WEBVTT - Ep2 "What would you do with robotic wings? (or How to get a better body)" 0:00:05.720 --> 0:00:09.799 Why does the world's best archer have no arms? How 0:00:09.800 --> 0:00:12.920 does a dog learn how to skateboard? How can a 0:00:13.080 --> 0:00:16.599 robot figure out what its body looks like? How can 0:00:16.800 --> 0:00:20.040 someone come to believe that her leg doesn't belong to 0:00:20.079 --> 0:00:23.000 her but to someone else? And what does any of 0:00:23.040 --> 0:00:26.479 this have to do with babies? Babbling or doc oc 0:00:26.640 --> 0:00:32.599 from spider Man. Welcome to innert Cosmos with me, David Eagleman. 0:00:34.080 --> 0:00:38.720 I'm a neuroscientist and an author at Stanford University, and 0:00:38.840 --> 0:00:43.360 I've spent my whole career studying the intersection between how 0:00:43.400 --> 0:00:54.880 the brain works and how we experience life. Have you 0:00:54.880 --> 0:00:59.200 ever texted while you're riding your bicycle? So on campus, 0:00:59.240 --> 0:01:02.280 i see students doing this all the time, and I'm 0:01:02.320 --> 0:01:05.920 amazed because what it tells me is how good the 0:01:05.959 --> 0:01:10.760 three pound brain is at controlling the body, running the 0:01:11.120 --> 0:01:14.320 petals with the legs, and steering the handlebars with one 0:01:14.360 --> 0:01:18.200 hand and hitting these very tiny targets with the other thumb, 0:01:18.600 --> 0:01:21.000 and pulling on the brake when they need to slow down, 0:01:21.120 --> 0:01:24.520 and so on. And this is all from inside the 0:01:24.560 --> 0:01:29.520 brain's mission control center in the skull, in total darkness. 0:01:30.080 --> 0:01:34.680 It's controlling all these limbs with a degree of expertise 0:01:34.720 --> 0:01:37.960 that we can't even scratch with robotics. So what I 0:01:38.040 --> 0:01:41.160 want to talk about today is how you can get 0:01:41.640 --> 0:01:44.240 even a better body. And I'm not talking about diet 0:01:44.360 --> 0:01:47.440 or fitness. I'm talking about the future of what we 0:01:47.480 --> 0:01:51.760 can do with our brains. For example, could you add 0:01:51.960 --> 0:01:58.880 new limbs. Let's start with the Spider Man comics from 0:01:58.880 --> 0:02:02.480 back in the day, So in July of nineteen sixty three, 0:02:02.520 --> 0:02:06.160 a new character got introduced. It was a scientist named 0:02:06.200 --> 0:02:10.680 Otto Gunther Octavius. Now he was interesting because he plugs 0:02:10.720 --> 0:02:15.400 a device directly into his brain to control four extra 0:02:15.639 --> 0:02:20.440 robotic arms. He's able to operate these metal limbs just 0:02:20.520 --> 0:02:24.280 as smoothly as his own natural arms, and so he's 0:02:24.320 --> 0:02:27.920 able to work this way with radioactive materials. Now in 0:02:27.960 --> 0:02:30.280 the comic book, each of his arms is able to 0:02:30.360 --> 0:02:34.320 operate independently, in the same way that you can steer 0:02:34.360 --> 0:02:37.360 your car with one hand while you change the radio 0:02:37.360 --> 0:02:40.000 station with the other. And this is while at the 0:02:40.080 --> 0:02:42.680 same time you're switching between the brake and the gas 0:02:42.720 --> 0:02:48.320 with your foot. Unfortunately, for doctor Octavius, there's an explosion 0:02:48.440 --> 0:02:52.320 and the explosion damages his brain and dooms him to 0:02:52.400 --> 0:02:55.640 a life of villany. So he's now lost all his 0:02:55.720 --> 0:02:59.639 sense of morality, and he capitalizes on these four extra 0:02:59.760 --> 0:03:03.760 arms to climb up buildings and pull safes out from 0:03:03.800 --> 0:03:07.399 walls and fight in new ways with multi hand combat. 0:03:07.960 --> 0:03:11.320 And now with his new evil personality, he becomes known 0:03:11.360 --> 0:03:18.800 as Doctor Octopus or doc OC. So when the comic 0:03:18.840 --> 0:03:22.320 book debuted in nineteen sixty three, it was pure sci 0:03:22.360 --> 0:03:26.160 fi fantasy to imagine that a human brain could control 0:03:26.360 --> 0:03:31.720 robotic limbs, but not anymore. So how close are we 0:03:32.280 --> 0:03:35.880 to actually reaching the point of a doc oc? Could 0:03:35.920 --> 0:03:40.880 you plug in new limbs like extra legs or wings? 0:03:41.440 --> 0:03:45.320 What are the limits? So to get started in understanding this, 0:03:46.040 --> 0:03:49.080 the key thing to orient ourselves too is that the 0:03:49.160 --> 0:03:53.640 brain has inputs and outputs. The inputs includes all the 0:03:53.640 --> 0:03:57.200 information from your senses like vision, hearing, and smell and 0:03:57.240 --> 0:04:01.280 so on. The output is how you're brain controls your 0:04:01.320 --> 0:04:05.080 body to interact with the world. In a different episode, 0:04:05.080 --> 0:04:08.960 I'll talk about input asking how our senses work and 0:04:09.000 --> 0:04:12.120 how we can create new senses. But today we're going 0:04:12.200 --> 0:04:15.800 to talk about how the brain controls the body and 0:04:15.840 --> 0:04:20.080 what the prospects are for changing that or adding on 0:04:20.160 --> 0:04:22.880 to that. So let's start back in the nineteen sixties 0:04:22.920 --> 0:04:27.960 when a Canadian neurosurgeon named Wilder Penfield was sticking small, 0:04:28.400 --> 0:04:32.360 thin wires called electrodes into the brain of a patient 0:04:32.680 --> 0:04:36.120 undergoing surgery. Now, it turns out you can stick things 0:04:36.120 --> 0:04:38.680 like that directly into the brain, and you can do 0:04:38.720 --> 0:04:41.480 that while the patient is awake and it doesn't hurt 0:04:41.560 --> 0:04:46.119 at all. Why it's because there are no pain receptors 0:04:46.160 --> 0:04:48.679 in the brain, so you can just dunk a metal 0:04:48.720 --> 0:04:51.280 electrode right in the tissue the way you'd stick a 0:04:51.360 --> 0:04:53.719 toothpick in a block of cheese, and the patient doesn't 0:04:53.760 --> 0:04:57.600 feel anything anyway. So Penfield was sticking the electrode into 0:04:57.600 --> 0:05:00.680 the brain while he talked with the patient and asking 0:05:00.760 --> 0:05:03.719 him what he was feeling. And what Penfield stumbled on 0:05:03.880 --> 0:05:08.200 was something that elevated neuroscience. He discovered in the brain 0:05:08.880 --> 0:05:15.279 a nap of the body. So let's say I have 0:05:15.320 --> 0:05:18.080 the electrode right here on a little strip of brain 0:05:18.160 --> 0:05:22.359 tissue where you'd wear a tiara or headphones, and the 0:05:22.360 --> 0:05:26.360 electrode is measuring the electrical spikes in the brain cells, 0:05:26.400 --> 0:05:32.360 the neurons, And now I touch your shoulder, and it 0:05:32.360 --> 0:05:35.600 turns out these neurons only respond to touch on your 0:05:35.640 --> 0:05:39.120 shoulder and nowhere else. So now let's say I move 0:05:39.160 --> 0:05:42.160 the electrode just a little bit over, still on this strip, 0:05:42.600 --> 0:05:47.680 and now I touch your elbow, and Penfield found that 0:05:47.720 --> 0:05:50.880 as he moved over a little more, there are neurons 0:05:50.880 --> 0:05:53.720 that respond to the forearm, and then next to that 0:05:54.160 --> 0:05:57.720 the hand, and elsewhere along this little strip of brain 0:05:57.800 --> 0:06:01.279 tissue he found cells that respond to your face, or 0:06:01.320 --> 0:06:04.160 your torso, or your legs or your feet. And so 0:06:04.200 --> 0:06:06.520 as you move along this strip in the brain you 0:06:06.560 --> 0:06:11.279 find the whole body represented where neighboring territories on the 0:06:11.320 --> 0:06:15.880 body have neighboring territory in the brain. And this came 0:06:15.920 --> 0:06:20.080 to be known as the somatos sensory cortex, which refers 0:06:20.120 --> 0:06:25.279 to sensation from the body, the soma. Now, the interesting 0:06:25.320 --> 0:06:28.280 part for today's podcast is that he also found a 0:06:28.440 --> 0:06:31.440 second map of the body, and this was on a 0:06:31.520 --> 0:06:35.000 neighboring strip that we call the motor cortex. It's right 0:06:35.040 --> 0:06:38.280 in front of that. So when the cells here are active, 0:06:39.080 --> 0:06:42.880 they drive very particular parts of the body. In other words, 0:06:42.960 --> 0:06:47.960 they contract particular muscles. So activity in these cells right 0:06:48.000 --> 0:06:51.599 here causes your shoulder to twitch, an activity right next 0:06:51.640 --> 0:06:55.200 to it causes your bicep to contract, and activity right 0:06:55.240 --> 0:06:58.800 next to that causes your forearm to move, and so on. 0:06:59.080 --> 0:07:02.159 With a map of the entire body, all the parts 0:07:02.200 --> 0:07:09.159 that you can control are represented in this strip here. Now, 0:07:09.200 --> 0:07:13.720 it turns out this map doesn't have equal representation everywhere. 0:07:14.320 --> 0:07:19.080 The body parts, which are more finely controlled, have larger 0:07:19.160 --> 0:07:22.880 areas of representation. So you have a bunch of territory 0:07:22.960 --> 0:07:26.360 devoted to your fingers, for example, but not a lot 0:07:26.400 --> 0:07:29.280 to the muscles that can move your kneecap or your scalp. 0:07:30.120 --> 0:07:32.320 Now we'll come back to this in later episodes, but 0:07:32.480 --> 0:07:35.400 what is wild is that this map of the body 0:07:35.960 --> 0:07:41.880 is not genetically determined as everyone originally guessed. Instead, it's 0:07:41.960 --> 0:07:46.560 shaped by the body's experience in the world. In other words, 0:07:46.640 --> 0:07:51.840 it devotes territory to what it can control. And if 0:07:51.920 --> 0:07:56.320 you lose your hand in a terrible car accident, your 0:07:56.480 --> 0:08:01.560 primary motor cortex begins to shift, often change itself. Over 0:08:01.600 --> 0:08:06.400 the course of weeks, the brain areas that control neighboring 0:08:06.640 --> 0:08:10.680 arm muscles like your biceps and triceps slowly take over 0:08:10.760 --> 0:08:16.080 the cortical territory that formerly operated your hand. Now we 0:08:16.120 --> 0:08:19.080 can look at it this way. Neurons that previously drove 0:08:19.120 --> 0:08:22.480 your hand, they get their job duty reassigned, and they 0:08:22.520 --> 0:08:26.000 now join the team of neurons that control the upper 0:08:26.080 --> 0:08:29.360 arm muscles. So what this tells us is that the 0:08:29.440 --> 0:08:33.840 motor areas of the brain, those neurons that are sending 0:08:33.840 --> 0:08:37.599 their signals down the spinal cord to drive the body, 0:08:37.760 --> 0:08:44.479 they optimize themselves to drive the available machinery. And this principle, 0:08:44.800 --> 0:08:47.360 as we're going to see, is what opens the door 0:08:48.080 --> 0:08:53.080 to rearranging body plans, something that's traditionally been done only 0:08:53.120 --> 0:08:57.400 when there's injury, but will soon enough be possible when 0:08:57.400 --> 0:09:00.880 we want to add things to the body. So to 0:09:01.000 --> 0:09:04.760 understand this, let's start with a wide angle lens looking 0:09:04.760 --> 0:09:07.880 at the world of our cousins in the animal kingdom. 0:09:08.440 --> 0:09:11.439 So the thing to notice is that there are all 0:09:11.440 --> 0:09:15.839 sorts of strange and amazing body plans. To look at 0:09:15.840 --> 0:09:20.040 the ant eater with its long proboscis, or an animal 0:09:20.120 --> 0:09:23.840 called the star nosed mole, which has essentially twenty two 0:09:23.880 --> 0:09:27.360 fingers on its nose with which it feels around in 0:09:27.360 --> 0:09:31.920 its dark tunnels. Or look at the sloth or the dragonfish, 0:09:32.000 --> 0:09:36.200 or the platypus or the octopus. You find very different 0:09:36.440 --> 0:09:39.720 bodies in the animal kingdom. But here's the thing to notice. 0:09:40.400 --> 0:09:46.959 All the animals, including us, have surprisingly similar genomes. So 0:09:47.000 --> 0:09:50.040 how do the animal's brains come to operate all this 0:09:50.320 --> 0:09:56.760 wildly different equipment like prehensile tails or claws, or larynxes 0:09:56.880 --> 0:10:02.559 or tentacles, whiskers or or wings. The question is are 0:10:02.600 --> 0:10:07.640 their brains preprogrammed for it? How do mountain goats get 0:10:07.679 --> 0:10:10.760 so good at leaping up rocks? And how do owls 0:10:10.800 --> 0:10:14.160 get so good at plunging down on mice? How do 0:10:14.240 --> 0:10:17.200 frogs get so good at hitting flies with their tongues? 0:10:17.760 --> 0:10:22.720 So here's what I think the answer is. In my 0:10:22.800 --> 0:10:26.199 book Live Wired, I proposed what I call the potato 0:10:26.280 --> 0:10:29.920 head model of the brain. And this model proposes that 0:10:29.960 --> 0:10:34.280 you can plug in whatever peripheral devices you want, like 0:10:34.520 --> 0:10:37.200 arms or fins or wings, just like plugging things into 0:10:37.240 --> 0:10:41.720 a potato head, and the brain will figure out how 0:10:41.800 --> 0:10:45.520 to drive them. It's kind of like with your computer. 0:10:45.760 --> 0:10:50.920 Your laptop manufacturer doesn't have to know the next model 0:10:50.960 --> 0:10:53.240 of peripheral that's going to come out in a couple 0:10:53.240 --> 0:10:57.720 of years. Your laptop is ready to drive anything whatever 0:10:57.760 --> 0:11:03.200 comes along. So in this potato head framework, mother nature 0:11:03.280 --> 0:11:08.080 has the freedom to experiment genetically with any kind of 0:11:08.480 --> 0:11:11.920 plug in play motor devices. You just plug in whatever 0:11:12.000 --> 0:11:15.680 limbs you want and the brain will figure out how 0:11:15.760 --> 0:11:20.800 to drive them. It doesn't matter if this is fingers 0:11:21.040 --> 0:11:24.920 or flappers or fins. It doesn't matter if your body 0:11:24.960 --> 0:11:28.079 shows up with two legs or four legs or eight legs. 0:11:28.120 --> 0:11:33.200 It doesn't matter whether you sprout hands or talons or wings. 0:11:33.840 --> 0:11:38.080 The fundamental principles of brain operation don't need to be 0:11:38.120 --> 0:11:42.360 redesigned every time. The motor system that we're talking about 0:11:42.440 --> 0:11:46.640 in the brain, well, it figures out how to drive 0:11:46.800 --> 0:11:51.920 the available machinery. So the advantage of such an adaptable 0:11:51.960 --> 0:11:55.920 brain is that it allows mother nature to mess around 0:11:55.960 --> 0:12:01.160 with genetics to develop new peripheral devices. And it turns 0:12:01.160 --> 0:12:05.480 out it's shockingly easy for her to make little adjustments 0:12:05.600 --> 0:12:08.480 to the a's and seas and teas and gees, and 0:12:08.600 --> 0:12:12.960 you end up with all kinds of different body plants. Okay, now, 0:12:13.240 --> 0:12:15.719 wait a mind it, you might say, If bodies are 0:12:15.800 --> 0:12:19.640 so easy to modify with tweaks of the genome, how 0:12:19.679 --> 0:12:23.480 can we don't see things like a human sometimes being 0:12:23.559 --> 0:12:27.559 born with a genetic mutation that gives him a tail 0:12:27.840 --> 0:12:32.600 or an extra arm. Well you do. Actually, it turns 0:12:32.600 --> 0:12:36.839 out that some genes in your genome act like movie directors. 0:12:37.000 --> 0:12:41.560 They carefully control which thing happens when and where, and 0:12:41.760 --> 0:12:46.599 in this case, which other gene cascades get triggered to unpack. 0:12:47.480 --> 0:12:51.240 So in fruit flies, a few decades ago, it was 0:12:51.320 --> 0:12:56.840 discovered that certain mutations in these director genes control the 0:12:56.880 --> 0:13:00.720 development of the larger body structure. One of the first 0:13:00.720 --> 0:13:05.200 discoveries involved a mutation in the fruit flies in which 0:13:05.200 --> 0:13:08.160 a pair of legs would grow where the antennae were 0:13:08.160 --> 0:13:11.480 supposed to be, and there's a reverse mutation which placed 0:13:11.520 --> 0:13:14.560 antennae where the legs should be. So when you start 0:13:14.679 --> 0:13:17.360 looking at the building of the body this way, you 0:13:17.400 --> 0:13:20.280 see it's sort of like lego. You can just swap 0:13:20.320 --> 0:13:24.760 one thing out for another. Based on these genes coated 0:13:24.800 --> 0:13:27.640 in a's and seas and teas and geese. If you 0:13:27.679 --> 0:13:30.880 want to look this up further, look up homeobox genes. 0:13:31.679 --> 0:13:34.040 The big point I want to make here is just 0:13:34.120 --> 0:13:36.800 that some genes act as a switch to turn on 0:13:36.840 --> 0:13:40.120 a cascade of other genes, and this is why many 0:13:40.200 --> 0:13:45.720 mutations involve the surprising appearance or disappearance of a full 0:13:45.760 --> 0:13:50.000 body part. So in humans you can find these surprisingly 0:13:50.080 --> 0:13:54.920 small mutations where, for example, a child is born with 0:13:54.960 --> 0:13:59.360 a tail, it's just a genetic program which extends the 0:13:59.400 --> 0:14:03.040 spinal column and keeps it going. Every year, there are 0:14:03.160 --> 0:14:06.800 hundreds of children born with tails, and the tail gets 0:14:06.920 --> 0:14:10.600 simply removed with an operation. In Live Wired, I tell 0:14:10.640 --> 0:14:13.800 the story of a baby named Gigi who was born 0:14:13.800 --> 0:14:19.240 in China a few years ago, and Gigi had three arms. Now, 0:14:19.280 --> 0:14:21.680 for the COGNISCINTI, I'll just mention that this sort of 0:14:21.680 --> 0:14:26.760 thing sometimes happens because of a parasitic twin in the womb, 0:14:27.320 --> 0:14:30.440 where one twin doesn't make it and gets absorbed into 0:14:30.480 --> 0:14:33.200 the body of the healthier twin. But that's not the 0:14:33.240 --> 0:14:37.720 case with Gigi. His genetics simply dictated the growth of 0:14:37.760 --> 0:14:42.240 a third arm. The surgeons in China took several hours 0:14:42.280 --> 0:14:45.080 to remove one of the arms because both arms on 0:14:45.120 --> 0:14:50.400 the left side were well developed and had individual shoulder blades. Now, 0:14:50.440 --> 0:14:55.000 what tails and extra arms illustrate is the way body 0:14:55.080 --> 0:15:00.160 plants can change with small alterations of the genetics. And 0:15:00.320 --> 0:15:03.240 it goes without saying that this sort of genetic wobble 0:15:03.400 --> 0:15:06.800 happens in minor ways all around us. Some people have 0:15:07.320 --> 0:15:10.880 longer arms, or stubby your fingers, or a big toe 0:15:10.920 --> 0:15:13.720 that's shorter than the second toe, or wider hips or 0:15:13.760 --> 0:15:19.040 broader shoulders. And although our nearest cousins, the chimpanzees, are 0:15:19.160 --> 0:15:22.240 nearly genetically identical to us, they have a lot of 0:15:22.280 --> 0:15:26.760 differences in their body plan. For starters, their bicep muscle 0:15:26.800 --> 0:15:30.440 has a higher insertion point, and their hips are turned 0:15:30.480 --> 0:15:34.320 more outward, and their toes are much longer. Now, the 0:15:34.360 --> 0:15:39.120 point is that the chimpanzee brain, with its mere ninety 0:15:39.200 --> 0:15:43.560 thousand genes, doesn't have to be reinvented to figure out 0:15:43.600 --> 0:15:47.200 how to drive a chimpanzee body to swing in trees 0:15:47.240 --> 0:15:50.600 and to walk on knuckles. And by the same token, 0:15:50.640 --> 0:15:54.160 the human brain doesn't have to be reinvented to figure 0:15:54.160 --> 0:15:57.920 out how to play pickleball or dance hip hop. In 0:15:57.920 --> 0:16:02.320 both cases, the brain just figures out how to best 0:16:02.680 --> 0:16:21.440 drive the machinery that it has. So to understand the 0:16:21.560 --> 0:16:26.320 power of this principle, consider Matt Stutsman. This is a 0:16:26.360 --> 0:16:30.080 guy who is born without arms. He found himself really 0:16:30.080 --> 0:16:34.240 attracted to archery, so he learns to manipulate a bow 0:16:34.280 --> 0:16:39.160 and arrow with his feet. What he does is notch 0:16:39.320 --> 0:16:42.520 the arrow into the string with his toes. Then he 0:16:42.880 --> 0:16:46.040 lifts the bow with his right foot, and he's got 0:16:46.080 --> 0:16:48.560 a strap around his neck which connects the bow to 0:16:48.640 --> 0:16:51.480 his shoulder, and that allows him to position it at 0:16:51.520 --> 0:16:54.280 eye level. And then he puts tension on the bow 0:16:54.360 --> 0:16:57.480 by pushing it forward with his foot, and when his 0:16:57.600 --> 0:17:00.520 aim is on target, he lets the arrow fly. Now, 0:17:00.560 --> 0:17:04.040 the thing is that Matt is not simply talented at archery. 0:17:04.119 --> 0:17:08.080 He is the best in the world. As of this podcast, 0:17:08.160 --> 0:17:12.520 he holds the record for the longest accurate shot in archery. 0:17:13.160 --> 0:17:16.119 And that's probably not what his doctors would have predicted 0:17:16.480 --> 0:17:19.520 for a baby who came out of the womb without arms, 0:17:20.200 --> 0:17:24.200 But perhaps they didn't realize how readily his brain would 0:17:24.200 --> 0:17:28.639 adapt its resources to solve problems in the outside world. 0:17:29.640 --> 0:17:32.879 Now we see this sort of flexibility everywhere in the 0:17:32.920 --> 0:17:37.439 animal kingdom. Consider this incredible dog whose name is Faith, 0:17:37.880 --> 0:17:41.920 who was born without front legs, and she grew from 0:17:42.000 --> 0:17:45.679 puppyhood to be able to walk on her two hind 0:17:45.800 --> 0:17:49.200 legs bipetally the way that a human walks. You can 0:17:49.240 --> 0:17:52.640 find YouTube videos of her walking around. It's totally amazing 0:17:52.640 --> 0:17:56.439 to watch. And although we might have guessed that dog 0:17:56.480 --> 0:18:02.200 brains come hardwired to drive standard dog bodies, Faith shows 0:18:02.280 --> 0:18:05.560 us how readily brains will move around the world with 0:18:05.600 --> 0:18:10.040 whatever machinery they find themselves in. So what we see 0:18:10.240 --> 0:18:13.680 from Matt or from Faith the Dog is that brains 0:18:13.720 --> 0:18:18.959 are not predefined for particular bodies. Instead, they adapt themselves 0:18:19.040 --> 0:18:22.960 to move and interact and succeed in the world. And 0:18:23.040 --> 0:18:26.000 this isn't simply about the body you're born in, but 0:18:26.200 --> 0:18:31.119 about whatever opportunities might come along. So take Sir Blake, 0:18:31.320 --> 0:18:37.040 a bulldog here in California who's mastered skateboarding. He steps 0:18:37.119 --> 0:18:39.840 up onto the skateboard and with his front paw he 0:18:40.040 --> 0:18:43.080 scrapes at the ground to get momentum, and at the 0:18:43.160 --> 0:18:46.560 right moment, he sets his front paw onto the board 0:18:47.040 --> 0:18:49.840 and he leans into the ride, and he shifts his 0:18:50.000 --> 0:18:53.679 body weight to steer the board around obstacles, just like 0:18:53.720 --> 0:18:56.520 a human wood. And when he's done, he lets the 0:18:56.560 --> 0:19:01.240 skateboard slow down almost to a stop, and then he dismount. Now, 0:19:01.320 --> 0:19:05.480 given the absence of wheels in the evolutionary history of dogs, 0:19:05.920 --> 0:19:09.960 what this shows is the adaptability of brains to steer 0:19:10.160 --> 0:19:15.000 new possibilities. Or take this other dog named Sugar who 0:19:15.040 --> 0:19:20.040 took up surfboarding and is inducted into the International Surf 0:19:20.119 --> 0:19:23.800 Dog Walk of Fame, or on second thought, forget Sugar 0:19:24.119 --> 0:19:27.160 and just revel in the fact that there is an 0:19:27.240 --> 0:19:31.320 International Surf Dog Walk of Fame, because there are lots 0:19:31.320 --> 0:19:33.879 of dogs that do this, and we don't usually think 0:19:33.960 --> 0:19:38.680 about studying dog brains in the context of how they 0:19:38.680 --> 0:19:42.160 hang ten on a longboard, but you can, because all 0:19:42.240 --> 0:19:46.480 the dog requires is the opportunity and their motor systems 0:19:46.520 --> 0:19:50.719 will figure it out. So how do these dogs do it? 0:19:51.320 --> 0:19:55.760 And what does this have to do with a baby babbling? Well, 0:19:55.800 --> 0:19:59.520 a baby learns how to shape its mouth and breathing 0:20:00.080 --> 0:20:03.679 to produce language. But this is not from genetics, and 0:20:03.720 --> 0:20:07.000 it's not by studying a book or surfing Wikipedia. It's 0:20:07.119 --> 0:20:11.160 from babbling. They listen to what's going on around them, 0:20:11.200 --> 0:20:15.639 and they try things out, and their brain compares how 0:20:15.680 --> 0:20:18.719 close their own sound was to what they're hearing from 0:20:18.760 --> 0:20:22.080 the adults around them. And this has helped long because 0:20:22.119 --> 0:20:26.240 they get positive reactions for some utterances and not for others. 0:20:26.800 --> 0:20:30.680 And so there's this constant feedback loop, and that allows 0:20:30.720 --> 0:20:35.680 babies to refine their speech to perfection in whatever language 0:20:35.720 --> 0:20:39.120 is being spoken around them, whether that's English or Chinese 0:20:39.160 --> 0:20:43.840 or Hindi or any of the seven thousand languages spoken 0:20:43.840 --> 0:20:47.960 around the globe. In exactly the same way, the brain 0:20:48.080 --> 0:20:52.760 learns how to steer its body by motor babbling, in 0:20:52.800 --> 0:20:56.879 other words, babbling with its slims. Just watch a baby 0:20:56.960 --> 0:21:01.360 in the crib. She bites her toes, she slaps her forehead, 0:21:01.840 --> 0:21:05.120 she tugs on her hair, she bends her fingers, she 0:21:05.520 --> 0:21:07.679 knocks on the bar of the crib, and so on. 0:21:08.080 --> 0:21:12.480 And by doing this, she's learning how her motor output 0:21:12.880 --> 0:21:18.040 corresponds to the sensory feedback she receives. And in this way, 0:21:18.240 --> 0:21:21.919 she's learning to understand the language of her body, how 0:21:21.960 --> 0:21:27.200 her outputs nap onto the next inputs. She's trying things 0:21:27.200 --> 0:21:30.480 out and she's getting feedback, and this is how she 0:21:30.560 --> 0:21:34.800 eventually learns how to walk and navigate food to her mouth, 0:21:35.160 --> 0:21:38.280 and eventually swim in a pool and dangle on monkey 0:21:38.280 --> 0:21:42.880 bars and master a cartwheel. She's trying things out, she's adjusting, 0:21:43.000 --> 0:21:48.320 she's motorically babbling. And even better, we use this same 0:21:48.359 --> 0:21:52.240 method to attach extensions to our bodies. So think about 0:21:52.320 --> 0:21:56.400 riding a bicycle, which is a machine that our genome 0:21:56.480 --> 0:22:00.199 presumably did not see coming to master bike riding. Have 0:22:00.240 --> 0:22:04.840 to carefully balance your torso, and you change direction by 0:22:04.880 --> 0:22:08.320 moving your arms, and you have to stop by squeezing 0:22:08.359 --> 0:22:11.520 your hands, and this is all totally different from the 0:22:11.560 --> 0:22:15.920 way we normally move. But despite these complexities, most five 0:22:16.000 --> 0:22:20.280 year olds can demonstrate that the extended body plan is 0:22:20.400 --> 0:22:24.960 easily added to the resume of their motor cortex. And 0:22:25.040 --> 0:22:29.360 this isn't just limited to typical bicycles. Consider the sky 0:22:29.440 --> 0:22:33.360 named Deston Sandlin. He's an engineer who has given this 0:22:33.560 --> 0:22:37.440 very strange bicycle by a friend. It had this elaborate 0:22:37.560 --> 0:22:40.879 gearing system so that if you turned the handlebars to 0:22:40.920 --> 0:22:43.000 the left, the front wheel would turn to the right, 0:22:43.400 --> 0:22:47.600 and vice versa. And so Deston was fairly sure that 0:22:47.680 --> 0:22:51.360 this wouldn't be too difficult to master because the concept 0:22:51.480 --> 0:22:55.280 is very straightforward. You just steer the opposite direction that 0:22:55.359 --> 0:22:57.960 you want to go. But as it turned out, the 0:22:58.000 --> 0:23:02.520 bicycle was just too difficult to ride because it required 0:23:03.200 --> 0:23:07.080 unlearning the normal operation of a bicycle steering wheel and 0:23:07.280 --> 0:23:11.280 training his motor cortex to master this new task was 0:23:11.320 --> 0:23:15.639 not as simple as having a cognitive understanding. In other words, 0:23:15.760 --> 0:23:18.680 he knew how the bicycle worked, but that didn't mean 0:23:18.720 --> 0:23:21.560 he could do the right thing with his body. But 0:23:21.680 --> 0:23:24.200 after some weeks he began to get the hang of it. 0:23:24.680 --> 0:23:27.960 He practiced every day, and each time he'd try to move, 0:23:28.560 --> 0:23:31.679 he would get feedback from the world, like you're falling 0:23:31.720 --> 0:23:34.200 to the ride, or you're crashing into a trash can, 0:23:34.280 --> 0:23:36.760 or you're swerving in front of the mail truck. And 0:23:36.840 --> 0:23:40.600 so he used that feedback to adjust his next moves, 0:23:41.160 --> 0:23:44.560 and after several weeks of practicing, he got pretty good 0:23:44.600 --> 0:23:47.119 at it. And he did this the same way that 0:23:47.240 --> 0:23:49.840 he learned how to ride a normal bike as a kid, 0:23:49.840 --> 0:23:52.800 by motor babbling. And by the way, you know what 0:23:52.880 --> 0:23:54.960 this is like If you drive and you go to 0:23:55.080 --> 0:23:58.000 a country that has the steering wheel on the other 0:23:58.040 --> 0:24:00.920 side of the car, if you or an American in 0:24:00.920 --> 0:24:04.320 England or vice versa, you keep swerving the wrong way, 0:24:04.600 --> 0:24:08.200 but you eventually get better because your visual system looks 0:24:08.200 --> 0:24:12.240 at the consequences of each action and adjusts things accordingly. 0:24:12.720 --> 0:24:15.480 It's just how Matt Stutsman learned how to shoot bows 0:24:15.760 --> 0:24:19.600 or sugar learned how to skateboard. Motor babbling is not 0:24:19.720 --> 0:24:23.520 only the way that babies and bicyclists learn, it's also 0:24:23.600 --> 0:24:27.760 become a new approach in robotics. So take this starfish 0:24:27.880 --> 0:24:32.159 robot developed by my colleague Hodd Lipson. The idea is 0:24:32.200 --> 0:24:34.760 that it's a very simple robot. It's just a small 0:24:34.800 --> 0:24:38.760 square body with four arms that stick out. The key 0:24:38.920 --> 0:24:42.800 is lips and doesn't teach it how to use its body. 0:24:42.960 --> 0:24:47.520 It figures itself out. The starfish tries out a move 0:24:47.800 --> 0:24:51.199 the way that an infant might flail a limb, and 0:24:51.320 --> 0:24:55.119 it analyzes what happens. In the robots case, it's just 0:24:55.480 --> 0:24:59.960 using gyroscopes to see how the move tilted the central bot. 0:25:00.680 --> 0:25:03.240 So if it does just a single move, that can't 0:25:03.280 --> 0:25:05.520 tell it what its body looks like and how it 0:25:05.560 --> 0:25:10.160 interacts with the world. But that feedback narrows the space 0:25:10.200 --> 0:25:14.399 of possibilities, so it now has a smaller space of 0:25:14.480 --> 0:25:17.760 hypotheses about what its body looks like. So now it 0:25:17.760 --> 0:25:20.000 does the next move, and the next and so on, 0:25:20.480 --> 0:25:24.040 and instead of choosing random movements, it chooses its next 0:25:24.119 --> 0:25:29.119 move to do a good job distinguishing the available remaining 0:25:29.200 --> 0:25:34.720 hypotheses so by doing this over and over, by motoric babbling, 0:25:35.119 --> 0:25:38.919 it develops a clearer and clearer picture of its body. 0:25:39.440 --> 0:25:42.119 In this way, it learns itself. You don't need a 0:25:42.240 --> 0:25:47.160 preprogram this robot. It learns its own capabilities. And what's 0:25:47.200 --> 0:25:49.760 wild is that if you snap off one of the 0:25:49.840 --> 0:25:53.639 legs of this robot, it'll figure itself out again. And 0:25:53.720 --> 0:25:58.160 it turns out that building a babbling, self exploring robot 0:25:58.520 --> 0:26:02.639 is way more flexible than preprogramming the robot. And in 0:26:02.680 --> 0:26:06.360 the animal kingdom, nature only has some tens of thousands 0:26:06.400 --> 0:26:09.480 of genes to work with to build a creature, so 0:26:09.520 --> 0:26:13.720 it can't possibly preprogram all of the actions that one 0:26:13.800 --> 0:26:17.560 might do in the world. So it's only choice is 0:26:17.560 --> 0:26:22.840 to build a system that figures itself out. Now, think 0:26:22.880 --> 0:26:25.720 about the stories that we just talked about with Matt Stutsman, 0:26:25.840 --> 0:26:28.760 the archer with no arms, or the skateboarding dog or 0:26:28.760 --> 0:26:32.320 the surfing dog or the starfish robot. What they all 0:26:32.400 --> 0:26:36.119 have in common is the same principle, whatever kind of 0:26:36.240 --> 0:26:38.680 way that you can move around in the world, the 0:26:38.720 --> 0:26:42.320 brain on the inside does not have to be redesigned. 0:26:42.359 --> 0:26:47.040 It just recalibrates to maximize what it can do. It 0:26:47.080 --> 0:26:50.879 figures out how to control whatever body it's in. A 0:26:51.040 --> 0:26:54.880 live wired brain doesn't need to be redesigned if there's 0:26:54.920 --> 0:26:58.680 a genetic change to the body, planet just adjusts itself. 0:26:59.040 --> 0:27:04.159 And that is how evolution can so effectively shape animals 0:27:04.200 --> 0:27:09.160