David Eagleman: The Psychology of Time, How the Brain Shapes Reality & Human Nature | Human Behavior | YAPClassic

When eight-year-old David Eagleman fell from a roof, his brain created the illusion that time slowed down during the 0.6-second fall. This accident sparked his lifelong fascination with human psychology and how the brain constructs our perception of time and reality, ultimately shaping his path as a leading neuroscientist. In this episode, David explores the concepts of time perception, sensory substitution, and livewiring, revealing how the brain rewires itself, why perception is an illusion, and whether humans could one day unlock a sixth or seventh sense. In this episode, Hala and David will discuss: (00:00) Introduction (01:26) Childhood Fall and Slowed Time Perception (06:46) Exploring the Concept of Umwelt (10:33) Animal Senses and Human Nature Limitations (16:46) Brain Plasticity vs. Livewiring Explained (27:50) Sensory Substitution and the Future of Senses (36:29) The Psychology of Why We Dream (42:02) The Intersection Between Science and Religion (48:47) The Future of Livewired Technology (51:39) AI vs. Livewired Systems and Human Potential David Eagleman is a neuroscientist at Stanford University, a bestselling author, and the founder of Neosensory and BrainCheck. He is the writer and presenter of the international PBS series The Brain with David Eagleman and The Creative Brain on Netflix. His bestselling book Livewired reveals how the brain adapts in real time, reshaping our understanding of perception, consciousness, and human psychology. Sponsored By: Airbnb - Find yourself a cohost at airbnb.com/host Indeed - Get a $75 sponsored job credit to boost your job's visibility at Indeed.com/PROFITING Shopify - Start your $1/month trial at Shopify.com/profiting. Mercury - Streamline your banking and finances in one place. Learn more at mercury.com/profiting Open Phone - Get 20% off your first 6 months at OpenPhone.com/profiting. DeleteMe - Remove your personal data online. Get 20% off DeleteMe consumer plans at to joindeleteme.com/profiting SKIMS - Shop SKIMS Fits Everybody collection at SKIMS.com Policy Genius - Secure your family’s future with Policygenius. Head to policygenius.com/profiting Masterclass - Get an additional 15% off any annual membership at https://masterclass.com/profiting BitDefender - Save 30% on your subscription at bitdefender.com/profiting Resources Mentioned: David’s Book, Livewired: bit.ly/Livewired David’s Website: eagleman.com Active Deals - youngandprofiting.com/deals Key YAP Links Reviews - ratethispodcast.com/yap YouTube - youtube.com/c/YoungandProfiting LinkedIn - linkedin.com/in/htaha/ Instagram - instagram.com/yapwithhala/ Social + Podcast Services: yapmedia.com Transcripts - youngandprofiting.com/episodes-new Entrepreneurship, Entrepreneurship Podcast, Business, Business Podcast, Self Improvement, Self-Improvement, Personal Development, Starting a Business, Strategy, Investing, Sales, Selling, Psychology, Productivity, Entrepreneurs, AI, Artificial Intelligence, Technology, Marketing, Negotiation, Money, Finance, Side Hustle, Startup, Mental Health, Career, Leadership, Mindset, Health, Growth Mindset, Human Behavior,, Habits, Positivity, Critical Thinking, Robert Greene, Chris Voss, Robert Cialdini

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:11Hala Taha?

  Hello, young and profiteers. What if I told you that everything you think you know about reality is just your brain's best guess? That you're living half a second in the past and your dreams are nothing more than your visual cortex defending its territory? Sounds pretty mind blowing, right? Well, that's exactly what we're covering in today's Yap Classic featuring Stanford neuroscientist David Eagleman, the brilliant researcher behind groundbreaking work on brain plasticity, sensory substitution, and time perception. In this conversation, David shared how our brains are constantly rewiring themselves in a process he calls "live wiring." We discuss why blind people can learn to see through vibrations on their skin and

• 0:54Hala Taha?

  how we might soon develop sixth and seventh senses through technology. We also explored his controversial take on dreams, how neurons literally fight for survival in your head, and what the future holds for expanding human capabilities beyond our biological limits. This conversation will completely reshape how you think about consciousness, perception, and even human potential. So without further delay, here's my mind blowing conversation with David Eagleman.

• 1:25Hala Taha?

  So David, let's open up this conversation with some background on your childhood. You had an accident when you were eight years old where you fell 12 feet from a roof. So tell us about that accident and how it influenced you to then learn about time perception years later.

• 1:40Speaker 01

  Yeah, so I slipped off the roof, ended up breaking my nose on the brick floor below. But the thing that really struck me about it was that it seemed to take a long time, the fall from the roof. And so I was thinking about Alice in Wonderland as I was falling and how this must have been what it was like for her. And I had, it felt like lots of time as I fell. And later, when I got to high school and I took physics and I learned d equals one half eighty squared, I realized, wow, the whole fall took place in point six of a second. And I couldn't reconcile that. I couldn't figure out how those, how it had seemed to have taken so long. So I got really interested in perception. I grew up, I became a neuroscientist, and I've studied a lot about time perception in my laboratory. And so one of the experiments

• 2:22Speaker 01

  I ended up doing then was dropping people from 150 foot tall tower backwards in free fall, and they're caught by a net below. And I measured time perception on the way down. I made a series of discoveries there. Essentially, the bottom line is, we don't actually see in slow motion. Instead, it's a trick of memory. When you're in a life-threatening situation, you're laying down really dense memories, such that when you read it back out, when you say, what just happened? What just happened? It feels like it must have taken a very long time.

• 2:54Hala Taha?

  Yeah, that's super interesting. So essentially, it's the way that we're perceiving time. It's not that time actually slows down. Our brain has evolved to perceive time in that way. And it turns out that we're, the whole world is sort of like an illusion in that sense. Can you talk to us about that?

• 3:10Speaker 01

  Well, that's right. There's a sense in which you're never perceiving time directly. You're always living at least half a second in the past. So it takes, right, photons hit your eyes, or air compression waves hit your ears, or whatever, you know, I touch your toe. And those signals have to travel along nerves, which are very slow. I mean, thousands of times slower than, you know, electronic signals travel in your computer. So it takes time for this stuff to move around in the brain, get to different places in the brain, and then it has to get stitched together with other senses. And by the time all of this gets done, and you're served up a conscious perception of what happened, the event's already long gone by that point, and you're living in the past. So, and by

• 3:52Speaker 01

  the way, I've been pursuing a hypothesis that taller people live farther in the past than shorter people, because it takes longer to get all the signals there. So anyway, yes, we're never perceiving time directly. And when you are thinking back on an accident situation, you are, you're probing your memory. You're saying, what just happened? A moment ago. And so all you're ever perceiving is your, your conscious perception. Now, by the way, of course, your body can do things much faster than that unconsciously. Like when, you know, your foot gets halfway to the brake, when you realize a, a car is pulling out of the driveway ahead of you, that happens before you're consciously aware. You, you become aware by, by the time your foot's already on the move.

• 4:33Speaker 01

  So your brain can do lots of things that way, you know, when you're hiking with friends and you find yourself ducking out of the way of a tree branch that's swinging back towards you before you even realize that you're ducking. You know, that kind of stuff can happen, but as far as our conscious perception of the world, that's always an old story.

• 4:52Hala Taha?

  So, so, so interesting. So I mentioned that I'm going to try to talk about the future in a lot of our conversation. And so you may not have the answer, but I'm curious, I'm sure you've thought about it. Humans hate to wait, especially as we get more technologically advanced. We don't even like to wait for our files to download on the computer. So do you think there's going to be some sort of a future where we can manipulate time in that way, where we feel like we're at least not waiting?

• 5:19Speaker 01

  I don't think so, actually, only because the human brain is enormous compared to, let's say a fly, a housefly brain. The reason it's really hard to swat a fly is because the signals are moving around fast in that brain. Sorry, I should say the signals are moving along the neurons in a fly brain, exactly the same speed that they're moving with us, but it can get across the brain and do everything it needs to and get to the motor system of the fly really quickly because there's just not that much territory to cover. In contrast, the human brain is enormous. You have to cross vast swaths of territory with these signals to get stuff to happen. So there's a sense in which we are always going to live in the past. Happily, technologically, things have sped up a lot. It's always struck me so funny, the way that we, um, once something speeds up, we say,

• 6:04Speaker 01

  oh, I, I never realized I could save time there. And then you can never go back, but often we don't realize there are ways that we could have saved up. Like, for example, if somebody invents something where you can wash all your dishes or wash all your clothes, you know, like in one second, and then the thing's done and unloaded automatically. You would say, oh, great, I'm never going back. But, you know, we do washing machines and laundry machines now, and it doesn't bother us too much.

• 6:28Hala Taha?

  Yeah, so interesting. So one concept that I think is really important as we start to get a foundation of your work, and I think a lot of my listeners are really beginners, right? I think a lot of the terms that we're going to talk about in this episode are going to be brand new terms. And one of them is this concept of umwelt.

• 6:46Speaker 01

  Umwelt, yeah.

• 6:47Hala Taha?

  Umwelt, so that's it?

• 6:49Speaker 01

  Yeah, it's, yeah.

• 6:50Hala Taha?

  It sounds German, right?

• 6:51Speaker 01

  Yeah, exactly.

• 6:52Hala Taha?

  So basically, it's this concept that our environment is perceived differently, like from human to human, right? We all are perceiving the world similarly, but differently at the same time. And so I'd love for you to explain that concept to us.

• 7:07Speaker 01

  Cool. Well, the easiest way to think about the umwelt is that looking across the animal kingdom, so, you know, for a tick, for example, all it can detect is temperature and body odor. That's, that's its only signaling mechanisms. And so its world is built out of that. Or for the blind echolocating bat, its world is built out of these echoing sound signals. Lets out a chirp and it gets an echo back. And that's how it figures out the three dimensional structure of the cave it's flying through. Or for the black ghost knife fish, it has electrical fields around it and it's detecting when that gets perturbed by, let's say, a rock or some predator there. And those are the only signals that it has

• 7:47Speaker 01

  that it can pick up on from the world. And so that's this concept of the umwelt, which is, you know, that's how it constructs its reality. And what I've always found interesting is that presumably, we all, you know, every animal species accepts its reality as the entire reality out there. Because why would you stop to ever question or think that maybe there's something beyond what, what you can detect? But what you said is, is also correct. And this is actually the topic of my next book, which is, the difference from human to human has been fascinating to me, just as one example. Well, an easy example is color blindness, right? So let's say, this person's colorblind, this person's not, they're actually seeing the scene differently. And we now know that a small fraction of women

• 8:30Speaker 01

  have not just three types of color photoreceptors in their eye, but four types, which means they're seeing colors the rest of us aren't seeing. Or take something like synesthesia, which is where you, someone, let's say, looks at letters or numbers and it triggers a color experience, or, or they taste something and it puts a feeling on their fingertips, or they hear something and that causes a visual for them. There are many forms of synesthesia, but the point is, It's not a disease or a disorder. It's just an alternative perceptual reality. And different people, you know, like 3% of the population has anesthesia and others don't. Or something that I've been studying a lot lately is what's called hyperphantasia, or at the other end of the spectrum, aphantasia, which is how you visually image something.

• 9:14Speaker 01

  So if I ask you to imagine an ant crawling on a tablecloth towards a jar of purple jelly, for some people, that's like a movie in their head. They can see the whole thing. Other people, it's just conceptual. There's no picture there at all. So the first group is called hyperfantasic. The second group's called aphantasic. And it turns out that across the population, everybody is smeared way out here. And so although we would assume that everyone has mental imagery that's like ours, in fact, everybody's totally different with this stuff. So this is, this is what I've been spending my time writing about lately is the differences between humans, extremely fascinating to me.

• 9:53Hala Taha?

  Yeah, and I feel like there's so many ways we can go. I'm going to do my best to try to navigate this conversation in a way that I feel like will really lock in the most important things for my listeners. So I feel like I do want to stick on the topic of animals. I think this is really interesting. You alluded to it before that as humans, we experience things that are normal to humans, our five senses, but then some, like a dog, has this amazing experience with their nose and smells, right? And all of these other animals have senses that we can't even imagine what that would be like. And so help us understand, what are the different senses out there that humans are essentially missing out on?

• 10:35Speaker 01

  Well, okay, so almost all animals have a sense of smell that's so much better than ours. I don't know if you saw my TED Talk, but I did this example of, you know, really imagine that you are a dog. Imagine you've got this long snout with 200 million scent receptors in it. And everything for you is about smell and you've got these wet nostrils that attract and trap, you know, scent molecules and you've got floppy ears to kick up more scent. Everything for you is about scent. And what it would be like if one day you looked at your human master and you thought, what is It's like to have the pitiful little nose of the human. You might imagine erroneously that there's sort of this missing black hole of smell and we all realize we have this missing smell. But of course, we're all trapped inside of our own umvelt.

• 11:19Speaker 01

  And so we think, oh, yeah, I've got a great umvelt. I'm detecting everything out there. We don't realize typically that there's so much that we could be sensing. Now, lots of animals have magneto-reception, which means they're picking up on the magnetic field of the earth. And that's how they navigate. That's how they know north and south. So insects, birds, they've all got this. Turns out cows have good magneto-reception as well. There's, you know, some animals see in the infrared range. So rattlesnakes, for example, they have these heat pits and they're picking up on infrared radiation. Others like honeybees see in the ultraviolet range. These are things that are just totally invisible to us. We don't pick this up at all. And I've been studying this for many years because I'm fascinated by the idea

• 12:02Speaker 01

  that there may be things that animals are picking up on that we can't even get, we're not even going to know for the next, you know, 50, 100 years when someone realizes, oh, my gosh. Turns out, you know, antelope are picking up on this thing that we didn't realize was a thing. So when you really study the biology across the kingdom, you find that there's lots of information out there and we are extremely limited. And I think this is a very counterintuitive thing to think that your biology actually constrains your perception of reality.

• 12:32Hala Taha?

  Yeah, it is mind blowing to think that like animals are having a totally different experience than you are. And I could be sitting here, there might be sounds that are going on that I don't even hear right now and you don't even hear right now. Which to me is just so crazy to even think about. We're so set on this is the way that the world is that we never stop and actually think about these things.

• 12:55Speaker 01

  Oh, yeah. And by the way, sounds, yeah, there are lots of animals that hear in what we call the infrasonic range and the ultrasonic range. So we hear from the details don't matter, but you know, from 20 hertz to 20,000 hertz. Don't worry if you don't know that. But you know, it's just, that's the range of human hearing. But there are animals that are communicating way above that and having conversations all the time, lots of insects and frogs and whatever. And elephants are communicating at the ranges below that. They're feeling it with their feet in the ground. They're feeling these bumps and so on and signals from other elephants. And this is totally invisible to us.

• 13:30Hala Taha?

  Do all animals and humans, have we evolved our senses based on our environment?

• 13:36Speaker 01

  Yeah, that's exactly right. The reason that we see in this very narrow range that we call visible light is precisely because that big ball of fire in the sky, the sun, is optimally giving photons that bounce off things on our planet's surface in that range. In other words, lots of stuff doesn't get through the atmosphere, so it wouldn't be useful for us to pick up on many of these other ranges. And so, yeah, we pick up on stuff that's super useful to us.

• 14:05Hala Taha?

  Yeah, and then I guess we just evolve and start to focus on certain senses that are more helpful than others, which I guess is why humans really focus on vision and hearing, I think, more than other senses.

• 14:18Speaker 01

  That's right. Now, it's not clear, for example, why we have lost so much skill with smell, but everything is constrained. So if you're getting better at this and you're devoting more real estate in your brain towards vision, then you're going to lose some real estate in smell, for example. And so somehow, when everything balances out, we've ended up exactly as we are.

• 14:38Hala Taha?

  Yeah. So something else that I found really fascinating when I was studying your work is this idea that we all have these different senses. All the animals have different senses, but the material of our brain, from my understanding, is very similar, at least with primates and mammals, right?

• 14:56Speaker 01

  Yeah.

• 14:57Hala Taha?

  So I'd love to hear about this. It's to me, I thought that our brains would be totally different. I mean, humans have took over the world, right? So we think we're really special, but in fact, our brain is made up of the same thing. So talk to us about that.

• 15:09Speaker 01

  That's right. Well, both statements are true. I mean, we are really special because our brains are running algorithms just slightly differently. And I can talk about that, why we have taken over the whole planet compared to all our brethren in the animal kingdom. But yes, it's all made of the same stuff. If I showed you a brain cell, a neuron, from a human, a horse, a cow, an insect, a squid, you couldn't tell me what's... I mean, they all look the same. They're doing exactly the same thing. It's just a cell that has these things, that these sort of roadways that come off of it, and we give them fancy names, and they have, you know, but it's just a cell. It's just trafficking proteins around and putting receptors there and spitting out chemicals. And it looks exactly the same across the animal kingdom. And so, all that we're doing, all Mother Nature is doing, I

• 15:54Speaker 01

  should say, is, you know, just wiring this up in different ways.

• 15:58Hala Taha?

  Yeah, so I think this is a great place to kind of get an understanding of plasticity and live wiring and the difference between it. You called your book Live Wired and you could have called it brain plasticity, but you called it Live Wired for a reason. So talk to us about the distinction between plasticity and your concept of Live Wired.

• 16:16Speaker 01

  Yeah, brain plasticity is what we term this in the field. And this just means, you know, the ability of the brain to reconfigure itself. So neurons, the cells in the brain, are spending their whole lives plugging and unplugging and seeking and finding other places and changing the strength of their connection with other neurons. Each neuron connects to about 10,000 other neurons. And this changeability is what we call plasticity. I call it Live Wired nowadays, Live Wiring, because plasticity feels to me just a bit like an outdated term in the sense that this was coined about 100 years ago because people were impressed by plastic manufacturing. And the idea with the material plastic is

• 16:58Speaker 01

  that you mold it into a shape and then it holds on to that shape. And that's what's useful about plastic. So the analogy to the brain that people saw was, oh, you know, you learned the name of your fifth grade teacher, and all these years later, you still remember that name. So it's like the system got molded by the information that came through, and it held on to that information. And so that, you know, stands as a very good analogy. The only thing is, with 86 billion neurons constantly changing every moment of your life, reconfiguring, it seemed to me that plastic was maybe a little too milquetoast a term. That's why I'm using the term Live Wired, because what really opens up when

• 17:41Speaker 01

  we start studying this in depth is an entirely new way to think about this and to build technologies moving forward. And that's one of the things I'm going to be doing, speaking of the future of the brain, is building Live Wired devices. So instead of being something like, you know, a phone which becomes outdated, and eventually the technology is not good enough, and you just throw it out, because it's a layer of hardware with a layer of software on the top. What if you could build something like a brain that is constantly reconfiguring and learning and getting better with time?

• 18:15Hala Taha?

  Yeah. So David, I really want to get an understanding of how the brain works. From my understanding, neurons are essentially fighting with each other for relevancy in the brain.

• 18:26Speaker 01

  This is the framework that I put forward in the book is that the right way to think about the brain actually is like a Darwinian competition where each neuron is fighting for its own survival. And when you look at single cell organisms, they're spinning out chemicals as a defense mechanism. And when you look at neurons in the brain, they're doing the same thing. It's just that we call those neurotransmitters and we say, oh, look, you're passing information along. But I don't think that was the intention. I think it's cells all fighting for survival. And in one of these, you know, amazing bizarre biological results, you get a human brain out of this. But yes, many of the neurons in your brain die. And what you get, you know, in your first two years of development is this massive

• 19:08Speaker 01

  overgrowth of all these things growing like, like a garden that's going nuts. And then from about the age of two onward, all you're doing is you're really pruning the garden. You're taking things away. And cells all over your body actually have this way of committing suicide. It's called apoptosis, where it's not that they're dying because of injury or something and releasing inflammatory chemicals. It's that they're saying, okay, I'm done here. And they fold up shop and they carefully kill themselves. And so this is a majorly important part of how the brain develops.

• 19:43Hala Taha?

  Okay. I want people to understand like how senses work and why somebody who's blind, for example, can hear really well and how those neurons actually can be, I guess, reutilized for something else.

• 20:00Speaker 01

  So it turns out that in the brain, no territory lies fallow. Everything is going to get used. And so we think about this area at the back of the head, we think of that as the visual cortex. But yes, if you go blind, it's no longer the visual cortex gets taken over by hearing, by touch, by memorization of words, by lots of things, because it's perfectly good territory. Now, the territory I'm talking about is called the cortex, which is the outer wrinkly bit of the brain. We have more of it in relation to our body size than anybody in the animal kingdom. This is sort of the magical stuff that makes us really good at what we're doing. So. It turns out that Cortex is a one-trick pony,

• 20:44Speaker 01

  which is to say it's not that this is fundamentally visual and that's fundamentally auditory and for touch and for controlling the motor system. But instead, any of it can trade off with any other of it. And so the really special thing with humans being live-wired is that we drop into the world half-baked and we absorb everything around us. That's how you absorb your language, your neighborhood, your culture, your parents, your way of acting, your way of acting in the 21st century and so on. In other words, if you were born with exactly your DNA 1,000 years ago, you'd be a really different person. If you were born 10,000 years ago, exactly you, with the same DNA, and you ended up in the world 10,000 years ago, you'd be totally different in terms of your cultural beliefs, whatever weird, you know, animistic religion you believe in,

• 21:29Speaker 01

  whatever kind of, you know, thing is appropriate for, you know, burning people at the stake or whatever, or how you hunt a lion or stuff like that. You would just be a different kind of person. And this is because we absorb the world around us. And this is what I flagged a little bit earlier. What separates us from our closest cousins in the animal kingdom is that most animals are still dropping into the world essentially pre-programmed. So if you drop in as a goat or an alligator, you essentially know, okay, here's how I eat, mate, sleep, whatever, and that's it. And you're doing the same thing that goats did 10,000 years ago. But when you drop in as a human, you, in your first several years, essentially get to learn everything that humans

• 22:14Speaker 01

  have discovered up until now, and then you springboard off the top of that. And that's what has led to the success of our species. We've taken over every corner of the planet. We've gotten off the planet. We've invented the internet and quantum computation and so on, precisely because we're able, we're not starting from square one every time, but we start from where humans have already gotten.

• 22:34Hala Taha?

  Yeah, I think this is such an important point. So essentially what you're saying is that we're born, and you kind of use the analogy of a computer very often, we're born with all these software packages that unpack at certain timelines, for example, the puberty software package that unpacks around 13 years old for everyone. But at the same time, we're supposed to interact and be social animals and absorb information, right? So what happens to people or children who don't get a chance to absorb information?

• 23:05Speaker 01

  Yeah, so happily, these examples are rare, but they're very heartbreaking, which is sometimes you find a child who's had such neglect and abuse that they haven't had all the normal input. So Mother Nature is taking a gamble when she drops a half-baked brain into the world. She's assuming, okay, well, you should get all the normal language and love and touch and interaction with other humans. And occasionally you'll find a child who's locked up by their parents and they're not talked to, and they have terrible cognitive development. They just don't develop correctly, as in they can never get language, they don't even know how to chew, they can't see very far. Yeah, it's just a half-baked brain that

• 23:47Speaker 01

  never gets cooked all the way. And they have real IQ deficits. It turns out there are these things in brain development called critical periods. And one of those is if you don't get enough exposure to language, lots of language in your first several years, you can never get language at that point. So often, these children are rescued at some point, and a whole horde of psychologists move in and give them lots of love and lots of training and language and things like that. But it turns out it's too late.

• 24:17Hala Taha?

  And to me, like, you know, as somebody who's not a brain scientist or anything like that, I thought that the brain was supposed to be plastic, you know, this idea of plasticity. So is it true then that there's certain parts of the brain that just cannot keep, I guess, changing or adopting?

• 24:35Speaker 01

  Plasticity diminishes with age and it doesn't do it smoothly. It does it with these sort of punctuated moments. So you've got, yeah, these critical periods for lots of different things. So for example, learning language, you have to do in the first, let's say, four or five years. If you're not exposed to language, you just can't get it. But other things like, let's say, accent. If you move to a new country before the age of 13, you typically won't have any accent in, you know, in the new country. But if you move after the age of 13, it's very difficult to, to sonically morph into that culture. You'll always retain an accent. So I use in the book, an example of Mila Kunis and Arnold Schwarzenegger, both of whom were born outside of America. But they, you know, Mila Kunis moved here when she was seven from Ukraine.

• 25:20Speaker 01

  She'd never spoken English before, but she doesn't have, you, you can't tell that she has any accent to her American English, but Arnold Schwarzenegger moved here when he was 20. So it was too late for him to get rid of his accent. So anyway, the point is there are many critical windows that happen here with learning. That said, there are many things where you retain plasticity your entire life. So for example, your body as controlled by your motor system and your sensory system from your body, this is plastic your whole life. You can learn how to kiteboard or parachute or do any, you can learn all kinds of new stuff. Take up a pogo stick if you want, at any age. But things like your visual system, that gets less and less plastic with time because it says, okay, I got it.

• 26:05Speaker 01

  This is what the world looks like and it sort of hardens into place.

• 26:09Hala Taha?

  So interesting. So I'd love to get your breakdown of how it actually works to hear or see. Like what's the mechanics behind that? And if you can go over your Mr. Potato Head model?

• 26:22Speaker 01

  Yeah, well, so it turns out that we've got these sensors like our eyes, which are these two spheres in the front of your skull that pick up on photons. And they have chemical reactions. They pick up on photons and they send electrical signals back into your, into the darkness of the brain. And you've got your ears, which are picking up on air compression waves. And they have, it's a very sophisticated little machine and it breaks frequencies of sound down into different areas and it sends spikes into the darkness of the brain and so on. And it turns out that I mean, this is the weird and wild part is that we sort of feel like, oh yeah, I'm just, I'm just seeing the world. It's like I'm piping light into my head and I'm piping

• 27:04Speaker 01

  sound into my head, but that's not it at all. Your brain is locked in silence and darkness. And all it has are these billions of neurons sending electrical signals around and that leads to chemical signals and that that's it. And so all of this is a construction of the brain, what you're seeing, what you're hearing. And this is a very wild and deep thing to get your head wrapped around. But anyway, that's just the biological truth of it. And so my potato head model that I proposed a little while ago was that actually doesn't matter how you get the information into the brain, as long as you get it there. You can send information through a very unusual channel. And as long as the information gets there, the brain will figure out what to do with it. And so this was first shown actually at the end of the 1800s, where

• 27:50Speaker 01

  some experimenters took someone who was blind and they had a little photo detector that would detect light and they turned that into patterns of vibration on the head. And the person could essentially come to see via patterns of vibration on their forehead. And this is so unusual to think about sight that way. And then I'll mention in 1969, another scientist put blind people into a modified dental chair, which had this little grid on the back and it would sort of poke you in the back in various ways. And he set up a video camera and whatever the video camera was seeing, you would feel that poked into your back. So if it was a face or a square or a coffee cup or a telephone, you'd feel the shape of that poked into your back. And blind people got really

• 28:35Speaker 01

  good at being able to see the world this way. And so it turns out, it doesn't matter how you get the information in there. The brain will say, oh, I got it. That's correlated with something out there that's useful and I'll figure out how to perceive it.

• 28:49Hala Taha?

  Really, really interesting stuff. So I know that you've been using skin in a really unique way, and now you have a product, a wristband, where you're actually helping deaf people. Can you tell us about that?

• 29:02Speaker 01

  Yeah, so I got interested in my lab many years ago about this question of could we make sensory substitution for people who are deaf? Could we feed in the information that would normally be going to the ears via a different channel? And there are actually 212 different reasons you can go deaf genetically. And most of these are not something that you can do anything about at the moment. So what I did first is I built a vest with vibratory motors on it. And the vest captures sound and turns that into patterns of vibration on the skin. So sound is broken up from high to low frequency, which is exactly what your inner ear is doing. And then that's going on your skin and up your spinal cord and into your brain. And deaf people could learn how to hear this way. So I gave a talk

• 29:46Speaker 01

  on this at TED, and then I spun this off in my lab as a company called Neosensory. And we ended up shrinking the vest down to a wristband. And the wristband does the same thing. It's capturing sound and it's turning that into patterns of vibration on the skin. And deaf people can come to understand the auditory world around them. Like, oh, that's somebody calling my name. That's the doorbell. That's a baby crying. There's a dog barking, things like that. So we're on wrists all over the world now. Lots of deaf schools, lots of individuals wearing this. And it's been so gratifying to take something that's a theoretical neuroscience idea and move it all the way to, you know, product that's that people are using every day.

• 30:25Hala Taha?

  Yeah, it's really awesome what you're doing. And so I'd love to understand, how long does it take for someone to get these vibrations and then eventually have them mean something?

• 30:35Speaker 01

  So the answer is, it's a linear increase. So people just get better and better each day. So on day one, we test people after they've been wearing it for the first 10 minutes or so. And they're slightly above chance on being able to recognize certain sounds. But then through time, over the course of weeks, they just get better and better and better. And the really wild part is that by about, let's say, four months, people will describe it as hearing. So I'll say, look, when the dog barks and you feel vibrations on your wrist, do you think, okay, wait, I just felt something. What is that? It must be something, you know, maybe there's a dog out there. They say, no, I just hear the dog. Which sounds crazy, except that's what you're, that's what's going on with your hearing. You feel right now like you're just hearing my voice out there, even though

• 31:19Speaker 01

  it's all taking place in your head. You've got spikes running around and you think, oh yeah, that sounds like Eagleman's voice. And then you attribute it to some source outside of you. But that's what it becomes when you're listening through the wristband.

• 31:33Hala Taha?

  Yeah. And from my understanding, this is called qualia, right?

• 31:37Speaker 01

  Yeah, qualia is the term we use for the private subjective experience we have of something. For example, colors don't exist in the outside world. There's just different wavelengths of light, of electromagnetic radiation. But we perceive it as, oh, that's red, that's green, that's, you know, fuchsia, whatever. That's a qualia. That's a private subjective experience we have of what's going on out there, even though it's really just spikes in the dark.

• 32:03Hala Taha?

  Yeah. So then would you say that humans eventually could have a sixth or seventh sense that just feels natural to us?

• 32:11Speaker 01

  So that's what I've been working on for a while now, which is, given that all these other animals have other kinds of things they can pick up on, what does it mean if we feed in that information? And the answer is yes, we can absolutely have six cents, maybe many more. We don't have any idea yet what the limit is on that. But the idea is, what can we pick up on computationally or with any machine or whatever, and then feed that into you? So for example, you know, something I've been very interested in is perceiving infrared light. So you can set up, we've, you know, set this up with the wristband very inexpensively for five bucks, you set up these infrared bolometers, they're called, they're, you know, just picking up on infrared light. And you can walk around

• 32:53Speaker 01

  and feel the temperature of things around you. And I can, as I'm walking through a parking lot, I can feel which cars have been parked there for a while versus which have just arrived in the last 20 minutes. Cause, you know, cause the engine block is a totally different temperature. But it's just something I know as I'm walking through, I'm just feeling that information. Or if I come across two chairs, I can tell which chair was more recently sat in, because there's still a temperature signature on it and so on. There's a million things about this that one can just come to perceive a new sense. But you can have much wackier things. We've done, we actually have 70 projects in progress. If anybody's interested, go to neo century.com slash developers. And you can see our blog of all these different projects we have. So, you know, stock market or

• 33:37Speaker 01

  Feeling social media with your skin, or firemen, or blind people, or people with prosthetics, or there's a million different projects we have where we're feeding in new data streams. And you can come to have perception that one of the things we've been doing is for drone pilots, where you feel the pitch yaw, roll, heading and orientation of the drone on your skin. So it's like you're becoming one with the drone. You're it's like you've stretched your skin up there where the drone is. And pilots can become much better at flying drones this way in the fog and in the dark. And in fact, right now, I'm working with a couple of young engineers in Ukraine to implement this for their defense.

• 34:16Hala Taha?

  Very interesting. Okay, so I want to switch back to what we were talking about a little bit earlier when we were talking about our senses or our neurons sort of fighting for their territory. Because I want to get into the concept of dreaming. I think it's super interesting. And I want you to explain why we actually dream.

• 34:37Speaker 01

  So this is hypothesis that my student and I came up with some years ago, which is the following. If you go blind, as we mentioned earlier, if you go blind, that territory or visual cortex gets taken over by neighboring kingdoms of data, like hearing and touch. But the surprise in neuroscience is how fast this can happen. So some colleagues of mine at Harvard did this experiment where they took normally sighted people and they blindfolded them and they put them in the brain scanner. And what they found to their surprise is that after about an hour, they could start seeing activity in the visual cortex. When you touch somebody or when you play a sound for them, you're actually seeing the visual cortex start responding to that.

• 35:18Speaker 01

  And what that means is that this takeover process can start happening really fast because essentially, everything in the brain is wired up to everything else. You know, there's these very long distance connections, such that everything has, you know, roadways to get wherever it needs to get. And so somehow this takeover starts after about an hour. So what we realized was, given the rotation of the planet, this causes a real problem for the visual system because you end up in the dark for half the cycle. And obviously, the thing of interest here is evolutionary time before we had lights, which is just the last, you know, nanosecond of evolutionary time where we had lights or even fire. Most of our history, it's been extremely dark at nighttime. And that means your visual system is disadvantaged during the night.

• 36:02Speaker 01

  You can still hear and smell and taste and touch during the night, but you can't see. And so we realized the problem is the visual system needs some way of defending itself against takeover. And that is what dreams are about. So every 90 minutes, you've got these very ancient circuits in your midbrain that just blast random activity just into your visual cortex. That's the only place it's hitting is just primary visual cortex. And every 90 minutes, just blasts random activity in there. And so dreaming is the brain's way of defending the visual cortex against takeover. It's essentially a screensaver. So we published this and we studied 25 different species of primates and looked at how plastic

• 36:43Speaker 01

  they are. In other words, humans are extraordinarily adaptable and plastic in their brains. And that means they're at higher risk of the visual cortex getting taken over. Whereas other primates, like the gray mouse lemur, it's called, happens to be very, let's call it pre-programmed, where it hits adolescence fast and learns how to walk fast and weans from its mother fast and all this stuff reproduces fast. And so we looked at how much dreaming there is. And it turns out humans have lots of dreaming to prevent takeover the visual cortex, whereas other, you know, less flexible animals have less dreaming because they just don't need it as much.

• 37:20Hala Taha?

  So if I have this right, and feel free to correct me if I'm wrong, basically, our visual neurons are being active at night and dreaming, even though we're not actually seeing anything in our head, those same neurons are basically working so that they can keep their territory, so that they can stay relevant in the brain.

• 37:41Speaker 01

  That's exactly right.

• 37:43Hala Taha?

  Yeah, it's so interesting. And I've heard you say you think dreams are meaningless and you feel like it's sticking your head in a night blender when you go to sleep. So I'd like to understand, like, why are dreams meaningless then? Because a lot of people make up these stories, like, I can tell the future with my dreams and things like that. But you say that's nonsense.

• 38:02Speaker 01

  Yeah, it's just random activity. What happens is the synapses, the connections that are hot during the day are the ones when you blast random activity in there, those tend to be the stories that get activated. So, you know, if I'm thinking about my boss who said this to me, or I'm thinking about this big thing that I have to do tomorrow, then it's likely that that's going to come up in my dreams. But we all know dreams are just, they're so weird in their plotlines. And because the brain is a natural storyteller, we end up imposing narrative. And by the way, when you wake up and you tell somebody else your dream, you're doing a whole nother layer of imposing narrative on it because even just saying it out loud, you have to sort of make things make sense.

• 38:47Speaker 01

  But truthfully, it's just random activity and it's kind of like a Rorschach blot. If you just look at some random blob of ink, can you see things that you think are relevant to your life? And you say, oh yeah, that looks like, you know, this is sort of a blob that's telling me that I should go change careers and whatever. We can do that with our dreams as well. It's just random activity and you can say, yeah, that, I really thought of something here, whatever. But yes, it's all, it's all random activity and what we do is we impose meaning on it. Some of us do.

• 39:16Hala Taha?

  Yeah, some of us do. I mean, I've done it. I think a lot of people try to make dreams as like magical experience, right? And I feel like so much of the human experience can be pretty silly in this way. So I'd love to talk about the intersection between science and religion. You've been studying the brain and I feel like you probably have a very unique perspective on the world. I mean, parts about our brain and our life is still really mysterious, right? We don't really know how consciousness exactly works still.

• 39:47Speaker 01

  Yep.

• 39:48Hala Taha?

  And so there is mystery and sort of magic to like still, because we don't understand everything.

• 39:54Speaker 01

  Yeah.

• 39:54Hala Taha?

  But I'd love to understand what, what you feel about all of this now.

• 39:58Speaker 01

  My general feeling on it is the world is full of mystery. The amount of stuff we know in science and have written down in big fat textbooks is a Tiny fraction of of what's going on out there. Actually, I wrote an article in Discover Magazine back in 2004 called 10 Unsolved Mysteries of Neuroscience, and they're still unsolved. I mean, we are in deep mysteries all around us. And yeah, take consciousness. I mean, consciousness, somehow you put together all this physical stuff of the brain, and you experience qualia, as we talked about, you know, you experience pain and the beauty of a sunset and the taste of cinnamon and, you know, the smell of lemon pie and all these things that we experience. But we have no idea how to build pieces of parts. We

• 40:40Speaker 01

  can't build with transistors, a computer, and say, oh, yeah, it's enjoying this. Even though I'm laughing at this YouTube video that I'm watching, the computer presumably is just moving around zeros and ones and not entertained by it. But somehow our brains, we think we're just made of cells, and yet we are feeling stuff. So there's lots of mystery around us. To my mind, the best way to tackle these mysteries is the scientific method. And this is so new for humans. I mean, this is really just the last few hundred years that we've kind of gotten this right, essentially since the Renaissance, about doing science, which is just, it's nothing but a method of saying, okay, we're gonna lay out our hypotheses on the table, and we're gonna do careful experiments. We're

• 41:24Speaker 01

  not gonna fool ourselves into into believing something unless there's evidence that supports it. And so to my mind, that's the way to tackle it. Now, the the issue is, we have a world full of religions. There are 2,000 different religions on on this little planet that we're on. And the part that's always struck me as crazy is that people are willing to fight and die for their version of their religion. So there's a real lack of intellectual humility there. Obviously, if one religion were true, we might expect that it spreads around the world, and everyone says, oh, yeah, that one seems pretty right. But obviously, they're all made up. And when you look at stuff like Judeo-Christian Islamic religion,

• 42:06Speaker 01

  you know, has this idea that the earth is 6,000 years old. Well, you know, I mean, the Japanese were making pottery 7,000 years ago, and people were writing on caves 30,000 years ago and so on. So you'd have to explain how they got there before the. Anyway, it's so goofy, this idea of like Adam and Eve and creation and so on, is so clearly incorrect that there's absolutely no reason to believe in in this religious story. But I have felt that It's difficult to say, given the amount of mystery that we face, to say, okay, well, we've got this all figured out. And so it's a cold universe and there's nothing but deterministic physics and so on. We just don't know enough to say that. That may well be the case. We

• 42:46Speaker 01

  just don't know enough to pretend that science has it all figured out. And so I call myself a possibillion, and that means I'm interested in the possibility space. In other words, this is the scientific temperament, is saying, what could be going on here? How, how did we get here? What is our purpose here? If anything, what is happening around here? And the best way to tackle that is with the tools of science, which means anything gets to be on the table at first, and then we use the tools of science to rule out particular things, like that the Earth is 6,000 years old. And we use the tools of science to open up new folds in the possibility space that we hadn't even thought of before. But the

• 43:28Speaker 01

  idea is, the scientific temperament always allows lots of hypotheses on the table. And then we gather evidence to weigh in favor of some of those and, you know, and against others. And that's what I think we should be doing. That's what I call possibillionism. And I actually presented this in a TEDx talk many years ago. And I got hundreds of emails right afterwards from people saying, hey, I think I'm a possibillion too. And it became this worldwide movement. There were newspapers and articles that people sent me from India, from Uganda, from whatever, Facebook groups sprang up. And now 11 years after this original talk, there's so much activity about possibillionism. And I'm so happy about this because I feel

• 44:12Speaker 01

  like there wasn't a position that people could take if they happened to feel the way I did about this. The only thing that was available is to say, okay, either I'm religious, and I believe what my parents and my culture told me, or I'm a strict atheist on the other end of the spectrum, where I think nothing interesting is going on here. There's nothing else in the universe for us to understand. Or you would call yourself an agnostic, which means I don't know. That's all agnosticism means, is not knowing. But possibillionism is a much more active thing of saying, hey, we're going to go out and explore the possibility space and shine a flashlight around this and try to figure out what's going on.

• 44:48Hala Taha?

  And I feel like this is so positive for mankind. I feel like it could really help solve a lot of the self-inflicted issues that we have as people.

• 44:58Speaker 01

  Yeah. To this day, it's every time I see religious conflict, it just blows my mind. I mean, the whole history of Europe was really defined over the last 500 years was defined by fights between the Catholics and the Protestants. I don't mean fights, I mean killing, like murdering. And, you know, it feels like you look at this stuff and it's, it's so goofy. And yet, this is the history that we have been surrounded with and still have to deal with in a lot of the world. I feel like, I think I'm correct in looking at the world now in 2022 and thinking, okay, we're maturing a bit, at least much of the world is maturing out of this idea of, okay, this particular ancient religion that I was taught is the truth. Yeah. But anyway,

• 45:43Speaker 01

  I hope that's right.

• 45:45Hala Taha?

  Okay, so let's talk about the future a little bit and then we can close this out, David. Thank you so much for your time. I want to talk about your book, Live Wired, right? Much of the world and how we view it is very much like hardware and software. And so I'd love to have you help us imagine what a future could be like if Live Wired was put in the picture in addition to this hardware and software world that we live in.

• 46:11Speaker 01

  Yeah. I mean, so this is gonna be my next, so I'm running three companies right now, but this is gonna be my next one is called Live Wired, because I'm really interested in building this. I mentioned this before. I just feel like the way we think about building all our technology now and the way that everything is set up, our factories are set up and our education system is set up is, okay, yeah, you make a hardware layer and then you put software on top of it. And that's been a great idea and it's been super successful, but it's just not the way that biology ever does anything. And biology can do extraordinary things that computers cannot. And as I mentioned earlier, you know, computers are obsolescent from the day they come off the factory. So I'm very, I'll give an example. Which is the Mars Rover, can't remember if it was Spirit of Curiosity, one of them.

• 46:56Speaker 01

  Anyway, it got up to Mars, it did an extraordinary job, rolled around the red planet and saw lots of stuff, but then it got its right front wheel stuck in the Martian soil and it couldn't move out of there and it died. Okay. Contrast that with what happens when a wolf gets its leg caught in a trap. The wolf chews its leg off and then figures out how to walk on three legs. It's not that it was pre-programmed to walk on three legs, it just figures it out. It figures out how to make that happen because it is driven by motivations. It wants to get to food, to water, back to its pack and so on. So it just figures out how to run its body differently. And wouldn't it be great if we could build a billion dollar Mars Rover? If we're spending all that money and effort on it, if it could just, you know, saw off

• 47:39Speaker 01

  its wheel and then figure out how to operate in a different way? So this is the idea of live wiring and it's still the case that almost everything we program and the robots we build and the Mars Rovers we build are all totally pre-programmed. This is what your body looks like. This is how you're going to operate it as opposed to letting it operate like a human infant where it has to figure out its body. I mean, imagine building a robot that flops around for years and eventually crawls and eventually learns how to walk. That's the kind of thing we need to do if we want it to be flexible and live-wired.

• 48:12Hala Taha?

  Yeah.

• 48:13Speaker 01

  And so I'm very interested in the possibilities. I think the future is going to be much more biological than the way we do it right now, which is we build hardwired machinery that is inflexible.

• 48:25Hala Taha?

  Yeah. And so my next question for you is what's the difference between live-wired and AI? Cause from my understanding, AI is supposed to be self, you know, it learns and can adapt. So I'd love to understand the difference there.

• 48:38Speaker 01

  I mean, the thing about AI can do very impressive things, but it's still not nearly as good as a kid, you know, a five-year-old. A five-year-old can walk into a room, navigate a very complex room, you know, between the couches and under the table and whatever, can find her way to food and put food in her mouth, can socially manipulate adults, can do all these things. AI is really stupid in comparison to that. It's very good. It's extraordinarily good at, for example, image recognition or categorization of things, but it can only tackle problems that are Discreet and rule-based. So for example, AI is great at chess and at Go. It's beat the world champions at that.

• 49:22Speaker 01

  But that's only because it's a constrained, uh, rule-based system that doesn't have anything outside of it. And the real world is nothing like that. And so, by the way, you know, even though people often think, oh, my gosh, AI can do anything. It's taking over everything. It can't even do any sort of, you know, strategy-based video game where you're running around with a gun and you're having to do strategies where it can't, it can't do well at any of that stuff. So that's the difference is that a live-wired child can figure out all kinds of things in the world. AI can only do these very, uh, basic things right now.

• 49:56Hala Taha?

  Yeah. And this makes me feel good because I think all of us are really worried about AI. We're, we're told to get worried about it. Right? We're sort of fed this. So as somebody who studies the brain, do we have anything to worry about?

• 50:08Speaker 01

  I mean, eventually, eventually we might. Certainly not right now. I mean, you could just, you know, turn the computer off. I mean, there's a, yeah, it's still doing what it is told as in, hey, I want you to absorb a billion pictures of cows and horses and then get really good at being able to, to determine the difference between these. So what it does is it trains on a training set of, let's say, a billion images where it's labeled. Okay. This is a cow. This is a horse. This is a cow. And then it's, it's extraordinarily good, better than a human at discriminating cows from horses. But in real life, we don't have training sets with billions of examples. We don't have that luxury. You have to learn everything on the fly. All animals do have to learn the world on the fly and get good

• 50:50Speaker 01

  at it. And this is where we outshine AI by a long way.

• 50:55Hala Taha?

  Okay. My last question to you on the future, and then we'll round out this interview, is really about how you imagine mankind in the future in terms of our brains, in terms of maybe live-wired materials. Tell us about how you imagine the future, knowing all that you know.

• 51:12Speaker 01

  It's going to be pretty different. I mean, for one thing, we'll be much better at actually being able to measure what's going on in the brain. So for example, right now, our best technology is called functional magnetic resonance imaging, FMRI. You stick somebody in the brain scanner and you can tell sort of crudely where the activity is happening in the brain. And, you know, we make all kinds of theories and we do, you know, I've written hundreds of papers on this topic, but the fact is it's a crude technology. What we really need to understand how the brain is working is to be able to see the activity in each one of the 86 billion neurons in real time and they're each chattering along, you know, 10 to hundreds of spikes per second. We're nowhere near that kind of technology,

• 51:56Speaker 01

  but eventually we will get there and that will generate a completely different kind of understanding of how the brain actually works. We're still missing really most of how the brain is actually doing what it does. And when we get to that point, we'll be able to read and write from the brain and to the brain. And that's going to change everything. Right now, the brain is really locked in this armored bunker plating of the skull and we can't do much with it, except for I can read your, I can try to read your intentions and you mine by our words and by our behavior, but it's pretty limited. So there may be in the distant future, straight brain to brain communication, which is a very different

• 52:38Speaker 01

  sort of bandwidth of communication. So that's one thing. I think another thing is that we'll be experiencing completely new senses. It'll just be trivial for everybody to experience, you know, whatever infrared and stock market data and what's going on on social media. You know, these things will just be like getting eyeglasses for a kid. We'll have all that. So I think we have more in common with our ancestors of 5,000 years ago than we have in common with our descendants of 100 years from now.

• 53:13Hala Taha?

  Wow. That is powerful. Awesome, David. Well, I end this show with two questions that I ask everyone and then we do something fun at the end of the year with them. So you're right at the end with us. What is one actionable thing our young improfitters can do today to become more profitable tomorrow?

• 53:30Speaker 01

  Seek novelty. So the key is doing things that you're not already good at, because that's how you exercise the brain and build a stronger brain is by doing things you have not done before.

• 53:44Hala Taha?

  Okay, so challenging your mind, learning new things.

• 53:46Speaker 01

  Yes.

• 53:47Hala Taha?

  And what is your secret to profiting in life?

• 53:50Speaker 01

  Relationships. It's all about other people. The brain has an extraordinary amount of its circuitry devoted to other people and making models of them and understanding them. And I think one of the key things in life, especially now during our polarized era, is to really try standing in the shoes of other people, especially people that you're disagreeing with, and try to understand the world from their point of view.

• 54:12Hala Taha?

  Awesome. That's awesome. You know, that was one of the biggest themes this year is everybody was talking about relationships. So, very cool, David. Where can everybody learn more about you and everything that you do?

• 54:21Speaker 01

  Eagleman.com.

• 54:23Hala Taha?

  Awesome. Well, thank you so much for your time.

• 54:24Speaker 01

  Thanks. Great to be here.