The Hidden Science Behind Brain-Computer Interfaces — With Sally Adee

0:00Let's talk about the promise and the danger of brain-computer interfaces and how harnessing electricity in our body may change everything about the way we live. That conversation with an award-winning science journalist is coming up right after this. Welcome to Big Technology Podcast, a show for cool-headed, nuanced conversation of the tech world and beyond. We're joined today by science journalist Sally Adi, author of the great book, We Are Electric, Inside the 200-Year Hunt for Our Body's Bioelectric Code and What the Future Holds. We're going to talk about brain-computer interfaces and all the crazy things electricity does in our body.

0:36I'm excited for this one. Sally, welcome to the show. Thank you so much for having me, Alex. It's nice to be here. Great to be here. It's always fun to speak with authors of books who I've read in depth, and I read yours in depth while I was preparing to speak with Nolan Arbaugh, the first Neuralink patient, just trying to figure out how is this guy actually able to control a computer with his brain? It seems to me like that would be physically impossible. But actually, as I went into your book and read it for prep for that interview, I realized that the role of electricity in the body is crazy.

1:07It can do everything from help us potentially regenerate limbs. It can, you know, potentially be a solution to cancer. I might be overbilling it. But it does unbelievable things. And I just thought when I finished the book, I had to get you on the show to talk to you about all this and bring this story to our readers because it turns out, or our listeners really, because it turns out the brain-computer interface within Nolan Arbaugh's brain is just the tip of the iceberg, so to speak. So let me ask you just a broad question to begin with. I mean, I am kind of stunned as a novice to this, that electricity plays a big role in the body.

1:45I was like, you have the sort of the bio side of things, and then you have the digital side of things. The digital is electricity. The bio is like flesh and blood. But actually, it turns out electricity plays a very big role in the body. everything from helping us communicate to basically channeling our physiology in ways. So can you talk just on a high level about the role of electricity in the body? Yeah, of course. So the reason that we're able to have brain-computer interfaces is because we're able to listen to the electrical activity of the brain and the nervous system. And the reason that we can do that is because every single thought you have And every sensation you have, whether it's sight or touch or hearing, this is the result of electrical impulses either coming up your nervous system to impart information about the external world to your brain or your brain driving impulses to actuate your limbs.

2:50you know if you want to scratch an itch if you want to have a cup of water you're thirsty whether you know that you're thirsty to begin with it's all based on an electrochemical impulse called the action potential and we've known about this since the 1850s or so and this is driven forward by something that happens with the cell membrane so cell membranes the thing that surrounds the cell at its outside. It's about minus 70 millivolts, more negative than the outside environment. And when a message is passed from one neuron to the next or from one neuron to the muscle, it depolarizes. That means that its electrical activity or its electrical state goes to zero.

3:44And this switch, the switching action between minus 70, which is its sort of resting potential, that means it's happy place, basically. And this zero, it's this quite violent electrical event from the perspective of the cell. And this is what drives muscle activity and nerve activity at a speed that, for example, you can yank your hand away from a hot stove before you've even registered that you've touched it. It's really important in giving us more or less real time information about the world around us and an ability to act on it. So when we move, that's electricity. When we feel things, that's effectively electricity conveying the message.

4:25And that's sort of, when I was reading your book, it all made sense to me about Noland and brain computer interfaces, being able to take these electrical signals and translate it to something on the computer because effectively, tell me if I have this right, the spine is the conduit from those electrical signals in your brain to your limbs. If the sign severs, then those electrical signals can't get to the limbs, but you can read them with an electrical device and that can then show up on your computer? Absolutely. So what they do is there's many ways to read the summed electrical activity of the brain or single neurons.

5:11So we have about 86 billion neurons in the brain. If you just put like an EEG cap on, if you, you know, these sensors, you can read all of them. And so you've got this sort of shouting match. Let's it's a lot of neuroscientists have told me that it's basically like if you were going to dangle a mic over a stadium during the middle of a football game, you can kind of get a sense of like, oh, somebody scored. You don't know who scored. You don't know like individual conversations. But if you can drill into the brain and place an electrode array into the brain, like on the motor cortex, for example, then you can zero in on a very much smaller group of neurons.

5:52And if you can get a good amount of neurons in that area that are talking to each other, then you're able to sort of deduce, like, what does that person want to do? So some of the most amazing work in this field right now is at Stanford, they've got people putting these little electrode arrays into the sort of speech and language area. So they're able to actually pick up speech from people who have lost the ability to speak. I think it's going at an incredible rate now. They're able to decode intended speech at a rate of something like 65 words a minute, I want to say. I might have gotten that slightly wrong, or maybe outdated already because it's moving so fast, but it's absolutely amazing.

6:37And then, of course, with people like the predecessors to Neuralink, the BrainGate people, they had these little pin cushion looking things that had about 96 to 196 electrodes. They were put in the motor cortex, where they pick up your intent to move. And then with the assistance of that, when they pick up those electrical signals, they can decode them using signal processing algorithms and then use those to drive robot arms, for example. There was a woman called Jan Scheuerman who was able to feed herself pieces of chocolate. She, of course, sorry, I didn't mention she had lost the use of her arms and legs.

7:18And she was able to use a robot arm to feed herself a piece of chocolate, move it around. She had it in many different dimensions. So that's what you can do when you can decode the electrical activity of the brain. Nolan, what was amazing when I visited him was that I saw him basically able to think about moving his hand in some way and the cursor moved. And he had another thought that he could use that would have the cursor click. we played a video game and he beat me at the video game, which wasn't an easy one. It was sort of like you direct a tank to shoot something and it shoots. And he's also paraplegic.

7:56And this Neuralink is, they've put 64 electrode threads into his brain with a thousand plus total electrodes because there's multiple electrodes there and they're able to decode his thoughts. And to me, I was just like, I've seen four technological miracles in my life. One, I think was the iPhone, just the advance that the iPhone made. The second was ChatGPT. The third was driving in a Waymo car, which, you know, with no driver at all in there. And then the fourth. I haven't been in one of those. Was it great? Unbelievable. Yeah. We talked about a lot on the show. It's pretty special. And I think it's just going to explode.

8:32And then the fourth was just watching Nolan control this computer. Just look at it. And his intent was being displayed on, you know, basically moving through a computer screen. And you talked about something interesting. It's moving so fast. And that's something that I came away with when I started doing some research into this as well, just that it is moving at an incredibly fast pace. And so Sally, I just want to put the question to you. Can you contextualize the speed that this is moving? Because bioelectricity is a multi-century study effectively? And why is it moving as fast as it is right now?

9:09Well, I think, first of all, there's the money thing there. The funding right now from various groups, government, university, private startups and things is enormous right now. Every time you look at one of these, you know, forecasting reports from people like Forrester, you see that the number has jumped another, you know, a couple of billion dollars of, of mark, you know, what the market is going to bear. Miniaturization of technology, of course, it has a big, I'm sorry, of chips has a lot to do with it. But generally, you know, this technology is, they spent about 20 years using the same type of implant it's called a Utah array it looks like a little pin cushion for a ladybird basically it's got it's tiny it's got 96 silicon electrodes that jut out of it 96 is a lot to jam into your skull I mean into your cortex but it is not it has its limitations because the more neurons you listen to, the more you can do.

10:26The more signal you can acquire, the more you can... Obviously, what you saw Nolan Arbaud do is incredible, and that is not the sort of thing you could have done with a Utah array. Having this new N1, this telepathy implant, It has given a volunteer something like 10 times the more than 10 times the amount of electrodes listening in. However, the technology is moving forward. What I'm a little bit worried about is that the legal, ethical, and sort of other infrastructure around it is not moving as fast, which is kind of funny because the four great miracles that you describe have had the same exact problem, which is that you've got this like fast moving, amazing technology.

11:22And like five years later, sort of legislators look up from their nap. No, sorry, that's rude. But I mean, they just, sorry, I don't mean to sound like grumpy about it, but I think that these things don't exist in a vacuum. They exist in human beings. And for example, one thing that I worry about is that with your smartphone, like let's say you got like a cool new smartphone that's made by some startup that has just like blown everybody away. and then two years later, the smartphone company dies off. You stop getting software updates. You stop being able to sort of send the phone somewhere for repairs.

12:11You don't really care that much. You know, you're maybe a little bit pissed off about it and you put it in your drawer and you get mad and you get a new smartphone. That looks really different when it's a brain implant. And I think this is a really live issue right now with brain implants. the ethics of how to deal with such a new technology that probably isn't in its, well, that certainly isn't in its final phase. It looks mature technologically, but in terms of what's required to support it, it's not. It's intense. Yeah, definitely. And I definitely have some more of these ethical questions to ask you in the second half, including the length at which these devices are able to remain in the brain.

12:54So let's put a pin in that. We're going to come back after the break and talk about that a bit more. I just want to, again, hit back on this velocity question. This stuff is moving fast. I mean, could you see it? Are we on pace? And I know it's tough to predict scientific progress, but are we on pace for a vast amount of new capabilities attaching the brain to computers to show up? I mean, so my sort of the, I guess the area of brain computer interfaces that I've been looking at most deeply is stuff like deep brain stimulation, which is a device that's right, that was until recently right only, basically, where you stimulate like a very deep part of the brain for people who have Parkinson's disease, which is a neurodegenerative disorder that is, its symptoms are incredibly cruel.

13:48You know, people will, you know, be unable to have a cup of tea because their hand is shaking so much. And, you know, for the past 20-ish years, you've been able to put an electrical device into the head that shuts that down immediately and people have control over themselves. The other thing that is, and they've actually started applying this for epilepsy as well, for depression. There's another entire group of brain implants that works with helping people. So you know how I was talking about Jan Sherman operating a robot arm? Well, there's a researcher, among many, there's several people working on this.

14:29There's one guy called Chad Boughton at the Feinstein Institute in New York. And he's been working on a way to instead of having like picking up people's intent to move their limbs and applying it to a robot arm, basically putting an electrode cuff around your arms and legs and be able to actually move your own arm as if it were a robot arm. So at your own will, which is incredible. um what's even more wild is that you know you can put um a utah array into the sensory um aspect um like a sensory area of your brain that maps to specific fingers you know sort of the feeling of sheer force the feeling of pressure and they've been able to work they've been able to actually take a robot arm and prick it on its fingers and the person perceives the sensation Yeah, as if it was their own.

15:24It is amazing. And, you know, there's people in Lausanne who've been able to use a brain implant attached to neurostimulating, sort of, they stimulate the leg muscles. So the guy who did not have the ability to walk is now walking again. that it is moving at such an unbelievable rate because there's so much buy-in right now and there's so much technological advance. Like now we have insights that are able to leapfrog, you know, other insights and everything is speeding up very quickly and it is incredible. Material security is transforming how companies protect their most critical cloud assets like Google Workspace and Microsoft 365 with modern purpose-built security that actually works the way people do.

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16:53Learn more and see how it works at Material. Okay, I am inspired and I'm pretty pumped as to where this is going to go. Let's just to, you know, as long as we're dreaming and thinking about the future, let's just do two more quick things on brain computer interfaces. And then I want to move on to talk about how bioelectricity could be used for things like limb regeneration, which is, I think the craziest side of this technology, but on the brain computer interface. And I think you just alluded to it, you know, with Noland and with Neuralink and with those type of companies, it's all about reading the signals from the brain.

17:26And I'm curious, like, what do you think about being able to write signals into the brain? I mean, of course there's the ability to like, you just spoke about to write sensation into the brain. But what about other stuff? I mean, there's a whole area of discussion about, could you write pleasure into the brain? Could you write a drug trip into the brain? Could you control people with the brain? I'm not saying we should pursue that, but I'm curious if that's possible. Well, so let's go back to sort of the basics. Well, basics. I mean, this is all like incredibly sci-fi stuff that didn't even exist when I was little but like um you know so what we're doing what is possible right now is to write sensory information so that a person can perceive um touch again even from a limb that has been neurologically severed from the brain so that is called i think a neural bypass that they're trying to work on um i think neural link is actually working on um restoring sight so that's another sensory aspect.

18:31That was my second question. Yeah, so they've got that blindsight thing. Sorry. No, let's talk about it. I mean, yeah, let's just go, let's do it right now. So blindsight, that's amazing, right? It's that they're trying to write signals into the visual cortex so the blind can see, even if you don't have eyes. Yeah. So there have been several versions of this in the past. I don't know if this is going to work out any better than the previous ones. I think they've just gotten the person. I haven't really kept up with exactly what the timeline is, but I know that they are giving that another crack.

19:08I think what they've done in the past has been quite... I'm trying to think... Imagine a 1950s computer with just bars on it. So as a part... Very sort of elementary shapes that are very pixelated. that would be the experience of what people saw when neural interfaces tried to, you know, reoccasion sight, basically. It's way better than nothing, but I think all the risk and versus reward stuff is very much up in the air with that. Saying that it restores sight is a little bit of oversimplification. So I don't know what blindsight is going to be like with more electrodes. We're going to have to see.

20:05But that is... If I was blind and I would see like a pixelated version of the world, I'd be pretty pumped. But not... It's even more rudimentary than that. I think people report seeing sort of... Blocks. Stults. I hate to say that word. I don't know what else to say. It's very basic. Obviously, I would also be very pumped because that means you can walk around in the world and not trip over obstacles. And it is a big deal, but for some reason, they haven't been able to make it really work. And blindsight might. We'll see. Okay. And then the other sensations. um well cochlear implants you know for hearing those are very mature what about there was this study about they i'm sure i think this might be from your book that they gave these rats uh this electrode in their brain and if and they could sort of hit a lever that would send a uh a signal to the brain for pleasure and then they just they just spent all day long uh hitting that lever and not really doing anything else.

21:19Yeah. So they did that to a guy too. That was, uh, yeah, it's, it's one of the, it's one of the experiments that, um, put, um, brain, uh, computer interfaces in the bad books for a long time. I think this was in the sixties or the seventies. And the guy do, well, so here's the problem. Uh, sorry, I've forgotten the name of either, but basically the doctor this was uh in the south in the u.s um in the like 1960s where like being gay was just like a real liability at the time so that so uh it you know it was uh it could get you fired from any job and like so this guy he was gay and he was like please i need i need some way to make myself not gay anymore and this quite unethical well we say today quite unethical doctor he said sure, I'll give you a brain implant.

22:12And so what he did is he put an electrode, kind of like a deep brain stimulating electrode into the guy's sort of pleasure producing area of the brain. And then he, sorry, this is not really for family listeners, but he showed him lots of porn that was, you know, heterosexual. And then he would just turn on the pleasure thing every time the person was watching heterosexual pornography. And then he even procured a prostitute. So he was trying to do almost like a, you know, like a behaviorist kind of thing where you just like have the rat in the cage and you're trying to change its behavior by giving it reward, reward, reward.

22:55It did not end up working. You know, this person did not end up changing their sexual orientation for reasons I think most of us are pretty familiar with. This is so disturbing. And also So totally when you said it gave the field a bad name, I understand why. Yeah, it was things didn't. Yeah, the scientist was run out of town. So that's. Yeah, but and it showed that this can work. So I'm wondering, do you think there's this is going to happen again now that brain computer interfaces are becoming more ubiquitous and safer? I mean, obviously, in different use cases. Like, I guess that what I'm getting at is, do you think we're just going to install these electrodes in our head and like future people who are sort of having a rough go at it will just be able to hit that pleasure button and have that shock sent there?

23:41So this is definitely above my pay grade because it requires philosophy. Yeah, this is also totally speculative. I'll speculate. I think it's definitely going to happen. Well, okay, so I'm going to push back a little bit based on a very tiny amount of knowledge that I have about something called habituation, which is number one habituation, which is where like, if you get used to something too much, then it stops really working for you. So it's possible that zapping this thing over and over and over again will lead to numbness. um the other issue uh that i am just i apologize but i'm gonna keep just like coming back to this is that you know how long is an implant like that gonna last in your brain if you keep jamming on the sort of pleasure button because you know these things we haven't come up with one yet that we know of that is gonna last more than a couple of years so okay i think i think yeah maybe but then you're going to have to get brain surgery to get it replaced.

24:43Okay, I'm not going to be the early adopter on that. But no, me neither. All right. So so the world of BCI is fascinating. I again, like I read your book in preparation for my conversation with Nolan, the neural link patient. And I think just to push it home, it is incredible the amount of progress that we're seeing. It's moving fast, it's gonna do it's gonna potentially do things, it's already doing things like writing as opposed to just reading brain signals. And to me, this is just an area that's going to continue to explode in the tech and the science world. And as it does, there's probably going to be more interest in some of the other use cases and some of the, I think, wilder use cases that you explored in your book, which again, if electricity is the thing that sends the signals to everything in the body, tells our body what to do, can you manipulate those signals and do things like change the cancer development or help regrow a limb.

25:44So let's talk first about limb regeneration and how electricity has been used in some animals to regenerate limbs in areas that we thought previously that would not that would be physically impossible to do. Yeah, absolutely. There have been a few studies now that show that suggest that changing the sort of electrical properties of the cells right after an amputation in this is this is not in humans. Obviously, this is this was done in tadpoles and frogs that you could regrow a severed limb in an animal that does not regenerate or that is at a stage where it doesn't regenerate. rate. So they were able to regrow a frog's leg.

26:32The regrown leg didn't look perfect, but it was functional. So the frog could sort of swim around. The feet looked a little messed up, but it was just by putting electricity on it. It wasn't by putting electricity on it. It was by changing the electrical properties of the membrane voltage of the cells. So would you mind if I back up a little bit to sort of explain how that works? Yeah, please do. You know how I was saying before the action potentials. The reason that information is passed between nerves or between nerves and muscle, the way that it works electrically is that there's like a bit of a switch from, you know, the cells, the nerve cells themselves being minus 70 degree, minus 70 millivoltz, really?

27:19Sorry. There's a switch between the nerve cell being minus 70 millivolts at its membrane, and then switching really fast to zero, being completely depolarized. So it's like an electrical switch. You get a negative charge to nothing, negative charge to nothing. That is an action potential. And so for a really long time, people thought, well, Well, that only exists in the nervous system, like all the other cells. They don't have any use for electricity. Like they don't have any signals to send. So they're probably not electric. But that's not true. Every other cell in your body actually has its own membrane voltage.

27:59So nerves are minus 70. Skin cells are like minus 70, more 65. Musculoskeletal tissue is minus 90. Fat cells are minus 50. Liver cells are minus 40. newly fertilized egg is zero. And that may sound just like a bunch of numbers that I'm rattling off. But if you notice, when you look at like, you know, the sort of high numbers or low numbers, but an absolute value high numbers, 90, 70, 50, those are cells that have already like achieved their electrical identity. Whereas around zero are the cells that are still in the process of becoming other things. They are, they're depolarized and they just, they haven't become anything yet.

28:46Stem cells and, you know, newly fertilized eggs. And so the reason that this is important is that as cells develop, you know, as like a developing embryo develops, as its cells join sort of particular groups like muscle, fat, whatever, nerve, with that change in identity comes a perfectly correlated change in electrical identity as well. And so you can actually see this electrical change in, there's an amazing experiment where this scientist called Danny Adams, she showed in developing frog embryos. You know, they're just a ball. They're just like a smooth ball, you know, still basically just embryonic.

29:37But then as, you know, it's basically all the cells are dividing and the thing is growing and growing. And right before actual features develop, there's this electrical pre-pattern that flashes across its face. And it's basically eyes, eyes, nose, mouth. But it's still like a smooth, there's no features. It's just this like electrical ghost, right? And then a few hours after that ghost sort of flashes, that's exactly where all the features develop. And the suggestion is that this is how we all develop. We have to have these electrical blueprints that tell the body how we're going to form. And so, of course, like a good scientist, she did like a loss of function study, which means that she was like, all right, well, what if I mess with the ability for this thing to have the electrical pre-pattern?

30:22And the result was like horrific, like birth defects on the, you know, tadpoles, like everything was in the wrong place. She called them Picasso tadpoles. And then when she reinstantiated the ability to make the flashing pre-pattern, they were able to have, you know, sort of typical faces again. Anyway, the reason that I'm saying this is because when you lose a limb, you have an electrical response in those cells that is very different from the electrical response that exists in animals that are able to regenerate full limbs like starfish, like salamanders. And so what they're looking into is, can we or should we try to figure out how to reinstantiate that developmental bioelectricity that we had, like as we were developing all of our features?

31:21Can we basically get the body to just make us a new one, like make this whatever part of you that has been amputated, just think that it's developing in the womb and so that it just grows itself a new one? So instead of, you know, sort of putting all these pieces back together, regrow something the way that you would in the womb. Does that make sense? Definitely. And that's definitely something that I would sign up for. I mean, I should fingers crossed that I get to keep all of them. But if I do lose them, I would be running to any scientist experimenting on this. Yeah, Michael Levin. Yeah, Michael Levin, who is one of the people who does the most work in this.