Christof Koch: Consciousness

A conversation with Christof Koch as part of MIT course on Artificial General Intelligence. Video version is available on YouTube https://www.youtube.com/watch?v=piHkfmeU7Wo&list=PLrAXtmErZgOdP_8GztsuKi9nrraNbKKp4. He is the President and Chief Scientific Officer of the Allen Institute for Brain Science in Seattle. From 1986 until 2013, he was a professor at CalTech. Cited more than 105,000 times. Author of several books including “Consciousness: Confessions of a Romantic Reductionist.” If you would like to get more information about this podcast go to https://lexfridman.com/ai or connect with @lexfridman on Twitter https://twitter.com/lexfridman, LinkedIn https://www.linkedin.com/in/lexfridman/, Facebook https://www.facebook.com/lexfridman, or YouTube https://www.youtube.com/lexfridman where you can watch the video versions of these conversations.

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

• 0:00Lex Fridman?

  Welcome to the Artificial Intelligence Podcast. My name is Lex Fridman. I'm a research scientist at MIT. If you would like to skip ahead to the conversation with Christoph Koch, I started introducing him at about the 1 minute and 30 second mark. This podcast is an extension of the courses on deep learning, autonomous vehicles, and artificial general intelligence that I've taught and organized. It is not only about machine learning, or robotics, or neuroscience, or philosophy, or any one technical field. It considers all these avenues of thought in a way that is, hopefully, accessible to everyone. The aim here is to explore the nature of human and machine intelligence,

• 0:44Lex Fridman?

  the big picture of understanding the human mind and creating echoes of it in the machine. To me, that is one of our civilization's most challenging and exciting scientific journeys into the unknown. I will first repost parts of previous YouTube conversations and lecture Q and A's that can be listened to without video. If you want to see the video version, please go to my YouTube channel. My username there, on Twitter, and everywhere else is LexFriedman, spelled F R I D without the E. So, reach out and connect if you find these conversations interesting. In this episode, I talk with Christoph Koch,

• 1:28Lex Fridman?

  who's one of the seminal figures in the fields of neurobiology, neuroscience, and generally in the study of consciousness. He's the president and chief scientific officer of the Allen Institute of Brain Science in Seattle. From 1986 until 2013, he was a professor at Caltech. His work has received over 100,000 citations. He's the author of several books, including Consciousness: Confessions of a Romantic Reductionist. His research, his writing, his ideas have had a big impact on the scientific community and the general public, in the way we think about consciousness, and in the way we think of ourselves as human beings. I enjoyed and learned a lot from this conversation.

• 2:12Lex Fridman?

  I hope you do as well.

• 2:31Lex Fridman?

  Okay, before we delve into the beautiful mysteries of consciousness, let's zoom out a little bit. And let me ask, do you think there's intelligent life out there in the universe?

• 2:43Speaker 02

  Yes, I do believe so. We have no evidence of it, but I think the probabilities are overwhelming in favor of it. Given the universe, well, we have 10 to the 11 galaxies, and each galaxy has between 10 to the 11, 10 to the 12 stars. And we know most stars have one or more planets.

• 3:01Lex Fridman?

  So how does that make you feel?

• 3:03Speaker 02

  It still makes me feel special because I have experiences. I feel the world, I experience the world. And independent of whether there are other creatures out there, I still feel the world. I have access to this world in this very strange, compelling way. And that's the core of human existence.

• 3:25Lex Fridman?

  Now, you said "human." Do you think if those intelligent creatures are out there, do you think they experience their world?

• 3:34Speaker 02

  Yes, they are evolved. If they are a product of natural evolution, as they would have to be, they will also experience their own world. So consciousness isn't just human, you're right. It's much wider. It's probably, it may be spread across all of biology. We have, the only thing that we have special is we can talk about it. Of course, not all people can talk about it. Babies and little children can talk about it. Patients who have, who have a stroke in the left inferior frontal gyrus can talk about it. But most normal adult people can talk about it. And so we think that makes us special compared to, let's say, monkeys, or dogs, or cats, or mice, or all the other creatures that we share the planet with. But all the evidence seems to suggest that they too experience the world. And so it's overwhelmingly likely that other aliens would also experience their world.

• 4:19Speaker 02

  Of course, differently, because they have a different sensorium, they have different sensors, they have a very different environment. But the fact that, I would strongly suppose that they also have experiences. They feel pain and pleasure and see in some sort of spectrum and hear and have all the other senses.

• 4:37Lex Fridman?

  Of course, their language, if they have one, would be different. So we might not be able to understand their poetry about the experiences that they have.

• 4:44Speaker 02

  That's correct.

• 4:46Lex Fridman?

  So in a talk, in a video, I've heard you mention supuzo, a Dachshund that you came up with, that you grew up with, was part of your family when you were young. First of all, you're technically a Midwestern boy.

• 5:00Speaker 02

  Technically.

• 5:03Lex Fridman?

  But after that, you traveled around a bit, hence a little bit of the accent. You talked about supuzo, the Dachshund, having these elements of humanness, of consciousness that you discovered. So I just wanted to ask, can you look back in your childhood and remember, when was the first time you realized you yourself, sort of from a third-person perspective, are a conscious being? This idea of, you know, stepping outside yourself and seeing, there's something special going on here in my brain?

• 5:37Speaker 02

  I can't really, actually, it's a good question. I'm not sure I recall a discrete moment. I mean, you take it for granted, because that's the only world you know. That the only world I know, you know, is the world of seeing and hearing voices and touching and all the other things. So it's only much later, at early in my unguided days, when I became, when I enrolled in physics and in philosophy, that I really thought about it and thought, well, this is really fundamentally very, very mysterious. And there's nothing really in physics right now that explains this transition from the physics of the brain to feelings. Where do the feelings come in? So you can look at the foundational equation of quantum mechanics, general relativity. You can look at the table of the elements.

• 6:19Speaker 02

  You can look at the endless ATG, seed, chat in our genes, and no way is consciousness. Yet I wake up every morning to a world where I have experiences. And so that's the heart of the ancient mind-body problem. How do experiences get into the world?

• 6:36Lex Fridman?

  So what is consciousness?

• 6:39Speaker 02

  Experience. Consciousness is any, any, any experience. Some people call it subjective feeling. Some people call it phenomenology. Some people call it quagmire, the philosopher. But they all denote the same thing. It feels like something, in the famous word of the philosopher Thomas Nagel. It feels like something to be a bat or to be, you know, an American, or to be angry, or to be sad, or to be in love, or to have pain.

• 7:09Speaker 02

  And that is what experience is. Any possible experience. Could be as mundane as just sitting here in a chair. Could be as exalted as, you know, having a mystical moment, uh, you know, in, in deep meditation. Those are just different forms of experiences.

• 7:23Lex Fridman?

  Experience. So if you were to sit down with maybe the next, skip a couple of generations of IBM Watson, something that won Jeopardy. What is the gap? I guess the question is between Watson, uh, that might be much smarter than you, than us, than all, any human alive, but may not have experience. What is the gap?

• 7:48Speaker 02

  Well, so that's a big, big question. That's occupied people for the last, um, certainly last 50 years since we, you know, since the advent, the birth of, um, of computers. That's a question Aaron Turing tried to answer. And of course, he did it in this indirect way by proposing a test, an operational test. So, but that's not really, that's, you know, he tried to get it, what does it mean for a person to think? And then he had this test, right? You lock them away and then you have a communication with them. And then you try to, to guess after a while whether that is a person or whether it's a computer system. There's no question that now or very soon, you know, Alexa or Siri or, you know, Google now will pass this test, right? And you can game it, but you know, ultimately certainly in your generation,

• 8:31Speaker 02

  there will be machines that will speak with complete poise. That will remember everything you ever said. They'll remember every email you ever had, like, like Samantha. Remember in the movie Her?

• 8:41Lex Fridman?

  Yeah.

• 8:41Speaker 02

  It's no question it's gonna happen. But of course, the key question is, does it feel like anything to be Samantha in the movie Her?

• 8:48Lex Fridman?

  True.

• 8:49Speaker 02

  Or to, or to, does it feel like anything to be Watson? And there one has to very, um, very strongly think, there are two different concepts here that we co-mingle. There is a concept of intelligence, natural or artificial. And there is a concept of consciousness, of experience, natural or artificial. Those are very, very different things. Now historically, we associate consciousness with intelligence. Why? Because we live in a world, leaving aside computers, of, of natural selection. Where we are surrounded by creatures, either our own kin that are less or more intelligent, or we go across species, some are more adapted to a particular environment, others are less adapted, whether it's a whale or dog, or you go talk about a permeatorium or a little worm, alright?

• 9:34Speaker 02

  And, and we see the complexity of the nervous system goes from one cell to, to specialized cells, to a worm that has three net, that has thirty percent of its cells are nerve cells, to a creature like us, or like a blue whale, that has hundred billion even more nerve cells. And so, based on behavioral evidence and based on the underlying neuroscience, we believe that as these creatures become more complex, they are better adapted to, to their particular ecological niche, and they become more conscious, partly because their brain grows, and we believe consciousness, unlike the ancient, ancient people thought most, almost every culture thought that consciousness with intelligence has to do with your heart. Uh huh. And you still say that today, you see, honey, I love you with all my heart. Yes.

• 10:19Speaker 02

  But what you should actually say is say, no, honey, I love you with all my lateral hypothalamus. And for Valentine's Day, you should give your sweetheart, uh, you know, a hypothalamic shaped piece of chocolate, not a heart shaped chocolate, right? Anyway, so we still have this language, but now we believe it's a brain, and so we see brains of different complexity, and we think, well, they have different levels of consciousness, they're capable of different experiences.

• 10:45Speaker 02

  But now we confront a world where we know, where we're beginning to engineer intelligence, and it's radical unclear whether the intelligence we're engineering has anything to do with consciousness and whether it can experience anything. Because fundamentally, what's the difference? Intelligence is about function. Intelligence, no matter exactly how you define it, sort of adaptation to new environments, being able to learn and quickly understand, you know, the setup of this, and what's going on, and who are the actors, and what's gonna happen next. That's all about function. Consciousness is not about function. Consciousness is about being. It's in some sense much fundamental. You can see this in several cases.

• 11:28Speaker 02

  You can see it, for instance, in the case of the clinic. When you're dealing with patients who are, let's say, had a stroke or were in a traffic accident, et cetera. They're pretty much immobile. Terri Scheibro, you may have heard historically. She was a person here in the 90s in Florida. Her heart stood still, she was reanimated. Then for the next 14 years, she was what's called in a vegetative state. There are thousands of people in a vegetative state. So they're like this. Occasionally, they open their eyes for two, three, four, five, six, eight hours and then close their eyes. They have a sleep-wake cycle. Occasionally, they have behaviors. They do like, you know. But there's no way that you can establish a lawful relationship between what you say, or the doctor says, or the mom says,

• 12:13Speaker 02

  and what the patient does. Right. So there isn't any behavior. Yet in some of these people, there is still experience. You can design and build brain-machine interfaces where you can see they still experience something. And of course, there are these cases of locked-in state. There's this famous book called The Diving Bell and the Butterfly, where you had an editor, a French editor, he had a stroke in the brainstem, unable to move except his vertical eye movement. He could just move his eyes up and down. He dictated an entire book. And some people even lose this at the end. And all the evidence seems to suggest that they're still in there. In this case, you have no behavior, you have consciousness.

• 12:57Speaker 02

  Second case is tonight, like all of us. You're gonna go to sleep. Close your eyes, you go to sleep. You will wake up inside your sleeping body and you will have conscious experiences. They're different from everyday experience. You might fly, you might not be surprised that you're flying. You might meet a long-dead pet, childhood dog, and you're not surprised that you're meeting them. But you have conscious experiences of love, of hate. They can be very emotional. Your body during this state, typically REM state, sends an active signal to your motor neurons to paralyze you. It's called atonia. Because if you don't have that, like some patients, what do you do? You act out your dreams. You get, for example, REM behavioral disorder, which is bad juju to get. Okay? The third case is pure experience.

• 13:42Speaker 02

  So I recently had this, what some people call a mystical experience. I went to Singapore and went into a flotation tank. Yeah. All right, so this is a big tub. Filled with water, that's body temperature and absent salt. You strip completely naked, you lie inside of it, you close the lid.

• 14:01Lex Fridman?

  Darkness.

• 14:01Speaker 02

  Complete darkness, soundproof. So very quickly you become bodyless because you're floating and you're naked. You have no rings, no watch, no nothing. You don't feel your body anymore. It's no sound, soundless, there's no photon, sightless, timeless. Because after a while, early on, you actually hear your heart. But then you sort of adapt to that and then sort of the passage of time ceases. And if you train yourself like in a meditation not to think, early on you think a lot. It's a little bit spooky, you feel somewhat uncomfortable or you think, well, I'm gonna get bored. But if you try not to think actively, you become mindless. There you are, bodyless, timeless, you know, soundless, sightless, mindless.

• 14:46Speaker 02

  But you're in a conscious experience, you're not asleep. You're not asleep, you are being a pure, you're a pure being. There isn't any function, you aren't doing any computation, you're not remembering, you're not projecting, you're not planning. Yet you are fully conscious.

• 15:00Lex Fridman?

  You're fully conscious, there's something going on there, it could be just a side effect. So what is the?

• 15:05Speaker 02

  You mean epiphenomena?

• 15:07Lex Fridman?

  So what's the select, meaning, why?

• 15:12Lex Fridman?

  What is the function of you being able to lay in this sensory free deprivation tank? And still have a conscious experience?

• 15:21Speaker 02

  Evolutionary?

• 15:21Lex Fridman?

  Evolutionary.

• 15:22Speaker 02

  Obviously, we didn't evolve with flotation tanks in our environment. I mean, so biology is notoriously bad at asking why question, teletological question. Why do we have two eyes? Why don't we have four eyes, like some creatures or three eyes or something? Well, no, there's probably, there is a function to that. But it's, we're not very good at answering those questions. We can speculate endlessly where biology is very, or science is very good about mechanistic question. Why is there charge in the universe, right? We find a certain universe where there are positive and negative charges, why? Why does quantum mechanics hold? You know, why doesn't some other theory hold? Quantum mechanics hold in our universe is very unclear why. So teletological question, why questions are difficult to answer. Clearly, there's some relationship between complexity, brain processing power and consciousness.

• 16:08Speaker 02

  But however, in these cases, in these three examples I gave, one is an everyday experience at night, the other one is a trauma, and third one is in principle, you can, everybody can have these sort of mystical experiences. You have a dissociation of function from, of intelligence from, from consciousness.

• 16:28Lex Fridman?

  From consciousness. You caught me asking a why question. Let me ask a question that's not a why question. You're giving a talk later today on the Turing test for intelligence and consciousness, drawing lines between the two. So is there a scientific way to say there's consciousness present in this entity or not? And to anticipate your answer, because you, you also, there's a neurobiological answer. So we can test the human brain, but if you take a machine brain that you don't know tests for yet, how would you even begin to approach a test if there's consciousness present in this thing?

• 17:06Speaker 02

  Okay, that's a really good question. So let me take it in two steps. So as you point out, for, for, for humans, let's just stick with humans, there's now a test called a zap and zip. It's a procedure where you ping the brain using transcranial magnetic stimulation. You look at the electrical reverberations, essentially using EEG, and then you can measure the complexity of this brain response. And you can do this in awake people, in the sleep, normal people, you can do it in awake people, and then anesthetize them, you can do it in patients, and it, it, it has 100% accuracy, that in all those cases, when you're clear, the patient or the person is either conscious or unconscious, the complexity is either high or low. And then you can adopt these techniques to similar creatures like monkeys and dogs and, and, and mice that have very similar brains.

• 17:50Speaker 02

  Now, of course, you, you point out that may not help you, because we don't have a cortex, you know, and if I send a magnetic pulse into my iPhone or my computer, it's probably going to break something.

• 18:01Lex Fridman?

  Yeah.

• 18:02Speaker 02

  So we don't have that. So what we need ultimately...

• 18:05Speaker 02

  We need a theory of consciousness. We can't just rely on our intuition. Our intuition is, well, yeah, if somebody talks, they're conscious. However, then there are all these children, babies, don't talk, right? But we believe that babies also have conscious experiences, right? And then there are all these patients I mentioned, and they don't talk. When you dream, you can't talk because you're paralyzed. So what we ultimately need, we can't just rely on our intuition. We need a theory of conscience that tells us, what is it about a piece of matter? What is it about a piece of highly excitable matter, like the brain or like a computer, that gives rise to conscious experience? We all believe, none of us believe anymore in the old story, it's a soul. That used to be the most common explanation, that most people accept.

• 18:48Speaker 02

  And still a lot of people today believe, well, there's God endowed, only us was the special thing that animals don't have. Rene Descartes famously said, "A dog, if you hit it with your carriage, it may yell, it may cry, but it doesn't have this special thing, it doesn't have the magic sauce." So, yeah. It doesn't have rescoritans, it's a soul. Now, we believe that isn't the case anymore. So what is the difference between brains and these guys, silicon? And in particular, once their behavior matches. So if you have Siri or Alexa in 20 years from now, that she can talk just as good as any possible human, what grounds do you have to say she's not conscious? In particular, if she says, of course she will, well, of course I'm conscious.

• 19:31Speaker 02

  You ask, "How are you doing?", and she'll say, "Well, you know, they'll generate some way to..." Yeah, yeah, exactly. Of course, she'll behave like a person. Now, there are several differences. One is, so this relates to the problem, the very hard, why is consciousness a hard problem? It's because it's subjective, right? Only I have it, for only I know, I have direct experience of my own consciousness. I don't have experience of your consciousness. Now, I assume, as a sort of Bayesian person who believes in probability theory and all of that, you know, I can do an abduction to the best available facts. I deduce your brain is very similar to mine. If I put you in a scanner, your brain is roughly going to behave the same way as I do. If, you know, if I gave you... Do this muesli and ask you how does it taste?

• 20:16Speaker 02

  You tell me things that, you know, that that I would also say more or less, right? So I infer based on all of that that you're conscious. Now with theory, I can't do that. So there I really need a theory that tells me what is it about about any system? This or this that makes it conscious? We have such a theory.

• 20:32Lex Fridman?

  Yes, so the the integrated information theory. But let me first, maybe as introduction for people who are not familiar, the car. Can you, you talk a lot about panpsychism. Can you describe what physicalism versus dualism? This, you you mentioned the soul. What what is the history of that idea? What it?

• 20:53Speaker 02

  The idea of panpsychism?

• 20:55Lex Fridman?

  Oh, no, the debate, really, out of which panpsychism can emerge of of dualism versus physicalism. Or do you not see panpsychism as fitting into that?

• 21:09Speaker 02

  No, you can argue there's some, well, OK, so let's step back. So panpsychism is a very ancient belief that's been around. I mean, Plato and Aristotle talks about it. Modern philosophers talk about it. Of course, in Buddhism, the idea is very prevalent that, I mean, there are different versions of it. One version says everything is in soul, everything, rocks and stones and dogs and people and forests and iPhones, all of a soul, right? All matter is in soul. That's sort of one version. Another version is that all biology, all creatures, small or large, from a single cell to a giant sequoia tree, feel like something. That's one I think is somewhat more realistic. So there are different versions.

• 21:50Lex Fridman?

  What do you mean by feel like something?

• 21:51Speaker 02

  Well, have.

• 21:52Lex Fridman?

  Have feeling, have some kind of.

• 21:53Speaker 02

  It feels like some, it may well be possible that it feels like something to be a paramecium. I think it's pretty likely it feels like something to be a bee or a mouse or a dog.

• 22:05Lex Fridman?

  Sure, so, okay.

• 22:06Speaker 02

  So, so that you can see that's also, so panpsychism is very broad. And you can, to some people, for example, Bertrand Russell, try to advocate this, this idea, it's called Rassalian monism, that, that panpsychism is really physics viewed from the inside. So the idea is that physics is very good at describing relationship among objects, like charges, or like gravity, right? You know, describe the relationship between curvature and mass distribution, okay? That's the relationship among things. Physics doesn't really describe the ultimate reality itself, it's just relationship among, you know, quarks or all these other stuff.

• 22:44Lex Fridman?

  Almost from like a third person observer.

• 22:47Speaker 02

  Yes, yes. And consciousness is what physics feels from the inside. So my conscious experience, it's the way the physics of my brain, particularly my cortex, feels from the inside. And so, if you are a paramitium, you've got to remember, you say paramitium, well, that's a pretty dumb creature it is, but it has already a billion different molecules, probably, you know, 5,000 different proteins assembled in a highly, highly complex system that no single person, no computer system so far on this planet has ever managed to accurately simulate. Its complexity vastly escapes us. Yes, and it may well be that that little thing feels like a tiny bit. Now, it doesn't have a voice in the head like me, it doesn't have expectations, you know, it doesn't have all that complex things, but it may well feel like something.

• 23:32Lex Fridman?

  Yep. So this is really interesting. Can we draw some lines and maybe try to understand the difference between life, intelligence, and consciousness? How do you see all of those? If you had to define what is a living thing, what is a conscious thing, and what is an intelligent thing? Do those intermix for you, or are they totally separate?

• 23:54Speaker 02

  Okay, so A, that's a question that we don't have a full answer.

• 23:57Lex Fridman?

  Right. A lot of the stuff we're talking about today is full of mysteries and fascinating ones, right?

• 24:02Speaker 02

  Well, for example, you can go to Aristotle, who's probably the most important scientist and philosopher who's ever lived, certainly in Western culture. He had this idea, it's called homorphism, it's quite popular these days, that there are different forms of. Soul, the soul is really the form of something. He says, he says, all biological creatures have a vegetative soul. That's life principle. Today, we think we understand something more. It is biochemistry in nonlinear thermodynamics. Right? Then he said they have a sensitive soul. Only animals and humans have also a sensitive soul or appetitive soul. They they can see, they can smell, and they have drives. They wanna reproduce, they wanna eat, etc. And then only humans have what he called rational soul.

• 24:45Speaker 02

  Okay, and that idea then made it into Christendom, and then the rational soul is the one that lives forever. He was very unclear. He wasn't really, I mean, different readings of Aristotle give different, whether did he believe that rational soul was immortal or not? I probably think he didn't. But then, of course, that made it into Plato and the Christianity, and then this soul became immortal and then became the connection to God. Now, you, so you asked me essentially, what is our modern conception of these three? Aristotle would have called them different forms. Life, we think we know something about it, at least life on this planet, right? Although we don't understand how it originated, but it's it's been difficult to rigorously pin down. You see this in modern definitions of death.

• 25:28Speaker 02

  It's in fact right now, there's a conference ongoing, again, that tries to define legally and medically what is death. It used to be very simple. Death is you stop breathing, your heart stops beating, you're dead. Totally unconventional. If you're unsure, you wait another ten minutes, if the patient doesn't breathe, you know, he's dead. Well, now we have ventilators, we have pacemakers, so it's much more difficult to define what death is. Typically, death is defined as the end of life, and life is defined before death. Before death. Okay, so we don't have really very good definitions. Intelligence, we don't have a rigorous definition. We know something how to measure. It's called IQ or G factors, right? And and we're beginning to build it in a narrow sense, right?

• 26:10Speaker 02

  Like Go, AlphaGo, and and and Watson, and you know, Google Cars and Uber Cars and all of that. That's still narrow AI, and some people are thinking about artificial general intelligence. But roughly, as we said before, it's something to do with the ability to learn and to adapt. Up to new environments. But that is, as I said also, it's radical difference from experience. And it's very unclear. If you build a machine that has AGI, it's not at all a priori. It's not at all clear that this machine will have consciousness. It may or may not.

• 26:40Lex Fridman?

  So let's ask it the other way. Do you think if you were to try to build an artificial general intelligence system? Do you think figuring out how to build artificial consciousness would would help you get to to an AGI? So or put another way, do you think intelligent requires consciousness?

• 27:00Speaker 02

  In human, it goes hand in hand. In human, I think in biology, consciousness, intelligence goes hand in hand. Que is illusion because the the brain evolved to be highly complex. Complexity via the theory, integrated information theory is sort of ultimately is is what is closely tied to consciousness. Ultimately, it's causal power upon itself. And so in evolve in evolve systems, they go together. In artificial system, particularly in digital machines, they do not go together. And if you ask me point blank, is Alexa twenty point O in the year twenty forty when she can easily pass every Turing test? Is she conscious? No. Even if she claims she's conscious. In fact, you could even do a more radical version of this thought experiment.

• 27:44Speaker 02

  We can build a computer simulation of the human brain. You know what Henry Markham in the Blue Brain Project or the Human Brain Project in Switzerland is trying to do? Let's grant him all the success. So in ten years, we have this perfect simulation of the human brain. Every neuron is simulated and it has a larynx and it has motor neurons. It has a a Broca's area and of course it'll talk and it'll say, hi, I just woke up. I feel great. Okay. Even that computer simulation that can imprints a map onto your brain will not be conscious. Why? Because it simulates. It's a difference between the simulated and the real. So it simulates the behavior associated with consciousness. It might be, it will, if it's done properly, will have all the intelligence that that particular person they're simulating has.

• 28:25Speaker 02

  But simulating intelligence is not the same as having conscious experiences. And I gave you a really nice metaphor that engineers and physicists typically get. I can write down Einstein's field equation, nine or ten equations that describe the link in general relativity between curvature and and mass. I can do that. I can run this on my laptop to to predict that the sample, the black hole at the center of our galaxy will be so massive that it'll twist spacetime around it so no light can escape. It's a black hole, right? But funny, have you ever wondered why doesn't this computer simulation suck me in? Right? It simulates gravity, but it doesn't have the causal power of gravity. It's a huge difference.

• 29:10Speaker 02

  So it's a difference between the real and and the simulated, just like it doesn't get wet inside a computer when the computer runs code that simulates a weather storm. And so in order to have to have artificial conscience, you have to give it the same causal power as the human brain.

• 29:26Lex Fridman?

  Yes.

• 29:27Speaker 02

  You have to build so-called a neuromorphic machine that has hardware that is very similar to the human brain, not a digital clock for Norman computer.

• 29:36Lex Fridman?

  So that's just to clarify, though, you think that consciousness is not required to create human-level intelligence. It seems to accompany in the human brain, but for machine not.

• 29:49Speaker 02

  That's correct.

• 29:51Lex Fridman?

  So maybe just because this is AGI, let's dig in a little bit about what we mean by intelligence. So one thing is the G factor, these kind of IQ tests of intelligence. But I think if you, maybe another way to say, so in 2040, 2050, people will have Siri that is just really impressive. Do you think people will say Siri is intelligent?

• 30:17Speaker 02

  Yes.

• 30:18Lex Fridman?

  Intelligence is this amorphous thing. So to be intelligent, it seems like you have to have some kind of connections with other human beings, in in a sense that you have to impress them with your intelligence. And there feels, you have to somehow operate in this world full of humans. And for that, there feels like there has to be something like consciousness. So you think you can have just the world's best natural NLP system, natural language understanding generation, and that will be, that will get us happy and say, you know what? We've created an AGI.

• 30:53Speaker 02

  I don't know, happy. But, yes, I do believe we can get what we call high-level functional intelligence, particularly sort of the G, you know, this, this fluid-like intelligence that we cherish, particularly at a place like MIT, right? In, in, in machines, I see abhorrent reasons, and I see a lot of reasons to believe it's gonna happen very, you know, over the next fifty years or thirty years.

• 31:18Lex Fridman?

  So for beneficial AI, for creating an AI system that's, so you mentioned ethics, that is exceptionally intelligent, but also does not do, does, you know, aligns its values with our values of humanity. Do you think then it needs consciousness?

• 31:34Speaker 02

  Yes, I think that that is a very good argument, that if we're concerned about AI and the threat of AI, ala Nick Bostrom, existentialist threat, I think having an intelligence that has empathy, right? Why do we find abusing a dog? Why do most of us find that abhorrent, abusing any animal? Right? Why do we find that abhorrent? Because we have this thing called empathy, which if you look at the Greek, really means feeling with. I feel a pathos, empathy, I have feeling with you. I see somebody else suffer that isn't even my con-specific. It's not a person, it's not a love, it's not my wife or my kids, it's, it's a dog. But I feel naturally, most of us, not all of us, most of us will feel emphatic.

• 32:15Speaker 02

  And so it may well be in the long-term interest of survival of Homo sapiens sapiens, that if we do build AGI and it really becomes very powerful, that it has an emphatic response and doesn't just exterminate humanity.

• 32:31Lex Fridman?

  So as part of the full conscious experience, to create a consciousness, artificial, or in our human consciousness, do you think fear, maybe we're gonna get into the earlier days with Nietzsche and so on, but do you think fear and suffering are essential to have consciousness? Do you have to have the full range of experience to have, to have a system that has experience? Or can you have a system that only has very particular kinds of very positive experiences?

• 33:01Speaker 02

  Look, you can have, in principle, you can, people have done this in a rat, where you implant an electrode in the hypothalamus, the pleasure center of the rat, and the rat stimulates itself above and beyond anything else. It doesn't care about food or natural sex or drink anymore. It just stimulates itself because it's such a pleasurable feeling. I guess it's like an orgasm, just you have, you know, all day long. And so a priori, I see no reason why you need different, why you need a great variety. Now, clearly, to survive, that wouldn't work, right? But if I engineered artificially, I don't think, I don't think you need a great variety of conscious experience. You could have just pleasure or just fear.

• 33:45Speaker 02

  It might be a terrible existence, but I think that's possible, at least on conceptual, logical count. Because any real creature, whether artificially engineered, you want to give it fear, the fear of extinction, right, that we all have. And you also want to give it positive, appetitive states, states that it wants to, that you want the machine encouraged to do because they give the machine positive feedback.

• 34:07Lex Fridman?

  So you mentioned panpsychism, to jump back a little bit, you know, everything having some kind of mental property. How do you go from there to something like human consciousness? So everything having some elements of consciousness to, well, is there something special about human consciousness?

• 34:28Speaker 02

  So just, it's not everything, like a spoon, there's no, I, the form of panpsychism, I think about doesn't ascribe consciousness to anything like this, the spoon on my liver. However, it is, the theory, integrated information theory, does say that system, even ones that look from the outside relatively simple, at least if they have this internal causal power, they are, they, it does feel like something. The theory a priori doesn't say anything what's special about human. Biologically, we know what the one thing that's special about human is we speak and we have an overblown sense of our own importance.

• 35:07Lex Fridman?

  Right.

• 35:08Speaker 02

  We believe we're exceptional and we're just gods give to, to, into the universe. But the, but behaviorally, the main thing that we have, we can plan, we can plan over the long term, and we have language, and that gives us enormous amount of power. And that's why we are the the current dominant species on the planet.

• 35:25Lex Fridman?

  So you mentioned God, you grew up a devout Roman Catholic, uh, Roman Catholic family. So, you know, with consciousness, you're sort of exploring some really deeply fundamental human things that religion also touches on. So where does, where does religion fit into your thinking about consciousness? And you've, you've grown throughout your life and changed your views on religion, as far as I understand.

• 35:52Speaker 02

  Yeah, I mean, I'm now much closer to, so I'm not a Roman Catholic anymore. I don't believe there's sort of this God, the God I was, I was educated to believe in, you know, sits somewhere in the fullness of time, I'll be united in some sort of everlasting bliss. I just don't see any evidence for that. Look, the world, the night is large and full of wonders, right? There are many things that I don't understand. I think many things that we as a cult, look, we don't even understand more than 4% of all the universe, right? Dark matter, dark energy. We have no idea what it is. Maybe it's lost socks. What do I know? So, so all I can tell you is it's a sort of my current religious or spiritual sentiment is much closer to some form of Buddhism.

• 36:36Lex Fridman?

  Can you describe-

• 36:36Speaker 02

  Without the reincarnation, unfortunately. There's no evidence for a reincarnation.

• 36:41Lex Fridman?

  So can you describe the way Buddhism sees the world a little bit?

• 36:45Speaker 02

  Well, so the, you know, they talk about, so when, when I spent several meetings with, with the Dalai Lama, and what always impressed me about him, he really, unlike, for example, let's say the Pope or some Cardinal, he always emphasized minimizing the suffering of all creatures. So they have this, from the early beginning, they look at suffering in all creatures, not just in people, but in, in everybody, this universal. And of course, by degrees, right, in the animal general will have, is less capable of suffering than a, than a well-developed, normally-developed human. And they think consciousness pervades in this universe, and they have these techniques, you know, you can think of them like mindfulness,

• 37:26Speaker 02

  et cetera, and meditation that tries to access sort of what they claim of this more fundamental aspect of reality. I'm not sure it's more fundamental. I think- About it, there's a physical and then there's this inside view consciousness and those are the two aspects. That's the only thing I've I've access to in my life. And you've got to remember, my conscious experience and your conscious experience comes prior to anything you know about physics. Comes prior to knowledge about the universe and atoms and superstrings and molecules and all of that. The only thing you directly are acquainted with is this world that's populated with with things and images and and sounds in your head and touches and all of that.

• 38:03Speaker 03

  Actually, I have a question. So it sounds like you kind of have a rich life. You talk about rock climbing and it seems like you really love literature and consciousness is all about experiencing things. So do you think that has helped your research on this topic?

• 38:20Speaker 02

  Yes, particularly if you think about it, the the various states, so for example, when you do rock climbing or now I do a rowing, crew rowing and a bike every day, you can get into this thing called the zone. And I've always I wanted I wondered about it, particularly with respect to consciousness, because it's a strangely addictive state. You want to you want to, I mean, once people have it once, you want to keep on going back to it. And you wonder, what is it so addicting about it? And I think it's the experience of of almost close to pure experience. Because in this in this zone, you're not conscious of inner voice anymore. There's always this inner voice nagging you, right? You have to do this, you have to do that, you have to pay your taxes, you had this fight with your ex and all of those things are always there.

• 39:02Speaker 02

  But when you're in the zone, all of that is gone and you're just in this wonderful state where you're fully out in the world, right? You're you're climbing or you're rowing or biking or or doing soccer or whatever you're doing. And sort of consciousness sort of is this, you're all action. Or in this case of pure experience, you're not action at all. But in both cases, you experience some aspect of of you touch some basic part of of of conscious existence that is so basic and so deeply satisfying. You, I think you touch the root of being. That's really what you're touching there. You're getting close to the root of being. And that's very different from intelligence.

• 39:41Lex Fridman?

  So what do you think about the simulation hypothesis, simulation theory, the idea that we all live in a computer simulation?

• 39:47Speaker 02

  Have you? That's a good note. Raptors for nerds.

• 39:51Lex Fridman?

  Raptors for nerds.

• 39:52Speaker 02

  I think it's as likely as the hypothesis that engaged hundreds of scholars for many centuries, are we all just existing in the mind of God?

• 40:02Lex Fridman?

  Right.

• 40:02Speaker 02

  And this is just a modern version of it. It's equally plausible. People love talking about these sort of things. I know they're book written about this simulation hypothesis. If that's what people want to do, that's fine. Seems rather esoteric. It's never testable.

• 40:18Lex Fridman?

  But it's not useful for you to think of in those terms. So maybe connecting to the questions of free will, which you've talked about. I think I vaguely remember you saying that the idea that there's no free will, it makes you very uncomfortable.

• 40:33Lex Fridman?

  So what do you think about free will? And from the physics perspective, from a conscious perspective, what is it all fit?

• 40:40Speaker 02

  Okay, so from the physics perspective, leaving aside quantum mechanics, we believe we live in a fully deterministic world, right? But then comes, of course, quantum mechanics. So now we know that certain things are in principle not predictable, which, as you said, I prefer because the idea that the initial condition of the universe and then everything else, we're just acting out the initial condition of the universe, that doesn't...

• 41:03Lex Fridman?

  It's not a romantic notion.

• 41:05Speaker 02

  Certainly not. Now, when it comes to consciousness, I think we do have certain freedom. We are much more constrained by physics, of course, and by our past and by our own conscious desires and what our parents told us and what our environment tells us. We all know that, right? There's hundreds of experiments that show how we can be influenced. But finally, in the final analysis, when you make a life, and I'm talking really about critical decision, where you really think, should I marry? Should I go to this school or that school? Should I take this job or that job? Should I cheat on my taxes or not? These are things where you really deliberate. And I think under those conditions, you are as free as you can be. When you bring your entire being, your entire conscious being to that question

• 41:50Speaker 02

  and try to analyze it under all the various conditions, then you make a decision, you are as free as you can ever be. That is, I think, what free will is. It's not a will that's totally free to do anything it wants. That's not possible.

• 42:05Lex Fridman?

  Right. So as Jack mentioned, you actually write a blog about books you've read. Amazing books from, I'm Russian, from Bulgakov to

• 42:16Speaker 02

  Maestra Magrita.

• 42:17Lex Fridman?

  Yeah. Neil Gaiman, Carl Sagan, Murakami. So what is a book that early in your life transformed the way you saw the world? Something that changed your life?

• 42:29Speaker 02

  Nietzsche I guess did. Das Buch sei trister, because he talks about some of these problems. You know, he was one of the first discoverer of the unconscious. This is, you know, a little bit before Freud, when it was in the air. And, you know, he makes all these claims that people sort of under the guise of, under the mask of charity, actually are very non charitable. So he is sort of really the first discoverer of the great land of the, of the unconscious. And that, that really struck me.

• 43:01Lex Fridman?

  And what do you think, what do you think about the unconscious? What, what do you think about Freud? What do you think about these ideas? What's, what's just like dark matter in the universe? What's over there in that unconscious?

• 43:11Speaker 02

  A lot. I mean, much more than we think. This is what a lot of last hundred years of research has shown. So I think he was a genius, misguided towards the end, but he was all, he started out as a neuroscientist, right? He contributed, he did the studies on the, on the lamprey. He contributed himself to the neuron hypothesis, the idea that they're discrete units that we call nerve cells now. And then he started, then he, he wrote, you know, about the unconscious. And I think it's true, there's lots of stuff happening. You feel this particular, when you're in a relationship and it breaks a thunder, right? And then you have this terrible, you can have love and hate and lust and anger and all of it's mixed in. And when you try to analyze yourself, why am I so upset?

• 43:54Speaker 02

  It's very, very difficult to penetrate to those basements, those caverns in your mind. Because the prying eyes of conscience doesn't have access to those. But they're there in the amygdala, you know, lots of other places. They make you upset or angry or sad or depressed. And it's very difficult to try to actually uncover the reason. You can go to a shrink, you can talk with your friend endlessly. You construct finally a story, why this happened, why you love her or don't love her, whatever. But you don't really know whether that's actually the, whether that actually happened. Because you simply don't have access to those parts of the brain and they're very powerful.

• 44:29Lex Fridman?

  Do you think that's a feature or a bug of our brain? The fact that we have this deep Difficult to dive into subconscious.

• 44:36Speaker 02

  I think it's a feature because otherwise, look, we are, we are like any other brain or nervous system or computer, we are severely bound limited. If we, if everything I do, every emotion I feel, every eye movements I make, if all of that had to be under the control of consciousness, I couldn't, I, I couldn't, I wouldn't be here. Right? So, so what you do early on, your brain, you have to be conscious when you learn things like typing or like riding on a bike. But then what you do, you train up, uh, Raul, I think that involved basal ganglia and striatum. You, you train up different parts of your brain. And then once you do it automatically, like typing, you can show you do it much faster without even thinking about it.

• 45:21Speaker 02

  Because you've got these highly specialized, what Franz Krieg and I called zombie agents, that are sort of, they're taking care of that. While your consciousness can sort of worry about the abstract sense of the text you want to write. And I think that's true for many, many things.

• 45:34Lex Fridman?

  But for the things like, uh, all the fights you had with the ex-girlfriend, things that you would think are not useful to still linger somewhere in the subconscious. So that seems like a bug that it would stay there.

• 45:48Speaker 02

  You think it would be better if you can analyze it and then get it out of the system?

• 45:51Lex Fridman?

  Get it out of the system or just forget it ever happened? You know, that, that seems a very buggy kind of.

• 45:57Speaker 02

  Well, yeah, in general, we don't have, and that's probably functional. We don't have an ability unless it's extreme. There are cases, clinical dissociations, right? When people are heavily abused, when they completely repress the, the memory. But that doesn't happen in, in, in, you know, in normal people. We don't have an ability to remove traumatic memories. And of course, we suffer from that. On the other hand, probably if you had the ability to constantly wipe your memory, you'd probably do it to an extent that isn't useful to you. So.

• 46:28Lex Fridman?

  Yeah, it's a

• 46:29Speaker 02

  It's a good question.

• 46:30Lex Fridman?

  The balance. So on the books, as Jack mentioned, correct me if I'm wrong, but broadly speaking, academia and the different scientific disciplines, certainly in engineering, reading literature seems to be a rare pursuit. Perhaps I'm wrong in this, but that's in my experience. Most people read much more technical texts and do not sort of escape or seek truth in literature. It seems like you do. So what do you think is the value? What do you think literature adds to the pursuit of scientific truth? Do you think it's good, it's useful for?

• 47:07Speaker 02

  It gives you access to much wider array of of human experiences.

• 47:12Lex Fridman?

  How valuable do you think it is?

• 47:14Speaker 02

  Well, if you want to understand human nature and nature in general, then I think you have to better understand a wide variety of experiences, not just sitting in a lab staring at a screen and having a face flashed onto you 400 milliseconds and pushing a button. That's what that's what I used to do. That's what most psychologists do. There's nothing wrong with that. But you need to consider lots of other strange states, you know.

• 47:36Lex Fridman?

  And literature is a shortcut for this.

• 47:38Speaker 02

  Well, yeah, because literature, that's that's what literature is all about. All sorts of interesting experiences that people have, you know, the contingency of it, the fact that, you know, women experience the world different, black people experience the world different. And, you know, the one way to experience that is reading all these different literature and try to find out, you see, everything is so relative. Right? You read a book 400 years ago, they thought about certain problems very, very differently than than us today. We today, like any culture, think we know it all. That's common to every culture. Every culture believes at its heyday, they know it all. And then you realize, well, there's other ways of viewing the universe. And some of them may have lots of things in their favor.

• 48:16Lex Fridman?

  So this is a question I wanted to ask about time scale or scale in general. When you with IIT or in general, try to think about consciousness, try to think about these ideas. We kind of naturally think in human time scales. Do you, or and also entities that are sized close to humans. Do you think of things that are much larger, much smaller as containing consciousness? And do you think of things that take, you know, well, you know, ages, eons to operate in their conscious cause-effect, cause-effect?

• 48:54Speaker 02

  It's a very good question. So I think a lot about small creatures because experimentally, you know, a lot of people work on flies and bees. Right, so and most people just think they are automata, they're just bugs for heaven's sake, right? But if you look at their behavior, like bees, they can recognize individuals, humans, they have this very complicated way to communicate. If you've ever been involved or you know your parents when they bought a house, what sort of agonizing decision that is? And bees have to do that once a year, right, when they swarm in the spring. And then they have this very elaborate way, they have three nut scouts, they go to the individual size, they come back, they have this power, this dance, literally where they dance for several days, they try to recruit other, this very complicated decision way. When they finally, once they make a decision, the entire swarm, the scouts warm up the entire swarm, then go to one location.

• 49:38Speaker 02

  They don't go to fifty location, they go to one location that the scouts have agreed upon by themselves. That's awesome. If we look at the circuit complexity, it's ten times more denser than anything we have in our brain. Now, they only have a million neurons, but the neurons are amazingly complex. Complex behavior, very complicated circuitry, so there's no question, they experience something. Their life is very different, they're tiny, they only live, you know, for, while workers live maybe for two months. So I think, and IIT tells you this, in principle, the substrate of consciousness is the substrate that maximizes the cause-effect power over all possible spatial temporal grains. So when I think about, for example, do you know the science fiction story, The Black Cloud? Okay, it's a classic by Fred Holt, the astronomer.

• 50:20Speaker 02

  He has this cloud intervening between the earth and the sun and leading to some sort of, to global cooling. This is written in the fifties. It turns out you can, using the, the radio dish, they communicate with actually an entity, it's actually an intelligent entity. And they, they, they sort of, they... Convinced to move away. So here you have a radical different entity and in principle IT says, well, you can measure the the integrated information in principle at least. And yes, if that if the maximum of that occurs at the time scale of month, rather than enough it's for the fraction of a second. Yes, and they would experience life where each moment is a month rather than a or microsecond, right? Rather than a fraction of a of a second in in the human case.

• 51:06Speaker 02

  And so there may be forms of conscience that we simply don't recognize for what they are because they are so radical different from anything you and I are used to. Again, that's why it's good to read or to watch science fiction movie or to think about this. Like this is, do you know Stanislav Lem, this Polish science fiction writer? He wrote Solaris, it was turned into a Hollywood movie. Yes. His best novel, so it was in the sixties, a very, very ingenious, an ingenious background. His most interesting novel is called The Victorious, where human civilization, they they they they have this mission to this planet. And everything is destroyed, they discover machines, humans got killed and then these machines took over. And there was this machine evolution, Darwinian evolution, he talks about this very vividly.

• 51:52Speaker 02

  And finally, the dominant, the the dominant machine intelligence organism that survived were gigantic clouds of little hexagonal universal cellular automata. This is written in the sixties. So typically, they're all lying on the ground individually by themselves, but in times of crisis, they can communicate, they assemble into gigantic nets, into clouds. Of trillions of these particles and then they become hyper intelligent and they can beat anything that humans can can control at it. It's a very beautiful and compelling, where you have an intelligence, where finally the humans leave the planet. They're simply unable to understand and comprehend this creature. And they can say, well, either we can nuke the entire planet and destroy it, or we just have to leave because fundamentally it's an it's an alien.

• 52:35Speaker 02

  It's so alien from us and our ideas that we cannot communicate with them.

• 52:41Lex Fridman?

  Yeah, actually, in the conversation cellular automotives, Stephen Wolfram brought up is that there could be, his ideas, that you know, you already have these artificial general intelligence, like, super smart, or maybe conscious beings in the cellular automotives, we just don't know how to talk to them. So it's the language of communication, we just don't know what to do with it. So that's one sort of view, is consciousness is only something you can measure. So it's not conscious if you can't measure it.

• 53:09Speaker 02

  But so you're making an ontological and an epistemic statement. One is there, there, it's just like seeing the multiverses, that might be true, but I can't communicate with them. I don't have, I can't have any knowledge of them. That's an epistemic argument, right? Those are two different things. So it may well be possible. Look, in another case that's happening right now, people are building these mini organoids. Do you know about this? So you know, you can take stem cells from under your arm, put it in a dish, add four transcription factors, and then you can induce them to grow, to grow into large, well, large, they're a few millimeter, they're like a half a million neurons, that look like nerve cells, in a dish called mini organoids. At Harvard, at Stanford, everywhere they're building them. It may well be possible that they're beginning to feel like something, but we, we can't really communicate with them right now. So people are beginning to

• 53:54Speaker 02

  think about the ethics of this. So yes, he may be perfectly right, but they may, it's one question, are they conscious or not? It's totally separate question, how would I know? Those are two different things.

• 54:05Lex Fridman?

  Right. If you could give advice to a young researcher, sort of dreaming of understanding or creating human level intelligence or consciousness, what would you say?

• 54:18Speaker 02

  Just follow your dreams. Read widely.

• 54:23Lex Fridman?

  No, I mean, I suppose what discipline, what, what is the pursuit that they should take on? Is it neuroscience? Is it computational cognitive science? Is it philosophy? Is it computer science or robotics?

• 54:36Speaker 02

  No, in a sense that, okay, so the only known system that have high level of intelligence is Homo sapiens. So if you wanted to build it, it's probably good to continue to study closely what humans do. So cognitive neuroscience, you know, somewhere between cognitive neuroscience on the one hand, then some philosophy of mind and then AI, AI computer science. You can look at all the original ideas, neural networks, they all came from neuroscience, right? Um, reinforced whether it's Snarky, Minsky, Billings, Snarky, or whether it's, you know, the early Hubel and Wiesel experiments at Harvard that then gave rise to networks and then multilayer networks. Um, so it may well be possible. In fact, some people argue that to make the next big step in AI, once we realize the limits of deep convolutional networks,

• 55:21Speaker 02

  they can do certain things, but they can't really understand. They don't, they don't, they can't really, I can't really show them one image. I can show you a single image of somebody, a pickpocket who steals a wallet from a purse. You immediately know that's a pickpocket. Now, computer system would just say, well, it's a man, it's a woman, it's a purse, right? Unless you train this machine on showing it a hundred thousand pickpockets, right? So it doesn't, it doesn't have this easy understanding that you have. Right? So, so some people make the argument in order to go to the next step, or you really want to build machines that understand in a way you and I, we have to go to psychology. We need to understand how we do it and how our brains enable us to do it. And so therefore being on the cusp is also so exciting, right? To try to understand better our nature and then to build,

• 56:06Speaker 02

  to take some of those insight and build them. So I think the most exciting thing is somewhere in the interface between cognitive science, neuroscience, AI, computer science and philosophy of mind.

• 56:16Lex Fridman?

  Beautiful. Yeah, I'd say if there is from the machine learning, from our, from the computer science, computer vision perspective, many of the researches kind of ignore the way the human brain works. Ignore even psychology or literature or studying the brain. I would hope Josh Tannenbaum talks about bringing that in more and more. And that's, yeah.

• 56:37Lex Fridman?

  So you've worked on some amazing stuff throughout your life. What's the thing that you're really excited about? What's the mystery that you would love to uncover? In the near term, beyond, beyond all the mysteries you're already surrounded by.

• 56:52Speaker 02

  Well, so there's this structure called the klausström. This is structured underneath our cortex, it's y big. You have one on the left, on the right, underneath this, underneath the insular, it's very thin, it's like one millimeter. It's embedded in, in wiring, in white matter, so it's very difficult to image. And it has, it has connection to every cortical region. And Francis Crick, the last paper he ever wrote, he dictated corrections the day he died in hospital on this paper. He now, we hypothesize, well, because it has this unique anatomy, it gets input from every cortical area and projects back to every cortical area.

• 57:30Speaker 02

  That the function of this structure is similar, it's just a metaphor, to the role of a conductor in a symphony orchestra. You have all the different cortical players, you have some that do motion, some that do theory of mind, some that infer social interaction and color and hearing and all the different modules in cortex. But of course, what consciousness is, consciousness puts it all together into one package, right, the binding problem, all of that. And this is really the function, because it has relatively few neurons compared to cortex, but it talks, it receives input from all of them and it projects back to all of them. And so we're testing that right now, we've got this beautiful neuronal reconstruction in the mouse called crown of thorn, um, crown of thorn neurons that are in the klausström.

• 58:12Speaker 02

  That have the most widespread connection of any neuron I've ever seen, they're very deep. You have individual neurons that sit in the klausström, tiny, but then they have this, single neurons have this huge axonal tree that cover both ipsi and contravertal cortex. And, and trying to turn, using, you know, fancy tools like optogenetics, trying to turn those neurons on or off and study it, what, what happens in the, in the mouse.

• 58:35Lex Fridman?

  So this thing is perhaps where the parts become the whole.

• 58:40Speaker 02

  Perhaps it's one of the structures, it's a very good way of putting it, where the, the individual parts turn into the whole of, the whole of the conscious experience.

• 58:51Lex Fridman?

  Well, with that, um, thank you very much for being here today.

• 58:55Speaker 02

  Thank you very much. Jack, thank you much.