Speaker 1- Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health, and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. And now for my discussion with Dr. Matthew MacDougall. Dr. MacDougall, welcome. - Good to be here. - Just to kick things off, as a neurosurgeon and as a neuroscientist, could you share with us your vision of the brain as an organ as it relates to what's possible there? Surgeons tend to view the world a little bit differently than most because they like to fix and they like to mend, and in your case, have the potential to add things into the brain that don't exist there already. So how do you think about and conceptualize the brain as an organ? And what do you think is really possible with the brain that most of us don't already probably think about? -
Speaker 2The brain really is a collection of functional modules pinned together, duct taped together in this bone box attached to your head. And sometimes you see very interesting failure modes. So one of the most memorable patients I ever had was very early on in my training. I was down at UC San Diego and saw a very young guy who had just been in a car accident. We had operated on him. And, you know, as is so often the case, in neurosurgery, we had saved his life, potentially at the cost of quality of life. When he woke from surgery with bilateral frontal lobe damage, he had essentially no impulse control left. And so we were called back by his, you know, 80-year-old recovery room nurse saying, "You've got to come see your patient right away. Something's wrong." And we walked in to see him and he points at his elderly nurse and says, "She won't have "sex with me." And, you know, it was apparent at that moment his frontal lobes were gone and that person is never going to have reasonable human behavior again. It's one of the most tragic ways to have a brain malfunction. But, you know, anything a brain does, anything from control of hormone levels in your body to vision, to sensation, to, you know, the most obvious thing, which is muscle movement of any kind, from eye movement to moving your bicep, all that comes out of the brain. All of it can go wrong, any part of it or all of it. So, yeah, working with the brain is the substance of the brain as a surgeon, very high stakes. But once in a while, you get a chance to really help. You get a chance to fix something that seems unfixable. And you have, you know, Lazarus-like miracles, not too uncommonly. So it's extremely satisfying as a career. -
Speaker 1Can you share with us one of the more satisfying experiences or what qualifies as satisfying in neurosurgery? -
Speaker 2Yeah, you know, one of the relatively newer techniques that we do is, you know, if someone comes in with a reasonably small tumor somewhere deep in the brain that's hard to get to, the traditional approach to taking that out would involve cutting through a lot of good normal brain and disrupting a lot of neurons, a lot of white matter that, you know, kind of the wires connecting neurons. The modern approach involves a two millimeter drill hole in the skull down which you can pass a little fiber optic cannula and attach it to a laser and just heat the tumor up deep inside the brain under direct MRI visualization in real time. So you're, this person is in the MRI scanner. You're taking pictures every second or so. As the tumor heats up, you can monitor the temperature and get it exactly where you want it, where it's going to kill all those tumor cells but not hurt hardly any of the brain surrounding it. And so not uncommonly nowadays, we have someone come in with a tumor that previously would have been catastrophic to operate on and we can eliminate that tumor with, you know, leaving a poke hole in their skin. Even in cases that previously would have considered totally inoperable, say a tumor in the brain stem or a tumor in a primary motor cortex or a primary verbal areas, Broca's area, where we would have expected to either not operate or do catastrophic damage. Those people sometimes now are coming out unscathed.
Speaker 1In your role at Neuralink and as a neurosurgeon in other clinical settings, surely you are using machines. It's, I think, a very exciting time in which engineers are starting to toss up big problems and go for it. And obviously, Elon is certainly among the best, if not the best, in terms of going really big to the extent that you are allowed. Could you share with us what the missions at Neuralink are and what the general scope of missions are? And then if possible, share with us some of the more specific goals. I can imagine basic goals of trying to understand the brain and augment the brain. I could imagine clinical goals of trying to repair things in humans that are suffering in some way.
Speaker 2Neuralink and I think Tesla and SpaceX before it end up being these blank canvases that people project their hopes and fears onto. And so we experience a lot of upside in this. People assume that we have superpowers in our ability to alter the way brains work. And people have terrifying fears of the horrible things we're going to do. Those extremes are not true. We are making a neural implant. We have a robotic insertion device that helps place tiny electrodes the size smaller than the size of a human hair all throughout a small region of the brain. In the first indication that we're aiming at, we are hoping to implant a series of these electrodes into the brains of people that have had a bad spinal cord injury. So people that are essentially quadriplegic. They have perfect brains, but they can't use them to move their body. They can't move their arms or legs. And so this pristine motor cortex up in their brain is completely capable of operating a human body. It's just not wired properly any longer to a human's arms or legs. And so our goal is to place this implant into a motor cortex and have that person be able to then control a computer. So a mouse and a keyboard, as if they had their hands on a mouse and a keyboard, even though they aren't moving their hands. Their motor intentions are coming directly out of the brain into-- into the device. And so they're able to regain their digital freedom and connect with the world through the internet. Why use robotics to insert these chips? These electrodes are so tiny and the blood vessels on the surface of the brain so numerous and so densely packed that a human physically can't do this. A human hand is not steady enough to grab this couple micron width loop at the end of our electrode thread and place it accurate. And so we have to be able to do this accurately, blindly, by the way, into the cortical surface accurately enough at the right depth to get through all the cortical layers that we want to reach. I would love if human surgeons were essential to this process. But very soon, humans run out of motor skills sufficient to do this job. And so we are required, in this case, to lean on robots to do this incredibly fast, incredibly numerous placement of electrodes into the right area of the brain.
Speaker 1I'd like to take a quick break and acknowledge our sponsor, BetterHelp. BetterHelp offers professional therapy with a licensed therapist carried out entirely online. Every time I do a therapy session, I come away feeling better and knowing that the time was well spent. And that's because whenever I finish a therapy session, I come away with a valuable insight or new perspective on something I'm working through. Whether that's with work, with relationships in my personal life, or with my relationship to myself. I've just consistently found that there's so much benefit that comes through effective therapy. With BetterHelp, they make it extremely easy to find an expert therapist who can help provide the benefits that come through effective therapy. They have a short questionnaire that helps match you to a therapist. And while BetterHelp has an industry-leading match rate, if you aren't happy with your match, you can switch to a different therapist at any time. And the data say it works. BetterHelp has an average rating of 4.9 out of 5 for its live sessions based on over 1.7 million client reviews. Also, because BetterHelp is done entirely online, it's extremely time efficient. There's no driving to a therapist's office, looking for parking, etc. If you would like to try BetterHelp, go to betterhelp.com/huberman to get 10% off your first month. Again, that's betterhelp.com/huberman. So in some ways, Neuralink is pioneering the development of robotic surgeons as much as it's pioneering the exploration and augmentation and treatment of human brain conditions.
Speaker 2Right. And as the device exists currently, as we're submitting it to the FDA, it is only for the placement of the electrodes, the robot's part of the surgery. I or another neurosurgeon still needs to do the more crude part of opening the skin and skull and presenting the robot a pristine brain surface to sew electrodes into. Broadly speaking, the mission of Neuralink is to reduce human suffering, at least in the near term, you know, there's hope that eventually there's a use here that makes sense for a brain interface to bring AI as a tool embedded in the brain that a human can use to augment their capabilities. I think that's pretty far down the road for us, but definitely on a desired roadmap. In the near term, we really are focused on people with terrible medical problems that have no options right now.
Speaker 1So to just give us a bit fuller picture of this, we're talking about a patient who can't move their limbs because they have spinal cord damage. The motor cortex that controls movement is, in theory, fine. You make a small hole in the skull, and through that hole, a robot is going to place electrodes, obviously in motor cortex, but then where? How? Is the idea that you're going to play a concert from different locations? You're going to hit all the keys on the piano in different combinations? I still don't understand how the signals are going to get out of motor cortex, past the lesion and into the brain. And out to the limbs, because the lesion hasn't been dealt with at all in this scenario.
Speaker 2So just to clarify there, I should emphasize, we're not in the immediate future talking about reconnecting the brain to the patient's own limbs. That's on the roadmap, but it's way down the roadmap a few years. What we're talking about in the immediate future is having the person be able to control electronic devices around them with their motor intentions alone, right? So prosthetic hand and arm, or just mouse and keyboard? Mouse and keys on a keyboard, for starters. So you wouldn't see anything in the world move. As they have an intention, the patient might imagine, say, flexing their fist or moving their wrist. And what would happen on the screen is the mouse would move down and left and click on an icon and bring up their word processor. And then a keyboard at the bottom of the screen would allow them to select letters in sequence, and they could type. So we're using smarter algorithms to decode the motor intentions out of the brain. We have been able to do this in monkeys really well. So we have a small army of monkeys playing video games for smoothie rewards, and they do really well. We actually have the world record of bit rate of information coming out of a monkey's brain to intelligently control a cursor on a screen. We're doing that better than anyone else.
Speaker 1Would you be willing, or are you willing, if allowed, to have these electrodes implanted into your motor cortex?
Speaker 2Yeah, absolutely. I would be excited to do that. I think for the first iteration of the device, it wouldn't be very useful because I can still move my limbs. And our first outputs from this are things that I can do just as easily with my hands, right? Moving a mouse, typing on a keyboard. We are necessarily making this device as a medical device for people with bad medical problems and no good options. It wouldn't really make sense for an able-bodied person to get one in the near term. As the technology develops and we make devices specifically designed to perform functions that can't be done even by an able-bodied person, say eventually refine the technique to get to the point where you can type faster with your mind and one of these devices, than you can with speech-to-text and your fingers, that's a use case that makes sense for someone like me to get it. It doesn't really make sense for me to get one when it allows me to use a mouse slightly worse than I can with my hand currently. That said, the safety of the device, I would absolutely vouch for from the hundreds of surgeries that I've personally done with this. I think it's much safer than many of the industry standard FDA-approved surgeries that I routinely do on patients that, you know, no one even thinks twice about their standard of care. Neuralink has already reached, in my mind, a safety threshold that is far beyond a commonly accepted safety threshold.
Speaker 1Along the lines of augmenting one's biological function or functions in the world, I think now's the appropriate time to talk about the small lump present in the top of your hand. For those listening, not watching, there's a small lump between Dr. McDougall's forefinger and thumb, or index finger and thumb, placed on skin on the top of his hand. You've had this for some years now because we've known each other for, gosh, probably seven years now or so, and you've always had it in the time that I've known you. What is that lump, and why did you put it in there?
Speaker 2Yeah. So it's a small writable RFID tag. So it's just a very small implantable chip that wireless devices can temporarily power. If you approach an antenna, they can power and send a small amount of data back and forth. Most phones have the capability of reading and writing to this chip. For years, it let me into my house. It unlocked a deadbolt on my front door. For some years, it unlocked the doors at Neuralink and let me through the various locked doors inside the
Speaker 1building. What other sorts of things could one put into these RFIDs? In theory, and how long can they stay in there before you need to take them out and recharge them or replace them?
Speaker 2Well, these are passive. They're coated in biocompatible glass. I'm a rock climber, and so I was worried about that glass shattering during rock climbing. I additionally coated them in another ring of silicone before implanting that. So it's pretty safe. They're passive. There's no battery. There's no active electronics in them. So they could last the rest of my life. I don't think I'd ever have to remove it for any reason. At some point, the technology is always improving, so I might remove it and upgrade it. Already, there's 10x more storage versions available that could be a drop-in replacement for this if I ever remove it. It has a small niche use case, and it's an interesting proof of concept tiptoeing towards the concept that you mentioned of you have to be willing to go through the things that you're suggesting to your patients in order to say with a straight face that you think this is a reasonable thing to do.
Speaker 1I'd like to take a quick break and acknowledge our sponsor, AG1. I'm excited to share that AG1 has just launched their newest formulation, AG1 Pro. AG1 Pro takes the clinically-backed AG1 formula, which is a blend of vitamins, minerals, probiotics, and adaptogens, and adds three important new ingredients, creatine monohydrate, calcium HMB, and zinc carnosine. Each serving has 5 grams of calcium HMB to support muscle strength and performance, as well as brain health. Calcium HMB to support muscle recovery and reduce muscle breakdown, and zinc carnosine to support and improve the lining of your gut. All three of these ingredients have compelling science to support them, and therefore, I love seeing them added to the existing AG1 formula. As most of you know, I've been taking AG1 every day for nearly 14 years now. I started taking it long before I even knew what a podcast was. It's a great product, and it's now made even better with the new AG1 Pro formula. If you'd like to try AG1 Pro, you can go to drinkag1.com slash Huberman to get a special offer. AG1 is giving away a free bottle of omega-3 coenzyme Q10 with your first subscription. Again, go to drinkag1.com slash Huberman to get a free bottle of omega-3 coenzyme Q10 with your first AG1 subscription. I'd like to go back to brain augmentation. You've made very clear that one of the first goals for Neuralink is to get quadriplegics walking again.
Speaker 2Well, again, just to be very clear, the first step is we aren't reconnecting the patient's own muscle system to their motor cortex.
Speaker 1Allowing them agency over the movement of things in the world, and eventually their body.
Speaker 2And you're exactly right. Yeah, eventually their body. We would love to do that, and we've done a lot of work on developing a system for stimulating the spinal cord itself. That gets to the question that you asked a few minutes ago of how do you connect the motor cortex to the rest of the body? Well, if you can bypass the damaged area of the spinal cord and have an implant in the spinal cord itself connected to an implant in the brain and have them talking to each other, you can take the perfectly intact motor signals out of the motor cortex and send them to the spinal cord, which most of the wiring should be intact in the spinal cord below the level of, say, the injury caused by a car accident or motorcycle accident or gunshot wound or whatever. And it should be possible. It's possible to reconnect the brain to the body in that way. So not out of the realm of possibility that in some small number of years that Neuralink will be able to reconnect somebody's own body to
Speaker 1their brain. Along the lines of augmentation, early on in some of the public discussions about Neuralink that I overheard between Elon and various podcast hosts, et cetera, there was this idea thrown out that, for instance, that you would have some chips in your brain and I would have some at each other or not, nodding or shaking our heads and essentially hear each other's thoughts. Is that possible that we could sit here and just hear each other's thoughts? And also how would we restrict what the other person could hear?
Speaker 2Yeah. Well, so absolutely. I mean, think about the fact that we could do this right now. If you pulled out your phone and started texting me on my phone and I looked down and started texting you, we would be communicating without looking at each other or talking. Shifting that function from a phone to an implanted device, it requires no magic advance, no leap forward. It's technology we already know how to do. If we say put a device in that allows you to control a keyboard. on a mouse, which is our stated intention for our first human clinical trial. And so texting each other with our brains is maybe an uninspiring rendition of this, but it's not very difficult to imagine the implementation of the same device in a more verbally focused area of the brain that allows you to more naturally speak the thoughts that you're thinking and have them rendered into speech that I can hear, you know, maybe via a bone conducting implant. So silently here, the thing that attracts a lot of us to a technology like Neuralink is that the ceiling is incredibly high. There's no obvious reason that you can't interface with millions of neurons as this technology is refined and developed further. So that's the kind of wide band, you know, high bandwidth brain interface that you want to develop if you're talking about a semantic prosthetic. Like an AI assistant to your cognitive abilities. You know, the more sci-fi things that we think about in the coming decades. So it's an important caveat when you're evaluating these technologies. You really want it to be something that you can expand off into the sci-fi.
Speaker 1To what extent can these brain machine interfaces learn and get better and better and better because it's also listening to the nervous system that it's trying to support?
Speaker 2It goes both ways. Basically, what you're doing is taking a very crude software intelligence. I would say not exactly a full-blown AI, but some well-designed software that can adapt to changes in firing of the brain. And you're coupling it with another form of intelligence, a human intelligence. And you're allowing the two to learn each other. So undoubtedly, the human that has a Neuralink device will get better at using it over time. Undoubtedly, the software that the Neuralink engineers have written will adapt to the firing patterns that the device is able to record and over time focus in on meaningful signals toward movement. So if a neuron has a high firing rate when you intend to move the mouse cursor up and to the right, it doesn't know that when it starts. When you first put this in, it's just a random series of signals. As far as the chip knows. But you start correlating it with what the person, what you know the person wants to do as expressed in a series of games. So you assume that the person wants to move the mouse on the screen to the target that's shown because you tell them that's the goal. And so you start correlating the activity that you record when they're moving toward an up and right target on a screen with that firing pattern. And similarly for up and left, down and left, down and right. And so you develop a model semi-intelligently in the software for what the person is intending to do and let the person run wild with it for a while. And they start to get better at using the model presented to them by the software as expressed by the mouse moving or not moving properly on the screen, right? Imagine a scenario where you're asking somebody to play piano, but the sound that comes out of each key randomly shifts over time, right? And so it's a very difficult problem, but a human brain is good enough with the aid of software to solve that problem and map well enough to a semi-stable state that they're going to know how to use that mouse, even when they say, turn the device off for the night, come back to it the next day. And some of the signals have shifted.
Speaker 1Let's talk about pigs. Sure. Elon and others there at Neuralink have shared some of the progress that they've made in experimental animals. That they've made a lot of progress in their experimental animals. They've made a lot of progress in their experimental animals. In fact, a 2020 study by the Environmental Working Group estimated that more than 200 million Americans are exposed to PFAS chemicals, also known as forever chemicals, through drinking tap water. These forever chemicals are linked to serious health issues, such as hormone disruption, gut microbiome disruption, fertility issues, and many other health problems, some of which are just now coming to light. For all these reasons, I was thrilled when I came across Rora water filters, and now they're a sponsor of this podcast. Rora makes what I believe are the best water filters on the market. I've been using the Rora countertop system for almost a year now. Rora's filtration technology removes harmful substances, including endocrine disruptors and disinfection byproducts, while preserving beneficial minerals like magnesium and calcium. It requires no installation or plumbing, so it's extremely convenient. It's built from medical-grade stainless steel, and it fits beautifully on your countertop. It's something that you would want to have in your kitchen. If you'd like to try Rora, you can go to rora.com slash Huberman and get an exclusive discount. Again, that's Rora. R-O-R-A. R-O-R-A.com slash Huberman. What is your wish for brain-machine interface and brain augmentation? So let's assume that the clinical stuff can be worked out. Or maybe you have a pet clinical condition that you just are just yearning to see resolved. That would be fine, too. But in addition to that, you really just expand out. Let's say we can extend your life 200 years, or we're thinking about the kind of world. That your children are going to live in and their grandchildren will live in. What do you think is really possible with brain augmentation and brain machine interface? interface. And here, please feel no bias whatsoever to answer in a way that reveals to us your incredible empathy and consideration of clinical conditions. Because that's how you spend your days is fixing patients and helping their lives be better. So if it lands in that category, great. But for sake of fun and for sake of delight and for sake of really getting us, the audience, to understand what's really possible here, please feel no shackles.
Speaker 2Yeah. I love the idea down the road, and we're talking a 10-year, maybe 20-year time frame, of humans just getting control over some of the horrible ways that their brains go wrong, right? So I think everybody at this point has either known someone or second order known someone, a friend of a friend, who has been touched by addiction or depression, suicide. Obesity. These functions of the brain or malfunctions of the brain are what drives me. These are the things that I want to tackle in my career. In terms of my kids' lifetime, I'm thinking full human expansion of human cognition into AI, full immersion in the internet of your cognitive abilities, having no limitation. I think that's a really important part of my life. I think that's a really important part of my life.
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