WEBVTT - From the Vault: The Livewired Brain with David Eagleman 0:00:05.720 --> 0:00:07.920 Hey, you welcome to Stuff to blow your mind. This 0:00:07.960 --> 0:00:11.040 is Robert Lamb and I'm Joe McCormick, and it's Saturday 0:00:11.160 --> 0:00:14.480 time for a Vault episode. This one originally aired September 0:00:14.520 --> 0:00:17.919 twenty nine. Rob, this was the interview that you did 0:00:18.079 --> 0:00:21.320 with the neuroscientist David Eagleman. Yeah, this is a lot 0:00:21.320 --> 0:00:24.120 of fun gets that he gets into some really cool ideas. 0:00:24.200 --> 0:00:28.920 Here a possible explanation for what dreams are for? And uh, 0:00:29.000 --> 0:00:32.040 one of my favorite parts, how in which ways? Uh? 0:00:32.240 --> 0:00:35.360 Is the human brain like a Mr Potato Is a 0:00:35.479 --> 0:00:38.839 Mr Potato different from Mr potato Head? Well it's Mr 0:00:38.840 --> 0:00:41.519 potato Head. Yes, Uh oh, I guess actually it's not 0:00:41.640 --> 0:00:44.200 Mr It's just potato Head now right, Well, I think 0:00:44.240 --> 0:00:46.480 now there is still a Mr. Potato Head, but there's 0:00:46.479 --> 0:00:50.120 also a broader potato head concept. Okay, yeah, I haven't 0:00:50.200 --> 0:00:52.360 followed all the potato head news, but I've I've caught 0:00:52.400 --> 0:00:55.080 wind of some of the like the faux outrage over 0:00:55.440 --> 0:00:59.320 over some of it. So at any rate, it's a 0:00:59.520 --> 0:01:02.760 eagle and uses the potato head um as a wonderful 0:01:02.800 --> 0:01:05.760 metaphor for exactly how our brain works when you plug 0:01:06.040 --> 0:01:09.960 different sensory inputs into it, so I highly recommend it. 0:01:09.959 --> 0:01:12.360 It's a great, great, really enjoyable interview. I enjoyed it. 0:01:12.400 --> 0:01:17.960 I think folks will enjoy it as well. Welcome to 0:01:18.000 --> 0:01:27.559 Stuff to Blow Your Mind, production of My Heart Radio. Hey, 0:01:27.600 --> 0:01:29.640 welcome to Stuff to Blow Your Mind. My name is 0:01:29.720 --> 0:01:33.320 Robert Lamb. Joe is away from work. He's realigning his 0:01:33.440 --> 0:01:35.920 gray matter at the moment, so it's just me today, 0:01:35.959 --> 0:01:39.800 but I'll be joined by neuroscientist, author, and science communicator 0:01:39.880 --> 0:01:43.720 David Eagleman about his new book Live Wired, The Inside 0:01:43.760 --> 0:01:47.240 Story of the Ever Changing Brain. Now we've mentioned David 0:01:47.240 --> 0:01:50.760 Eagelman on the show many times before. He's an adjunct 0:01:50.800 --> 0:01:54.960 professor at Stanford University and his CEO of Neo Sensory, 0:01:55.000 --> 0:01:58.720 a company that develops devices for sensory substitution. You may 0:01:58.760 --> 0:02:01.480 also know him from his previous books about the human brain, 0:02:01.840 --> 0:02:04.880 his TV series The Brain with David Eagleman, and his 0:02:05.000 --> 0:02:08.240 role as a scientific advisor on HBO's Westworld and the 0:02:08.280 --> 0:02:12.000 TNT series Perception. I'm recording this on a Monday, and 0:02:12.040 --> 0:02:14.640 I actually read Live Wired over the weekend. It's a 0:02:14.760 --> 0:02:17.480 highly addictive read and one that I think our listeners 0:02:17.480 --> 0:02:20.320 will will really enjoy. David does an amazing job breaking 0:02:20.320 --> 0:02:24.200 down the inner workings of the brain via relatable pop 0:02:24.240 --> 0:02:27.560 culture and historical metaphorth everything from the colonization of the 0:02:27.560 --> 0:02:31.440 America's to Mr Potato Head and Ellen Ripley from Aliens. 0:02:32.040 --> 0:02:35.000 It's published by Pantheon Books and you can currently grab 0:02:35.040 --> 0:02:38.160 it as a hardcover, an e book, or an audio book. 0:02:38.160 --> 0:02:40.280 And the fun thing is that that David reads the 0:02:40.320 --> 0:02:42.399 audio book. It's always great when you when you get 0:02:42.400 --> 0:02:46.680 that with an audio book. So, without without any further ado, 0:02:46.919 --> 0:02:52.639 let's jump right in. David Eagleman, thanks for joining me today. 0:02:52.760 --> 0:02:54.720 Great to be here, Robert. First of all, I have 0:02:54.919 --> 0:02:56.600 I just have to say that this book was such 0:02:56.639 --> 0:02:59.440 an engaging read. I actually read it all over the weekend, 0:02:59.520 --> 0:03:02.079 and while I was familiar with some of the findings 0:03:02.080 --> 0:03:05.639 and technologies discussed, there was plenty I hadn't been exposed 0:03:05.639 --> 0:03:07.440 to yet, and it was all delivered in such a 0:03:07.480 --> 0:03:09.799 fashion that it all ended up feeling like, you know, 0:03:09.880 --> 0:03:12.519 it's kind of like a revelation, um, and I feel 0:03:12.560 --> 0:03:15.880 like that revelation is really well summarized in the title 0:03:15.919 --> 0:03:18.880 of the book, Live Wired. If you would, could you 0:03:18.919 --> 0:03:22.600 summarize the basic difference between the idea of the live 0:03:22.680 --> 0:03:26.280 wired understanding of our brain as opposed to previous notions 0:03:26.280 --> 0:03:29.200 of how the brain worked. Yeah, I mean the whole 0:03:29.320 --> 0:03:31.680 The whole thing is that when you first pick up 0:03:31.720 --> 0:03:34.320 a neuroscience textbook as a young person, you see a 0:03:34.400 --> 0:03:36.920 picture of the brain and it says this parts or vision, 0:03:36.920 --> 0:03:38.600 this parts are hearing, the parts are touch, and so on. 0:03:39.080 --> 0:03:42.480 But in fact, um, I guess what I've spent the 0:03:42.560 --> 0:03:46.240 last twenty years, you know, in my laboratory really understanding 0:03:46.280 --> 0:03:48.920 the lesson of is that the brain is a is 0:03:48.920 --> 0:03:52.720 a dynamic system that's constantly moving around. And so for example, 0:03:52.720 --> 0:03:55.360 if you go blind, the part that we would have 0:03:55.360 --> 0:03:57.960 called your visual system gets taken over by hearing and touch. 0:03:58.040 --> 0:04:00.560 If you lose an arm, the part of your body 0:04:00.600 --> 0:04:03.640 map that has an arm gets taken over by neighboring 0:04:03.640 --> 0:04:06.360 areas and so on. The whole thing is this incredibly 0:04:06.480 --> 0:04:09.520 dynamic system. It's not like anything that we know how 0:04:09.520 --> 0:04:12.200 to build. Um. You know, here in Silicon Valley where 0:04:12.200 --> 0:04:16.320 I live, everything is about hardware and software, and engineers 0:04:16.320 --> 0:04:19.240 are praised for building an efficient system where you've got 0:04:19.240 --> 0:04:22.160 these two layers and that's it. Um. But what's happening 0:04:22.400 --> 0:04:26.840 in our skulls is an entirely different kind of technology, 0:04:26.960 --> 0:04:29.840 and so I in the book, I ended up coining 0:04:29.839 --> 0:04:32.840 a new term for this, live wired or live ware. 0:04:33.400 --> 0:04:36.679 And the idea with live ware is that every moment 0:04:36.720 --> 0:04:39.920 of your life, this is reconfiguring itself. So you've got 0:04:39.920 --> 0:04:43.279 eighty six billion neurons, these are the cell types of 0:04:43.320 --> 0:04:48.680 the brain. You've got about point to quadrillion connections, and 0:04:49.520 --> 0:04:52.120 every moment in your life, these things are changing their 0:04:52.240 --> 0:04:56.279 strength of connection. They're unplugging, they're replugging elsewhere, they're seeking around. 0:04:56.960 --> 0:05:01.160 What you have are these dense jungles. And you know, 0:05:01.200 --> 0:05:04.320 this level of complexity is something that bankrupts our language. 0:05:04.360 --> 0:05:07.160 We don't have any way of talking about point two 0:05:07.240 --> 0:05:10.920 quadrillion connections moving and changing. But everything in your life, 0:05:10.920 --> 0:05:15.320 every experience that you have um changes who you are. 0:05:15.360 --> 0:05:18.080 When you learn, for example, that my name is David, 0:05:18.360 --> 0:05:20.480 there's a physical change in the structure of your brain. 0:05:20.480 --> 0:05:22.600 And that's what it means for you to then remember, 0:05:23.040 --> 0:05:24.640 you know, two months later, who's the guy you had 0:05:24.680 --> 0:05:27.480 on your podcast David. You know, it's like it's it's 0:05:27.560 --> 0:05:31.880 this constantly changing system and it's UM unlike anything that 0:05:31.920 --> 0:05:36.080 we know how to build at the moment. So, um, 0:05:36.120 --> 0:05:38.240 you know, as you as you saw in the book. 0:05:38.320 --> 0:05:41.120 I tell these different stories just by way of introduction 0:05:41.640 --> 0:05:45.559 that are so fascinating, Like you can take out half 0:05:45.600 --> 0:05:47.880 the brain in a child. For example, when children have 0:05:47.960 --> 0:05:51.560 this really bad type of epilepsy, there's a surgery that 0:05:51.600 --> 0:05:53.680 they go through. Half the brain is removed, and they're 0:05:53.720 --> 0:05:57.479 just fine cognitively, they're totally fine because the rest of 0:05:57.520 --> 0:05:59.960 their brain, the other half says, okay, I'm gonna read 0:06:00.080 --> 0:06:02.840 are the functions that are that went missing from there. 0:06:03.720 --> 0:06:06.080 Sometimes a child is born with only half a brain, 0:06:06.600 --> 0:06:09.840 you know, and things just get get rewired so that 0:06:09.960 --> 0:06:13.120 it all is there and we can't you know, you 0:06:13.160 --> 0:06:15.799 can't do this with your cell phone or your computer. 0:06:15.880 --> 0:06:18.320 You can't take out half the circuitry and expect it 0:06:18.360 --> 0:06:21.599 to still function. But it works just fine, especially with 0:06:21.640 --> 0:06:23.880 a young brain. Now, with all of this in mind, 0:06:24.440 --> 0:06:27.920 into this live wired understanding of the brain in mind, um, 0:06:28.640 --> 0:06:31.080 I thought we might back up to a very basic question, 0:06:31.480 --> 0:06:33.320 uh that sometimes I guess we don't think about because 0:06:33.320 --> 0:06:36.159 we're I mean, we were trapped in the brain. We 0:06:36.160 --> 0:06:38.479 can't see the forest for the trees. But what what 0:06:38.600 --> 0:06:41.919 does the brain do? So the brain is locked in 0:06:42.120 --> 0:06:45.480 silence and darkness inside the vault of your skull, and 0:06:45.520 --> 0:06:48.520 all it's trying to do is make a model of 0:06:48.560 --> 0:06:52.000 the world, as in, I've got all this incoming data. 0:06:52.160 --> 0:06:54.200 And by the way, the data that comes into the 0:06:54.200 --> 0:06:58.919 brain is just spikes, just little electrical spikes in these neurons. 0:06:59.160 --> 0:07:02.120 It doesn't know that these spikes represent photons, and these 0:07:02.160 --> 0:07:05.720 spikes represent air compression waves, and these spikes represent mixtures 0:07:05.720 --> 0:07:08.000 of molecules hitting a membrane and so on. All it 0:07:08.080 --> 0:07:10.760 knows is I've got data coming in as zeroes and 0:07:10.840 --> 0:07:14.880 ones and um and it knows that it can control 0:07:15.120 --> 0:07:18.920 a body. And so it's job is to figure out, 0:07:18.920 --> 0:07:20.520 all right, how do I control the body, how does 0:07:20.560 --> 0:07:22.440 that change the spikes coming in? And how do I 0:07:22.480 --> 0:07:24.880 make a model of the world. And this is an 0:07:24.920 --> 0:07:29.600 extraordinary technology that we have carrying around on our shoulders. 0:07:30.160 --> 0:07:33.000 Um As I said, we we don't know how to 0:07:33.000 --> 0:07:35.240 build technology like this, and we're just scratching the surface 0:07:35.240 --> 0:07:37.360 of even trying to figure this out. But that's what 0:07:37.400 --> 0:07:40.400 the brain is doing, locked in its in its vault, 0:07:40.920 --> 0:07:43.480 is figuring out, okay, how do I understand the world, 0:07:43.560 --> 0:07:47.120 and and it's really extraordinarily good at at extracting patterns 0:07:47.760 --> 0:07:52.760 and eventually making predictions. And um, yeah, that is that 0:07:52.880 --> 0:07:55.200 is the main job that is trying to accomplish. Now, 0:07:55.240 --> 0:07:57.440 the big part of the book deals with how our senses, 0:07:57.720 --> 0:07:59.840 uh you know, speak to the brain and how the 0:08:00.040 --> 0:08:03.160 rain works around limitations uh, such as they are the 0:08:03.160 --> 0:08:05.000 ones you mentioned with the half of the brain being 0:08:05.040 --> 0:08:08.160 missing at etcetera. And also uh you know, relating limbs 0:08:08.480 --> 0:08:11.400 uh and uh and I love how you use these 0:08:11.480 --> 0:08:14.440 various metaphors to explain that to the reader. Would you 0:08:14.480 --> 0:08:17.760 mind uh explaining to our listeners how our brains are 0:08:17.760 --> 0:08:21.040 like Mr potato head. Yeah, so this is something that 0:08:21.080 --> 0:08:23.920 struck me many years ago where I realized that, so 0:08:23.960 --> 0:08:26.680 we've got all these sensors like our eyes and our 0:08:26.720 --> 0:08:29.760 ears and our nose and our fingertips, all these things 0:08:29.760 --> 0:08:31.640 were used to and so we just sort of think 0:08:31.680 --> 0:08:34.280 of these as fundamental. But but when you look across 0:08:34.280 --> 0:08:36.720 the animal kingdom, what you find are all these other 0:08:36.840 --> 0:08:39.200 weird kinds of sensors, things that you could take in 0:08:39.320 --> 0:08:44.800 like snakes taken infrared information, honeybees taken ultra violet when 0:08:44.800 --> 0:08:47.200 you look at something like the black ghost knifefish, it 0:08:47.240 --> 0:08:51.720 has electro receptors where it's pulling in information about perturbations 0:08:51.720 --> 0:08:56.480 and electrical fields. UM. Lots of birds and cows and 0:08:56.559 --> 0:08:59.560 insects have magneto reception where they are picking up on 0:08:59.559 --> 0:09:02.040 the magnet field of the planet and they're navigating that 0:09:02.080 --> 0:09:04.840 way and so on. And what I realized is Mother 0:09:04.920 --> 0:09:08.520 Nature doesn't actually have to recreate the brain every time 0:09:08.559 --> 0:09:13.200 she does this. Instead, the principles of brain operation, she's 0:09:13.240 --> 0:09:15.520 figured that out at the beginning, and then she can 0:09:15.559 --> 0:09:18.680 just plug in anything she wants in terms of what 0:09:18.840 --> 0:09:21.640 is the information that would be useful to sense. And 0:09:21.679 --> 0:09:25.200 that's why I suggested this potato head model of how 0:09:25.240 --> 0:09:27.440 to think about this, which is to say, you just 0:09:27.480 --> 0:09:29.280 take any sensors and you stick it in and it's 0:09:29.320 --> 0:09:31.520 good to go. The brain figures out, Okay, I've got 0:09:31.600 --> 0:09:35.680 this kind of spikes coming in UM, and it seems 0:09:35.720 --> 0:09:37.720 to correlate with this other sense, and it seems to 0:09:37.720 --> 0:09:40.880 allow me to find food or avoid predators or whatever. 0:09:41.320 --> 0:09:43.000 And so it just figures out what to do with 0:09:43.040 --> 0:09:46.000 that information. And so this is a very new kind 0:09:46.040 --> 0:09:48.920 of way to think about the brain. It's essentially understanding 0:09:48.960 --> 0:09:52.840 the brain as a general purpose compute device. You feed 0:09:52.880 --> 0:09:55.360 in whatever kind of data stream you want, and it's 0:09:55.520 --> 0:09:57.439 and it's good to go. And this, you know, explains 0:09:57.480 --> 0:10:00.400 a lot of what happens evolutionarily with janet x. It 0:10:00.520 --> 0:10:03.440 just what it allows mother nature to do is just 0:10:03.720 --> 0:10:08.040 tweak around with the genetics to make new kinds of sensors. 0:10:08.080 --> 0:10:10.360 But one of the really amazing things you discussed in 0:10:10.400 --> 0:10:13.520 this is that is that you can plug an eye 0:10:13.559 --> 0:10:15.320 into an ear hole or an ear into an eye 0:10:15.320 --> 0:10:17.320 hole on the Mr Potato head of our of our brain, 0:10:17.360 --> 0:10:20.600 and the brain will roll with the data that that's 0:10:20.640 --> 0:10:25.240 exactly right. And so this is an area called sensory substitution, 0:10:25.280 --> 0:10:28.599 which is to say, you can feed information into the 0:10:28.640 --> 0:10:32.320 brain via an unusual channel. And so something I started 0:10:32.320 --> 0:10:34.640 in my lab about ten years ago was seeing if 0:10:34.640 --> 0:10:37.920 we could build sensory substitution for people who are deaf. 0:10:38.720 --> 0:10:41.600 So what we do. We started by building this as 0:10:41.640 --> 0:10:44.440 a vest with vibratory motors in it. So you've got 0:10:44.440 --> 0:10:47.640 a whole bunch of little buzzers like the buzzer in 0:10:47.679 --> 0:10:51.959 your cell phone, and um, it captures sound and turns 0:10:52.000 --> 0:10:55.679 out into patterns of vibration on the torso. And it 0:10:55.679 --> 0:10:57.880 turns out that that worked really well. We could get 0:10:57.920 --> 0:11:01.800 people who are profoundly deaf to start understanding what is 0:11:01.840 --> 0:11:06.040 happening in the auditory world, just predicated on this spatio 0:11:06.120 --> 0:11:09.480 temporal pattern of vibrations on their skin. And the reason 0:11:09.520 --> 0:11:12.360 it worked is because it doesn't matter how the information 0:11:12.360 --> 0:11:13.880 gets to the brain. As long as it gets there, 0:11:14.240 --> 0:11:16.400 the brain will establish the correlations and figure out what 0:11:16.440 --> 0:11:18.240 to do with it. So, as an example, if you see, 0:11:18.679 --> 0:11:21.040 you know, the dog's mouth moving and you feel the 0:11:21.080 --> 0:11:23.480 buzzing on your skin, you know, your brain puts that 0:11:23.559 --> 0:11:26.360 together really easily. Or you know, you see somebody speaking, 0:11:26.440 --> 0:11:28.920 or or we train people by showing a word and 0:11:28.960 --> 0:11:30.959 you you know, you feel the word on the vest 0:11:31.040 --> 0:11:34.080 and you start understanding what's going on. So what we 0:11:34.120 --> 0:11:36.560 did then is we shrunk it down to the size 0:11:36.600 --> 0:11:39.840 of a wrist band. And because you and I are 0:11:39.880 --> 0:11:42.160 on video, Robert, you can see the wristband that I'm 0:11:42.200 --> 0:11:43.640 wearing right now. It's you know, it looks about the 0:11:43.640 --> 0:11:47.160 size of a fitbit, and it has very sophisticated computation 0:11:47.240 --> 0:11:50.040 in here where it's capturing sound and turning that into 0:11:50.040 --> 0:11:54.240 patterns vibration around the skin of the wrist and um. 0:11:54.520 --> 0:11:58.600 So what we've been doing is we uh this Actually 0:11:58.640 --> 0:12:01.320 now I spun a company out of my lab called 0:12:01.360 --> 0:12:05.320 Neo Sensory, and we have been on the market since 0:12:05.480 --> 0:12:08.520 March and we're now on risks all around the world. 0:12:08.600 --> 0:12:11.280 So people who are deaf, for have hearing loss of 0:12:11.280 --> 0:12:14.280 some degree where this and they are picking up on 0:12:14.320 --> 0:12:17.800 the auditory world through their skin. Now, the interesting part 0:12:17.840 --> 0:12:19.720 is this is exactly what the inner ear is doing. 0:12:19.760 --> 0:12:23.600 Your inner ear is just registering vibrations of your ear 0:12:23.679 --> 0:12:27.320 drum and it breaks sound up into from high to 0:12:27.360 --> 0:12:29.520 low frequency, and then it ships it off to the brain. 0:12:30.240 --> 0:12:32.720 And all we're doing is transferring the inner ear to 0:12:32.720 --> 0:12:36.160 to the wrist and it works. So that's the idea 0:12:36.160 --> 0:12:40.280 of sensory substitution. Is your um just getting the information 0:12:40.360 --> 0:12:42.800 there via a different route and the brain figures out 0:12:42.800 --> 0:12:45.040 what to do with it. And if this weren't amazing enough, 0:12:45.120 --> 0:12:48.520 there's this then this this other additional step, this idea 0:12:49.120 --> 0:12:52.920 of of plugging all new things into like new forms 0:12:52.960 --> 0:12:57.320 of sensory information, new even uh you know, not only 0:12:57.640 --> 0:13:00.720 limbs of replacement, but artificial addition. No limbs. You use 0:13:00.760 --> 0:13:05.480 the example of doctor Octopus from the spider Man comics. Um, 0:13:06.000 --> 0:13:07.840 can you tell us a little bit about how even 0:13:07.960 --> 0:13:11.120 like this nineteen sixties sci fi concept is not that 0:13:11.240 --> 0:13:16.119 far removed from our current understanding of the brain. Yeah, so, um, 0:13:16.240 --> 0:13:18.840 let me actually let me say two things. Actually, one 0:13:19.040 --> 0:13:22.959 is what we can do. So let me just separate 0:13:22.960 --> 0:13:26.040 out sensory information coming in and motor information going out. 0:13:26.080 --> 0:13:29.079 So sensory information coming in. One of the things we're 0:13:29.160 --> 0:13:33.120 doing with the with our wristband called buzz um is 0:13:33.320 --> 0:13:36.160 we can not only take in sound information for people 0:13:36.200 --> 0:13:40.120 who are deaf, but we could actually expand the sensory 0:13:40.120 --> 0:13:42.040 information that you would normally have. So, for example, with 0:13:42.080 --> 0:13:45.200 somebody who's not deaf, we feed in ultra violet or 0:13:45.240 --> 0:13:47.880 infrared or or things like that, where we're expanding senses 0:13:47.920 --> 0:13:49.640 that you already have. And then we're doing this other 0:13:49.679 --> 0:13:53.040 thing called sensory addition, where we're feeding in brand new 0:13:53.120 --> 0:13:55.719 senses that you've never had. So we can feed in 0:13:55.760 --> 0:13:58.520 any day to stream with this, like stock market data 0:13:58.559 --> 0:14:02.880 or Twitter data or factory information or anything at all. 0:14:03.720 --> 0:14:05.520 Feeding this in and as long as your brain can 0:14:05.520 --> 0:14:08.280 make correlations with what it's seeing or hearing around it. 0:14:08.600 --> 0:14:11.920 Then the brain can figure out how to utilize that information. 0:14:12.040 --> 0:14:15.400 So we actually just finished a big developer contest where 0:14:15.440 --> 0:14:19.240 people did all kinds of projects with you know, um 0:14:19.240 --> 0:14:23.080 monitoring air quality or monitoring you know, blood sugar and 0:14:23.120 --> 0:14:27.520 your bloodstream or um, um, many many different kinds of 0:14:27.680 --> 0:14:31.000 monitoring of feeling, electrical fields and so on. UM. So 0:14:31.040 --> 0:14:33.320 all this, by the way, if if anybody is interested, 0:14:33.400 --> 0:14:35.840 we have an open a p I and an s 0:14:35.920 --> 0:14:39.120 d K four buzz. You can get this on neo 0:14:39.160 --> 0:14:41.520 central dot com and pursue any kind of project you 0:14:41.520 --> 0:14:43.800 want this way. So we've had hundreds of people just 0:14:43.880 --> 0:14:45.640 making their own thing, which has been which has been 0:14:45.720 --> 0:14:48.680 very cool. Now to switch to the second thing about 0:14:48.760 --> 0:14:52.680 motor output. UM, yeah, it turns out that your brain 0:14:53.240 --> 0:14:57.680 UM is not pre programmed to drive your body, but 0:14:57.760 --> 0:15:02.000 instead can figure out whatever the affordances are of whatever 0:15:02.080 --> 0:15:04.480 is there. So just as an example, you know, one 0:15:04.480 --> 0:15:06.480 of the things I tell the story about this dog 0:15:07.200 --> 0:15:09.480 um that was born without fore limbs. It didn't have 0:15:09.560 --> 0:15:12.120 his front legs, and so it just she walks by petally. 0:15:12.200 --> 0:15:14.360 She walks on her back legs like a human, and 0:15:14.520 --> 0:15:17.840 presumably any dog could do this, but they're not sufficiently motivated, 0:15:17.880 --> 0:15:20.960 but so she just walks around her hind legs and um. 0:15:21.080 --> 0:15:24.080 What this illustrates is that dog brains are not pre 0:15:24.200 --> 0:15:27.040 programmed to drive dog bodies, but instead they figure out, Okay, 0:15:27.120 --> 0:15:28.480 here's what I can do. I need to get to 0:15:28.520 --> 0:15:30.600 my food, to my water, to my mother whatever. This 0:15:30.640 --> 0:15:34.280 is how I do it. And so um. Also, I, 0:15:34.680 --> 0:15:36.360 you know, tell the story of the guy who's the 0:15:36.360 --> 0:15:39.920 world's best archer. He has the world's record for best 0:15:40.000 --> 0:15:42.680 archery shot, and he doesn't have arms, so he does 0:15:42.680 --> 0:15:46.080 this with his legs. And it's just another illustration that 0:15:46.120 --> 0:15:48.800 the brain figures out whatever body it's in says okay, 0:15:48.800 --> 0:15:50.360 I figure how to drive this. Of course, we see 0:15:50.400 --> 0:15:53.440 this when people, for example, get an amputation. Let's say 0:15:53.440 --> 0:15:55.920 they lose an arm and a motorcycle accent or something. 0:15:56.320 --> 0:16:01.000 The map of their body in their brain readjust to say, okay, 0:16:01.200 --> 0:16:03.680 I see I've got a body without an arm, so 0:16:03.720 --> 0:16:08.239 I'm just gonna figure that out now. Okay. So, because 0:16:08.800 --> 0:16:14.160 it is not pre programmed, it's extremely flexible. Um, I 0:16:14.200 --> 0:16:17.120 think that we could actually build any kind of body 0:16:17.160 --> 0:16:20.920 we want. So UM, coming back to your question, I 0:16:21.320 --> 0:16:24.840 you know, mentioned about Doc Cock in the nineteen sixties, 0:16:25.000 --> 0:16:29.080 which debuted in Spider Man. This scientist who plugs in 0:16:29.200 --> 0:16:32.200 four robotic arms so that he can actually do extra 0:16:32.280 --> 0:16:34.920 things and poor beakers and so on, and he controls 0:16:34.960 --> 0:16:36.560 us with his brain. But then there's an explosion in 0:16:36.600 --> 0:16:39.120 his lab and he turns evil and he scales buildings 0:16:39.120 --> 0:16:41.480 and learns new forms of martial arts with with eight 0:16:41.560 --> 0:16:44.440 arms and so on, and um, Dr Octavia starts to 0:16:44.440 --> 0:16:48.960 go by Doc Cock anyway, Um, the exactly as you said, 0:16:49.000 --> 0:16:51.520 this is not as far off and weird as we 0:16:51.600 --> 0:16:54.480 used to think, because now what we're doing is with 0:16:54.560 --> 0:16:58.480 for example, patients who are paralyzed. Um, you can put 0:16:58.600 --> 0:17:02.160 electrodes into their motor cortex and they can learn to 0:17:02.280 --> 0:17:04.960 drive a robotic arm even though they are paralyzed. They 0:17:05.080 --> 0:17:08.480 drive the robotic arm with their thoughts, which sounds weird, 0:17:08.520 --> 0:17:10.680 but that's of course, how you drive your fleshy arm. 0:17:10.720 --> 0:17:12.280 You just you know, you think about it, you learn 0:17:12.359 --> 0:17:15.479 the you learn what the output signals are that make 0:17:15.520 --> 0:17:17.840 your arm respond. It's the same thing with the robotic arm, 0:17:17.840 --> 0:17:20.080 and you can do that. And there have been experiments 0:17:20.080 --> 0:17:24.520 with monkeys where they their bodies work fine. They're not paralyzed, 0:17:24.720 --> 0:17:27.119 but they can drive a third arm with you know, 0:17:27.160 --> 0:17:29.240 with their thoughts. So they're driving a robotic arm with 0:17:29.280 --> 0:17:32.440 their thoughts. There was an experiment done where a monkey 0:17:32.560 --> 0:17:36.920 um uses his motor cortex to make a robot walk. 0:17:37.000 --> 0:17:40.280 But the interesting part was the robot happened to be 0:17:40.320 --> 0:17:42.800 across the world. The monkey was in North Carolina and 0:17:42.800 --> 0:17:45.639 the robot was in Japan, and the signals from the 0:17:45.640 --> 0:17:48.119 monkey's brain were being sent over the internet and you 0:17:48.119 --> 0:17:51.679 can get the robot, you know, the monkey to control 0:17:51.720 --> 0:17:55.040 the robot just with the spikes in its motor cortex. 0:17:55.520 --> 0:17:58.560 And so, UM, I think it's going to be no 0:17:58.720 --> 0:18:02.360 time at all before we really to start controlling external 0:18:02.400 --> 0:18:05.840 devices with our thoughts. And one of the things, one 0:18:05.880 --> 0:18:08.640 of the frameworks that I build is this issue that 0:18:08.880 --> 0:18:11.359 what we think of as the self, what you think 0:18:11.400 --> 0:18:13.919 of as your body, just as a matter of control, 0:18:14.000 --> 0:18:15.880 what can you control with your body? And I think 0:18:15.920 --> 0:18:20.120 this is, by the way, why we understand our reflections 0:18:20.119 --> 0:18:22.639 in the mirror to be us, because you move and 0:18:22.680 --> 0:18:26.560 it moves, and so you're driving what you're seeing over there, 0:18:26.600 --> 0:18:29.879 so you think, oh, yeah, that's me over there. Um, 0:18:29.960 --> 0:18:32.480 But what this means is in you know, make up 0:18:32.520 --> 0:18:36.480 a number thirty five years when we are controlling a 0:18:36.720 --> 0:18:40.040 robot with our thoughts, it is essentially an extension of 0:18:40.080 --> 0:18:44.280 our body. What it means is that that will become us. 0:18:44.359 --> 0:18:48.359 It will be a part of of your body. All right, 0:18:48.359 --> 0:18:50.159 We're gonna take a quick break, but I'll be right 0:18:50.200 --> 0:18:56.400 back with David Eagleman. Thank alright, I'm back with David Eagleman. 0:18:56.960 --> 0:18:59.520 In the book, you talk about the live wired brain 0:19:00.040 --> 0:19:04.280 is um is being a place of competition, um based 0:19:04.320 --> 0:19:06.760 on the input that's coming in. And I was just 0:19:06.840 --> 0:19:10.879 really uh intrigued by this, uh, this new theory of 0:19:11.000 --> 0:19:13.920 dreaming that you discuss. So would you would you mind 0:19:14.000 --> 0:19:17.439 uh sharing that with our listeners. Yeah, um, yeah, this 0:19:17.520 --> 0:19:19.800 is something very cool that's come out of our studies 0:19:19.800 --> 0:19:24.240 of plasticity and UM here it is. It's that when 0:19:24.280 --> 0:19:27.320 any part of the brain goes unused, it gets taken over. 0:19:27.400 --> 0:19:32.240 And so for example, if you go blind, your systems 0:19:32.320 --> 0:19:34.920 for hearing and touch and all of that real estate 0:19:35.000 --> 0:19:36.760 will take over the part of the brain that we 0:19:36.840 --> 0:19:40.159 used to call the visual cortex. So the surprise in 0:19:40.240 --> 0:19:44.720 neuroscience has been how rapidly this happens um. What group 0:19:44.760 --> 0:19:48.359 found about thirteen years ago was that if you take 0:19:48.520 --> 0:19:51.160 sighted people and you blindfold them tightly and you stick 0:19:51.200 --> 0:19:54.240 them in a brain scanner, within about an hour, you 0:19:54.320 --> 0:19:58.000 can start seeing activity in the visual cortex just based 0:19:58.040 --> 0:20:01.439 on um hearing or touch. If you touch them on 0:20:01.480 --> 0:20:03.960 the hand or something, you start seeing activation in the 0:20:04.040 --> 0:20:07.159 visual cortex. Now, it's not because the neurons have had 0:20:07.160 --> 0:20:10.160 a chance to grow that fast from hearing and touch 0:20:10.280 --> 0:20:13.920 into the visual cortex. Instead, there's all kinds of cross 0:20:13.960 --> 0:20:17.720 wiring in the brain where those systems are already reaching 0:20:17.960 --> 0:20:20.439 over into the visual cortex. It's just that they're normally 0:20:20.520 --> 0:20:23.280 silenced and they're inhibited, so they don't get to do anything. 0:20:23.280 --> 0:20:27.359 But that inhibition starts wearing off very quickly. And so 0:20:27.920 --> 0:20:30.720 I was really shocked by the speed at which hearing 0:20:30.720 --> 0:20:32.520 and touch could take over. And so my student and 0:20:32.520 --> 0:20:34.440 I were talking about this one day, and what we 0:20:34.520 --> 0:20:37.199 realized is there's a very critical thing that happens because 0:20:37.240 --> 0:20:40.240 we live on a planet that rotates into darkness for 0:20:40.280 --> 0:20:43.040 half the time. You know, in the dark, you can 0:20:43.040 --> 0:20:45.080 still hear and touch and taste and smell and all 0:20:45.080 --> 0:20:47.320 that just fine, but you can't see, and of course 0:20:47.359 --> 0:20:52.520 I'm talking about evolutionary time, not recent electricity times. And so, um, 0:20:52.640 --> 0:20:54.879 what this means is that the visual cortex has always 0:20:54.920 --> 0:20:58.920 been in a big disadvantage when the planet rotates into darkness. 0:20:58.920 --> 0:21:00.639 And so what we realized is, wow, if it doesn't 0:21:00.640 --> 0:21:03.399 want to get taken over by the other senses, it 0:21:03.480 --> 0:21:06.280 has to have some way of defending its territory. And 0:21:06.320 --> 0:21:08.760 what we realized was that that's what dreams are. You 0:21:09.000 --> 0:21:12.440 have this very specific circuitry that starts in the midbrain 0:21:12.840 --> 0:21:15.920