course is because obviously back to plasticity the way that we the way our brain gets molded is by absorbing everything from the world all of the all of the knowledge and the data and so on that it can get and then um and then springboarding off of that and we're in a very lucky time now because we grew up with a lot of just in case learning so you know just in case you ever need to know these dates in mongolian history here there um but what kids are growing up with now like my kids is tons of just in time learning so as soon as they're curious about something they ask alex or they ask google home they get the answer right there in the context of the curiosity the reason this matters is because for plasticity to happen you need to care you need to be curious about something and this is something by the way that the ancient romans had had noted they had outlined seven different levels of learning and the highest level is when you're curious about a topic but anyway so kids now are getting tons of just in time learning and as a result they're going to be so much smarter than we are they're just and we can already see that i mean my boy is eight years old my girl is five but i mean the things that he knows are amazing because it's not just him having to do the rote memorization stuff that we did yeah that's it's just fascinating what the brain what young brains look like now because of all those ted talks just just loaded in there and there's there's also i mean a lot of people write kind of there's a sense that our attention span is growing shorter but you know it's complicated because um you know for example you know most people majority of people it's the 80 plus percent of people listen to the entirety of this thing it's just two three hours forward podcast long long-form podcasts or are becoming more and more popular so like that's that's it's all really giant complicated mess and the point is that the brain is able to adjust to it and somehow like form a world view within this new medium of like information that we have you have like these short tweets and you have these three four hour podcasts and you have netflix movie i mean it's just it's adjusting to the entirety and just absorbing it and taking it all in and then pops up kovid that forces us all to be home and it all just adjusts and and uh and figures it out yeah yeah it's fascinating you know been talking about the brain as if it's something separate from the human that carries it a little bit like whenever you talk about the brain it's easy to forget that that that's like that's us um like how much do you how much is the whole thing like predetermined like how much is it already encoded in there and how much is it the what's the uh the the actions the decisions the judgments this you mean like who you are who you are oh yeah yeah okay great question right so there used to be a big debate about nature versus nurture and we now know that it's always both you can't even separate them because you come to the table with a certain amount nature for example your whole genome and so on the experiences you have in the womb like whether your mother is smoking or drinking things like that whether she's stressed so on those all influence how you're going to pop out of the womb from there everything is an interaction between all of your experiences and the and the nature what i mean is i think of it like a space time cone where you have you drop in the world depending on the experience that you have you might go off in this direction or that direction in that direction because there's interaction all the way your experiences determine what happens with the expression of your genes so some genes get repressed some get expressed and so on and you actually become a different person based on your experiences there's a whole field called uh epigenomics which is or epi epigenetics i should say which is about the epigenome and that is the you know sort of the layer that sits on top of the dna and causes the genes to express differently that is directly related to the experiences that you have so if you know just as an example they take rat pups and you know one group is sort of placed away from their parents and the other group is groomed and licked and taken good care of that changes their gene expression for the rest of their life they go off in different directions in this in the space time cone um so yeah this is this is of course why it matters that we take care of children and pour money into things like education and good child care and so on for children broadly um because these formative years matter so much so is there a free will this is this is a great apologize for the for the absurd high-level philosophical questions no these are my favorite kind of questions here's the thing here's the thing we don't know if you ask most neuroscientists they'll say that we can't really think of how you would get free will in there because as far as we can tell it's a machine it's a very complicated machine enormously sophisticated 86 billion neurons about the same number of glial cells each of these things is as complicated as the city of san francisco each neuron in your head has the entire human genome in it it's expressing millions of gene products these are incredibly complicated biochemical cascades each one is connected to 10 000 of its neighbors which means you have you know like half a quadrillion connections in the brain so it's it's incredibly complicated but it is fundamentally appears to just be a machine and therefore if there's nothing in it that's not being driven by something else then it seems it's hard to understand where free will would come from so that's the camp that pretty much all of us fall into but i will say our science is still quite young and you know i'm a fan of the history of science and what the thing that always strikes me is interesting is when you look back at any moment in science everybody believes something is true and they just they simply didn't know about you know what einstein revealed or whatever and so who knows and they all feel like that we've at any moment in history they all feel like we've converted to the final answer exactly exactly like all the pieces of the puzzle are there and i think that's a funny illusion that's worth getting rid of and and in fact this is what drives good science is recognizing that we don't have most of the puzzle pieces so as far as the free will question goes i don't know at the moment it seems wow it would be really impossible to figure out how something else could fit in there but you know 100 years from now our textbooks might be very different than they are now i mean could i ask you to speculate where do you think free will could be squeezed into there like what's that even um is it is it possible that our brain just creates kinds of illusions that are useful for us or like what where where could it possibly be squeezed in well let me let me give a speculation and answer to your very nice question but but you know don't and the listeners podcast don't quote me on this i'm not saying this is what i believe to be true but let me just give an example i gave this the end of my book incognito so the whole book of incognito is about you know all the what's happening in the brain and essentially i'm saying look here's all the reasons to think that free will probably does not exist but at the very end i say look imagine that you are um you know imagine that you're a kalahari bushman and you find a radio in the sand and you've never seen anything like this and you you look at this radio and and you realize that when you turn this knob you hear voices coming from their voices coming from it so being a you know a radio materialist you try to figure out like how does this thing operate so you take off the back cover and you realize there's all these wires and when you take out some wires the voices get garbled or stop or whatever and so what you end up developing is a whole theory about how this connections pattern of wires gives rise to voices but it would never strike you that in distant cities there's a radio tower and there's invisible stuff beaming and that's actually the origin of the voices and this is just necessary for it so i mentioned this just as a speculation saying look how would we know what we know about the brain for absolutely certain is that if when you damage pieces and parts of it things get jumbled up but how would you know if there's something else going on that we can't see like electromagnetic radiation that is what's actually generating this yeah you paint a beautiful example of uh of how totally because we don't know most of how our universe works how totally off-base we might be with our science yeah until i mean we i mean um yeah i mean that's inspiring that's beautiful it's kind of terrifying it's humbling it's all all of the above and the important and the important part just to recognize is that of course we're in the position of having massive unknowns and you know we have of course the known unknowns and that's all the things we're pursuing in our labs and trying to figure out that but there's this whole space of unknown unknowns things we haven't even realized we haven't asked yet let me kind of ask a weird maybe a difficult question part of the it has to do with i've been recently reading a lot about world war ii i'm currently reading a book i recommend for people which is uh uh as a jew it's been difficult to read but uh the horizon follows the third reich so let me just ask about like the nature of genius the nature of evil if we look at somebody like uh einstein we look at hitler stalin modern day jeffrey epstein just folks who through their life have done with einstein done works of genius and with the others i mentioned have done evil on this world what do we think about that in a live wired brain like how do how do we think about these extreme people here's here's what i'd say this is a very big and difficult question but what i would say briefly on it is um you know first of all i saw a cover of time magazines some years ago uh and it was a big you know sagittal slice of the brain and it said something like um what makes us good and evil and there was a little spot pointing to it there's a picture of gandhi and there's a little spot that was pointing to hitler and these time magazine covers always make me mad because it's so goofy to think that we're going to find some spot in the brain or something instead the interesting part is because we're live-wired we are all about the world and the culture around us so somebody like adolf hitler got all this positive feedback about what was going on and the crazier and crazier the ideas he had he's like let's set up death camps and murder a bunch of people and so on somehow he was getting positive feedback from that and all these other people they're all you know spun each other up and you look at anything like i mean look at the you know um the the cultural uh revolution in china or the um you know the russian revolution or things like this where you look at these things my god how do people all behave like this but it's easy to see groups of people spinning themselves up in particular ways where they all say well would i have thought this was right in a different circumstance i don't know but fred thinks it's right and steve thinks everyone around you seems to think it's right and so um part of the maybe downside of having a live wired brain is that you can get crowds of people doing things um as a group so it's interesting to you know we would pinpoint hitler saying that's the evil guy but in a sense i think it was tolstoy you said the the king becomes um slave to the to the people in other words you know hitler was just a representation of whatever was going on with that huge crowd that he was surrounded with so um so i only bring that up to say that it's you know it's very difficult to say what it is about this person's brain or that person's brain he obviously got feedback for what he was doing the other thing by the way about what we often think of as being evil in society is um my lab recently published some work on in groups and out groups which is a very important part of this puzzle so it turns out that we are very we are very you know engineered to care about in-groups versus out-groups and this seems to be like a really fundamental thing so we did this experiment lab where we brought people in we stick them in the scanner and we i don't know it's something if you know this but uh we show them on the hand sorry we showed them on the screen six hands and uh the computer boop goes around randomly picks a hand and then you see that hand gets stabbed with a syringe needle so you actually see a syringe needle enter the hand and come out and it's really uh what that does is that triggers uh parts of the pain matrix this areas in your brain that involved in feeling physical pain now the interesting thing is it's not your hand that was stabbed so what you're seeing is is empathy this is you seeing someone else's hand get stabbed you feel like oh god this is awful right okay um we contrast that by the way with somebody's hand getting poked as a q-tip which is you know looks visually the same but it's um you don't have that same level of response now what we do is we label each hand with a with a one word label christian jewish muslim atheist scientologist hindu and now the computer goes around picks a hand stabs the hand and the question is how much does your brain care about all the people in your out group versus the one label that happens to match you and it turns out for everybody across all religions they care much more about their in group than their accurate and when i say they care what i mean is you get a bigger response from their brain everything's the same it's the same hands it's just a one-word label you care much more about your in-group than your outgroup and i wish this weren't true but this is how humans are i wonder how fundamental that is or if it's a it's the emergent thing about culture like if we lived alone with like if it's genetically built into the brain like this this longing for tribe so i'll so i'll tell you we addressed that so here's what we did there are two [Music] actually there are two other things we did as part of this study that i think matter for this point one is so okay so we show that you have a much bigger response by the way this is not a cognitive thing it's a very low level basic response to seeing pain in somebody okay great study by the way thanks thanks what we did next is we we next have it where we say okay the year is 2025 and these three religions are now in a war against these three religions and it's all randomized right but what you see is your thing and you have two allies now against these others and now it happens over the course of many trials you see everybody gets stabbed at different times and the question is do you care more about your allies and the answer is yes suddenly people who a moment ago you didn't really care when they got stabbed now simply with this one word thing that you're they're now your allies you care more about them but then what i wanted to do was look at how ingrained is this or how arbitrary is it so we brought new participants in and we said here's a coin toss the coin if it's heads you're an augustinian if it's a tails you're a justinian these are totally made up okay so they toss it they get whatever we give them a a ban that says you know augustinian on it whatever tribe they're in now um and they get in the scanner and they see a thing on the screen that says the augustinians and justinians are two warring tribes then you see a bunch of hands some are labeled augustine some are justinian and now you care more about whichever team you're on than the other team even though it's totally after and you know is arbitrary because you're the one to toss the coin yeah so it's it it's a state that's very easy to find ourselves in in other words just before walking in the door they'd never even heard of augustinian versus justinian and now their brain is representing it simply because they're told they're on this team you know uh now i did my own personal study of this uh it's uh so once you're an augustinian that tends to be sticky because i've been a packers fan uh going back pakistan my whole life now when i'm in boston with like the the patriots it's been tough going for my livewire brain to switch to the patriots to be so once you become it's it's interesting once the tribe is sticky yeah oh but that's true that's that's it you know you know we never tried that about saying okay now you're adjusting the enemy we're in august how sticky it is but there are studies of this of monkey troops uh on some island um and what happens is they look at the way monkeys behave when they're part of this tribe and how they treat members of the other tribe of monkeys and then what they do i forgotten how they do that exactly but they end up switching a monkey so he ends up in the other troop and very quickly they end up becoming a part of that other troop and and hating and behaving badly towards their original troop these are fascinating studies by the way yeah this is this is beautiful uh in your in your book you have uh you have a good light bulb joke uh how many psychiatrists does it take to change a light bulb only one but the light bulb has to want to change i'm sorry i'm a sucker for a good light bulb okay so given uh you know i've been interested in psychiatry uh my whole life just maybe tangentially i've kind of early on dream to be a psychiatrist until i understood what it entails uh but you know what um you know is there hope for psychiatry for somebody else to help this live wired brain to adjust oh yeah i mean in the sense that and this has to do with this issue about us being trapped on our own planet forget psychiatrists just think of like when you're talking with a friend and you say oh i'm so upset about this and your friend says hey just look at it this way uh you know all we have access to under normal circumstances is just the way we're seeing something and so it's super helpful to have friends and communities and psychiatrists and so on to help things change that way so that's just like interesting of help to us but but more importantly the role that psychiatrists have played is that there's this sort of naive assumption that we all come to the table with which is that everyone is fundamentally just like us and when you're a kid you you believe this entirely but as you get older and you start realizing okay there's something called schizophrenia and that's a real thing and to be inside that person's head is totally different than what it is to be inside my head or their psychopathy and and to be inside this psychopath's head he doesn't care about other people he doesn't care about hurting other people he's just doing what he needs to do to get what he needs um that's a different head there's a million different things going on and it is different to be inside those heads that this is where the field of psychiatry comes in now i think it's an interesting question about the degree to which is leaking into and taking over psychiatry and what the landscape will look like 50 years from now it may be that psychiatry as a profession you know changes a lot or maybe goes away entirely and neuroscience will essentially be able to take over some of these functions but it has been extremely useful to understand the differences between how people behave and why and what you can tell about what's going on inside their brain just based on observation of their behavior you uh this this might be years ago but i'm not sure there's an atlantic article you've written about moving away from a distinction between neurological disorders unquote brain problems and psychiatric disorders or quote unquote mind problems so so on that topic how do you think about this gray area yeah this is exactly this is exactly the evolution that things are going is you know there was psychiatry and then there were guys and gals in labs poking cells and so on those are the neurosciences but yeah i think these are moving together for exactly the reason you decided and where this matters a lot the atlantic article uh that i wrote was called the brain on trial where this matters a lot is it's the legal system because the way we run our legal system now and this is true everywhere in the world is you know someone shows up in front of the judge's bench or let's say there's five people in front of the judge's bench and they've all committed the same crime what we do because we feel like hey this is fair is alright you're gonna get the same sentence you'll all get three years in prison or whatever it is but in fact brains can be so different this guy's got schizophrenia this guy's a psychopath this guy's tweaked down on drugs and so on so that um it actually doesn't make sense to keep doing that and what we what we do in this country more than anywhere in the world is we imagine that incarceration is a one-size-fits-all solution and you may know we have the america has the highest incarceration rate in the whole world in terms of the percentage of our population we put behind bars so um there's a much more refined thing we can do as neuroscience comes in and changes and has the opportunity to change the legal system which is to say this doesn't let anybody off the hook it doesn't say oh it's not your fault and so on but what it does is it changes the equation so it's not about hey how blameworthy are you but instead is about hey what do we do from here what's the best thing to do from here so if you take somebody with schizophrenia and you have them break rocks in the hot summer sun in a chain gang all yeah that that doesn't help the schizophrenia that doesn't fix the problem um if you take somebody with a drug addiction who's in jail for you know being caught two ounces of some illegal substance and you put him in prison it doesn't actually fix the addiction it doesn't help anything happily what neuroscience and psychiatry bring to the table is lots of really useful things you can do with schizophrenia with drug addiction things like this um and that's why so i i don't know if he knows but i run a national non-profit called the center for science and law and it's all about this intersection of neuroscience and legal system and we're trying to implement changes in every county and every state um i'll just without going down that rabbit hole i'll just say one of the very simplest things to do is to set up specialized court systems where you have a mental health court that has judges and juries with expertise in mental illness because if you go by the way to a regular court and the person says um or the the defense lawyer says this person is schizophrenia most of the jury will say man i call bullshit on that why because they don't know about because they don't they don't know what it's about and it turns out people who who know about schizophrenia feel very differently as a juror than someone who happens not to know anybody schizophrenia they think it's an excuse so um you have judge injuries with expertise in mental illness and they know the rehabilitative strategies that are available that's one thing having a drug court where you have judges and jurors with expertise and rehabilitative strategies and what can be done and so on a specialized prostitution core and so on all these different uh things by the way this is very easy for counties to implement this sort of thing and this is this is i think where this matters to get neuroscience into public policy what's the process of injecting expertise into this so yeah i'll tell you exactly what it is a county needs to run out of money first i've seen this happen over and over so what happens is a county has a completely full jail and they say you know what we need to build another jail and then they realize god we don't have any money we can't afford this we've got too many people in jail and that's when they turn to god we need something smarter and that's when they set up specialized court systems oh we all function best when when our back is against the wall and that's what kovit is good for yeah it's because we we've all had our routines and we are optimized for the things we do and suddenly our backs are against the wall all of us yeah it's really i mean one of the exciting things about uh kovet i mean i'm a big believer in the the possibility of what government can do for the people and uh when it becomes too big of a bureaucracy it starts functioning poorly starts wasting money it's nice to uh i mean covers and reveals that nicely and lessons to be learned about who gets elected and who goes into government hopefully this hopefully this inspires talented and young people to go into government to revolutionize different aspects of it yeah so it's uh this that's the positive silver lining of of covid i mean i thought it'd be fun to ask you i don't know if you're paying attention to machine learning world and gpt3 so the gpt3 is this language model this neural network that's able to uh it has 175 billion parameters so it's very large and it's trained in an unsupervised way on the internet it just reads a lot of unstructured text and it's able to generate some pretty impressive things the human brain compared to that has about you know a thousand times more synapses people get so upset when machine learning people compare the brain and we know synapses are different it was very different very different right but like do you um what do you think about gpt3 here's what i think here's what i think a few things what gpt 3 is doing is extremely impressive but it's very different from what the brain does so um it's a good impersonator but just as one example everybody takes a passage that gpt three has has written and they say wow look at this and it's pretty good right but it's already gone through a filtering process of humans looking at it and saying okay well that's crap that's correct okay oh here's here's a sentence that's pretty cool now here's the thing human creativity is about absorbing everything around it and remixing that and coming up with stuff so in that sense we're sort of like gpt3 you know we're we're remixing what we've gotten in before but we also know we also have very good models of what it is to be another human and so um you know i don't know if you speak uh french or something but i'm not gonna start speaking in french because then you'll say wait what are you doing i don't understand it instead everything coming out of my mouth is meant for your ears i know what you'll understand i know the vocabulary that you know and don't know i know what parts you care about that's a huge part of it and so of all the possible sentences i could say i'm navigating this thin bandwidth so that it's something useful for our conversation yeah in real time but also throughout your life i mean you're you're coval we're co-evolving together we're learning exactly how to uh communicate together exactly but this is this is what gpt does not do all it's doing is saying okay i'm gonna take all these senses and remix stuff and pop some stuff out but it doesn't know how to make it so that you lex will feel like oh yeah that's exactly what i needed to hear um that's the next sentence that i needed to know about for something well of course it could be all the impressive results we'll see the question is when if you raise the number of parameters whether it's going to be after something it will not be it will not be no raising more parameters won't here's the thing it's not that i don't think neural networks can't be like the human brain as i suspect they will be at some point 50 years you know who knows but what we are missing in artificial neural networks is we've got this basic structure where you've got units and you've got synapses they're connected and and that's great and it's done incredibly mind-blowing impressive things but it's not doing the same algorithms as a human brain so when i look at my children as little kids as infants they can do things that no gpt3 can do they can navigate a complex room they can navigate social conversation with an adult um they can lie they can do a million things they they are active thinkers in our world and doing things and this of course i mean look we totally agree on in how incredibly awesome artificial neural networks are right now but we also know the things that they can't do well like you know like be generally intelligent do all these different reasons reason about the world efficiently learn efficiently adapt exactly but it's still the rate of improvement it's uh to me it's it's possible they'll be surprised like that but what i would what i would assert and then and i'm glad i'm going to say this on your podcast so we can look back at this in two years and 10 years is that we've got to be much more sophisticated than units and synapses between them let me give you an example and this is something i talk about in livewire is despite the amazing impressiveness mind-blowing impressiveness um computers don't have some basic things artificial neural networks don't have some basic things that we like caring about relevance for example so as humans we are confronted with tons of data all the time and we only encode particular things that are relevant to us we have this very deep sense of relevance that i mentioned earlier is based on survival at the most basic level but then all the things about my life and your life what's relevant to you that we encode um this is very useful computers at the moment don't have that they don't have a yen to survive and things like that so we filter out a bunch of the junk we don't need we're really good at efficiently zooming into the things we need again could be argued you know let me put on my freud hat maybe it's uh i mean that's our conscious mind uh you know we're not you know there's no reason that neural networks aren't doing the same kind of filtration i mean in the sense what gpt3 is doing so there's a priming step it's doing an essential kind of filtration when you ask it to generate tweets from from i don't know from from an elon musk or something like that it's doing a filtration of it's throwing away all the parameters it doesn't need for this task and it's figuring out how to do that successfully and then ultimately it's not doing a very good job right now but it's doing a lot better job than we expected but it won't ever do a really good job and i'll tell you why i mean so so let's say we say hey produce an elon musk tweet and we see like oh wow it produced these three that's great but again it's not we're not seeing the three thousand that produce that didn't really make any sense it's because it has no idea what it is like to be a human and all the things that you might want to say and all the reasons you wouldn't like when you go to write a tweet you might write something yeah it's not going to come off quite right in this modern political climate or whatever like you know you can change things so and it somehow boils down to fear and mortality and all of these human things at the end of the day all contained with that tweeting experience well interestingly the fear of mortality is at the bottom of this but you've got all these more things like you know oh i want to just in case the chairman of my department reads this i wanted to come off there just in case my mom looks at this tweet i want to make sure she you know and so on so that those are all the things that humans are able to sort of throw into the calculation but i mean uh what it required what it requires though is having a model of your chairman having a model of your mother having a model of the you know the person you want to go on a date with who might look at your tweet and so on all these things are uh you're running the reason about what it is like to be them so in terms of the structure of the brain again this may be going into speculation land i hope you go along with me is uh okay so the brain seems to be intelligent and our ai systems aren't very currently so where do you think intelligence arises in the brain like what what is it about the brain so if you mean where location wise it's no single spot it would be equivalent to asking i'm looking at new york city where is the economy the answer is you can't point to anywhere the economy is all about the interaction of all of the pieces and parts of the city and that's what you know intelligence whatever we mean by that in the brain is interacting from everything going on at once in terms of a structure so we look humans are much smarter than fish maybe not dolphins but dolphins are mammals right but i assert that what we mean by smarter has to do with live wiring so so what we mean when we say oh we're smarter is oh you can figure out a new thing and figure out a new pathway to get where we need to go and that's because fish are essentially coming to the table with you know okay here's the hardware go swim mate eat but we have the capacity to say okay look i'm gonna absorb oh oh but you know i saw someone else do this thing and and i read once that you could do this other thing and so on so do you think there's is there something i know the these are mysteries but like architecturally speaking what feature of the brain of uh of the live wire aspect of it that is really useful for intelligence so like is it the ability of neurons to reconnect like is there something is there any lessons about the human brain you think might be inspiring for us and to take into the artificial into the machine learning world yeah i'm actually just trying to write some up on this now called you know if you want to build a robot start with the stomach and what i mean by that what i mean by that is a robot has to care it has to have hunger it has to care about surviving that kind of thing here's an example so the penultimate chapter in my book um i titled the the wolf in the mars rover and i just look at this simple comparison of you look at a wolf it gets its leg caught in a trap what does it do it gnaws its leg off and then it figures out how to walk on three legs no problem now the mars rover curiosity got its front wheel stuck in some martian soil and it died this project that cost billions of dollars died because guys wheels so wouldn't it be terrific if we could build a robot that chewed off its front wheel and figured out how to operate with a slightly different body plan that's the kind of thing that we want to be able to build and to get there what we need the whole reason the wolf is able to do that is because its motor and somatosensory systems are live wired so it says oh you know what turns out i've got a body plan that's different than what i thought a few minutes ago but i i have a yen to survive and i care about relevance which in this case is getting to food getting back to my pack and so on so i'm just gonna figure out how to operate with this oh oops that didn't work oh okay i'm kind of getting it to work but the mars rover doesn't do that it just says oh geez i was pre-programmed to have four wheels and i have three i'm screwed yeah you know i i don't know if you're familiar with a philosopher named ernest becker he wrote a book called denial of death and there's a few psychologists sheldon solomon i think he i just spoke with him on his podcast who developed terror management theory which is uh like ernest becker is a philosopher that basically said that uh mortality fear of mortality is at the core of it yeah and so i i don't know if it sounds compelling as an idea that we're all i mean that all of the civilization we've constructed is based on this but it's i'm familiar with his work here's what i think i think that yes fundamentally this desire to survive is at the core of it i would agree with that but but how that expresses itself in your life it ends up being very different the reason you do what you do is i mean you could list the 100 reasons why you chose to write your tweet this way and that way and it really has nothing to do with the survival part it has to do with you know trying to impress fellow humans and surprise them and say something yeah so many things built on top of each other but it's it's fascinating to think that in artificial intelligence systems we want to be able to somehow engineer this drive for survival for immortality i mean because as humans we're not just about survival we're aware of the fact that we're going to die which is a very kind of where we're like space-time by the way aren't all right confucius said uh he said each person has two lives the second one begins when you realize that you have just one yeah but but most people it takes a long time for most people to get there i mean you could argue this kind of freudian thing which ernest becker uh argues is they it's they they actually figured it out early on and the terror they felt was like the reason it's been suppressed and the reason most people when i ask them about whether they're afraid of death they basically say no they basically say like um i'm afraid i won't get like submit the paper before i die like they kind of see they see death as a kind of uh inconvenient deadline for a particular set of like a book you're writing yeah it's as opposed to like what the hell this thing ends this at any moment like most people as if i have encountered do not meditate on the idea that like right now you could die like right now like it it's like it in in the next five minutes it could be all over and you know meditate on that idea i think that somehow brings you closer to like the core of the motivations and the core of the human cognition condition but like i said it is not yeah there's so many things on top of it but it is interesting i mean as the ancient poet said uh death whispers at my ear live for i come so it's it is certainly motivating when we think about that okay i've got some deadline i don't know exactly what it is but i better make stuff happen it is motivating but i don't think uh i mean i know for just speaking for me personally that's not what motivates me day to day it's instead oh i want to get this you know program up and running before this or i want to make sure my co-author isn't mad at me because i haven't gotten this in there i don't want to miss this grant deadline or you know whatever the thing is yeah it's too it's too distant in a sense nevertheless it is good to reconnect but for the ai systems none of that is there uh like a neural network does not fear it's mortality uh and that that seems to be somehow fundamentally missing the point i think that's missing the point but i wonder it's an interesting speculation about whether you can build an ai system that is much closer to being a human without the mortality and survival piece but just the thing of relevance just i care about this versus that right now if you have a robot roll into the room it's going to be frozen because it doesn't have any reason to go there versus there it doesn't have any particular set of things about this is how i should navigate my next move because i want something yeah there's a that's the thing about humans is they seem to generate goals they're like you said live wired i mean it it's very flexible in terms of the goals and creative in terms of the goals you generate when we enter a room you show up to a party without a goal usually and then you figure it out alone yes but this goes back to the question about free will which is when i walk into the party if you rewound it 10 000 times would i go and talk to that couple over there versus that person like i might do this exact same thing every time because i've got some goal stack and i think okay well at this party i really want to meet these kind of people or i feel awkward or i whatever you know whatever my goals are by the way so there was something that i meant to mention earlier if you don't mind going back which is this when we were talking about bci um so i don't know if you know this but what i'm spending ninety percent of my time doing now is running a company do you know about this yes i wasn't sure what the company is involved in right so talk about it yeah yeah so when it comes to the future of bci um you know you can put stuff into the brain invasively but my interest has been how you can get data streams into the brain non-invasively so i run a company called neosensory and what we build is this little um wristband we've built this in many different oh wow that's it yeah this is it and it's got these vibratory motors in it so these things as i'm speaking for example it's you know capturing my voice and running algorithms and then turning that into patterns of vibration here so people who are deaf for example learn to hear through their skin so the information is getting up to their brain this way and they learn how to hear so it turns out on day one people are pretty good like better than you would expect at being able to say oh that's weird it was that was that a dog barking was that a baby crying was that a door knock a doorbell like people are pretty good at it but with time they get better and better and what it becomes is a new qualia in other words a new subjective internal experience so on day one they they say whoa what was that oh oh that was the dog barking but by you know three months later they say oh there's dog barking somewhere oh there's the dog that's fascinating and by the way that's exactly how you learn how to use your ears so what you of course need to remember this but when you're an infant all you have are you know your eardrum vibrating causes spikes to go down your auditory nerves and impinging your you know auditory cortex your brain doesn't know what those mean automatically but what happens is you learn how to hear by looking for correlations you know you clap your hands as a baby you know you look at your mother's mouth moving and and that correlates with what's going on there and eventually your brain says i'm just going to summarize this as an internal experience as a conscious experience and that's exactly what happens here the weird part is that you can feed data into the brain not through the ears but through any channel that gets there as long as the information gets there your brain figures out what to do with it that's fascinating like expanding the set of sensors it could be could be arbitrarily uh could could it could yeah it could expand arbitrarily which is fascinating well exactly and by the way the reason i use this skin you know there's all kinds of cool stuff going on in the ar world class but the fact is your eyes are overtaxed and your ears are overtaxed and you need to be able to see and hear other stuff but you're covered with the skin which is this incredible computational material with which you can feed information and we don't use our skin for much of anything nowadays um my joke in the lab is that i say we don't call this the waste for nothing because originally we built as the vest and you know you're passing in all this information um that way and um what i'm doing here with with the deaf community is is what's called sensory substitution where i'm capturing sound and scent you know i'm just replacing the ears with the skin and that works um one of the things i talk about in livewire is sensory expansion so what if you took something like your your visual system which picks up on a very thin slice of the electromagnetic spectrum and you could see infrared or ultraviolet so we've hooked that up infrared and ultraviolet detectors and you know i can feel what's going on so just as an example the first night i built the infrared one of my engineers built at the infrared detector i was walking in the dark between two houses and suddenly i felt all this infrared radiation i was like where does that come from and i just followed my wrist and i found a um an infrared camera a night vision camera that was but like you know i immediately oh there there's that thing there but of course i would have never seen it but now it's just part of my reality that's fascinating yeah and then of course what i'm really interested in is sensory addition what if you could pick up on stuff that isn't even part of what we normally pick up on like you know like the magnetic field of the earth or twitter or stock market or things like that or the i don't know some weird stuff like the moods of other people or something like that sure now what you need is a way to measure that so as long as there's a machine that can measure it it's easy it's trivial to feed this in here and you come to be it comes to be part of your reality it's like you have another sensor and that that kind of thing is without doing like if you look in your link without i forgot how you put it but it was eloquent you know without getting cutting into the brain basically yeah exactly exactly so this this costs at the moment 399 dollars that's not going to kill you and yeah it's not going to kill you it's you just put it on and when you're done you take it off yeah um yeah and so uh and the name of the company by the way is neo sensory for new senses because the whole idea is beautiful you can as i said you know you come to the table with certain plug and play devices and then that's it like i can pick up on this little bit of the electromagnetic radiation you can pick up on on this little frequency band for hearing and so on but but but i'm stuck there and there's no reason we have to be stuck there we can expand our oom velt by adding new senses yeah what's um oh i'm sorry the umvelt is the slice of reality that you pick up on so each animal has its own hell of a word umvelt yeah exactly so i'm sorry i forgot to define it before it's it's it's such an important concept which is to say um for example if you are a a tick you pick up on uh butyric acid you pick up on odor and you pick up on temperature that's it that's how you construct your reality is with those two sensors if you are a blind echolocating bat you're picking up on air compression waves coming back you know echolocation if you are the black ghost knife fish you're picking up on changes in the electrical field around you with electro reception that's how they swim around and tell there's a rock there and so on but but that's that's all they pick up on that's their umvelt it's that's their the signals they get from the world from which to construct their reality and they can be totally different ooh belts and so our human umvelt is you know we've got little bits that we can pick up on one of the things i like to do with my students is talk about um imagine that you are a bloodhound dog right you are a blendhead dog with a huge snout with 200 million scent receptors in it and your whole world is about smelling you know you've got slits in your nostrils like big nose fulls of air and so on do you have a dog do you nope you used to used to okay so you know you walk your dog around and your dog is smelling everything the whole world is full of signals that you do not pick up on it so imagine if you were that dog and you looked at your human master and thought my god what is it like to have the pitiful little nose of a human yeah how could you not know that there's a cat 100 yards away or that your friend was here six hours ago and so the idea is because we're stuck in our own belt because we have this little pitiful noses we think okay well yeah we're seeing reality but but you can have very different sorts of realities depending on the peripheral plug-and-play devices you're equipped with it's fascinating to think that like if we're being honest probably our own belt is uh you know some infinitely tiny percent of the possibilities of how you can sense quote unquote reality even if you could i mean there's a guy named don uh donald uh hoffman yeah who based basically says uh we're really far away from reality in terms of our ability to sense anything like we we're very we're almost like we're floating out there that's almost like completely attached to the actual physical reality it's fascinating that we could have extra senses that could help us get a little bit a little bit closer exactly and by the way this has been the the fruits of science is realizing like for example you know you open your eyes and there's the world around you right but of course depending on how you calculate it it's less than a 10 trillion of the electromagnetic spectrum that we call visible light uh the reason i say it depends because you know it's actually infinite in all directions yeah and so that's exactly that and then science allows you to actually look into the rest of it exactly start understanding how big the world is out there and the same with the the world of really small and the world of really large exactly that's beyond our ability to sense exactly and so the reason i think this kind of thing matters is because we now have an opportunity for that first time in human history to say okay well i'm just going to include other things in my umvelt so i'm going to include infrared radiation and and have a direct perceptual experience of that and so i'm very you know i mean so you know i've given up my lab and i run this company 90 of my time now that's what i'm doing i still teach at stanford and i'm you know teaching courses and stuff like that but this is like this is your your passion the fire is as on this yeah i feel like this is the most important thing that's happening right now i mean obviously i think that because that's what i'm devoting my time and my life to but i mean it's a brilliant set of ideas it certainly is like it uh it's a step in uh in a very vibrant future i would say like that the possibilities there are are endless exactly so if you ask what i think about neural link i think it's amazing what those guys are doing and working on but i think it's not practical for almost everybody for example for people who are deaf they buy this and you know every day we're getting tons of emails and tweets or whatever from people saying wow i picked up on this and then i had no idea that was a i didn't even know that was happening out there yeah they're coming to here dude by the way this is you know less than a tenth of the price of a hearing aid and like 250 times less than a cochlear implant that's amazing uh people love hearing about uh what you know brilliant folks like yourself uh could recommend in terms of books of course you're an author of many books so i'll in the introduction mention all the books you've written people should definitely read live wired i've gotten a chance to read some of it it's amazing but is there three books technical fiction philosophical that had an impact on you when you were younger or today and books perhaps some of which you would uh want to recommend that others read ah you know as an undergraduate i majored in british american literature that was my major because i loved literature i grew up with literature my father had these extensive bookshelves and so i grew up in the mountains in new mexico and so that was mostly where i spent my time was reading books but um you know i love uh you know faulkner hemingway i love many south american authors gabriel garcia marquez and italo calvina i would actually recommend invisible cities i just i loved that book by italo calvino sorry it's a book of fiction um uh anthony door wrote a book called all the light we cannot see which actually uh was inspired by incognito by exactly what we were talking about earlier about how you can only see a little bit of the what we call visible light in the electromagnetic radiation i wrote about this in incognito and then he reviewed incognito for the washington oh no that's awesome and then he wrote this book the book has nothing to do with that but that's where the title comes from yeah all the light we cannot see is about the rest of the spectrum but um the that's a absolutely gorgeous book jesus that's the book of fiction yeah it's a book of fiction what's it about it takes place during world war ii uh about these two young people one of whom is blind and yeah anything else so any so you mentioned hemingway i mean uh old man the sea what uh what's your favorite uh um snows of kilimanjaro uh oh wow short stories that i love um as far as not as far as nonfiction goes i grew up uh with cosmos both watching the pbs series and then reading the book and that influenced me a huge amount in terms of what i do i as from the time i was a kid i felt like i want to be carl sagan like i just that's what i loved and in the end i just you know i studied space physics for a while as an undergrad but then i in my last semester discovered neuroscience last semester and i just thought well i'm hooked on that so the carl sagan of the brain is the aspiration yeah i mean uh you're doing you're doing um an incredible job of it so you open the book livewire with a quote by heidegger every man is born as many men and dies as a single one well what do you mean or what i'll tell you what i meant by it yeah i'll tell you so he he had his own reason why he was writing that but i meant this in terms of brain plasticity in terms of the library which is this issue that i mentioned before about this yeah this cone the space time cone that we are in which is that when you dropped into the world you lex had all this different potential you could have been a great surfer or a great chess player or you could have been thousands of different men when you grew up but what you did is things that were not your choice and your choice along the way you know you ended up navigating a particular path and now you're exactly who you are you still have lots of potential but the day you die you will be exactly lex you will be one person yeah so on that in that context i mean first of all it's just a beautiful it's a humbling picture but it's a beautiful one because that's uh all the possible trajectories and you pick one you walk down that road it's the robert frost poem but on that topic let me ask the the biggest and the most ridiculous question so in this live wide brain when we choose all these different trajectories and end up with one what's the meaning of it all what's uh is there is there a why here what's the meaning of life yeah david engelman that's it i mean this is the question that everyone has attacked from their own lifewire point of view by which i mean culturally if you grow up in a religious society you have one way of attacking that questions on if you grow up in a secular scientific society you have a different way of attacking that question obviously i i don't know i abstain on that question i mean i think one of the fundamental things i guess in that in all those possible trajectories is uh you're always asking i mean that's the act of asking what the heck is this thing for is equivalent to or at least runs in parallel to all the choices that you're making because it's kind of that's the underlying question well that's right and by the way you know this is the interesting thing about human psychology we've got all these layers of things at which we can ask questions and so if you keep asking yourself the question about what is the optimal way for me to be spending my time what should i be doing what charity should i get involved with and so on if you're asking those big questions that that steers you appropriately if you're the type person who never asks hey is there something better i could be doing with my time then presumably you won't optimize whatever it is that is important to you so you've uh i think just in your eyes in your work there's a passion uh that just is obvious and it's inspiring it's contagious what um if you were to give advice to us a young person today in the crazy chaos that we live today about life about how to how to uh how to discover their passion is there some words that you could give first of all i would say the main thing for a young person is stay adaptable and and this is back to this issue of why covet is useful for us because it forces us off our tracks the the fact is the jobs that will exist 20 years from now we don't even have names for we can't even imagine the jobs that exist and so when young people that i know go into college and they say hey what should i major in and so on college is and should be less and less vocational as in oh i'm going to learn how to do this and then i'm going to do that the rest of my career the world just isn't that way anymore with the the exponential speed of things so the important thing is learning how to learn learning how to be live wired and adaptable that's really key and what i tell what i advise young people when i talk to them is you know what you digest that that's what gives you the raw storehouse of things that you can remix and and be creative with and so eat broadly and widely and and obviously this is the wonderful thing about the internet world we live in now is you kind of can't help it you're constantly whoa you know you go down some mole hole of wikipedia and you think oh i didn't even realize that it was a thing i didn't know that existed and so embrace that embrace that yeah exactly and what i tell people is just always do a gut check about okay i'm reading this paper and yeah i think that but this paper wow that really i really cared about that in some way i tell them just keep a real sniff out for that and when you find those things keep going down those paths yeah don't be afraid i mean that that's one of the the challenges and the downsides of having so many beautiful options is that uh sometimes people are a little bit afraid to really commit but that that's very true if if there's something that just sparks yeah your interest and passion just run with it i mean that's it goes back to the hydera quote um i mean we only get this one life and that trajectory it does it doesn't last forever so just if something sparks your imagination your passion is wrong with it yeah exactly i don't think there's a more uh beautiful way to end it david it's a huge honor to finally meet you your work is inspiring so many people i've talked to so many people who are passionate about neuroscience about the brain even outside that uh read your book so i hope uh i hope you keep doing so i i think you're already there with carl sagan i hope you continue growing um yeah it was honor talking today thanks so much great you too lex wonderful thanks for listening to this conversation with david eagleman and thank you to our sponsors athletic greens betterhelp and cash app click the sponsor links in the description to get a discount and to support this podcast if you enjoy this thing subscribe on youtube review it with five stars and apple podcast follow on spotify support on patreon or connect with me on twitter at lex friedman and now let me leave you with some words from david eagleman in his book some for details from the afterlife imagine for a moment there were nothing but the product of billions of years of molecules coming together and ratcheting up to natural selection that were composed only of highways of fluids and chemicals sliding along roadways within billions of dancing cells the trillions of synaptic connections hum in parallel that this vast egg-like fabric of micro thin circuitry runs algorithms undreamt of in modern science that these neural programs give rise to our decision making loves desires fears and aspirations to me understanding this would be a numinous experience better than anything ever proposed in any holy text thank you for listening and hope to see you next time you