Rewiring the Brain w/ David Eagleman
EPISODE #30
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Neuroscientist David Eagleman shares his insights into the mystery of neuroplasticity, how modern technology impacts our brains’ development, and the different ways we might soon be able to augment our senses and enhance our cognition.
Dr David Eagleman is a neuroscientist and internationally bestselling author. He teaches brain plasticity at Stanford University, is the creator and host of the Emmy-nominated television series The Brain, and is the CEO of NeoSensory, a company that builds the next generation of neuroscience hardware. The author of seven other books, he lives in California.
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Luke Robert Mason: You're listening to the FUTURES Podcast with me, Luke Robert Mason.
On this episode I speak to the neuroscientist, David Eagleman.
"You can actually plug in completely new kinds of data streams. The brain will say, "Oh, oh, I get it! It's correlated with reward or with this" and it figures out how to use it. - David Eagleman, excerpt from interview.
David shared his insights into the mystery of neuroplasticity, how modern technology impacts our brain's development, and the different ways we might soon be able to augment our senses and enhance our cognition.
This episode is an edited version of a recent livestream event. You can view the full, unedited video of this conversation at FUTURES podcast dot net.
Luke Robert Mason: Exciting new discoveries have revealed that the brain is a dynamic system, constantly modifying its own circuitry. In his beautiful new book, 'Live Wired', neuroscientist David Eagleman looks at how this unique property known as 'neuroplasticity' enables us to gain the skills, faculties and practices that make us who we are. But more important than that, he shows by testing the limits of this odd quirk, we might be able to develop a profoundly new relationship with technology - one that might eventually enable us to augment our senses and choose how to experience our reality.
So, David, it seems to me that when we talk about the brain, we use so many computational metaphors. We compare the organ itself to a computer and then claim that the mind is like software running on a machine. This book attempts to get away from these limited metaphors and you've done that by coining a brand new term. That term is 'livewired'. So what does it mean to have a brain that's livewired, and what are some of the key features of this livewiring?
David Eagleman: Yeah, so first of all, Luke, it's great to see you again and great to be back here. The key in answering that question is: I live in Silicon Valley and all the talk is on hardware and software. Engineers are praised for making very efficient and trim versions of this, but in fact what's going on under the hood is so different from that. What you have is this three pounds of remarkable machinery which is constantly reconfiguring itself, every moment of its life. You have 86 billion neurons, each of which has about 10,000 connections. You have 0.2 quadrillion connections in the brain. These are constantly seeking and finding and plugging and then unplugging and replugging and so on. Everything that you know and everything that you do causes physical changes to the structure of your brain.
Luke, we've known each other for some years. When I first learned your face and your name, there's a physical change in the structure of my brain and that's what allows me to remember that. Over the course of years, these massive changes orchestrated across the gargantuan fabric of your brain adds up to what we call you, and this is a completely different sort of thing than hardware and software. It's not about efficiency. Instead, it's about taking things that you're doing that are relevant to you, that are rewarding and punishing, and burning this down into the circuitry at different levels, all the way down to the DNA. Changing the way that the DNA is expressed as a reflection of your experiences.
The term of art in our field is 'brain plasticity', but the reason I kind of want to get over that term is because that was coined 100 years ago to represent the way that you can mould, for example, a plastic toy - it holds onto that shape. That's what a plastic thing means, is that you can mould it and it holds it. Although people were impressed by that 100 years ago, that's not what the brain is up to. It is constantly changing - as I said, every moment of your life - and so I needed a new term for that. 'Liveware' is the term that I use now.
Mason: What does this process teach us about the profound relationship that we as human beings have with both our environment that we inhabit, and the society that we live in?
Eagleman: It turns out, I'm old enough to remember in the year 2000, when the Human Genome Project got completed. We were all so excited about this because we thought: wow, once we have all the letters of the DNA we're going to understand so much. It turns out that doesn't tell us much at all. It's not that the project was a failure, but it only tells us half of what we need to know. The other half of what makes your brain and my brain is all around us. It's every experience we've ever had; it's the language we're exposed to; the culture; the beliefs; the parents; the friends. Everything in our lives is what determines how our brains wire from there. DNA is just the first domino that gets kicked over. From there, people go off on very different trajectories.
I actually start the book - Live Wired - with a quotation from Martin Heidegger that I love. The quotation is: "Every man is born as many men, and dies as a single one." What he's getting at there is that we start with so much potential for what could happen to us, but of course life happens and it moulds us into a particular shape. By the time we're on our deathbed, you're exactly you. You are your experiences in the world. In fact, the way I'm thinking about it a lot lately is that each of us is a little vessel of space and time. As in, where you grew up in your year that you were born and so on, and where I grew up and exactly where I was born and the experiences I have had - I'm a vessel of all of those and you're a vessel of yours. As a result, by the way, everyone is quite different from one another.
We all like to think when we're kids that everyone is the same on the inside, but in fact because of our experiences, people can end up being quite different from one another. We have this very low bandwidth communication channel of language with which we can communicate from my planet to your planet. But yeah, it's because our experiences are so vastly different from one another.
Mason: It reminds me of the children's poem:
I am the only ME I AM
who qualifies as me;
no ME I AM has been before,
and none will ever be.
When we hear this idea that our brain is neuroplastic or that our brain changes, that feels really odd. We've all seen photographs of the brain and it's this three pounds of grey gloop, and it looks very fixed. How exactly do these changes in the brain actually occur, and what motivates these sorts of changes?
Eagleman: Yeah, I mean it's an excellent point that you raise, and that I think is why for the last hundreds of years we've just assumed the brain is fixed. When you look at any neuroscience textbook, what you find is: here's a picture of the brain. This is the part for seeing, this is the part for hearing, for touch, for taste, for smell and so on. In fact, I feel like it's such a wrong-headed start in thinking about the brain, because it's an extremely fluid system.
An analogy that I make in the book, actually, is that it would be as though, for example, when a child looks at the globe, and all of those country lines in there - they assume that those are somehow fixed and they have to be that way. We know as you get older that if history had changed even just a little bit - this King had died young, or this battle had tipped the other way, or whatever - the country lines would be different. It's a very fluid sort of thing. Anyway, what happens in the brain for example, is if somebody goes blind, the visual cortex - the part at the back of the brain that we label in the textbooks as the visual cortex - gets taken over. That becomes used for touch, for hearing, for memorisation of vocabulary words, for other things. It's not the visual cortex at all. The way to think about this is that colonisation is a full-time business.
An analogy that I give in the book is just what happened with the Americas when the French, British and Spanish were all competing for the territory. In 1750, the French had a huge area here. The French had a whole major swathe of the Americas, straight down the middle. But what happened is they just weren't sending enough ships over compared to the British and the Spanish, and so eventually they lost their territory. The reason I use that analogy is because this is the key about how the brain makes a map of the body and understands the body. It depends on how many ships of data are coming in. For example, if you lose an arm, there's no more ships coming from the arm and so your brain's map changes. It says, "Okay, I got it. I'm a body without an arm, that's cool." It changes. If you go blind, the visual cortex gets taken over. If you go deaf, the auditory cortex gets taken over, and so on.
The key is that nothing lies fallow in the brain. There's competition for territory. It'd be like if a restaurant in London went out of business, it's going to get taken over by some other business because none of the real estate can get unused.
Mason: It seems like this process is so delicate, in many ways. Is brain plasticity one of those things that is highly active when we're very, very young? Is it really important how we grow as children? Especially in those first ten years of our life. If it is, how should we encourage more playful interactions with the world that have positive outcomes for our neuroplasticity?
Eaglemen: What you're pointing at is something very important. Mother Nature has tried a particular trick with homosapiens, which is: drop our brains in the world essentially half baked, as opposed to many other animals. Let's say an alligator - when it drops in the world, it pretty much knows what's up. It knows it has been programmed to eat, swim, mate and so on. When a zebra is born, it runs for 45 minutes. A dolphin is born swimming, and so on. But human infants have these super long infancies and a helplessness period. It takes a long time to learn how to walk and a long time before it reaches adolescence, and so on. It's because we don't come pre-programmed. We come ready to absorb the world around us and all of our culture, language, beliefs and so on.
That's a really great strategy on Mother Nature's part, but it's also a gamble because what it depends on is getting the right sorts of input. Most of us do get that. Most of us are lucky to get that from our parents - love and language and attention and touch and things like that. But there are these tragic natural cases where children don't get that.
One case that I cover in my television show 'The Brain' is the issue of the Romanian orphanages. After the fall of Ceaușescu there were hundreds of thousands of kids in these orphanages because their parents have been killed, and it was too much for the staff. They said, "Look, just don't talk to the kids. Don't pick them up, because otherwise the kids will get clingy." So these kids grew up without the proper input and as a result, they had major cognitive deficits. We see this in really tragic cases where a child is so severely neglected that they don't have an adult talking to them or giving them love. They end up with really deep problems, like they don't even learn language. They can't even learn how to chew solid food, or see across the room or things like this. The problem is - as you pointed to - the door closes at some point. You only have a certain number of years to get that input and to develop the brain. After that, it is too late. Yes, it is a lesson for all parents to make certain that you're giving your child plenty of love and attention and touch and language, and so on.
Mason: You talk about those tragic moments. It seems as if sometimes, those tragic moments are the things that can teach us the most about the human brain. With things like neuroplasticity, surely neurological disease and damage to the brain, those things can teach us so much about our ability and about our resilience of our brain. I guess David, my question is: do neuroscientists sit around all day and wait for motorcycle accidents where they can get split brain syndromes? Or are there other ways to observe this property in the brain as a scientist?
Eagleman: Yeah, so I'll tell you how I do it. By the way, as far as waiting for clinical cases, tragically there are plenty of clinical cases that come in every week and so it's easy enough to see evidence of these things and understand what's going on that way. Then of course there's animal research where people do things like implant an infrared detector directly into the cortex of a rat, and you see whether the rat can come to understand infrared light. By the way, it can. It can come to understand and then do tasks based on seeing infrared. Why? Because the cortex - the wrinkly part on the outside - is a one trick pony. The whole key with the brain - and this is really the framework that I lay out in the book - the whole framework is that you can feed it any kind of data, and the brain will just figure out how to use it. The brain is locked in science and darkness. All it ever sees are spikes. It doesn't know whether those spikes represent photons for the eyes or air compression waves from the ears, or mixtures and molecules from the nose, or pressure on the fingertips. It doesn't know. All it knows is that there are spikes coming in, and it's good at putting together a story of how to correlate these things. It knows that whenever this comes in, this is coming in. The point is, you can actually plug in completely new kinds of data streams and the brain will say, "Oh, oh, I get it. It's correlated with reward or with this." It figures out how to use it.
One of the things I've done is I ended up spinning a company off of my lab where we built devices. For those of you on YouTube, you can see I'm wearing a wristband. This is a wristband that has vibratory motors in it. It has these little buzzers like the buzzers in your cell phone. This is called the Neosensory Buzz. What it does is converts any kind of datastream into patterns of vibration on the skin. For example, one of our main areas is with people who have hearing loss. We capture sound, turn sound into patterns on the skin, and people who are completely deaf can learn how to hear through the skin of their wrist. It's because that data climbs up the spinal cord into the brain and the brain says, "Oh, I get it. I'm seeing the dog's mouth move and I'm feeling the buzzing on my wrist. I understand that those are correlated." Then I clap, I ring my doorbell and do these things, and I see that the sounds are correlated with what's happening on my wrist. They come to hear that way.
By the way, nobody remembers but when you're an infant, you have to learn how to use your ears. Your ears don't come pre-programmed to work. You're getting all these spikes coming into your brain but you see your mother's mouth moving or you bang on the bars of your crib, or you clap your hands, or whatever. Your brain starts putting together these correlations and eventually you hear.
Mason: I want to talk so much about Neosensory but before we do that, let's just establish this idea around the senses. It feels like at the heart of this is how we interact with our sense organs. Correct me if I'm wrong, but it feels like we receive signals via our sense organs, our brain then processes these signals and we almost project the world back out there. In doing that, we often obscure many aspects of objective reality. You talk about in the book how we don't see the blood vessels in our eyes, for example. What exactly is going on here with this feedback loop between the sense organs, the signals it receives and the brain?
Eagleman: Great question. It turns out the brain's job is to build an internal model of the world that's out there. It's just in this little three-pound control room that it's in, and it's controlling this huge empire of the body. It's moving through the world and getting this electromagnetic radiation and air compression waves and so on, and it's trying to understand what's going on out there. What you see isn't actually reality, of course. Just as an example, colours don't exist. It's just different wavelengths of electromagnetic radiation. Your brain puts together this thing. Why? Because it's a fast way of tagging something. It says, "Oh, there's ripe fruit in the trees. The red against the green there, great." Instead of saying, "Okay let's see. That's 462 nanometer wavelength and that's 570", it says, "Okay great, I'm just going to call that red and green and have a direct perceptual experience."
One thing that's really interesting to me is for example visual illusion. It's something that's interesting to little kids and then to neuroscientists when they grow up. What it demonstrates is this issue about: wow, what's actually out there has nothing to do with what I believe I'm seeing. This is because what you're seeing is just an internal representation. I'll give you an example. Take vision: vision has very little to do with the eyes. You can have rich, full visual experience with your eyes shut. This is what we do every day when we dream. This is because vision is all about the internal activity going on in the brain and your eyes - just from the point of view of the number of fibres that it sends to the visual cortex - the visual cortex only gets 5 percent of its input from the eyes. All the rest is feedback loops and other parts of the brain.
You're not exactly seeing the world out there. It's just you have the capacity to - if you're confused about something, you can stare at it and try to incorporate more data - but mostly what you're seeing is an internal model that you believe is out there. This is why magicians and illusionists and so on can do what they do, because that's all you're seeing and you can believe that you've seen something.
Mason: That's such a wild and crazy idea. You talk about dreaming actually a lot in the book. You have a theory for why dreaming exists, and it's very heavily tied to brain plasticity. It's because our brain has this property that we need to dream, otherwise basically, it sounds like we'd go crazy. Is that right?
Eagleman: Well, so here's the whole key. One of the big discoveries in neuroscience...I mention that when you go blind, your visual cortex gets taken over - it's no longer visual, right? One of the big discoveries to my mind was how fast this happens. It turns out if you take sighted people and you blindfold them, and stick them in a brain scanner, within about an hour you can start seeing little blips of activity in the visual cortex. From things like sound and touch. In other words, this encroachment of one territory onto another starts happening very rapidly. That was the big surprise to me: how fast the system is wired up for this.
With a student of mine - we started this project years ago - we realised that there's a problem that the visual system has that the other senses don't, which is that the planet rotates into darkness for half the time. In the dark, you can still hear and smell and touch and taste just fine, but you can't see. Of course I'm talking about evolutionary time, not recent electricity time. The theory that we ended up deriving was that dreams are the brain's way of defending the visual cortex at night time against takeover from sound and touch and other areas.
We've now done deep studies on this. For example, the paper we just published is on 25 different species of primates. We look at how plastic the primates are. Some, like lemurs, are not particularly plastic. They drop out, they walk quickly, they reach adolescence quickly and so on. Whereas homosapiens at the other end of the spectrum are very plastic and have to absorb the whole world. It turns out you can correlate the amount of REM sleep - rapid eye movement sleep, which is what correlates with dreams - you can correlate that exactly. This is to say if you're not a very plastic animal, you don't have much dream sleep because you don't need it. You don't need to defend the visual cortex because it's not in danger of being taken over, because the system isn't moving around very much.
In contrast, if you're a homosapien, the whole system is very fluid and flexible and so you need to defend the visual cortex at night time against takeover, by having dreams. If you look up the circuitry that underlies dreaming, it's very specific. It's this circuitry that comes on every 90 minutes and just blasts the visual cortex with activity. That's all it does, is just shoves activity in there. Of course, because it's the visual cortex you see and think you're running across a meadow and seeing leprechauns - whatever you dream about - but that's how you keep it defended.
Mason: So if you have very, very vivid dreams, does that mean your brain is very, very neuroplastic or brain plastic?
Eagleman: Ah, I think it's a separate issue about the vividness of your memory. One of the things we're looking at now, by the way - as a side note - is what happens when people don't have much in the way of dreaming. It turns out that some people on tricyclic antidepressants or monoamine oxidase inhibitors have less dream sleep. We're just starting to study this - about whether there are changes in the size and activity of their visual cortex in the morning as a result of not having dream sleep.
Mason: It feels like the brain is so fickle, then. That any small thing within the environment could have a massive change, and the environment then has this profound effect on our brains. As I was reading your book it just reminded me of artist Douglas Copeland's famous quote, where he lamented, "I miss my pre internet brain." I have to ask, what do you think the role of modern interconnectivity and modern technology and things like the internet have on the Western brain?
Eagleman: I am very cyber optimistic about this, and I'll tell you why. It's because what makes your brain what it is is the diet of information that you're taking in. When I grew up, I had my home room teacher and when I really wanted to know something my mother would drive me down to the library and I'd pull out the Encyclopedia Britannica and would look at an outdated article - 10 or 20 years old - and I'd hope to find what I needed that way. Of course in school, I had lots of just-in-case information. Just in case you just need to know these seven important dates in Canadian history, or something. It's hard to make brain changes when you don't really care about the thing.
In contrast, for my kids, we have an Alexa and a Google Home and of course they're on Wikipedia and whatever. Whenever they're curious about something, bang, there's the answer. It turns out that when you are curious, you have the right cocktail of neurotransmitters present and so it really sticks. This is just in time information versus just in case information. It makes a big difference in terms of brain plasticity.
By the way, I run into 13 year old kids all the time who say something really smart. I say, "My gosh, how do you know this?" and they say, "Oh I saw it in a TED talk." We didn't have that opportunity when I was growing up. I had my home room teacher, I didn't have the best person on the planet giving the best talk of their lives, in 15 minutes giving me a whole sense of what is going on. This is just standard mother's milk for these kids growing up now. This is why I think the next generation is going to be much smarter than we are. They've had a much richer diet of intake and they can actually surf into the...if you imagine all of the world's information as a big sphere, they can enter any door they want to. They're interested in whatever - bugs or baseball or ballet or whatever, they can enter that door and then they start seeing other things. They think: oh, that's interesting. Then they follow a path and so on. So I'm very optimistic about this.
Let me just say one other thing, which is: people - even neuroscientists - often have strong opinions and make declarative statements about the effect of growing up digital. But from a scientific point of view, this is a very difficult thing to study because there's no appropriate control group. If you take an 18 year old kid who's grown up wired, you can't find kids who did not grow up with the internet as a comparison group. You can find kids, of course, who are totally impoverished and don't have the internet because they're in rural China or the favelas of South America or something, but there's a hundred other differences there. You can compare them to 18 year olds of the previous generation but there's also a hundred other differences there in terms of politics and economics and nutrition and pollution. There's tonnes of other things. It's very difficult to do that comparison, so what I'm basing my answer on is just an understanding of how the brain works in terms of the diet of information it brings in, and it remixes things and that's how it comes out with new ideas about stuff.
Mason: I love that you're a cyber optimist, David, but have you recently spent any time on Twitter? In other words, what I mean is that the media space we're in - it already feels like it has this massive impact on our perception of reality. We live in these media silos, these reality bubbles. It must be having some form of effect on our brain, whether negative or positive.
Eagleman: I agree, though as I say we're just not really going to know what that effect is. I will say this whole thing about bubbles - I'm not totally convinced that anybody's living in a bubble. The reason people go on Twitter, Facebook and so on is because they want to get outraged by the fact that someone's saying this or that. Everyone reads the other comments on things. It's not like we're in a silo or bubble. In fact what you're seeing is magnified or exaggerated opinions of the whole world around us. That's the thing. In a sense, we are exposed to more information than we used to be. It might make everybody mad and we might feel like that person is crazy for believing X, Y, Z - but at least we're seeing it.
Mason: Unfortunately sometimes, we're seeing it. I was so happy to see this book come out. It was a book that you spent 10 years working on and I'm seeing a multitude of your talks teasing this possibility of what I see as creating cyborgs using this unique ability of the human brain. As I was reading your book, I kept thinking of Marshall McLuhan's famous quote where he said, "The extension of any one sense alters the way we think and act - the way we perceive the world. When these ratios change, then men change." Some of the best examples are captured in this book in the field of sensory substitution. What is sensory substitution and why is it such a good example of brain plasticity in action?
Eagleman: Sensory substitution is feeding data to the brain via an unusual channel. For example, with the Neosensory Buzz, feeding sound information through the skin. One would think well that's crazy, that would never work - but it works just fine. It turns out it's because the brain is just so good at taking in data and doing something with it. People have been building devices like artificial retinas and artificial hearing - cochlear implants and retinal implants - these things don't act exactly like your natural biological sense but people figure out how to use them because their brains are plastic. They say, "Oh, I get it. The data is now doing something a little bit differently. That's cool, I've got it."
With sensory substitution, one of the exciting areas is for blindness. People feeding in data that way. Just as one example of many, some colleagues of mine have a device they made called 'The vOICe'. The idea is that you're taking, say, headphones in your phone, and you turn the video feed of the phone into sound. It scans across the scene from left to right. You're scanning what's going on and what's happening is the brightness and the edges and so on all get turned into pitch and amplitude and so on. At first, it sounds like a cacophony and you bump into things. After a while, people get pretty good at understanding the visual world through their ears. As long as the brain gets the data, it figures out what it's going to do with it. This is the idea with sensory substitution. It works and the reason I am spending all this time launching a company out of my lab is because it's such a cool opportunity to take an idea in neuroscience and take it all the way from theory to practice. Now it's on wrists all over the world.
Mason: I think we've got to spend a little more time on this idea of sensory substitution because the crazy thing about Peter Meijer's voice from the OIC is that people actually report seeing through the ears. What they're describing is recognising objects in three-dimensional space. In other words, what's experienced is actually a quasi-visual property. It's not an auditory property. It's visual. That revelation is so important.
Eagleman: Yeah, I totally agree. I mean the thing is, look at something like reading a book. You're looking at these strange squiggles on a page, but because you're totally practiced at it, the meaning just flows off the page for you. This is a sentence, this is what the meaning is. It's only when you look at a foreign script - for example if you don't speak Chinese or the North Western Iranian language of Balochi or whatever - if you don't speak those, you look at them and think: Oh my God, how can anybody understand what these weird shapes and squiggles are. But it's the same thing with all of our senses. You're capturing photons or air compression waves and you're having a direct perceptual experience. It turns out you can get the data coming in through your ears or there's another device called the Brainport which is a little electrotactile grid that sits on your tongue and translates a video feed into shocks on your tongue. You can come to understand the world that way - people get pretty good with this thing.
The idea of seeing with your tongue is so weird, but remember the way we normally think about vision is that we've got these two spheres in our skull that are capturing photons and translating them into spikes, but we don't think twice about that. We think: oh yeah of course, that's what eyes do and of course I'm seeing. You can get the information there via a different route.
Mason: But the key is that it's not something you can just plug and play. It's more of a plug and wait sort of experience. A plug and pause sort of experience. These things take time to integrate themselves into the body schema - is that right?
Eagleman: That's exactly right. You have to learn and you have to make those correlations. It's just like learning to ride a bicycle, for example. You can know everything about how it should go, but you need to go and practice it and figure out the relationship between input and output. I lean this way and this happens. I turn that way and that happens. It's the same thing with this.
Just by way of example with the Neosensory Buzz, the first day that people put it on they see a dogs mouth moving and they feel buzzing on their wrist and they say, "Oh, I get it. That's the dog's bark." but it's still a cognitive translation. After wearing it for a few weeks or months, they're hearing. It's not that they're cognitively translating. They're saying, "Oh, I heard a dog bark." and they look around for the dog. That's because it just takes time until the brain starts having a direct perceptual translation of this.
This is what all of our senses are but we don't stop to think about this normally. Vision, hearing, touch, taste and smell - it's just the brain's way of summarising a whole bunch of data. Oh you've got this mixture of molecules, I'm going to call that the smell of cinnamon. That's what we're always experiencing, and as I said it takes babies a while to learn what any of this means.
Mason: That's what this book seems to do such a good job of. It's that moment of: oh I see. Suddenly this thing that seems so normal - almost invisible to me - oh goodness, there's all these things that are going on in the background. All these things that are being made invisible to allow me to have this perception.
Eagleman: Boy, that's right, and I certainly think the main function of science communication is trying to make those things that are normally invisible to us, visible. Where we realise: Jesus, what a weird situation we're living in here. Then understanding what we can do with it and what we can build with that.
Mason: I have to ask. You've been wearing this Neosensory Buzz device. Do you mind me asking how long have you been wearing it for now?
Eagleman: Oh I've been wearing it for a long time. Different prototypes of it along the way. For now, this is the actual one on the market. It's interesting for a hearing person, there's an effect called blocking which is to say your brain's trying to make changes so that it understands what's going on in the world. My ears work fine, so when I get this data stream, it doesn't cause much change in my brain because it's redundant for me. But for a person who is deaf or hard of hearing, it makes big changes in their brains because that's the only way they're getting the auditory data. All that auditory data is a surprise for them and so brains change predicated on surprise. If you were going to ask what it's like for me, it's just a redundant thing. I tell you what one experience is for me wearing it. We predict a way of things that we know are coming. Just as one example, when my hearing friends put on the Buzz, they say, "Whoah, I'm hearing my own voice." Of course you're hearing your own voice. Your voice is probably the loudest thing you ever hear in your ear when you're in a conversation, but you don't feel normally like you're hearing your own voice. Why? Because it's totally predictable. You know exactly what's going to hit your ears and so you totally ignore it. It's the same way with things like toilet flushes and water in the sink and whatever. People say, "Oh my God, that's so loud.", but normally we don't even pay attention to a toilet flush because we know it's coming and so it doesn't seem that loud. In fact, it is quite a loud event when you're getting the data through a different channel, you recognise which things are loud.
Mason: So do you think you should ship the device with a pair of earplugs, perhaps? Maybe that's the way forward.
Eagleman: Yeah, I think so. For hearing people, yes. So people who are deaf or hard of hearing over the planet now are using this and having really wonderful experiences with this, in so many ways. From the simple things like: oh, I never knew that my microwave made noise - or whatever the thing is - to really understanding that: somebody is calling my name, or I left this machine on and the machine is making noise. There's all sorts of ways in which this is helping people. But what we're doing with hearing people is we've built this to have an open API. People can feed in any sort of data stream they want. We're experimenting with all kinds of new senses. This is not sensory substitution but now sensory expansion or addition. By expansion, I mean something like I hooked up an infrared version of this with one of the engineers from my company where I can walk around and feel infrared light. The very first night that I was wearing it, I was walking in between two buildings and suddenly I felt a bunch of infrared light. I thought: where the heck is that coming from? I followed my wrist and it took me to an infrared camera that was surrounded by infrared LEDs. Normally totally invisible to us, but it's shining this big blast of infrared - you know, the night vision thing. It was totally obvious to me. I immediately saw through the camouflage because I was wearing this thing and had another sense. I'm expanding the visual sense that I already have.
Sensory addition is plugging in a completely new sense. For example, I think I mentioned this but drone pilots...we can feed in the orientation heading of a drone so as they're flying, it's like they've stretched their skin up there. They're at one with the drone and they're feeling the data directly from the drone. That allows them to be able to fly in the fog or the dark, because they know what the drone is feeling. That's an example of sensory expansion, because now it's something that's not even part of you. It's not an extension of a sense that you already have, and there are many, many examples like this. As you know from the book, there are tonnes of examples of this: ways that we can expand our sensory capacities.
Mason: I want to get onto sensory expansion in a second but before we do, there's another thing that this wonderful, weird brain plasticity allows us to do in addition to adding new senses. It also allows us to leverage brain plasticity to interface with entirely new limbs or control alternative anatomies. I guess my question is, might it soon be possible to control a robot with our thoughts?
Eagleman: Yeah, absolutely. This is one of the chapters that I wrote because from the time I was a kid, I would look at things like - just as an example - you look of x-rays of different animals and you see that rats and bats and dogs and camels and elephants - they all essentially have the same architecture as we do. But they all have longer this and shorter that, or bigger this. It's just like tweaks on the same basic plan. What we've learned from genetics over the past 20 years is that this has to do with not a completely different sort of genetic plan. Instead, it's simply that you turn on this gene for a little bit longer and you turn on this one for a little bit shorter during the developmental programme, and that gives you long legs or big, long arms for wings like a bat. You're just tweaking, very subtly, these genetic knobs and then they get very different body plans. The thing I started wondering is that I don't get it - does the brain have to figure out how to operate a different body plan? Genetically, do you have to pre-programme it? What I realised is not that at all. Brains just figure out whatever body they happen to be trapped in.
One example I use in the book which is just a lovely example - very visual - this dog named Faith that was born without front legs. Faith needed to get to food and water, and her mother and so on, so she learned how to walk on her back legs bipedally like a human. Faith walks around on her back legs. It's not that any dog couldn't do this, it's just that they simply don't need to and so they don't bother. The point is, it is not that her brain is pre-programmed to drive a dog body. Her brain is pre-programmed to seek relevance and get information, and get out there and do what it needs to do. It just figures out how to operate based on the limbs that it has available.
So, can we drive robots? We already know the answer is yes. For example, there are people who are paralysed who can drive robotic arms just using thoughts in their motor cortex. As in, move my real arm - but of course the real arm isn't getting the signals so it drives that robotic arm. We also know it's easy to add, for example, a new limb - called supernumerary limbs. Just one example in VR, you can do these things where let's say I'm holding two controllers, and in this game I can control my two virtual arms. There's a third arm coming out of my chest in this virtual reality game and I control this by tilting the controllers in a particular way and that allows me to do that. I'm supposed to grab boxes and in about three minutes, people can figure out how to use a third arm pretty well. What this tells us is that it just doesn't matter what body you find yourself in. People get into cranes and mech suits and so on, and it just doesn't take that long to figure out: oh, I see. I tilt to the left and move this and that moves that. Great, done. It's extremely flexible, and so one of the things that I suggest is that as we get better and better at using these tele limbs, we'll be able to control a robot without even being connected to it; just wirelessly.
Mason: I keep arguing this with anyone I get on the podcast who wants to talk about space. I keep arguing that maybe we don't have to actually send human beings to the Moon or to other planets. What we can do is send a robot ahead of us - a bipedal robot - and then embody that robot through this use of a thing like tele limbs. Where basically, if the brain is as plastic as you say, we'd basically get the same sort of feeling as being on the Moon but here on planet Earth.
Eagleman: Yeah, I think that is probably our only option for long distance space exploration because our bodies have evolved in this very particular oxygen-rich environment and we stink at going out to outer space. The only downside is, of course, the delay. It takes X number of minutes to get a signal there and to get a signal back. It wouldn't be exactly like you're running around the surface of Mars. Instead, it'd be a very slow process.
Mason: Or we could become another body entirely. You talk about in the book Jaron Lanier's term 'homuncular flexibility' which sounds so odd and weird and wonderful, but that is because it is so odd and weird and wonderful. What he's talking about is embodying these new weird morphologies using virtual avatars to extend ourselves beyond the boundary of our skin and developing these profoundly new weirder morphologies of tentacle beings floating in cyberspace. There's so much possibility here, isn't there?
Eagleman: That's exactly right, and it all comes down to this very basic thing that the brain is trapped inside the skull. It doesn't know what your body looks like, it just figures out what it needs to do. This is why we can jump on pogo-sticks and onto hang gliders and onto any weird device. You just figure it out. Okay, that's how it works - and then you're off to the races.
Mason: I mean the word you avoid using in the book is 'cyborg'. You mention one or two examples of individuals who are cyborgs but hearing about all these developments and hearing about all the things that our brain can do, it just conjures for me this concept of the cyborg. It feels to me like neuroplasticity might actually be the key to interfacing, I guess, with advanced technology. When I use the word cyborg I don't mean terminator, but what I mean is profoundly embodied cyborgs. People like Neil Harbisson, for example.
Eagleman: Yeah that's exactly right. It depends what you mean by advanced technology, because the advanced technology is this three pounds of wetware in the skull. That's the advanced one. The other stuff we have is just clunky metal limbs and stuff. But yes, we can marry those two technologies together and that almost certainly is our future. The world a hundred years from now is going to be very different. The reason I wrote this book is because I feel like we are now on the cusp of a massive revolution that can happen in terms of our engineering and in terms of the way we build things. As I said, I've set up a company on the back of my lab to do this sensory bit. As far as the motor output bit, there's so much opportunity there and I feel like with Darwin and his theory of evolution, the idea was: hey, wow, DNA is really important - and that was a massive step. Now we know that DNA is only half of the story and the other half of the story is everything that happens to you, everything around you that you absorb from the world. That feels like that's the next step of where we're going now.
One of the things that I write about in the book that feels very important to me is when we send the Mars Rover, Spirit, up to Mars, that's a multi-billion dollar project. It landed on the surface of Mars, rolled around for a while, did a great job and then it got its right-front wheel stuck in the soil and it died. If you compare that to, let's say, a wolf, a wolf will get its leg caught in a trap and then it will chew its leg off and its brain will say, "Okay, how do I figure out how to operate a body with only three limbs? Okay cool, got it." Wouldn't it be great if we could be building robots that say, "Oh, my right-front wheel stuck in the martian soil. I'm going to chew my wheel off and then I'm going to figure out how to operate this - not in the way that I was pre-programmed - but I'm going to figure this out because I need to get somewhere." That's the kind of machinery that we will be building next.
Mason: That's what makes artists like Neil Harbisson - the colourblind artist who has an antenna that allows him to hear colour - that's what makes him so interesting. He's not thinking about the cyborg as something whereby we have to cram data and ones and zeros into the brain and avoid the bottleneck of the senses. He's actually embracing the senses or the sense organs, creating new sense organs and developing devices which eventually he sees as an organ. You go up to Neil and you try to touch his camera and he recoils as if I came up to you, David, and tried to touch your nose. These individuals doing these sorts of experiments become very profoundly embodied with the devices that they're wearing and the new organs that they're creating. Part of that comes from just duration - being with it and allowing the brain to eventually adopt it. In Neil's case, he now dreams these crazy, sonochromatic dreams when he's not even wearing the device. It just feels like this is the place we should be starting at.
Eagleman: Oh that's exactly right, and that's exactly what Neil's sensory is doing. For that reason - and by the way, I think the reason you would recoil with your eyes, your nose, your ears or something if I tried to touch it would be for exactly the same reason as you're saying which is that - but the thing I want to point out is that these are random, weird devices that Mother Nature has cooked out, but we have incorporated them into our sense of self. I have a section in the book, as you know, where I'm talking about what it means for something to be part of the self. It's something that you're getting data from or that you can control with your motor output. Anything that fits that becomes incorporated into your sense of: okay, that's part of me. Therefore I think when we launch robots in outer space and so on, it will really feel like me and so the robot you're controlling that's on the Moon - if someone comes up and kicks it or threatens it - you're going to feel that in a bodily way. You're going to recoil at that.
Mason: You're developing a company from this - this wonderful little quirk that we have about the human brain. So many people could start developing their own devices, if it's just purely about creating something that translates available data into some sort of waveform analogue information through a software process that then the body can understand. Potentially, anyone could design a bespoke sensoria. We could create bespoke synaesthesia and start designing our own sensoriums. Surely, that's a wonderful, egalitarian view of how we might all individually navigate the world.
Eagleman: Absolutely and there are biohackers all around us who are doing cool things like that. Just one example you know about is implanting magnets into your fingertips. People who do this can feel, for example, the electromagnetic bubble around a plug and adaptor. I know one guy who does debugging computer systems in this way. He feels that, oh wait, this part's off - but it's supposed to be on - but you can feel where there's electricity running through an electromagnetic bubble. I think you're right. People will increasingly be doing this and again, the reason I feel like we're on the cusp of an important moment is history is exactly because we're going to start doing this.
One of the things that I find fascinating - and this is part of the book - is that there's this issue that if you develop a new sense, and I develop a different new sense, we might not actually be able to communicate to each other what it is like. That's because of the fence line around our experience. What I mean by that is if I ask you to imagine a new colour - go ahead and imagine a new colour - it turns out it's impossible. You've got these firm boundaries around your experience and you say, "Actually, I can't think of a new one." It's the same thing if I ask you to imagine a new scent, something that's not hearing, or taste, or touch, or smell. You feel like I just can't even imagine something else. But no doubt, when we start feeding in data from the stock market or Twitter or the drone or whatever, you will develop a new sense. Not just a new capacity to detect and act on something but a quality; an internal experience. If you're doing one thing and I'm doing a different one, there's just no way for us to communicate that. For example, if you have a blind friend and you try to explain what vision is - that you capture photons from great distances and you're able to put together pictures - your blind friend might pretend that she knows what you're talking about but she won't. She cannot understand what vision is, just like a colourblind person can't understand what purpleness is, unless they've experienced it.
Mason: That's the wonderful thing about Neil Harbisson's sono-chromatic sound portraits. He creates these beautiful, colourful portraits and only Neil or only people wearing the device that he has - anyone who has an eyeborg - can truly experience that artwork in the way in which he's experiencing the artwork. Everybody else who isn't 'enhanced' or doesn't have sensory addition sees just a very colourful square. We're going to end up in this moment of possible subspeciation. We're going to have a multitude of differentiated bodies all sensing the world very differently. How do we co-exist if we ever got to that stage?
Eagleman: Yeah, I mean look, there's this sense in which people are all very different anyway because of their experiences and their political beliefs and so on - as we see on Twitter and Facebook and so on - and so this may just be the next step of that where people are often in a different direction in terms of their sensorium.
Mason: So we're going to go from identity politics to morphology politics. It's going to be a whole new swathe of differentiated ways of experiencing this world. Before we do go to YouTube questions, I want to ask you, David, about how this idea of sensory addition actually inspired an episode from HBO's Westworld.
Eagleman: So I'm a scientific advisor for that show and I said to them, "Look, we've got this great thing where you can feel any kind of data stream." I said, "What if the military contractors - who drop in in Season Two to deal with these bad robots - what if they were wearing this as a way of detecting the location of the robots. They could say, "Oh, there's one off to the left here, I'm feeling the vibration on my skin. There's one behind me about 500 yards away because I'm feeling the vibration on my skin."" If anyone happened to catch this on episode seven of season two, that's what happened. They drop in and they can feel where the robots are, and they can dispatch them accordingly.
That of course takes place 30 years in the future, but we've used that exact idea in my lab for blind people. People who are blind - they can feel the location of people around them. Oh, there's someone walking up from behind me and they're getting closer and closer. There's someone over here and they're getting farther away. They can have, in a sense, vision that is better than the rest of us. We only see at an angle in front of us but they can see 360, like a jedi. On top of that, we add in navigation direction, so for sending them to some particular office space or whatever. Then go forward, turn left here, go forward here. It turns out that exact idea that we use in Westworld, we're now using in real life with participants who are blind.
Mason: We have our first question from YouTube from Lesley Anne Daley who asks: what ethics need to be considered with things like sensory enhancement? I actually want to take that one step further and ask what happens when we start developing the next wave of sense altering technologies such as neural manipulations, nanoscale technologies and cognitive enhancers? What happens when they find their way into our hands and eventually into our heads? What sort of ethical questions will we need to start asking?
Eagleman: Yeah, great questions. There are a host of ethical things and one of the important things in science is to always make sure that we're not steaming ahead of our moral compass, but instead we're dealing with these questions. Just before we all got locked down I was part of a terrific small conference with the top ethicists and developers of technologies to really understand and wrestle with these questions. I'll tell you just very briefly. I think something like what I'm developing with feeding data streams in - that doesn't have too much in terms of ethical problems because in a sense, this is no different than wearing earpods and listening to a message or wearing glasses and watching your screen of a phone. It's just another way of getting data in, and so the same question would apply to: hey, should we not have phone screens or earpods? That's not too big a deal.
The bigger issues are when we start reading and writing from the brain. For example, with Elon Musk's Neuralink - which by the way, no one has to worry about that because that's just a clinical application. What I mean is that it's great technology but it's just going to be used clinically for probably our lifetimes. The mythology around Neuralink is that everyone will get one and then you can communicate with your cell phone faster. No way, because neurosurgeons aren't going to do it because there's risk of infection and death on the operating table and it's just simply not worth it for consumers to go in and have open head surgery so they don't have to use their thumbs. That category of thing is the bigger ethical question: how do we make absolutely certain that if people get that, there are no security concerns with them and there's no way to make it so the company or a hacker could get in there and actually change something about what's going on with your life.
As far as cognitive enhancers go, that's an interesting, tough one. We drink coffee and things like that which is a cognitive enhancer. People for decades smoked cigarettes and nicotine is a cognitive enhancer, and so on. It's not clear that we're going to be able to do anything about that as those get developed. People will use them if they want to. Yeah I think to my mind, the main one is the reading and writing to the brain. We have to be super careful that we know exactly what we're doing with those.
Mason: I do want to ask you about Neuralink because the announcement was made on Friday and there are a lot of promises being made by Elon Musk and equally Bryan Johnson from Braintree has a similar device, KernelCo, which we don't know a lot about yet. It feels like both of these individuals, what they want to do is create devices that jack into the brain. It feels like what you're proving with Neosensory is that you don't actually have to cut the hole in the head and drill in and jack onto the brain. In actual fact, the way through to the brain is through our pre-existing sense organs. How do you feel about these sorts of things being evangelised and advocated for?
Eagleman: Yeah, I'll tell you generally. What I'm developing in Neosensory is for feeding data streams into the brain. For a few hundred bucks and with this wristband, you can get much of what we're talking about done that way, and that's great. For anything very specific, you actually need to get into the brain. For example, if you want to help somebody with Parkinson's disease or depression that's not reacting to any other kind of medications or approaches, or epilepsy, you need to actually be able to get into the brain and deal with the brain that way. That's where that comes in. I think it's going to have lots of clinical applications.
By the way, what Elon's doing is - just for context - people have been putting electrodes into the brain and simultating cells and measuring from cells for 70 years now. He's just come up with a better way to do it to achieve a higher density and to make sure that you don't hit any blood vessels as you're essentially sewing these electrodes into the brain - and that also you don't have wires; it wirelessly transmits out. He's just making very wonderful improvements on this and it will clinically be very useful. That's sort of how that spectrum works. There are a lot of things you can get by just feeding new data externally, but for anything fine like needing to change the way the circuit behaves so that you don't have the symptoms of Parkinson's disease, that's where you need more detail.
Mason: We have another question from YouTube - this time from Ben Greenaway - who actually gave me the phrase plug and wait as opposed to plug and play for some of these devices. Ben asks: you spoke of where the neuroplasticity of a child ends and if that child lacked a 'good diet of sensory experience', it can negatively affect their adult life. Could things like sensory expansion actually cure that?
Eagleman: Very cool question. I don't know. I wouldn't say we have any evidence that we could do it yet because as far as we can tell, if you've missed the critical window to learn, for example, language - it's too late. There's no way to catch up on that, even if I stick whatever data in through the wrist. I think it is probably too late. There are lots of doors that close pretty rapidly in the brain as the visual cortex comes into shape, as the auditory cortex comes into the shape - you need the right input at that point.
Mason: There's another question from YouTube here from Lewis Johnson, who asks: is there a risk of a new breed of computer brain viruses if we start inputting new information into the brain? To me, it feels like there are so many media viruses out there that seem to get into our brains through things like Twitter or just social media. It's really nothing new, but I guess what they mean by that question is will people start hacking our brains directly through these new devices?
Eagleman: As I mention, this is maybe one of the key ethical questions. How do you make absolutely sure that this is not hackable? Now you're in the inner sanctum of the skull and you have to make absolutely certain that nobody can start manipulating your thoughts any better than they already do with politics and social media.
Mason: I saw an event in London I think almost 10 years ago - the prosthetic limb user Bertolt Meyer handed over his iPhone to a gentleman called Anders Sandberg who is a wonderful individual but he has this very Bond villain-esque way about him. He handed him his iPhone that was Bluetooth connected to his prosthetic device and allowed Anders to start randomly pressing buttons which started to control the limb. It was such a wonderful demonstration of what actually might be possible if we were able to hack at least the connection between the phones that we use and these external devices. Again, the thing that was being hacked was the Bluetooth - not the brain itself. I guess there still is a possibility here.
We have another question from Erris who asks: are there any things that you can do to 'train the brain'?
Eagleman: Yeah, I mean the main thing that the brain needs if you want to have good brain plasticity is novel challenges all the time. Most of us are getting that in various ways but for example, when people retire their lives tend to really shrink and they're no longer dealing with a hundred challenges all the time. It turns out you need that. There are these very great ongoing studies about taking people's brains at the time of their death and doing analysis to their brains. One of the things they discovered is some people have Alzheimer's disease but nobody knew it when they were alive because even though their brain was getting chewed up with Alzheimer's, they're constantly challenged and they're dealing with other people. They have chores and responsibilities and they're playing games and so they're building new bridges in there all of the time. They're constantly building these new bridges and so that means they don't have the cognitive deficits.
What I do - and what I think is the most important aspect for brain plasticity for everyone - is to constantly do things that are hard for you and new for you. Just one dumb example is that I always brush my teeth with my other hand or shave with my other hand. I always drive a different route home from work. I always dive into new software and learn how to do new things. During the pandemic, I know that a lot of us have sort of been forced off of our path of least resistance to learn completely new things. That is possibly the one silver lining to this whole lockdown. It's great for the brain despite the stress and anxiety that everyone's feeling about this. It's great that we're off of our hamster wheels and doing something totally new and rethinking everything that we thought we knew.
Mason: We've talked a lot about the role of brain plasticity on external limbs and new senses but what role does brain plasticity plan in things like memory?
Eagleman: Memory is the key example of brain plasticity. Everything that you can remember - who your parents are, where you grew up, what you did last week - all of these things are because of brain plasticity. You're actually writing them down into the structure of the circuitry. I actually think it's a shame that we call computer memory, memory, because what's going on in the brain is so different than what happens in a computer. Computers write things down as files and it's all these zeros and ones. The brain doesn't do a video recording or something. I can tell you a joke in English and if you speak another language, you can turn right around to someone and tell them that same joke in another language. You're not storing the sequence of phonemes - you're storing the gist of it; the concept of the joke.
One of the things we've discovered over the last 50 years is all the different aspects of memory in the brain. There's short term and there's long term, and in long term there's declarative memories - in other words things that you can declare like "This is what I did. This was a fact. This was an event." Then there's all the other non-declarative memories such as how I ride a bicycle. I can't tell you how I ride a bicycle, I just know how to do it. I have remembered how to do it.
All these different types of memory are underpinned by different strategies and structures in the brain and the brain has all these weird properties like - I'll just mention one - older memories are more stable than new memories in the brain. That's very weird. You don't find other things like that. In an institution or a company, you don't find that older memories are more stable. I don't know if anyone has ever seen somebody at the end of their lives on their deathbed, they'll often revert to their original language. They'll be speaking in their original language. They'll even have forgotten things that they learned in their teens, and they'll remember their childhood. This is because there are many parameters that can change in the brain.
One of the things I argue in the book is this new framework about daisy chaining timescales together. You have things that change rapidly and if they present enough evidence to the next layer down, those things say, "Oh, okay. I guess I'll change too." If those things present enough evidence to the next layer, those guys say, "Right, well I guess I'll change too." and so on. You have this working its way down into the circuitry and by the way this goes all the way down to the DNA in the sense of things that happen a lot that change your genetic expression. There's a whole field called epigenetics which is about how the whole confirmation of your genome changes so that some genes are expressing more and getting suppressed and so on.
Mason: When we talk about memory it raises some problematic and very interesting philosophical questions - especially about memory and this idea of consciousness. You're a possibilian so you've been so wonderful, especially in the last book 'Incognito', at being playful with some of the multitude of possibilities for where consciousness and memory might exist. The current consensus in neuroscience is that consciousness is an emergent property of the brain. This feels like it's fast becoming a dogmatic, entrenched position. That isn't the only theory of consciousness, is it? Where do you stand on the idea that consciousness might actually exist independently outside of the brain, and as a preexisting condition of the universe itself - much like dark matter or dark energy, or even gravity?
Eagleman: So that's a school of thought called panpsychism which is, as you said, maybe it's like a property of Adam's - like spin or something. Here's what I would say: we don't know. In 2020, everyone can speculate and argue and have philosophical debates but at the moment, we have to have a wide table to accept lots of hypotheses because we simply don't know the answer. What's funny is that a lot of people have strong opinions and get angry about one version of theories or another, but nobody knows.
What is clear is that you need the physical structure to have its integrity in order to experience consciousness, and when you put even small molecules into your body - whether alcohol or drugs, or whatever - that changes your consciousness. We understand a lot. For example, take psychedelic drugs - these are molecules that bind to particular receptors on neurons and they change the behaviour of the neurons in slight ways. That causes the whole network to behave say, five percent differently. Now, you're seeing silver leprechauns and having a completely different kind of experience. I interpret that actually as an illustration of how fragile consciousness is. It has to run just right for us to experience the kind of consciousness we're used to. You change it just a tweak and now you're having a very bizarre kind of thing. I've totally forgotten where we were going, what was the question?
Mason: Hang on, what I really wanted to ask is it feels like when we talk about this idea of memory, we go back to those computational metaphors and we think of the brain as storing memory. The brain again is this thing like a computer, in which the memories are stored within the organ; within the device. It could be that the brain is not this computational storage device. It could actually be more like an antenna. It could be more like a radio or a terrestrial TV. It might actually be tuning into consciousness that's somewhere out there - memories that are out there and not within the brain - which is why memory is so fickle; which is why we can sometimes share memories. I know you have such a wonderful radio metaphor to describe that possible way in which we can understand consciousness.
Eagleman: Yeah, cool. I mean let me say a couple of things about that. What is absolutely clear is that you need the integrity of the system to have normal memory consciousness - that's number one. Number two is let's separate memory from consciousness. Memory is an issue of what I can recall. Consciousness is the thing that flickers to life when I wake up in the morning. It's my internal, subjective experience. The general view of neuroscience - and I don't think this is so much dogma as just where we've sort of landed as a field - is little bits of damage, in particular spots, damage you in very particular ways. You get damage in one spot and you don't have consciousness anymore. You get damage in another spot and you cannot understand music anymore. You get damage in another spot and you cannot name animals anymore. You get damage in another spot and you cannot see colours anymore, and so on.
We know that the physical stuff maps onto what you're able to see. What I suggest at the end of 'Incognito' was something that I have to discuss carefully because it's not something that I'm suggesting is true. I'm simply saying it's something that still could be true, which is that although we know the physical structure is important, it could be that the brain is like a radio. I gave the analogy of if you were a primitive man and you found a radio in the sand and you'd never seen anything like this. You figured out how to take off the back of the radio and you saw these wires and you start realising that if you take out this wire it garbles the voices and if you take out that wire it stops the voices altogether. You might become a radio materialist where you say, "Alright, I've got it. If the wires are in this configuration then you get voices.", but what you didn't even realise is that there's this invisible electromagnetic radiation coming from a distant radio tower and that's actually where the voices are coming from. It would be the same situation where you need the integrity of all the circuitry to function fine, but it's not actually the origin of it.
I suggested this radio hypothesis just as a way of completing the picture of what is possible on this wide table of what we should be thinking about. As far as panpsychism goes, by the way, I think it's fair with all these theories to say we just don't know. The weird part about consciousness is that not only do we not have a theory to explain it, we don't even know what such a thing would look like. Because of the difficulty of what we're trying to explain as in I can say I've got these tools and mathematics, but at what point do I say, "Okay, that equals the smell of cinnamon or the taste of feta cheese, or the beauty of a sunset, or the redness of red, or the pain of a stubbed toe." This is one domain over here and experiences this other domain. It's not even clear how to bridge those.
Mason: Might it actually be the case that we'll never bridge it because of the limitations of knowledge in the human brain? I'm reminded of your story and some of the details from 'Sum: Forty Tales from the Afterlives', where you wake up on the slab surrounded by the aliens prodding you, going, "What is answer? What is answer?" but you're too evolved to explain it to them. I just wonder if we will just never get there, purely because we'll never be able to look at ourselves objectively because we'll always have this subjective thing called a brain which is filtering the information that we receive about the world.
Eagleman: Yeah, it's a good possibility. It's impossible to know, because every generation feels like: okay, here's what we know. It's impossible to think about the next step, but then a hundred years later, you look back. Just think about what our neuroscience textbooks will look like in 2120. When people look at the shit that we have now and they'll say, "God, how did you guys not know this?" For example, the main textbook in our field is called 'Principles of Neuroscience' and it's that thick - it's like 800 pages. That's not principles - if it were principles it'd be the size of a pamphlet. All we've done is we've dumped every piece of data in there. We don't know the principles yet. That was actually one of my big goals in writing 'Livewire' - it was to figure out what are the key things that we should be paying attention to here.
Mason: It does feel to me like Elon Musk is a radio materialist that is going to go with neuralink poking around the brain in the hope that he's going to eventually find memories so that can upload those into whatever uploaded consciousness that he and other transhumanists potentially want. I do wonder whether what he should actually be doing is developing a Wilhelm Reich-esque morphogenic field detector and that might actually have a way to discover where consciousness is...maybe. I tell you what, Peter Thiel should take up that. He could be the heretic who goes after the idea of trying to tune into collective consciousness. Elon can go after the idea of memory and consciousness existing in the brain and we can have a Frued vs. Reich style fight on our hands.
Eagleman: I think that's a great idea. I want to say that the idea of materialism is probably right. That's where I'd put my chips given that we don't know - maybe in a hundred years we'll think very differently about this - I think it's probably a good idea to rule that our first. To go after that, and only if you fail and say, "Wow, we've measured everything in the brain now at high resolution, every spike in the brain, and we're still stuck.", then we'll go to the next thing. But you have to solve that first thing first in order to rule out materialism.
Mason: Well that's the joy of being a self-styled possibilian. Perhaps you could quickly explain that to our audience who don't know. When I first came across that idea as an undergraduate I thought that was such a wonderful way with which to look at the world. To be open to a multitude of possibilities. We have good knowledge about certain ones but that doesn't mean that we won't have alternative knowledge later on down the road. Why do you think it's so important to stay open to a multitude of new ideas? To be a possibilian.
Eagleman: The thing that always strikes me as strange - and by the way you see this with everyone's political opinions on Twitter and Facebook and so on - what started this whole thing for me is that I would go to the bookstore and see the books by the religious fundamentalists, and the books by the neo-atheists. They were polarising each other and arguing, but the fact is there are so many more possibilities than there's a guy with a beard sitting on a cloud or there's nothing at all of interest in the cosmos besides that. There's this whole space of possibilities. We don't know what the heck's going on. That's why I coined this term possibilianism where the goal is to understand the structure of the possibility space so that we can drive our science forward and rule out parts of the possibility space, opening up folds that we didn't even realise were there in other parts of the possibility space.
My whole view on this is - and I think this is just an expression of the scientific mentality - if you know something for sure, then great. Most things, we don't actually know for sure. There's no point in fighting and dying and pretending that I absolutely know the answer to this, when you just don't. If you look at the history of science, in every generation people feel like we've got all the facts and so this should be the thing. But you can't even imagine understanding the Northern Lights before you understand the magnetosphere of the Earth or how muscles work before you have the concept of electricity. You didn't have the facts there and so you can argue until you're blue in the face but you just need to find the next step and that's what possibilianism is about.
Mason: It's always going to be this process. We have another couple of questions from YouTube, as always a fantastic question from Tracey Follows who asks: you talked about enhancements to individual brains, but how will the sensory expansions or data streams connect with each other in a collective consciousness or hive mind? How will these ideas help us to connect with each other better?
Eagleman: Very cool question. One of the things we've built in my lab is you can use a smartwatch to pick up on things like heart rate and galvanic skin response and other things like that. What we've done is use the API in the watch to feed that data to the wristband. It's not your own wristband - it's someone else's. Imagine, Tracey, that you and - say you have a husband - feel each other's physiology. You are across the nation and are feeling your husband's heartbeat and everything. You can think oh man, he's feeling really stressed. I'd better call up and see what's the matter with him. By the way, married couples may think this is the worst thing in the world. The key is: what is it like to be tapped into someone's body physiology? Even just an expression of it. This is our first foray into having a different kind of thing where you're not just experiencing your own body but you're experiencing other people's bodies and from there we can expand that. I love your question, Tracey, and check back in in a year to see where we've got with this.
Mason: We have another question from YouTube and it's from Anne McQueen who asks: insulin regulation and blood sugar impact on long term brain health. Is there any benefit to a ketogenic diet and low carb approach to maximise long term brain health and/or dementia prevention? Really it's a question about is there anything we can do in terms of our diet or in terms of our health that will improve our possibility for things like neuroplasticity?
Eagleman: That's a great question and people have been studying this. It turns out - I didn't realise this until a few years ago - these studies in nutrition and what you eat and so on are extraordinarily hard to pull off well, because people lie on these things. When nutritionists are running these studies, they run a thousand people and they say, "Yeah, I didn't eat any high carb things." but in fact they just scoffed the chocolate cake in the fridge and they just don't want to admit it. It's difficult to know and it's certainly difficult to know how that plays out 50 years later in terms of dementia. I don't know.
The reason I smiled when I first started hearing the question is because one of the things we're doing, by the way, is hooking the Neosensory Buzz to a continuous glucose monitor for people with diabetes so that they can just have an awareness of where their blood sugar is without having to check their phone and look at the graph through time and so on. You just have a sense of: oh, okay, it's going down. It's no problem yet but it's on the way down. Now it's getting worse so now I'd better find food. You're getting all of these signals to tell you that continuously, in a way that you don't have to pay attention to but you're aware of that at all times. I think this is going to be really useful as an immediate step to help people with their blood glucose.
Mason: We've got another question from YouTube - this time about AI - which is from Omar who asks: is it possible to generate a really creative AI without a plasticity like structure of the brain? I guess to add onto that question, do you think we're actually going to learn from brain plasticity and how we create future machines, future AI, future robots? Right now, AI seems very fixed. It doesn't have that plasticity. It doesn't have the ability to self-configure or to livewire. Do you think all of these things will eventually inform the way in which we design machines or even architecture in the future?
Eagleman: This is exactly my hope - that this book will launch a whole new era of the way we think about designing machines. I will say that the way machine learning and AI work currently is a form of plasticity, which is to say you've got this giant network with lots of units and connections and depending on the data coming in, it's changing the strength of these connections all around. It's exactly something that took inspiration from the brain but then went off in its very simplified direction. What's happening in AI is amazing stuff, but it is sort of like a simplified cartoon of the brain. You can get really good things. What you can't get right now is artificial generalised intelligence, where it's good at many things and doesn't fail catastrophically if you change the game on it a little bit. I just want to clarify that it is using the very basic things that we've figured out about plasticity some decades ago which is that neurons change the strength of their connection.
One of the arguments that I make in the book is the connection strength between neurons is only a tiny bit of what's going on. What you have are changes in not only the synaptic strength but the receptor distribution, the biochemical cascades inside the cells - as I mentioned - all the way down to the nucleus with the expression of genes. You've got lots of plastic parameters and current machine learning only uses a tiny sliver of that. We're learning a lot from it and I think AI and neuroscience are in an interesting dance, learning from one another as we go along.
Mason: We've got a great question from Sarah Atika who asks about representation in the field of neuroscience. She asks: what are the ethical implications of entrepreneurs and researchers developing novel models of sensory communication when they tend to represent a demographic unrepresentative of the population as a whole? I guess really it's a question about the diversity of people - not just neurodiversity but the diversity of thought and diversity of individuals within the neuroscience field.
Eagleman: I mean, look. Everybody's interested in getting more diversity and a diversity of ideas as a result of that. That's something as you may know Silicon Valley is an extremely liberal place and so everybody's trying their hardest to make sure that they have their funnel for applications for employment as wide as possible so that that can be achieved. That said, I think that science can be actually independent of that. When Newton discovered f = ma, or d= 180 squared, it doesn't matter that he's a white male. It's just a true piece of the universe that anybody can then use. What's lovely about science is that it doesn't actually have to traffic in this issue of the politics of: was that a black man who discovered that or a white man? It doesn't matter. It's a true piece of the universe that has been discovered.
Our job is, as members of society, to make sure that we've got a wide funnel and to try to get everyone participating in this. The good news is that I think the most important step that's ever been taken in this direction is the advent of the internet. It means that knowledge is available to everybody - any kid, any boy or girl, any ethnicity - anyone in the world can access all of the world's knowledge and springboard from there.
Mason: For anyone who's listening to this podcast or watching online now and they hear about this idea of livewiring and they want to explore it personally themselves, how can they go about leveraging the neuroplasticity of our brain today? What do you think they might be able to do in the near future to explore previously invisible aspects of reality?
Eagleman: I'd say a couple of things. One is that what we've done with the Neosensory Buzz is that we have an open API. We have SDKs for Android, iOS and other computer languages. What we encourage people to do is try feeding in any data stream that they're interested in. we actually just ran a developer contest that's still in the middle now but have eight semi-finalists who are all doing extraordinarily cool projects where they're feeding data into Buzz. If anyone's interested, if you go to neosensory.com and scroll all the way to the bottom where it says 'for developers' - click on that and you can find out exactly how to do that. All the SDKs are free, of course. That's a way that people can do it. The second of course is by buying the book and reading the experiments there. The third thing I'll just mention: there's a new company here called Silicon Valley called Luminary Cafe - it's luminary.cafe - and they just launched last week. I am proud to be the first luminary on the site because they're just getting rolling. They did this in time for my book. What I've done is filmed a series of lectures with videos and colour and incredible ways of experiencing the stuff that goes beyond the pages of the book. If anyone's interested, go to luminary.cafe and you can actually watch the videos and take a deeper dive that way.
Mason: So I guess there you have it. It's time to use the body and the brain as a platform for a multitude of possibilities of sensoriums and of experiences. David Eagleman, I just want to say this has been an absolute pleasure. Thank you for joining us today.
Eagleman: Great to see you again, Luke.
Mason: Thank you to David for sharing his unique perspective on how humanity might use neuroplasticity to its advantage. You can find out more by purchasing his new book, 'Livewired: The Inside Story of the Ever-Changing Brain', available now.
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Credits
Produced by FUTURES Podcast
Recorded, Mixed & Edited by Luke Robert Mason
Transcript by Beth Colquhoun
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