Speaker 1: Welcome to Scoot to Blow Your Mind production of My
Speaker 1: Heart Radio. Hey, welcome to Stuff to Blow Your Mind.
Speaker 1: My name is Robert Lamb. Joe is away from work.
Speaker 1: He's realigning his gray matter at the moment, so it's
Speaker 1: just me today, but I'll be joined by neuroscientist, author,
Speaker 1: and science communicator David Eagelman about his new book Live Wired,
Speaker 1: The Inside Story of the Ever Changing Brain. Now we've
Speaker 1: mentioned David Eagelman on the show many times before. He's
Speaker 1: an adjunct professor at Stanford University and his CEO of
Speaker 1: Neo Sensory, a company that develops devices for sensory substitution.
Speaker 1: You may also know him from his previous books about
Speaker 1: the human brain, his TV series The Brain with David Eagleman,
Speaker 1: and his role as a scientific advisor on HBO's Westworld,
Speaker 1: and the t NT series Perception. I'm recording this on
Speaker 1: a Monday, and I actually read Live Wired over the weekend.
Speaker 1: It's a highly addictive read and one that I think
Speaker 1: our listeners will will really enjoy. David does an amazing
Speaker 1: job breaking down the inner workings of the brain via
Speaker 1: relatable pop culture and historical metaphors. Everything from the Colonization
Speaker 1: of the America's to Mr Potato Head and Ellen Ripley
Speaker 1: from Aliens. It's published by Pantheon Books and you can
Speaker 1: currently grab it as a hardcover, an e book, or
Speaker 1: an audio book. And the fun thing is that that
Speaker 1: David reads the audio book. It's always great when you
Speaker 1: when you get that with an audio book. So, without
Speaker 1: without any further ado, let's jump right in. David Eagleman,
Speaker 1: thanks for joining me today. Great to be here, Robert.
Speaker 1: First of all, I have I just have to say
Speaker 1: that this book was such an engaging read. Actually read
Speaker 1: it all over the weekend, and while I was familiar
Speaker 1: with some of the findings and technologies discussed, there was
Speaker 1: plenty I hadn't been exposed to yet, and it was
Speaker 1: all delivered in such a fashion that it all ended
Speaker 1: up feeling like, you know, it's kind of like a revelation. Um,
Speaker 1: and I feel like that revelation is really well summarized
Speaker 1: in the title of the book, live Wired. If you would,
Speaker 1: could you summarize the basic difference between the idea of
Speaker 1: the live wired understanding of our brain as opposed to
Speaker 1: previous notions of how the brain worked. Yeah, I mean
Speaker 1: the whole The whole thing is that when you first
Speaker 1: pick up a neuroscience textbook as a young person, you
Speaker 1: see a picture of the brain and it says this
Speaker 1: parts or visions, parts are hearing, the parts are touch,
Speaker 1: and so on. But in fact, UM, I guess what
Speaker 1: I've spent the last twenty years, you know, in my
Speaker 1: laboratory really understanding the lesson of is that the brain
Speaker 1: is a is a dynamic system that's constantly moving around.
Speaker 1: And so, for example, if you go blind, the part
Speaker 1: that we would have called your visual system gets taken
Speaker 1: over by hearing and touch. If you lose an arm,
Speaker 1: the part of your body map that has an arm
Speaker 1: gets taken over by neighboring areas, and so on. The
Speaker 1: whole thing is this incredibly dynamic system. It's not like
Speaker 1: anything that we know how to build. Um. You know,
Speaker 1: here in Silicon Valley where I live, everything is about
Speaker 1: hardware and software, and engineers are praised for building an
Speaker 1: efficient system where you've got these two layers and that's it, um.
Speaker 1: But what's happening in our skulls is an entirely different
Speaker 1: kind of technology. And so I in the book, I
Speaker 1: ended up coining a new term for this live Wired
Speaker 1: or live where. And the idea with live where is
Speaker 1: that every moment of your life, this is reconfiguring itself.
Speaker 1: So you've got eighty six billion neurons, these are the
Speaker 1: cell types in the brain. You've got about point two
Speaker 1: quadrillion connections, and every moment in your life, these things
Speaker 1: are changing their strength of connection. They're unplugging, they're replugging elsewhere,
Speaker 1: they're seeking around. What you have are these dense jungles.
Speaker 1: And you know, this level of complexity is something that
Speaker 1: bankrupts our language. We don't have any way of talking
Speaker 1: about point two quadrillion connections moving and changing. But everything
Speaker 1: in your life, every experience that you have, UM changes
Speaker 1: who you are. When you learn, for example, that my
Speaker 1: name is David, there's a physical change in the structure
Speaker 1: of your brain. And that's what it means for you
Speaker 1: to then remember, you know, two months later, who's the
Speaker 1: guy you had on your podcast David. You know, it's
Speaker 1: like it's it's this constantly changing system and it's UM
Speaker 1: unlike anything that we know how to build at the moment.
Speaker 1: So UM you know, as you as you saw in
Speaker 1: the book, I tell these different stories just by way
Speaker 1: of introduction that are so fascinating, Like you can take
Speaker 1: out half the brain in a child. For example, when
Speaker 1: children have this really bad type of epilepsy, there's a
Speaker 1: surgery that they go through. Half the brain is removed,
Speaker 1: and they're just fine cognitively, they're totally fine because the
Speaker 1: rest of their brain, the other half says, Okay, I'm
Speaker 1: gonna rewire the functions that are that went missing from there.
Speaker 1: Sometimes a child is born with only half a brain,
Speaker 1: you know, and things just get get rewired so that
Speaker 1: it all is there and we can't you know, you
Speaker 1: can't do this with your cell phone or your computer.
Speaker 1: You can't take out half the circuitry and expect it
Speaker 1: to still function. But it works just fine, especially with
Speaker 1: a young brain. Now, with all of this in mind,
Speaker 1: into this live wired understanding of the brain in mind, um,
Speaker 1: I thought we might back up to a very basic question. Uh.
Speaker 1: Sometimes I guess we don't think about because we're I mean,
Speaker 1: we were trapped in the brain. We can't see the
Speaker 1: forest for the trees. But what what does the brain do?
Speaker 1: So the brain is locked in silence and darkness inside
Speaker 1: the vault of your skull, and all it's trying to
Speaker 1: do is make a model of the world, as in,
Speaker 1: I've got all this incoming data. And by the way,
Speaker 1: the data that comes into the brain is just spikes,
Speaker 1: just little electrical spikes, and these neurons. It doesn't know
Speaker 1: that these spikes represent photons, and these spikes represent air
Speaker 1: compression waves, and these spikes represent mixtures of molecules hitting
Speaker 1: a membrane and so on. All it knows is I've
Speaker 1: got data coming in as zeroes and ones and um
Speaker 1: and it knows that it can can troll a body.
Speaker 1: And so it's job is to figure out, all right,
Speaker 1: how do I control the body? How does that change
Speaker 1: the spikes coming in? And how do I make a
Speaker 1: model of the world. And this is an extraordinary technology
Speaker 1: that we have carrying around on our shoulders. Um, As
Speaker 1: I said, we we don't know how to build technology
Speaker 1: like this, and we're just scratching the surface of even
Speaker 1: trying to figure this out. But that's what the brain
Speaker 1: is doing, locked in its in its vault, is figuring out, Okay,
Speaker 1: how do I understand the world. And and it's really
Speaker 1: extraordinarily good at at extracting patterns and eventually making predictions
Speaker 1: and um, yeah, that is that is the main job
Speaker 1: that is trying to accomplish. Now, the big part of
Speaker 1: the book deals with how our senses, uh you know,
Speaker 1: speak to the brain and how the brain works around
Speaker 1: limitations uh such as that are the ones you mentioned
Speaker 1: with the half of the brain being missing at etcetera.
Speaker 1: And also uh you know relating limbs uh and uh
Speaker 1: and I love how use these various metaphors to explain
Speaker 1: that to the reader. Would you mind explaining to our
Speaker 1: listeners how our brains are, like Mr potato Head. Yeah,
Speaker 1: So this is something that struck me many years ago
Speaker 1: where I realized that, so we've got all these sensors
Speaker 1: like our eyes and our ears and our nose and
Speaker 1: our fingertips. All these things were used to and so
Speaker 1: we just sort of think of these as fundamental. But
Speaker 1: but when you look across the animal kingdom, what you
Speaker 1: find are all these other weird kinds of sensors, things
Speaker 1: that you could take in like snakes taken infrared information,
Speaker 1: honey bees taken ultra violet. When you look at something
Speaker 1: like the black Ghost knifefish, it has electro receptors where
Speaker 1: it's pulling in information about perturbations and electrical fields. Um.
Speaker 1: Lots of birds and cows and insects have magneto reception
Speaker 1: where they are picking up on the magnetic field of
Speaker 1: the planet and they're navigating that way and so on.
Speaker 1: And what I realized is Mother Nature doesn't actually have
Speaker 1: to recreate the brain every time she does this. Instead,
Speaker 1: the principles of brain operation, she's figured that out at
Speaker 1: the beginning in ing, and then she can just plug
Speaker 1: in anything she wants in terms of what is the
Speaker 1: information that would be useful to sense. And that's why
Speaker 1: I suggested this potato head model of how to think
Speaker 1: about this, which is to say, you just take any
Speaker 1: sensors and you stick it in and it's good to go.
Speaker 1: The brain figures out, Okay, I've got this kind of
Speaker 1: spikes coming in um, and it seems to correlate with
Speaker 1: this other sense, and it seems to allow me to
Speaker 1: find food or avoid predators or whatever. And so it
Speaker 1: just figures out what to do with that information. And
Speaker 1: so this is a very new kind of way to
Speaker 1: think about the brain. It's essentially understanding the brain as
Speaker 1: a general purpose compute device. You feed in whatever kind
Speaker 1: of data stream you want, and it's and it's good
Speaker 1: to go. And this, you know, explains a lot of
Speaker 1: what happens evolutionarily with genetics. It just what it allows
Speaker 1: Mother Nature to do is just tweak around with the
Speaker 1: genetics to make new kinds of sensors. But one of
Speaker 1: the really amazing things you you discussed in this is
Speaker 1: that is that you can plug an eye into an
Speaker 1: ear hole or an ear into an eye hole on
Speaker 1: the Mr Potato head of our of our brain, and
Speaker 1: the brain will roll with the data that that's exactly right.
Speaker 1: And so this is an area called sensory substitution, which
Speaker 1: is to say, you can feed information into the brain
Speaker 1: via an unusual channel. And so something I started in
Speaker 1: my lab about ten years ago was seeing if we
Speaker 1: could build sensory substitution for people who are deaf. So
Speaker 1: what we do. We started by building this as a
Speaker 1: vest with vibratory motors in it. So you've got a
Speaker 1: whole bunch of little buzzers like the buzzer in your
Speaker 1: cell phone, and um, it captures sound and turns out
Speaker 1: into patterns of vibration on the torso. And it turns
Speaker 1: out that that worked really well. We could get people
Speaker 1: who are profoundly deaf to start understanding what is happening
Speaker 1: in the auditory world just predicated on this spatio temporal
Speaker 1: pattern of vibrations on their skin. And the reason it
Speaker 1: worked is because it doesn't matter how the information gets
Speaker 1: to the brain. As long as it gets there, the
Speaker 1: rain will establish the correlations and figure out what to
Speaker 1: do with it. So, as an example, if you see,
Speaker 1: you know, the dog's mouth moving and you feel the
Speaker 1: buzzing on your skin, you know, your brain puts that
Speaker 1: together really easily. Or you know, you see somebody speaking,
Speaker 1: or or we train people by showing a word and
Speaker 1: you you know, you feel the world on the vest
Speaker 1: and you start understanding what's going on. So what we
Speaker 1: did then is we shrunk it down to the size
Speaker 1: of a wrist band. And because you and I are
Speaker 1: on video, Robert, you can see the wrist band that
Speaker 1: I'm wearing right now. It's you know, it looks about
Speaker 1: the size of a fitbit and it has very sophisticated
Speaker 1: computation in here where it's capturing sound and turning that
Speaker 1: into patterns vibration around the skin of the wrist. And um,
Speaker 1: so what we've been doing is we uh this Actually
Speaker 1: now I spun a company out of my lab called
Speaker 1: neosensory and we have been on the market since March
Speaker 1: and we're now on wrists all around the world. So
Speaker 1: people who are deaf for have hearing loss of some
Speaker 1: degree where this and they are picking up on the
Speaker 1: auditory world through their skin. Now, the interesting part is
Speaker 1: this is exactly what the inner ear is doing. Your
Speaker 1: inner ear is just registering vibrations of your ear drum
Speaker 1: and it breaks sound up into from high to low frequency,
Speaker 1: and then it ships it off to the brain. And
Speaker 1: all we're doing is transferring the inner ear to to
Speaker 1: the wrist and it works. So that's the idea of
Speaker 1: sensory substitution. Is your um just getting the information there
Speaker 1: via a different route and the brain figures out what
Speaker 1: to do with it. And if this weren't amazing enough,
Speaker 1: there's this then this this other additional step, this idea
Speaker 1: of of plugging all new things into it, like new
Speaker 1: forms of sensory information, new even uh, you know, not
Speaker 1: only limbs of replacement, but artificial additional limbs. Use the
Speaker 1: example of doctor Octopus from the spider Man comics. Um,
Speaker 1: can you tell us a little bit about how even
Speaker 1: like this nineteen sixties sci fi concept is not that
Speaker 1: far removed from our current understanding of the brain. Yeah,
Speaker 1: so um, let me actually let me say two things. Actually,
Speaker 1: one is what we can do, so let me just
Speaker 1: separate out sensory information coming in and motor information going out.
Speaker 1: So sensory information coming in. One of the things we're
Speaker 1: doing with the with our wristband called buzz Um is
Speaker 1: we can not only take in sound information for people
Speaker 1: who are deaf, but we could actually expand the sensory
Speaker 1: information that you would normally have. So for example, with
Speaker 1: somebody who's not deaf, we feed in ultra violet or
Speaker 1: infrared or or things like that, where we're expanding senses
Speaker 1: that you already have. And then we're doing this other
Speaker 1: thing called sensory addition, where we're feeding in brand new
Speaker 1: senses that you've never had. So we can feed in
Speaker 1: any day to stream with this, like stock market data
Speaker 1: or Twitter data or factory information or anything at all.
Speaker 1: Feeding this in and as long as your brain can
Speaker 1: make correlations with what it's seeing or hearing around it,
Speaker 1: then the brain can figure out how to utilize that information.
Speaker 1: So we actually just finished a big developer contest where
Speaker 1: people did all kinds of projects with you know um
Speaker 1: monitoring air quality or monitoring you know, blood sugar and
Speaker 1: your bloodstream or um. Um many many different kinds of
Speaker 1: monitoring of feeling, electrical fields and so on. UM. So
Speaker 1: all this, by the way, if if anybody is interested,
Speaker 1: we have an open a p I and an s
Speaker 1: d K four buzz. You can get this on neo
Speaker 1: central dot com and pursue any kind of project you
Speaker 1: want this way. So we've had hundreds of people just
Speaker 1: making their own thing, which has been which has been
Speaker 1: very cool. Now to switch to the second thing about
Speaker 1: motor output. UM, Yeah, it turns out that your brain
Speaker 1: UM is not pre programmed to drive your body, but
Speaker 1: instead can figure out whatever the affordances are of whatever
Speaker 1: is there. So just as an example, you know, one
Speaker 1: of the things I tell the story about this dog
Speaker 1: UM that was born without four limbs. It didn't have
Speaker 1: his front legs, and so it just she walked bipetally.
Speaker 1: She walks on her back legs like a human and
Speaker 1: presumably any dog could do this, but they're not sufficiently motivated,
Speaker 1: but so she just walks around her hind legs and UM.
Speaker 1: What this illustrates is that dog brains are not pre
Speaker 1: programmed to drive dog bodies, but instead they figure out, Okay,
Speaker 1: here's what I can do. I need to get to
Speaker 1: my food, to my water, to my mother whatever. This
Speaker 1: is how I do it. And so um. Also, I
Speaker 1: you know, tell the story of the guy who's the
Speaker 1: world's best archer. He has the world's record for best
Speaker 1: archery shot, and he doesn't have arms, so he does
Speaker 1: this with his legs. And it's just another illustration that
Speaker 1: the brain figures out whatever body it's in says okay,
Speaker 1: I figure how to drive this. Of course, we see
Speaker 1: this when people, for example, get an amputation. Let's say
Speaker 1: they lose an arm in a motorcycle, accent or something.
Speaker 1: The map of their body in their brain readjusts to say, Okay,
Speaker 1: I see I've got a body without an arm, so
Speaker 1: I'm just gonna figure that out now. Okay. So, because
Speaker 1: it is not pre programmed, it's extremely flexible. Um. I
Speaker 1: think that we could actually build any kind of body
Speaker 1: we want. So um, coming back to your question, I
Speaker 1: you know mentioned about Doc Cock in the nineteen sixties,
Speaker 1: which debuted in spider Man, the scientist who plugs in
Speaker 1: four robotic arms so that he can actually do extra
Speaker 1: things and poor beakers and so on, and he controls
Speaker 1: us with his brain. But then there's an explosion his
Speaker 1: lab and he turns evil and he scales buildings and
Speaker 1: learns new forms of martial arts with with eight arms
Speaker 1: and so on, and um, Dr Octavia starts to go
Speaker 1: by Doc Dock. Anyway, UM, the exactly as you said,
Speaker 1: This is not as far off and weird as we
Speaker 1: used to think, because now what we're doing is with
Speaker 1: for example, patients who are paralyzed. Um, you can put
Speaker 1: electrodes into their motor cortex and they can learn to
Speaker 1: drive a robotic arm even though they are paralyzed. They
Speaker 1: drive the robotic arm with their thoughts, which sounds weird,
Speaker 1: but that's of course, how you drive your fleshy arm.
Speaker 1: You just you know, you think about it, you learned
Speaker 1: the you learned what the put signals are that make
Speaker 1: your arm respond. It's the same thing with the robotic arm,
Speaker 1: and you can do that. And there have been experiments
Speaker 1: with monkeys where they their bodies work fine, they're not paralyzed,
Speaker 1: but they can drive a third arm with you know,
Speaker 1: with their thoughts. So they're driving a robotic arm with
Speaker 1: their thoughts. There was an experiment done where a monkey
Speaker 1: um uses his motor cortex to make a robot walk.
Speaker 1: But the interesting part was the robot happened to be
Speaker 1: across the world. The monkey was in North Carolina and
Speaker 1: the robot was in Japan, and the signals from the
Speaker 1: monkey's brain were being sent over the internet. And you
Speaker 1: can get the robot, you know, the monkey to control
Speaker 1: the robot just with the spikes in its motor cortex.
Speaker 1: And so, UM, I think it's going to be no
Speaker 1: time at all before we really start controlling external devices
Speaker 1: with our thoughts. And one of the things, one of
Speaker 1: the frameworks that I build is this issue that what
Speaker 1: we think of as the self, what you think of
Speaker 1: as your body, just as a matter of control, what
Speaker 1: can you control with your body? And I think this
Speaker 1: is by the way, why we understand our reflections in
Speaker 1: a mirror to be us. Because you move in it moves,
Speaker 1: and so you're driving what you're seeing over there, so
Speaker 1: you think, oh, yeah, that's me over there. Um. But
Speaker 1: what this means is in you know, make up a
Speaker 1: number thirty five years, when we are controlling a robot
Speaker 1: with our thoughts, it is essentially an extension of our body.
Speaker 1: What it means is that that will become us. It
Speaker 1: will be a part of of your body. All right,
Speaker 1: we're going to take a quick break, but I'll be
Speaker 1: right back with David Eagleman. Thank alright, I'm back with
Speaker 1: David Eagleman. In the book, you talk about the live
Speaker 1: wired brain as as being a place of competition, um,
Speaker 1: based on the input that's coming in. And I was
Speaker 1: just really uh intrigued by this, this new theory of
Speaker 1: dreaming that you discuss. Would you would you mind h
Speaker 1: sharing that with our listeners. Yeah, um, yeah, this is
Speaker 1: something very cool that's come out of our studies of plasticity,
Speaker 1: and UM here it is. It's that when any part
Speaker 1: of the brain goes unused, it gets taken over. And
Speaker 1: so for example, if you go blind, your systems for
Speaker 1: hearing and touch and all of that real estate will
Speaker 1: take over the part of the brain that we used
Speaker 1: to call the visual cortex. So the surprise in neuroscience
Speaker 1: has been how rapidly this happens. Um. What group found
Speaker 1: about thirteen years ago was that if you take sighted
Speaker 1: people and you blindfold them tightly and you stick them
Speaker 1: in a brain scanner, within about an hour you can
Speaker 1: start seeing activity in the visual cortex just based on
Speaker 1: um hearing or touch. If you touch them on the
Speaker 1: hand or something, you start seeing activation in the visual cortex. Now,
Speaker 1: it's not because the neurons have had a chance to
Speaker 1: grow that fast from hearing and touch into the visual cortex. Instead,
Speaker 1: there's all kinds of cross wiring the brain where those
Speaker 1: systems are already reaching over into the visual cortex. It's
Speaker 1: just that they're normally silenced and they're inhibited, so they
Speaker 1: don't get to do anything. But that inhibition starts wearing
Speaker 1: off very quickly. And so I was really shocked by
Speaker 1: the speed at which hearing and touch could take over.
Speaker 1: And so my student and I were talking about this
Speaker 1: one day, and what we realized is there's a very
Speaker 1: critical thing that happens because we live on a planet
Speaker 1: that rotates into darkness for half the time. You know,
Speaker 1: in the dark you can still hear and touch and
Speaker 1: taste and smell and all that just fine, but you
Speaker 1: can't see. And of course I'm talking about evolutionary time,
Speaker 1: not recent electricity times. And so um, what this means
Speaker 1: is that the visual cortex has always been in a
Speaker 1: big disadvantage when the planet rotates into darkness. And so
Speaker 1: what we realized is, Wow, if it doesn't want to
Speaker 1: get taken over by the other senses, it has to
Speaker 1: have some way of defending its territory. And what we
Speaker 1: realized was that that's what dreams are. You have this
Speaker 1: very specific circuitry that starts in the midbrain and goes
Speaker 1: through a series of depths and just blasts activity into
Speaker 1: the visual cortex every night about every ninety minutes, and
Speaker 1: and that's its only job. It's just blast activity in there.
Speaker 1: It's very specialized circuitry. It's very specific of the type
Speaker 1: of thing that to the ananimouss eye is not accidental.
Speaker 1: And so and of course, because it's our visual cortex,
Speaker 1: we you know, we see and we think, oh, I'm
Speaker 1: having this full, rich visual experience. Um. And of course
Speaker 1: dream content might have to do with you know, it
Speaker 1: certainly has to do with what you've experienced during the
Speaker 1: day in which synapses are still hot and so on.
Speaker 1: But but the point is that it's just blasting activity
Speaker 1: in there to defend the visual system against takeover. And
Speaker 1: so we've now done big studies on this. For example,
Speaker 1: where I'll just give you one thing that we just
Speaker 1: published recently where we compared twenty five different species of
Speaker 1: primates and we looked at how plastic they were, because
Speaker 1: across even the primate kingdom, you have this um you know,
Speaker 1: spectrum of how plastic you drop into the world and
Speaker 1: then how much rems sleep they get in other words,
Speaker 1: how much you know, rapid eye movement or or dream sleep,
Speaker 1: because this is when dreams happen. And it turns out
Speaker 1: that the more plastic you are as a species, the
Speaker 1: more dream sleep you have because you need to defend
Speaker 1: it more. As opposed to the other end of the spectrum.
Speaker 1: And say, lemurs drop into the world and they're pretty
Speaker 1: much fully baked um and they have very short you know,
Speaker 1: adolescents time and walking time and weaning time and all
Speaker 1: that stuff. Um, they don't have much dream sleep because
Speaker 1: they don't need it because their brain is sort of
Speaker 1: baked into place. And by the way, I'll just mention
Speaker 1: one other thing because people sometimes ask about this, which
Speaker 1: is um you know, they say, do blind people dream? Yes,
Speaker 1: blind people have dreams where activity is getting shot into
Speaker 1: their occipital lobe at the back of their head. But
Speaker 1: because they are blind, they don't experience that is vision. Instead,
Speaker 1: they experience. It is hearing and touch. So blind people's
Speaker 1: dreams are all about you know, weird bizarre things just
Speaker 1: like ours, but it's not involving vision. It's you know,
Speaker 1: I'm I'm walking around the house and all my furniture
Speaker 1: is rearranged and I'm feeling stuff, and then there's a
Speaker 1: air and I'm feeling the bear and all that kind
Speaker 1: of stuff. So um, but it's exactly the same circuitry
Speaker 1: that they have, because this is a very fundamental circuitry
Speaker 1: that has burned into the system. And it doesn't care
Speaker 1: whether your eyes are working or not, because it's it's more,
Speaker 1: it's deeper than that, and has working on this has
Speaker 1: has changed the way you reflect on your own dreams
Speaker 1: at all. You know, I've always actually felt that dreams
Speaker 1: are not terribly meaningful like my own. You know, I
Speaker 1: wake up. I've always described this as sort of sticking
Speaker 1: your head in the night blender each night. I kind
Speaker 1: of hate trede Um, But now I have a deeper
Speaker 1: appreciation for why I'm going through that night blender because um,
Speaker 1: if not, I would wake up in my visual system
Speaker 1: would be really disadvantaged. It would be taken over in
Speaker 1: large part by hearing it by touch. Especially in the
Speaker 1: later portions of the book, you you get into two
Speaker 1: memories and and even identity, and there's there's a lot
Speaker 1: that really seems to resonate with the state of the
Speaker 1: world right now. How do you feel this book speaks
Speaker 1: to the reader? Yeah, I think there. I think there
Speaker 1: are many ways. Um I'll mention too. One is actually,
Speaker 1: let me start with this optimistic one, which is um
Speaker 1: as lousy as has been for everybody. And you know,
Speaker 1: this is a year where there's serious spikes for everybody
Speaker 1: in stress, anxiety, depression. It's just there's all kinds of
Speaker 1: bad stuff. But I will mention one tiny silver lining
Speaker 1: of this is that, from the point of view of
Speaker 1: brain plasticity, we've all been kicked off of our hamster
Speaker 1: wheels and we're all being forced to rethink many things
Speaker 1: that we never thought about before. So I mentioned before
Speaker 1: that our brain is locked in silence and darkness, is
Speaker 1: trying to make an internal model of the world out there,
Speaker 1: and we all pretty much had that. We thought, Okay,
Speaker 1: I get how the world works, I get how things operate,
Speaker 1: how people respond, how to get toilet paper, how to
Speaker 1: get food in my fridge, stuff like that, and all
Speaker 1: of a sudden everything changed. And from the point of
Speaker 1: view of brain plasticity, this is actually really useful. It
Speaker 1: has forced a kind of creativity, an unwanted one for sure,
Speaker 1: but it's forced kind of creativity where you're having to
Speaker 1: rethink everything. We're having to understand many things in more
Speaker 1: depth that we never thought twice about before. And um
Speaker 1: it turns out when we look at things like you know, dementia,
Speaker 1: what happens is people retire and they stop challenging themselves,
Speaker 1: and their brains end up in a worse and worse state.
Speaker 1: And the people who retire and end up fine and
Speaker 1: much better off are those who keep challenging themselves with
Speaker 1: novel things. And that includes even basic things like just
Speaker 1: you know, making sure you're not just sitting around watching TV,
Speaker 1: but instead, you know, taking on new sorts of challenges
Speaker 1: and tasks and keeping an active social life and stuff
Speaker 1: like that. So anyway, this is what's happening to all
Speaker 1: of us. And I have a slight suspicion this will
Speaker 1: be hard to prove, but just an intuition that we
Speaker 1: may find a slight dip in dementia UM in in
Speaker 1: the coming years. For people who have been you have
Speaker 1: lived through this early twenties, um, simply because they've really
Speaker 1: gotten a chance to build all kinds of new roadways
Speaker 1: in their brain, whereas they might not have done that
Speaker 1: as as adults. The second thing that I'll mention as
Speaker 1: far as is one of the things that my lab
Speaker 1: has been studying for a very long time is social neuroscience,
Speaker 1: which is this issue of how there's a lot of
Speaker 1: the brain circuitry that's devoted to other people. In other words,
Speaker 1: you know, we normally look at the brain and we
Speaker 1: think already there's hearing, these touchows, vision and so on,
Speaker 1: But in fact, a lot of your circuitry has to
Speaker 1: do with modeling other people. And you might know a
Speaker 1: thousand people and you've actually got circuitry devoted to every
Speaker 1: one of them, and circuitry devoted to okay, who knows
Speaker 1: who and have they dated before and blah blah blah.
Speaker 1: I mean, it's it's a very sophisicated social system that
Speaker 1: we're carrying around. And so one of the things that
Speaker 1: got me interested a long time ago, and we've published
Speaker 1: and written on this for years, but suddenly it really
Speaker 1: is important. Is this issue about in groups and out groups,
Speaker 1: and it turns out that, um we here, I'll just
Speaker 1: tell you really quickly about a study we did. We
Speaker 1: take people into the brain scanner and we show them
Speaker 1: six hands on a screen, and the computer goes around
Speaker 1: and selects one of the hands at random, and then
Speaker 1: you see that hand get stabbed with a syringe needle.
Speaker 1: And what happens is you really cringe when you see that.
Speaker 1: It's it's awful to see somebody's hand get stabblished with
Speaker 1: a needle. And that activates this network in your brain
Speaker 1: that summarized as the pain matrix, which is to say,
Speaker 1: you're you're such a feeling the pain of that. Um
Speaker 1: that is the neural basis of empathy. You care about
Speaker 1: somebody else because you're immediately running a simulation of what
Speaker 1: if that was my hand, even though it's not physically
Speaker 1: your hand getting touched. But what we do then is
Speaker 1: we put a one word label on each of these
Speaker 1: hands Christian, Jewish, Muslim, Atheist, Hindu, scientologist, and then the
Speaker 1: computer goes around and picks a hand and see the
Speaker 1: hand gets stabbed. And the question is do you care?
Speaker 1: Does your brain care as much if it's someone in
Speaker 1: your out group versus a member of your in group,
Speaker 1: And that's exactly what happens. If it's a member of
Speaker 1: your in group, you have a much bigger response, and
Speaker 1: if it's remember of your outgroup, your brain doesn't really
Speaker 1: care that much. And it turns out that we do
Speaker 1: all kinds of versions of this. Just as one example,
Speaker 1: we then say, okay, the year is twenty five, and
Speaker 1: these three religions have teamed up against these three religions,
Speaker 1: and now your two allies you care slightly more than
Speaker 1: you did a minute ago, just because you're told in
Speaker 1: this one sense thing that that they're allied with you,
Speaker 1: and the others are still clearly in your outgroups. So
Speaker 1: your brain just doesn't care as much. And by the way,
Speaker 1: just as a side note, atheists have exactly the same
Speaker 1: thing about seeing atheist hands get stud So it's not
Speaker 1: an indictment of religion. It's just an issue about in
Speaker 1: groups and out groups who you feel like you know
Speaker 1: what your labels are. UM. So we've done a lot
Speaker 1: of work on that. If anyone's interested, I wrote in
Speaker 1: uh an article in The Economist last year called does
Speaker 1: your brain care about other people? It depends um, But
Speaker 1: all of a sudden in. Unfortunately, all of this stuff
Speaker 1: is more relevant because society is really finding ways to
Speaker 1: divide themselves up with in groups and now groups. Um.
Speaker 1: You know, some people blame social media. The fact is,
Speaker 1: you know, I'm a real student of history, and the
Speaker 1: fact is that we've had this kind of stuff happened
Speaker 1: all the time, with the Chinese Cultural Revolution or the
Speaker 1: Russian Revolution or you know, or what happened in Nazi
Speaker 1: Germany or we we've we've seen this stuff lots of
Speaker 1: times before the Internet. So it's not like the Internet.
Speaker 1: Is this the single thing to blame here, This is
Speaker 1: just human nature. Um. So anyway, this is what I
Speaker 1: think is relevant to Alright, we're gonna take one more break,
Speaker 1: but I'll be right back with David Eagleman. Thank alright,
Speaker 1: I'm back with David Eagleman. So well, let's let's take
Speaker 1: a brief journey into the future here again coming back
Speaker 1: to the idea of neural technology in the future allowing
Speaker 1: us to augment our senses our bodies. If you, let's
Speaker 1: say you were to enter a state of suspended animation
Speaker 1: and emerge a hundred years from now, how much of
Speaker 1: the human sensory experience will have changed, and how different,
Speaker 1: How difficult do you think it would be for a
Speaker 1: twenty second century human to relate these senses to you? Yeah,
Speaker 1: I think I think this is a key issue, which
Speaker 1: is to say, we have certain what are called quality
Speaker 1: of which is, you know, our internal experience of something
Speaker 1: like vision and hearing and so on. And you know,
Speaker 1: obviously the stuff is completely made up by our brains
Speaker 1: in the sense that just as example, colors don't exist
Speaker 1: in the world. All you have is different wavelength of
Speaker 1: electromagnetic radiation. But your brain comes up with a way
Speaker 1: of summarizing things quickly, so it can see the ripe
Speaker 1: fruit against the green leaves. It says, okay, I'm gonna
Speaker 1: call that red that green perfect um, even though that
Speaker 1: doesn't exist. So we have this internal experience of the world.
Speaker 1: And of course, you know, sound also doesn't exist as such,
Speaker 1: You've just got air compression waves, but we turn it
Speaker 1: into you know, beautiful voices in music and so on. Um. Okay,
Speaker 1: But here's the thing. It's because your brain has lots
Speaker 1: of experience with this that it eventually turns it into
Speaker 1: this direct perceptual experience. And so the question is, now,
Speaker 1: if you fed in a new kind of data stream
Speaker 1: through the neo century buzz, for example, the wristband. If
Speaker 1: you fed in a completely new kind of thing, would
Speaker 1: you come to have a direct perceptual experience of it?
Speaker 1: And our data right now suggests yes, that that you would.
Speaker 1: And the thing that's so weird about this is there's
Speaker 1: actually no way to describe it to somebody who has
Speaker 1: not had that experience. So imagine that you had a
Speaker 1: friend who is color blind and you tried to explain
Speaker 1: orange to your friend. There's no way that she would understand.
Speaker 1: She could eventually pretend and say, okay, Robert just quit
Speaker 1: talking and I'm gonna pretend I understand, but she wouldn't
Speaker 1: ever understand orange nous. Why because you have to experience
Speaker 1: it to get it and so um. And you know,
Speaker 1: if you have a blind friend, try to explain what
Speaker 1: vision is your friends, I don't understand. You're you're trying
Speaker 1: to You're you're capturing folte that you're capturing millions of
Speaker 1: photons of second from across great distances, and there's just
Speaker 1: no way that they can understand what that's like. And
Speaker 1: so the same thing applies, I think for twenty second
Speaker 1: century people who are getting direct data streams fed to
Speaker 1: their brain of stock market or microwave data information or
Speaker 1: um you know, gamma ray information or whatever the thing
Speaker 1: is that they're feeding in. You're like the person who
Speaker 1: doesn't understand what orange is or what vision is to them.
Speaker 1: And they can try really hard to explain to you,
Speaker 1: and you can even pretend at some point they understand,
Speaker 1: but you you just won't. And UM, So I think
Speaker 1: we're on the verge of a really interesting moment in
Speaker 1: history where where we're gonna essentially start speciating, as in,
Speaker 1: people are going to have such different experiences that they
Speaker 1: won't be able to relate them to each other. Now,
Speaker 1: let me just say there's a sense in which this
Speaker 1: is no different from what we've always had in the
Speaker 1: sense that you know, you grew up in your hometown
Speaker 1: and had your experience. I grew up my hometown and
Speaker 1: had my experiences. Then there's a sense in which brains
Speaker 1: are very different anyway. Um, but this is just going
Speaker 1: to be more of that where I'm you know, plugged
Speaker 1: directly into Twitter, and you're plugged directly into infrared information
Speaker 1: and we just can't quite get what the other person
Speaker 1: is experiencing. So you worked as a science advisor on
Speaker 1: HBO's Westworld. That's right, that's right, um. And you know,
Speaker 1: one of the things that I've found in advising for
Speaker 1: television in general is that there are all these topics
Speaker 1: that I and my colleagues have debated for years, were
Speaker 1: you know, for example, the question of could robot become
Speaker 1: conscious and what would that mean? And would they have
Speaker 1: free will? And so on? Um, and you know, we
Speaker 1: write all these academic papers on it, but it's it's
Speaker 1: such a cool opportunity to get these questions to, you know,
Speaker 1: into the public square with fiction. And so something like
Speaker 1: West World is tremendously successful into getting people to think
Speaker 1: about these sorts of questions. And one of the things
Speaker 1: that I did as scientific advisor was, UM, got our
Speaker 1: vest or neosensory vest into the show. So you know,
Speaker 1: it was I don't know if anybody out there I
Speaker 1: saw this episode during season two, but um, these military
Speaker 1: contractors drop into west World to take care of the hosts,
Speaker 1: the bad robots, and they are feeling on their vest
Speaker 1: their location of the robots. So there's location over there there. Sorry,
Speaker 1: there's a there's robbot over there. There's one over there
Speaker 1: and then they can shoot them accordingly. But we've actually
Speaker 1: used exactly that. For people who are blind, we've used
Speaker 1: the same idea, which is they're wearing the vest and
Speaker 1: they're feeling where people are around them, and oh, there's
Speaker 1: somebody coming up behind me, there's someone over here on
Speaker 1: my left, and so on, and then we can add
Speaker 1: navigation directions on top of that. Um you know, so
Speaker 1: it buzzes okay, go four, oh go, the left now
Speaker 1: goes straight and so on. Um. So yeah, that was
Speaker 1: a very cool, very cool opportunity that we had to
Speaker 1: get our technology into this futuristic show. I love that
Speaker 1: sequence in the show because I felt like like a
Speaker 1: lesser show would have just copied Aliens and just had
Speaker 1: you know, blips on a map. Uh And but this
Speaker 1: felt this this fell thoroughly science fictional in nature, you know.
Speaker 1: I mean, but then a GO course is using actual
Speaker 1: technology that we're developing today. Exactly right now. You mentioned
Speaker 1: West World bringing scientific topics or just topics concerning things
Speaker 1: like consciousness out into the public square. The first season
Speaker 1: at least discussed Julian James b cameral mind hypothesis or
Speaker 1: brought that up a little bit and I know you
Speaker 1: wrote about this a little bit in Incognito, but what
Speaker 1: are your general thoughts on this hypothesis. You know, what's
Speaker 1: interesting is that no one actually knows if it's correct
Speaker 1: or not correct. So what Julian James proposed is that
Speaker 1: it may be that you essentially have two sides to
Speaker 1: the brain, the left and the right side, literally the
Speaker 1: two hemispheres, and that those used to be more separate
Speaker 1: and um, so it was as though people were hearing
Speaker 1: a voice from somebody else. And what he argues is
Speaker 1: that if you look at ancient literature, like ancient Greek
Speaker 1: literature and so on, there's always this thing about hearing
Speaker 1: a voice from God and so on. Um. And the
Speaker 1: argument is that very recently the left and right hemisphere
Speaker 1: started connecting in a deeper way. Um, and so there
Speaker 1: was this super highway of fibers that goes back and
Speaker 1: forth between them. And so what we have now is
Speaker 1: a unified consciousness instead of two separate voices going on
Speaker 1: in our heads. As I said, nobody really knows that
Speaker 1: this is right or not, because there's no simple way
Speaker 1: to test this directly. What I argued an incognito, though,
Speaker 1: is essentially a a distant cousin of that, which is
Speaker 1: that What is absolutely clear is that we are not
Speaker 1: a single thing. So we think of ourselves as individuals,
Speaker 1: meaning not divisible into different parts. But but in fact
Speaker 1: who you are is a collection of different neural networks
Speaker 1: that all have different drives. And this is why we
Speaker 1: can argue with ourselves and custed ourselves in contract with ourselves,
Speaker 1: and canjole ourselves who's talking with whom? Here? It's all us,
Speaker 1: but it's different parts of us. So this is why
Speaker 1: if I take some warm chocolate chip cookies out of
Speaker 1: the oven and put them in front of you, part
Speaker 1: of your brain says, don't need your get fat, and
Speaker 1: part of brain says that looks like a high energy sort.
Speaker 1: You know, I totally want to eat those cookies. And
Speaker 1: part of your brain says, okay, how about I eat
Speaker 1: the cookies, but I'll go to the gym tonight or whatever.
Speaker 1: Like everything that we do in our lives, we have
Speaker 1: arguments with ourselves about okay, what should I do here?
Speaker 1: Part of me want to eat, this part of me
Speaker 1: doesn't want to, And so what's going on? There are
Speaker 1: all the different voices, the different political parties of this
Speaker 1: neural parliament that we have running under the hood. And
Speaker 1: this is the framework that I built in an incognito,
Speaker 1: is that we've got this parliament and the way you
Speaker 1: go just depends on the majority vote in any given moment,
Speaker 1: and so you're not one thing, You're a collection of voters.
Speaker 1: All right. I have one one last question for you. Um,
Speaker 1: if if you could go back in time and serve
Speaker 1: as a science advisor on any past science fiction film,
Speaker 1: what would it be. What would you most like to
Speaker 1: go back and tweak or correct or make a little
Speaker 1: more neuroscientifically interesting. Oh gosh, I have to think about
Speaker 1: that off the top of my head. Um. Something like
Speaker 1: the Matrix is terrific, because that's an example actually of
Speaker 1: of a piece of fiction that got everybody talking about
Speaker 1: this issue of how do you know? Like you know,
Speaker 1: Descartes said, how would I know if I'm a brain
Speaker 1: in a vat um and and I just think that
Speaker 1: I'm feeling and hearing and seeing these different things, And
Speaker 1: that that got upgraded that question by philosophers um at
Speaker 1: different stages in history. But but essentially that's the question
Speaker 1: is how do I how do I know? If there's
Speaker 1: a bunch of scientists that are zapping my brain with
Speaker 1: electrodes that are making me feel that I'm talking with
Speaker 1: you on zoom, and the weather is nice outside and
Speaker 1: so on. But then the matrix, I think, singlehandedly upgraded
Speaker 1: that question too. How do I know if I'm in
Speaker 1: the matrix if I am a simulation? And and as
Speaker 1: things have gone on, especially in the last I don't
Speaker 1: know ten years in Silicon Valley, it feels like people
Speaker 1: talk about that question more and more seriously all the
Speaker 1: time because you look at our computational capacity and you think, well,
Speaker 1: it's it's really not that hard to make super sophisticated
Speaker 1: VR in So what's this gonna look like in one twenty?
Speaker 1: I mean, you could make something that is absolutely convincing.
Speaker 1: I mean, forget it. You can do that. It's just
Speaker 1: like a convincing So the question is, how would you
Speaker 1: know if you exist in a simulation or not? And
Speaker 1: what they cart concluded, by the way, is that there
Speaker 1: is no way for him to know um, And this
Speaker 1: is what led to his very famous declaration japon suit
Speaker 1: I think therefore I am um, because what he meant
Speaker 1: by that is, look, I don't know if I'm in
Speaker 1: a simulation, but all I can tell you is that
Speaker 1: there's somebody thinking about this question. So I exist, whoever, whoever,
Speaker 1: whatever situation I'm actually and it doesn't matter. There's some
Speaker 1: I that exists, and that was actually a quite important
Speaker 1: move in philosophy. But the point is, we have absolutely
Speaker 1: no way of knowing if we are in a simulation
Speaker 1: or not. And uh, we don't even have any good
Speaker 1: hypotheses about how we would be able to find that out.
Speaker 1: And by the way, it might not matter. I mean,
Speaker 1: you know, if I told you with certainty that we
Speaker 1: are or are not, it would it might not change
Speaker 1: anything about what you're doing. Um so, But so I
Speaker 1: would love to have been involved in in that movie
Speaker 1: and and add in just a few neuroscience e uh
Speaker 1: twists and sentences and questions there. Awesome, David, thanks again
Speaker 1: for chatting with me today. Great, Thank you, Robert. This
Speaker 1: is blessed all right, So there you have it again.
Speaker 1: The book is Live Wired, The Inside Story of the
Speaker 1: Ever Changing Brain by David Eagleman. It's out now and
Speaker 1: if you want to check out Neosensory, you can just
Speaker 1: go to neo sensory dot com. If you'd like to
Speaker 1: listen to other episodes of Stuff to Blow Your Mind.
Speaker 1: You can find us wherever you get your podcast and
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Speaker 1: review and subscribe. Thanks as always to Seth Nicholas Johnson
Speaker 1: for his recording skills and editing skills and bringing all
Speaker 1: this together especially short to turn around Today. And if
Speaker 1: you would like to eat ellis about this interview, about
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