Speaker 1: Why does the world's best archer have no arms? How
Speaker 1: does a dog learn how to skateboard? How can a
Speaker 1: robot figure out what its body looks like? How can
Speaker 1: someone come to believe that her leg doesn't belong to
Speaker 1: her but to someone else? And what does any of
Speaker 1: this have to do with babies? Babbling or doc oc
Speaker 1: from spider Man. Welcome to innert Cosmos with me, David Eagleman.
Speaker 1: I'm a neuroscientist and an author at Stanford University, and
Speaker 1: I've spent my whole career studying the intersection between how
Speaker 1: the brain works and how we experience life. Have you
Speaker 1: ever texted while you're riding your bicycle? So on campus,
Speaker 1: i see students doing this all the time, and I'm
Speaker 1: amazed because what it tells me is how good the
Speaker 1: three pound brain is at controlling the body, running the
Speaker 1: petals with the legs, and steering the handlebars with one
Speaker 1: hand and hitting these very tiny targets with the other thumb,
Speaker 1: and pulling on the brake when they need to slow down,
Speaker 1: and so on. And this is all from inside the
Speaker 1: brain's mission control center in the skull, in total darkness.
Speaker 1: It's controlling all these limbs with a degree of expertise
Speaker 1: that we can't even scratch with robotics. So what I
Speaker 1: want to talk about today is how you can get
Speaker 1: even a better body. And I'm not talking about diet
Speaker 1: or fitness. I'm talking about the future of what we
Speaker 1: can do with our brains. For example, could you add
Speaker 1: new limbs. Let's start with the Spider Man comics from
Speaker 1: back in the day, So in July of nineteen sixty three,
Speaker 1: a new character got introduced. It was a scientist named
Speaker 1: Otto Gunther Octavius. Now he was interesting because he plugs
Speaker 1: a device directly into his brain to control four extra
Speaker 1: robotic arms. He's able to operate these metal limbs just
Speaker 1: as smoothly as his own natural arms, and so he's
Speaker 1: able to work this way with radioactive materials. Now in
Speaker 1: the comic book, each of his arms is able to
Speaker 1: operate independently, in the same way that you can steer
Speaker 1: your car with one hand while you change the radio
Speaker 1: station with the other. And this is while at the
Speaker 1: same time you're switching between the brake and the gas
Speaker 1: with your foot. Unfortunately, for doctor Octavius, there's an explosion
Speaker 1: and the explosion damages his brain and dooms him to
Speaker 1: a life of villany. So he's now lost all his
Speaker 1: sense of morality, and he capitalizes on these four extra
Speaker 1: arms to climb up buildings and pull safes out from
Speaker 1: walls and fight in new ways with multi hand combat.
Speaker 1: And now with his new evil personality, he becomes known
Speaker 1: as Doctor Octopus or doc OC. So when the comic
Speaker 1: book debuted in nineteen sixty three, it was pure sci
Speaker 1: fi fantasy to imagine that a human brain could control
Speaker 1: robotic limbs, but not anymore. So how close are we
Speaker 1: to actually reaching the point of a doc oc? Could
Speaker 1: you plug in new limbs like extra legs or wings?
Speaker 1: What are the limits? So to get started in understanding this,
Speaker 1: the key thing to orient ourselves too is that the
Speaker 1: brain has inputs and outputs. The inputs includes all the
Speaker 1: information from your senses like vision, hearing, and smell and
Speaker 1: so on. The output is how you're brain controls your
Speaker 1: body to interact with the world. In a different episode,
Speaker 1: I'll talk about input asking how our senses work and
Speaker 1: how we can create new senses. But today we're going
Speaker 1: to talk about how the brain controls the body and
Speaker 1: what the prospects are for changing that or adding on
Speaker 1: to that. So let's start back in the nineteen sixties
Speaker 1: when a Canadian neurosurgeon named Wilder Penfield was sticking small,
Speaker 1: thin wires called electrodes into the brain of a patient
Speaker 1: undergoing surgery. Now, it turns out you can stick things
Speaker 1: like that directly into the brain, and you can do
Speaker 1: that while the patient is awake and it doesn't hurt
Speaker 1: at all. Why it's because there are no pain receptors
Speaker 1: in the brain, so you can just dunk a metal
Speaker 1: electrode right in the tissue the way you'd stick a
Speaker 1: toothpick in a block of cheese, and the patient doesn't
Speaker 1: feel anything anyway. So Penfield was sticking the electrode into
Speaker 1: the brain while he talked with the patient and asking
Speaker 1: him what he was feeling. And what Penfield stumbled on
Speaker 1: was something that elevated neuroscience. He discovered in the brain
Speaker 1: a nap of the body. So let's say I have
Speaker 1: the electrode right here on a little strip of brain
Speaker 1: tissue where you'd wear a tiara or headphones, and the
Speaker 1: electrode is measuring the electrical spikes in the brain cells,
Speaker 1: the neurons, And now I touch your shoulder, and it
Speaker 1: turns out these neurons only respond to touch on your
Speaker 1: shoulder and nowhere else. So now let's say I move
Speaker 1: the electrode just a little bit over, still on this strip,
Speaker 1: and now I touch your elbow, and Penfield found that
Speaker 1: as he moved over a little more, there are neurons
Speaker 1: that respond to the forearm, and then next to that
Speaker 1: the hand, and elsewhere along this little strip of brain
Speaker 1: tissue he found cells that respond to your face, or
Speaker 1: your torso, or your legs or your feet. And so
Speaker 1: as you move along this strip in the brain you
Speaker 1: find the whole body represented where neighboring territories on the
Speaker 1: body have neighboring territory in the brain. And this came
Speaker 1: to be known as the somatos sensory cortex, which refers
Speaker 1: to sensation from the body, the soma. Now, the interesting
Speaker 1: part for today's podcast is that he also found a
Speaker 1: second map of the body, and this was on a
Speaker 1: neighboring strip that we call the motor cortex. It's right
Speaker 1: in front of that. So when the cells here are active,
Speaker 1: they drive very particular parts of the body. In other words,
Speaker 1: they contract particular muscles. So activity in these cells right
Speaker 1: here causes your shoulder to twitch, an activity right next
Speaker 1: to it causes your bicep to contract, and activity right
Speaker 1: next to that causes your forearm to move, and so on.
Speaker 1: With a map of the entire body, all the parts
Speaker 1: that you can control are represented in this strip here. Now,
Speaker 1: it turns out this map doesn't have equal representation everywhere.
Speaker 1: The body parts, which are more finely controlled, have larger
Speaker 1: areas of representation. So you have a bunch of territory
Speaker 1: devoted to your fingers, for example, but not a lot
Speaker 1: to the muscles that can move your kneecap or your scalp.
Speaker 1: Now we'll come back to this in later episodes, but
Speaker 1: what is wild is that this map of the body
Speaker 1: is not genetically determined as everyone originally guessed. Instead, it's
Speaker 1: shaped by the body's experience in the world. In other words,
Speaker 1: it devotes territory to what it can control. And if
Speaker 1: you lose your hand in a terrible car accident, your
Speaker 1: primary motor cortex begins to shift, often change itself. Over
Speaker 1: the course of weeks, the brain areas that control neighboring
Speaker 1: arm muscles like your biceps and triceps slowly take over
Speaker 1: the cortical territory that formerly operated your hand. Now we
Speaker 1: can look at it this way. Neurons that previously drove
Speaker 1: your hand, they get their job duty reassigned, and they
Speaker 1: now join the team of neurons that control the upper
Speaker 1: arm muscles. So what this tells us is that the
Speaker 1: motor areas of the brain, those neurons that are sending
Speaker 1: their signals down the spinal cord to drive the body,
Speaker 1: they optimize themselves to drive the available machinery. And this principle,
Speaker 1: as we're going to see, is what opens the door
Speaker 1: to rearranging body plans, something that's traditionally been done only
Speaker 1: when there's injury, but will soon enough be possible when
Speaker 1: we want to add things to the body. So to
Speaker 1: understand this, let's start with a wide angle lens looking
Speaker 1: at the world of our cousins in the animal kingdom.
Speaker 1: So the thing to notice is that there are all
Speaker 1: sorts of strange and amazing body plans. To look at
Speaker 1: the ant eater with its long proboscis, or an animal
Speaker 1: called the star nosed mole, which has essentially twenty two
Speaker 1: fingers on its nose with which it feels around in
Speaker 1: its dark tunnels. Or look at the sloth or the dragonfish,
Speaker 1: or the platypus or the octopus. You find very different
Speaker 1: bodies in the animal kingdom. But here's the thing to notice.
Speaker 1: All the animals, including us, have surprisingly similar genomes. So
Speaker 1: how do the animal's brains come to operate all this
Speaker 1: wildly different equipment like prehensile tails or claws, or larynxes
Speaker 1: or tentacles, whiskers or or wings. The question is are
Speaker 1: their brains preprogrammed for it? How do mountain goats get
Speaker 1: so good at leaping up rocks? And how do owls
Speaker 1: get so good at plunging down on mice? How do
Speaker 1: frogs get so good at hitting flies with their tongues?
Speaker 1: So here's what I think the answer is. In my
Speaker 1: book Live Wired, I proposed what I call the potato
Speaker 1: head model of the brain. And this model proposes that
Speaker 1: you can plug in whatever peripheral devices you want, like
Speaker 1: arms or fins or wings, just like plugging things into
Speaker 1: a potato head, and the brain will figure out how
Speaker 1: to drive them. It's kind of like with your computer.
Speaker 1: Your laptop manufacturer doesn't have to know the next model
Speaker 1: of peripheral that's going to come out in a couple
Speaker 1: of years. Your laptop is ready to drive anything whatever
Speaker 1: comes along. So in this potato head framework, mother nature
Speaker 1: has the freedom to experiment genetically with any kind of
Speaker 1: plug in play motor devices. You just plug in whatever
Speaker 1: limbs you want and the brain will figure out how
Speaker 1: to drive them. It doesn't matter if this is fingers
Speaker 1: or flappers or fins. It doesn't matter if your body
Speaker 1: shows up with two legs or four legs or eight legs.
Speaker 1: It doesn't matter whether you sprout hands or talons or wings.
Speaker 1: The fundamental principles of brain operation don't need to be
Speaker 1: redesigned every time. The motor system that we're talking about
Speaker 1: in the brain, well, it figures out how to drive
Speaker 1: the available machinery. So the advantage of such an adaptable
Speaker 1: brain is that it allows mother nature to mess around
Speaker 1: with genetics to develop new peripheral devices. And it turns
Speaker 1: out it's shockingly easy for her to make little adjustments
Speaker 1: to the a's and seas and teas and gees, and
Speaker 1: you end up with all kinds of different body plants. Okay, now,
Speaker 1: wait a mind it, you might say, If bodies are
Speaker 1: so easy to modify with tweaks of the genome, how
Speaker 1: can we don't see things like a human sometimes being
Speaker 1: born with a genetic mutation that gives him a tail
Speaker 1: or an extra arm. Well you do. Actually, it turns
Speaker 1: out that some genes in your genome act like movie directors.
Speaker 1: They carefully control which thing happens when and where, and
Speaker 1: in this case, which other gene cascades get triggered to unpack.
Speaker 1: So in fruit flies, a few decades ago, it was
Speaker 1: discovered that certain mutations in these director genes control the
Speaker 1: development of the larger body structure. One of the first
Speaker 1: discoveries involved a mutation in the fruit flies in which
Speaker 1: a pair of legs would grow where the antennae were
Speaker 1: supposed to be, and there's a reverse mutation which placed
Speaker 1: antennae where the legs should be. So when you start
Speaker 1: looking at the building of the body this way, you
Speaker 1: see it's sort of like lego. You can just swap
Speaker 1: one thing out for another. Based on these genes coated
Speaker 1: in a's and seas and teas and geese. If you
Speaker 1: want to look this up further, look up homeobox genes.
Speaker 1: The big point I want to make here is just
Speaker 1: that some genes act as a switch to turn on
Speaker 1: a cascade of other genes, and this is why many
Speaker 1: mutations involve the surprising appearance or disappearance of a full
Speaker 1: body part. So in humans you can find these surprisingly
Speaker 1: small mutations where, for example, a child is born with
Speaker 1: a tail, it's just a genetic program which extends the
Speaker 1: spinal column and keeps it going. Every year, there are
Speaker 1: hundreds of children born with tails, and the tail gets
Speaker 1: simply removed with an operation. In Live Wired, I tell
Speaker 1: the story of a baby named Gigi who was born
Speaker 1: in China a few years ago, and Gigi had three arms. Now,
Speaker 1: for the COGNISCINTI, I'll just mention that this sort of
Speaker 1: thing sometimes happens because of a parasitic twin in the womb,
Speaker 1: where one twin doesn't make it and gets absorbed into
Speaker 1: the body of the healthier twin. But that's not the
Speaker 1: case with Gigi. His genetics simply dictated the growth of
Speaker 1: a third arm. The surgeons in China took several hours
Speaker 1: to remove one of the arms because both arms on
Speaker 1: the left side were well developed and had individual shoulder blades. Now,
Speaker 1: what tails and extra arms illustrate is the way body
Speaker 1: plants can change with small alterations of the genetics. And
Speaker 1: it goes without saying that this sort of genetic wobble
Speaker 1: happens in minor ways all around us. Some people have
Speaker 1: longer arms, or stubby your fingers, or a big toe
Speaker 1: that's shorter than the second toe, or wider hips or
Speaker 1: broader shoulders. And although our nearest cousins, the chimpanzees, are
Speaker 1: nearly genetically identical to us, they have a lot of
Speaker 1: differences in their body plan. For starters, their bicep muscle
Speaker 1: has a higher insertion point, and their hips are turned
Speaker 1: more outward, and their toes are much longer. Now, the
Speaker 1: point is that the chimpanzee brain, with its mere ninety
Speaker 1: thousand genes, doesn't have to be reinvented to figure out
Speaker 1: how to drive a chimpanzee body to swing in trees
Speaker 1: and to walk on knuckles. And by the same token,
Speaker 1: the human brain doesn't have to be reinvented to figure
Speaker 1: out how to play pickleball or dance hip hop. In
Speaker 1: both cases, the brain just figures out how to best
Speaker 1: drive the machinery that it has. So to understand the
Speaker 1: power of this principle, consider Matt Stutsman. This is a
Speaker 1: guy who is born without arms. He found himself really
Speaker 1: attracted to archery, so he learns to manipulate a bow
Speaker 1: and arrow with his feet. What he does is notch
Speaker 1: the arrow into the string with his toes. Then he
Speaker 1: lifts the bow with his right foot, and he's got
Speaker 1: a strap around his neck which connects the bow to
Speaker 1: his shoulder, and that allows him to position it at
Speaker 1: eye level. And then he puts tension on the bow
Speaker 1: by pushing it forward with his foot, and when his
Speaker 1: aim is on target, he lets the arrow fly. Now,
Speaker 1: the thing is that Matt is not simply talented at archery.
Speaker 1: He is the best in the world. As of this podcast,
Speaker 1: he holds the record for the longest accurate shot in archery.
Speaker 1: And that's probably not what his doctors would have predicted
Speaker 1: for a baby who came out of the womb without arms,
Speaker 1: But perhaps they didn't realize how readily his brain would
Speaker 1: adapt its resources to solve problems in the outside world.
Speaker 1: Now we see this sort of flexibility everywhere in the
Speaker 1: animal kingdom. Consider this incredible dog whose name is Faith,
Speaker 1: who was born without front legs, and she grew from
Speaker 1: puppyhood to be able to walk on her two hind
Speaker 1: legs bipetally the way that a human walks. You can
Speaker 1: find YouTube videos of her walking around. It's totally amazing
Speaker 1: to watch. And although we might have guessed that dog
Speaker 1: brains come hardwired to drive standard dog bodies, Faith shows
Speaker 1: us how readily brains will move around the world with
Speaker 1: whatever machinery they find themselves in. So what we see
Speaker 1: from Matt or from Faith the Dog is that brains
Speaker 1: are not predefined for particular bodies. Instead, they adapt themselves
Speaker 1: to move and interact and succeed in the world. And
Speaker 1: this isn't simply about the body you're born in, but
Speaker 1: about whatever opportunities might come along. So take Sir Blake,
Speaker 1: a bulldog here in California who's mastered skateboarding. He steps
Speaker 1: up onto the skateboard and with his front paw he
Speaker 1: scrapes at the ground to get momentum, and at the
Speaker 1: right moment, he sets his front paw onto the board
Speaker 1: and he leans into the ride, and he shifts his
Speaker 1: body weight to steer the board around obstacles, just like
Speaker 1: a human wood. And when he's done, he lets the
Speaker 1: skateboard slow down almost to a stop, and then he dismount. Now,
Speaker 1: given the absence of wheels in the evolutionary history of dogs,
Speaker 1: what this shows is the adaptability of brains to steer
Speaker 1: new possibilities. Or take this other dog named Sugar who
Speaker 1: took up surfboarding and is inducted into the International Surf
Speaker 1: Dog Walk of Fame, or on second thought, forget Sugar
Speaker 1: and just revel in the fact that there is an
Speaker 1: International Surf Dog Walk of Fame, because there are lots
Speaker 1: of dogs that do this, and we don't usually think
Speaker 1: about studying dog brains in the context of how they
Speaker 1: hang ten on a longboard, but you can, because all
Speaker 1: the dog requires is the opportunity and their motor systems
Speaker 1: will figure it out. So how do these dogs do it?
Speaker 1: And what does this have to do with a baby babbling? Well,
Speaker 1: a baby learns how to shape its mouth and breathing
Speaker 1: to produce language. But this is not from genetics, and
Speaker 1: it's not by studying a book or surfing Wikipedia. It's
Speaker 1: from babbling. They listen to what's going on around them,
Speaker 1: and they try things out, and their brain compares how
Speaker 1: close their own sound was to what they're hearing from
Speaker 1: the adults around them. And this has helped long because
Speaker 1: they get positive reactions for some utterances and not for others.
Speaker 1: And so there's this constant feedback loop, and that allows
Speaker 1: babies to refine their speech to perfection in whatever language
Speaker 1: is being spoken around them, whether that's English or Chinese
Speaker 1: or Hindi or any of the seven thousand languages spoken
Speaker 1: around the globe. In exactly the same way, the brain
Speaker 1: learns how to steer its body by motor babbling, in
Speaker 1: other words, babbling with its slims. Just watch a baby
Speaker 1: in the crib. She bites her toes, she slaps her forehead,
Speaker 1: she tugs on her hair, she bends her fingers, she
Speaker 1: knocks on the bar of the crib, and so on.
Speaker 1: And by doing this, she's learning how her motor output
Speaker 1: corresponds to the sensory feedback she receives. And in this way,
Speaker 1: she's learning to understand the language of her body, how
Speaker 1: her outputs nap onto the next inputs. She's trying things
Speaker 1: out and she's getting feedback, and this is how she
Speaker 1: eventually learns how to walk and navigate food to her mouth,
Speaker 1: and eventually swim in a pool and dangle on monkey
Speaker 1: bars and master a cartwheel. She's trying things out, she's adjusting,
Speaker 1: she's motorically babbling. And even better, we use this same
Speaker 1: method to attach extensions to our bodies. So think about
Speaker 1: riding a bicycle, which is a machine that our genome
Speaker 1: presumably did not see coming to master bike riding. Have
Speaker 1: to carefully balance your torso, and you change direction by
Speaker 1: moving your arms, and you have to stop by squeezing
Speaker 1: your hands, and this is all totally different from the
Speaker 1: way we normally move. But despite these complexities, most five
Speaker 1: year olds can demonstrate that the extended body plan is
Speaker 1: easily added to the resume of their motor cortex. And
Speaker 1: this isn't just limited to typical bicycles. Consider the sky
Speaker 1: named Deston Sandlin. He's an engineer who has given this
Speaker 1: very strange bicycle by a friend. It had this elaborate
Speaker 1: gearing system so that if you turned the handlebars to
Speaker 1: the left, the front wheel would turn to the right,
Speaker 1: and vice versa. And so Deston was fairly sure that
Speaker 1: this wouldn't be too difficult to master because the concept
Speaker 1: is very straightforward. You just steer the opposite direction that
Speaker 1: you want to go. But as it turned out, the
Speaker 1: bicycle was just too difficult to ride because it required
Speaker 1: unlearning the normal operation of a bicycle steering wheel and
Speaker 1: training his motor cortex to master this new task was
Speaker 1: not as simple as having a cognitive understanding. In other words,
Speaker 1: he knew how the bicycle worked, but that didn't mean
Speaker 1: he could do the right thing with his body. But
Speaker 1: after some weeks he began to get the hang of it.
Speaker 1: He practiced every day, and each time he'd try to move,
Speaker 1: he would get feedback from the world, like you're falling
Speaker 1: to the ride, or you're crashing into a trash can,
Speaker 1: or you're swerving in front of the mail truck. And
Speaker 1: so he used that feedback to adjust his next moves,
Speaker 1: and after several weeks of practicing, he got pretty good
Speaker 1: at it. And he did this the same way that
Speaker 1: he learned how to ride a normal bike as a kid,
Speaker 1: by motor babbling. And by the way, you know what
Speaker 1: this is like If you drive and you go to
Speaker 1: a country that has the steering wheel on the other
Speaker 1: side of the car, if you or an American in
Speaker 1: England or vice versa, you keep swerving the wrong way,
Speaker 1: but you eventually get better because your visual system looks
Speaker 1: at the consequences of each action and adjusts things accordingly.
Speaker 1: It's just how Matt Stutsman learned how to shoot bows
Speaker 1: or sugar learned how to skateboard. Motor babbling is not
Speaker 1: only the way that babies and bicyclists learn, it's also
Speaker 1: become a new approach in robotics. So take this starfish
Speaker 1: robot developed by my colleague Hodd Lipson. The idea is
Speaker 1: that it's a very simple robot. It's just a small
Speaker 1: square body with four arms that stick out. The key
Speaker 1: is lips and doesn't teach it how to use its body.
Speaker 1: It figures itself out. The starfish tries out a move
Speaker 1: the way that an infant might flail a limb, and
Speaker 1: it analyzes what happens. In the robots case, it's just
Speaker 1: using gyroscopes to see how the move tilted the central bot.
Speaker 1: So if it does just a single move, that can't
Speaker 1: tell it what its body looks like and how it
Speaker 1: interacts with the world. But that feedback narrows the space
Speaker 1: of possibilities, so it now has a smaller space of
Speaker 1: hypotheses about what its body looks like. So now it
Speaker 1: does the next move, and the next and so on,
Speaker 1: and instead of choosing random movements, it chooses its next
Speaker 1: move to do a good job distinguishing the available remaining
Speaker 1: hypotheses so by doing this over and over, by motoric babbling,
Speaker 1: it develops a clearer and clearer picture of its body.
Speaker 1: In this way, it learns itself. You don't need a
Speaker 1: preprogram this robot. It learns its own capabilities. And what's
Speaker 1: wild is that if you snap off one of the
Speaker 1: legs of this robot, it'll figure itself out again. And
Speaker 1: it turns out that building a babbling, self exploring robot
Speaker 1: is way more flexible than preprogramming the robot. And in
Speaker 1: the animal kingdom, nature only has some tens of thousands
Speaker 1: of genes to work with to build a creature, so
Speaker 1: it can't possibly preprogram all of the actions that one
Speaker 1: might do in the world. So it's only choice is
Speaker 1: to build a system that figures itself out. Now, think
Speaker 1: about the stories that we just talked about with Matt Stutsman,
Speaker 1: the archer with no arms, or the skateboarding dog or
Speaker 1: the surfing dog or the starfish robot. What they all
Speaker 1: have in common is the same principle, whatever kind of
Speaker 1: way that you can move around in the world, the
Speaker 1: brain on the inside does not have to be redesigned.
Speaker 1: It just recalibrates to maximize what it can do. It
Speaker 1: figures out how to control whatever body it's in. A
Speaker 1: live wired brain doesn't need to be redesigned if there's
Speaker 1: a genetic change to the body, planet just adjusts itself.
Speaker 1: And that is how evolution can so effectively shape animals
Speaker 1: to fit any habitat in different environments. Animals will evolve
Speaker 1: hoofs or toes or fins or forearms or trunks or
Speaker 1: tails or talons, and Mother Nature doesn't need to reinvent
Speaker 1: the principles of the brain or do anything extra to
Speaker 1: make the new animal operate correctly. And you know what,
Speaker 1: Evolution really couldn't work any other way. It couldn't operate
Speaker 1: quickly enough unless body plan changes were easy to deploy
Speaker 1: and brain changes just followed without difficulty. And this massive
Speaker 1: flexibility is why we can so easily install ourselves into
Speaker 1: new bodies. If you ever saw the movie Aliens from
Speaker 1: a long time ago, you may remember this climactic deathmatch
Speaker 1: that the hero Ellen Ripley has with this giant, slimy alien.
Speaker 1: So she scrambles into this enormous robotics just like a
Speaker 1: mech suit that allows her movements to be magnified into
Speaker 1: these powerful metal arms and legs, and at first, she's
Speaker 1: swinging around awkwardly, but after some practice, she's able to
Speaker 1: land punches right on the alien. Now what we see
Speaker 1: is that Ripley learns how to control her new gargantuan
Speaker 1: body plan, and she does so thanks to her brain's
Speaker 1: capacity to adjust her relationship between her outputs like swinging
Speaker 1: my arm and her inputs. Wears that giant arm right now.
Speaker 1: So it's not difficult to learn these kinds of new associations.
Speaker 1: Just think about forklift drivers who are using their arms
Speaker 1: and these little levers to control something really large, or
Speaker 1: crane operators who are sitting in their little booth and
Speaker 1: operating this thing that's one hundred feet high, or laparoscopic
Speaker 1: surgeons who are controlling levers to control something that's very
Speaker 1: very tiny. So all of these folks get out of
Speaker 1: bed every morning to pilot strange new bodies. And let's
Speaker 1: take another example. There was a very successful young man
Speaker 1: named Jean Dominique Bobie who lived in Paris, and he
Speaker 1: was on top of the world. He was editor in
Speaker 1: chief at El magazine in Paris, and he revolved at
Speaker 1: the top of French social circles. And one afternoon in
Speaker 1: nineteen ninety five, without any warning, he had a massive
Speaker 1: stroke and he instantly fell into a deep coma. So
Speaker 1: he stayed in this coma for twenty days, and just
Speaker 1: when everyone was giving up hope, he regained consciousness. But
Speaker 1: there was a problem. It's the type of thing that
Speaker 1: gives everyone who hears about this nightmares, which is that
Speaker 1: he was mentally aware. He could see his surroundings, he
Speaker 1: could understand everything everyone was saying, but he could not move.
Speaker 1: He couldn't twitch his arm, his fingers, his face, his toes.
Speaker 1: He couldn't speak, he couldn't cry out. He discovered that
Speaker 1: his only available action was to blink his left eyelid.
Speaker 1: Other than that, he was locked in the frozen dungeon
Speaker 1: of his body. This is called locked in syndrome. So
Speaker 1: luckily he had a heroic nurse with a plan. She
Speaker 1: would sit with him and recite all of the letters
Speaker 1: in the alphabet in the order of their frequency, and
Speaker 1: he would blink his eye when she arrived at the
Speaker 1: next letter he wanted, and in this way, one letter
Speaker 1: at a time, he could communicate, and eventually he wrote
Speaker 1: out an entire book called The Diving Bell in the Butterfly.
Speaker 1: He died just before I was published. But this became
Speaker 1: a huge international bestseller, in part because it allowed readers
Speaker 1: to appreciate, probably for the first time, this simple pleasure
Speaker 1: of having a brain that successfully drives this enormous meat robot,
Speaker 1: and does so with such expertise that were totally unaware
Speaker 1: of the massive operations running under the hood. Now here's
Speaker 1: the question, what if we could have measured the little
Speaker 1: electrical signals in Bobie's brain, the spikes and his neurons,
Speaker 1: instead of having to look just at his eyeblinks. What
Speaker 1: if we could have eaves dropped on his neural circuits
Speaker 1: to figure out what they were trying to say to
Speaker 1: the muscles, and then by passed the injury to make
Speaker 1: something happen in the outside world. Well, a year after
Speaker 1: Bobie's death, researchers at Emory University implanted a brain computer
Speaker 1: interface into another locked in patient named Johnny Ray, and
Speaker 1: Johnny Ray lived long enough to control a computer cursor
Speaker 1: simply by imagining the movement. His motor cortex was unable
Speaker 1: to get the signals through the damaged spinal cord, but
Speaker 1: this implant could listen to the signals and then pass
Speaker 1: along that message to the computer. Then, in two thousand
Speaker 1: and six, a paralyzed former football player named Matt Nagel
Speaker 1: was able to control lights and open an email, and
Speaker 1: play the video game Pawn and draw a circle on
Speaker 1: the screen. And this was all because of a four
Speaker 1: by four millimeter grid of almost one hundred electrodes implanted
Speaker 1: directly into his motor cortex. He would imagine moving his muscles,
Speaker 1: which caused activity in his motor cortex, and the researchers
Speaker 1: could measure that activity to at least crudely determine the intention.
Speaker 1: The technology used with Johnny and Matt it was makeshift
Speaker 1: and unpolished, but had proved the possibility, and by twenty eleven,
Speaker 1: my neuroscience colleague Andrew Schwartz and his colleagues at the
Speaker 1: University of Pittsburgh built a prosthetic arm was almost as
Speaker 1: sophisticated and lie as a real arm. And a woman
Speaker 1: named Jan Schumann had become paralyzed from a disorder called
Speaker 1: spinocerebellar degeneration, and she volunteered herself for a neurosurgery that
Speaker 1: would give her control of this arm. So, with the
Speaker 1: signals recorded from her motor cortex, Jan imagines making a
Speaker 1: movement with her arm, and the robotic arm moves. This
Speaker 1: robotic arm is part way across the room, but this
Speaker 1: makes no difference because through the bundle of wires that
Speaker 1: attaches these electrodes in her brain to the computer and
Speaker 1: to the robotic arm, she can make it turn and grasp,
Speaker 1: essentially the way that she would have done with her
Speaker 1: own arm years ago. Normally, when you think about moving
Speaker 1: your arm, the signals traveled from the motor cortex down
Speaker 1: your spinal cord, into the peripheral nerves into your muscle fibers.
Speaker 1: With Jan, the signals recorded from the brain just take
Speaker 1: a different root. They're going long wires connected to motors
Speaker 1: instead of neurons connected to muscles. So Jan gets better
Speaker 1: and better at using the arm, in part because of
Speaker 1: improving technology, but also because her brain is rewiring to
Speaker 1: understand how to best control its new limb, just as
Speaker 1: it would with a reversed bicycle or a surfboarder Ellen
Speaker 1: Ripley's mex suit. Jan is doing motor babbling to figure
Speaker 1: out how to drive the arm smoothly, and in an interview,
Speaker 1: by the way, Jan said, I'd so much rather have
Speaker 1: my brain than my legs. Why did she say that.
Speaker 1: It's because if you have the brain, you can build
Speaker 1: a new body, but not the other way around. So
Speaker 1: we see that brain machine interfaces can restore or replace
Speaker 1: damaged limbs, But the question is could you use this
Speaker 1: same technology to add an additional limb. So in two
Speaker 1: thousand and eight, a monkey with two normal arms used
Speaker 1: its thoughts to control a third arm made of metal.
Speaker 1: This was again the work of my colleague Andrew Schwartz.
Speaker 1: He and his team put a tiny array of electrodes
Speaker 1: into the monkey's brain, and when the monkey thought about
Speaker 1: different things, that could control the robotic arms to pluck
Speaker 1: marshmallows and stick them in his mouth with the robotic arm.
Speaker 1: The monkey initially trained for this by moving a cursor
Speaker 1: on the screen towards a target, and he'd get rewarded
Speaker 1: when he got it right. And at first, the monkey
Speaker 1: would move his own arms while he was doing the task.
Speaker 1: But something remarkable happened, which is eventually he stopped moving
Speaker 1: his arms and the cursor continued to move on its own.
Speaker 1: His brain was rewiring to separate out these tasks, so
Speaker 1: some neurons corresponded to his real arms and some to
Speaker 1: the cursor on screen. Eventually, these signals were able to
Speaker 1: be used to control the robotic arm for marshmallow gathering
Speaker 1: and sticking in his mouth, all without any physical movement
Speaker 1: of his real arms. It had become a new limb,
Speaker 1: a third limb. The way that the monkey learned to
Speaker 1: use the robotic arm independently of its real arms recalls
Speaker 1: docc the character from Spider Man, who controlled his robotic
Speaker 1: limbs even while doing other tasks with his flesh hands.
Speaker 1: So it shouldn't seem surprising that humans and monkeys can
Speaker 1: figure out how to move robotic arms with their thoughts.
Speaker 1: It's the same process by which your brain learned to
Speaker 1: control your natural, fleshy limbs. As we've seen. Your process
Speaker 1: as a baby was to flail your appendages around and
Speaker 1: bite your toes in grass your crib bars and poked
Speaker 1: yourself in the eye and turn yourself over. For years,
Speaker 1: this is how you fine tuned the operation of your machinery.
Speaker 1: Your brain sends out commands, compares those with feedback from
Speaker 1: the world, and eventually learns the capabilities of your limbs.
Speaker 1: So your skin covered arm is really no different from
Speaker 1: the clunky, silver robotic arm of the monkey. It just
Speaker 1: happens to be the standard operating equipment you're used to,
Speaker 1: so you often end up blind to its amazingness. So
Speaker 1: for both jan and the monkeys, the robotic arms were
Speaker 1: not directly connected to their torsos, but instead connected by
Speaker 1: a bundle of wires. The electrodes in their brain sent
Speaker 1: wires to a computer which does the processing, and then
Speaker 1: the bundle of wires goes from the computer to the
Speaker 1: robotic arm. But increasingly this can be done wirelessly, and
Speaker 1: that means the robotic arm that you're controlling does it
Speaker 1: need to be right next to you or even in
Speaker 1: the same room. So could you control a robot on
Speaker 1: the other side of the world. While in two thousand
Speaker 1: and eight, my colleague Miguel Nikolaylis and his team from
Speaker 1: Duke University hooked up electrodes to a monkey and that
Speaker 1: monkey controlled the walking patterns of a robot halfway across
Speaker 1: the globe. So the monkey would walk on a treadmill,
Speaker 1: and the signals from his motor cortex were recorded and
Speaker 1: translated into zeros and ones and transmitted via the Internet
Speaker 1: to a laboratory in Japan and fed into a robot there.
Speaker 1: And while the monkey walked, the five foot tall, two
Speaker 1: hundred pound robot would also walk like a metal doppelganger.
Speaker 1: So after they demonstrated this proof of principle, the Duke
Speaker 1: team stopped the treadmill. But as the monkey looked at
Speaker 1: its avatar on the screen, it's thought about walking, and
Speaker 1: so the robot Japan kept marching along. So in the
Speaker 1: same way that Jan imagines movements and the arm executes
Speaker 1: our internal commands, the monkeys motor cortex continued to think
Speaker 1: about walking even while he wasn't doing it, and the
Speaker 1: robot kept going. So in the not too distant future,
Speaker 1: it seems inevitable that we're going to have mind controlled
Speaker 1: robots in factories or underwater or on the surface of
Speaker 1: the moon. And it's all from the comfort of our
Speaker 1: own couches. And this is because our cortical maps, after
Speaker 1: extensive training, will be able to incorporate whatever the limbs
Speaker 1: of the robot are. That's going to become our tell limbs.
Speaker 1: So think about the way we watch television, which means
Speaker 1: far sight. I'm coining the term tell limbs because in
Speaker 1: the near future, we're going to be control rolling far bodies.
Speaker 1: So the bodies that we have right now have evolved
Speaker 1: for the conditions of this particular oxygen rich planet. But
Speaker 1: leveraging the brain's plasticity to build long distance bodies, that's
Speaker 1: surely going to be our main strategy for space exploration.
Speaker 1: So what consequence would expanding your body, say with a
Speaker 1: robotic arm or a metal avatar across town. What consequence
Speaker 1: would this have for your conscious experience? The answer is
Speaker 1: that the robot will be perceived as a part of you.
Speaker 1: The robot will just be another limb. Now, it's an
Speaker 1: unusual limb because of the physical gap between you and it,
Speaker 1: but it nonetheless will qualify just as a new limb.
Speaker 1: The only reason we're accustomed to connected limbs is that
Speaker 1: Mother Nature is a talented seamstress with muscle and sinew
Speaker 1: and nerves, but she never worked out how to control
Speaker 1: distant limbs via bluetooth. Now, if extra limbs or telelimbs,
Speaker 1: if the seems exotic, recall that you have everyday experience
Speaker 1: with them. Just look in a mirror and move your arm.
Speaker 1: You see a distant object, move in perfect synchrony with
Speaker 1: your motor commands. And although babies are at first confused
Speaker 1: by mirror images, they come to understand the reflections as themselves,
Speaker 1: because although they don't feel any direct sensation from those
Speaker 1: distant limbs, they can witness their control over them, and
Speaker 1: that's enough for these limbs to be annexed by self hood.
Speaker 1: So this notion of this self is analogous to the
Speaker 1: borg in Star Trek, who assimilate everything in their path
Speaker 1: into their singular identity, except for those things that can't control,
Speaker 1: like the impossibly unpredictable Captain Picard. Now this led me
Speaker 1: to propose an axiom in Live Wired about the nature
Speaker 1: of selfhood. What the body can control becomes the self.
Speaker 1: And I think this all pivots on predictability. In other words,
Speaker 1: can I predict that signals from my brain will cause
Speaker 1: something to happen out there? So this relationship of selfhood
Speaker 1: and predictability it allows us to understand disorders such as
Speaker 1: asmatic noosa, which translates to not knowing one's body. So
Speaker 1: in asmatic noosa, damage to the right pridal lobe of
Speaker 1: the brain, say by a stroke or a tumor, means
Speaker 1: that a person is no longer able to control a limb,
Speaker 1: and as a completely gobsmacking result, the patient will deny
Speaker 1: that the limb belongs to her, and sometimes will insist
Speaker 1: that the limb belongs to someone else. She will attribute
Speaker 1: the arm to a dead friend or a relative, or
Speaker 1: a phantasm or a devil, or one of the medical
Speaker 1: professionals taking care of her. She'll say that it's not
Speaker 1: her arm. She'll explain that her own real arm was
Speaker 1: stolen or is simply missing. The manifestations of this can
Speaker 1: be varied and strange, So a patient may feel totally
Speaker 1: indifferent towards her no longer self limb, or she might
Speaker 1: be delusional about it and come up with strange fabrications
Speaker 1: to explain what happened, such as saying someone's so this
Speaker 1: onto my body, or other patients might sympathetically describe their
Speaker 1: limbs as something that they dislike, like a deadweight. And
Speaker 1: in a more vicious version of this breakdown of selfhood,
Speaker 1: a patient may hate her alien limb, and she might
Speaker 1: curse at it and hit it. So there's no gold
Speaker 1: standard for this disorder, but you probably have no trouble
Speaker 1: guessing my proposal in Live Wired, which is the brain
Speaker 1: can no longer control the limb, and so the limb
Speaker 1: falls from the brotherhood of the self. It no longer
Speaker 1: is part of you. Now. Sometimes these patients will have
Speaker 1: a small window of lucidity in which they re recognize
Speaker 1: their limb as their own, but it doesn't last long,
Speaker 1: And I hypothesize that this may result when the arm
Speaker 1: happens to behave like they intended. So it's accidental predictability.
Speaker 1: Given a person's lifelong experience of controlling her arm, it
Speaker 1: doesn't come as a surprise that even a temporary impression
Speaker 1: of control can snap it back into alignment with this self,
Speaker 1: if only for a moment. Now, by the way, I
Speaker 1: suspect this sense of predictability is related to the way
Speaker 1: that a person that you know deeply, like a family member,
Speaker 1: becomes something like a part of yourself. Of course, humans
Speaker 1: are way too complex to predict perfectly, and the degree
Speaker 1: to which your spouse acts surprisingly is the extent to
Speaker 1: which he or she remains independent. Okay, Now, one doesn't
Speaker 1: need prosthetics or brain surgery to try out new bodies.
Speaker 1: The developing field of avatar robotics allows the user to
Speaker 1: control a robot at a distance, seeing what it sees
Speaker 1: and feeling what it feels. So take something called the
Speaker 1: shadow hand, which is one of the most intricate artificial
Speaker 1: hands in existence. Each fingertip is equipped with sensors which
Speaker 1: feed their data back into haptic gloves that are worn
Speaker 1: by the user, So sending data over the internet, one
Speaker 1: can control a robotic hand. In London from Silicon Valley
Speaker 1: and other groups are working on disaster recovery avatars. These
Speaker 1: are robots that are sent in after earthquakes or terrorist
Speaker 1: attacks or fires, and the ideas that they can be
Speaker 1: piloted by drivers that are sitting somewhere else that's safe. Now,
Speaker 1: I haven't yet heard of people using strange bodied avatars,
Speaker 1: but they certainly could. Just as the brain learns skis
Speaker 1: or trampolines or pogo sticks, it can learn to become
Speaker 1: one with a weird and wonderful avatar body. So this
Speaker 1: field of avatar robotics is going to allow people to
Speaker 1: try out extended or strange bodies. But let's note that
Speaker 1: it's super expensive and luckily there's a better way to
Speaker 1: try out different body plans, and that's inside virtual reality.
Speaker 1: So inside a simulated space, you can make massive changes
Speaker 1: to your body plan instantly, inexpensively. So imagine looking into
Speaker 1: a mirror in your VR world, you lift your arm,
Speaker 1: and you see your virtual avatar in the mirror, raise
Speaker 1: its arm, you tilt your neck in the avatar tilts
Speaker 1: its neck. Now, imagine that this avatar has not your face,
Speaker 1: but that of an Ethiopian woman, or a Norwegian man,
Speaker 1: or a Pakistani boy, or a Korean grandmother. So, for
Speaker 1: the reasons that we just saw about how the brain
Speaker 1: determines selfhood, if I can control what it does, it
Speaker 1: becomes me. It only takes a few moments of motor
Speaker 1: babbling in front of this VR mirror to convince yourself
Speaker 1: that you now inhabit a different body. You can then
Speaker 1: walk around in the VR world as a different in person,
Speaker 1: experiencing life through a modified identity. Self identity, by the way,
Speaker 1: is surprisingly flexible. Researchers have been studying this in recent years,
Speaker 1: how taking on the face of a different person can
Speaker 1: enhance empathy, but taking on a new face that's just
Speaker 1: the beginning. So in the late nineteen eighties, because of
Speaker 1: a coding error, the VR study of unusual bodies began.
Speaker 1: A scientist was inhabiting the avatar of a dockworker in
Speaker 1: VR when a programmer accidentally made his arm enormous, like
Speaker 1: the size of a construction crane because he inserted too
Speaker 1: many zeros into the scaling factor. And to everyone's surprise,
Speaker 1: the person in VR was none less able to figure
Speaker 1: out how he could operate accurately and efficiently with this megaarm.
Speaker 1: And so this led people to wonder what kind of
Speaker 1: bodies could be occupied. So my friend Jaron Lanier and
Speaker 1: his colleague An Lasco made an experience in which people
Speaker 1: inhabited the bodies of eight legged lobsters. So your two
Speaker 1: arms controlled the first two arms of the lobster, and
Speaker 1: then they tried out several complicated algorithms to control the
Speaker 1: other arms. And it was pretty tough work to control
Speaker 1: the eight legs of the lobster, but apparently some people
Speaker 1: were able to make it come to pass. So Jaron
Speaker 1: coined the term homuncular flexibility. The homunculus is the little
Speaker 1: man inside your head, the little naps. He coined this
Speaker 1: term homuncular flexibility to capture the surprising elasticity of the
Speaker 1: brain's representation of its body. Some years later, my Stanford
Speaker 1: colleague Jeremy Baylinson and his team set out to test
Speaker 1: homuncular flexibility more scientifically. They asked whether people could learn
Speaker 1: to act accurately control a third arm in VR. So
Speaker 1: imagine strapping on the VR goggles and you grasp two
Speaker 1: controllers in your hand, and so you can see your
Speaker 1: own arms in virtual space, and you see an additional
Speaker 1: arm as well, coming out from the middle of your chest.
Speaker 1: The task is pretty simple. You touch a box as
Speaker 1: soon as it changes color. But there are a lot
Speaker 1: of boxes, and to do well you have to employ
Speaker 1: all three arms. So the first two virtual arms are
Speaker 1: simply controlled by your own arms, and the third arm
Speaker 1: is controlled by rotating your wrists. Within three minutes, users
Speaker 1: got it. They could accommodate the new body plan with
Speaker 1: this third arm and do the task really well. There's
Speaker 1: really no limit to the physiques or body plans that
Speaker 1: you could explore. Imagine finding a virtual tail protruding from
Speaker 1: your tail moan which you could accurately control with your movement,
Speaker 1: or becoming the size of a golf ball or the
Speaker 1: size of a building, or having six fingers, or becoming
Speaker 1: a housefly with wings, or like doc oc, becoming an octopus.
Speaker 1: Marrying the flexibility of the brain to the burgeoning creativity
Speaker 1: of the VR design world. This is why we're moving
Speaker 1: into an era in which our virtual identities are not
Speaker 1: going to be limited by the bodies that we happen
Speaker 1: to have evolved. What we can do instead is speed
Speaker 1: up evolution from eons to hours. We can explore bodies
Speaker 1: that Mother Nature couldn't dream of, making virtual avatars reel
Speaker 1: to the brain. So let's wrap this up. We saw
Speaker 1: with Matt the archer or Faith the dog that brains
Speaker 1: adjust to drive whatever body they find themselves in, and
Speaker 1: like Jam's robotic arm, brains can also figure out how
Speaker 1: to operate new hardware additions. Massive networks of brain cells
Speaker 1: pull off this trick by putting out motor commands like
Speaker 1: lean to the left and assessing the feedback like the
Speaker 1: skateboard tilted and wobbled, and then it adjusts its parameters
Speaker 1: to climb the mountain of expertise. So our progeny won't
Speaker 1: have to limit themselves to the boundaries of their bodies. Instead,
Speaker 1: they're going to be able to extend across the universe
Speaker 1: according to whatever is under their control. Imagine learning how
Speaker 1: to control a drone as part of your body, or
Speaker 1: build robotic wings and control them with your thoughts, just
Speaker 1: how you control your arms and flying across the city
Speaker 1: that way, or imagine having a sail for balancing, or
Speaker 1: a propeller or peripheral devices like a forklift. How would
Speaker 1: you build a better body than the one you inherit
Speaker 1: it from a long road of evolution. That's all for
Speaker 1: this week. To find out more and to share your thoughts,
Speaker 1: head over to eagleman dot com, slash podcasts, and you
Speaker 1: can also watch full episodes of Inner Cosmos on YouTube.
Speaker 1: Subscribe to my channel so you can follow along each
Speaker 1: week for new updates until next time. I'm David Eagleman,
Speaker 1: and this is Inner Cosmos.