Christopher: Everything you see, hear, and feel right now is a hallucination. Not a metaphor—a hallucination, just one that your brain happens to agree on with everyone else. And the most convincing hallucination of all? The person you call 'you'. Lucas: Okay, hold on. My morning coffee was a lie? I feel betrayed. Are you telling me this very real, very solid microphone in front of me is just a figment of my imagination? That sounds a little too much like my freshman year philosophy class. Christopher: (Laughs) It feels real, I grant you that. But that feeling is the masterpiece of the illusion. This is the radical idea at the heart of a book that has been rattling my brain for weeks: Being You: A New Science of Consciousness by Anil Seth. Lucas: Anil Seth. I’ve heard that name. Isn't he a pretty big deal in the neuroscience world? Christopher: A huge deal. He's a professor of neuroscience at the University of Sussex and runs a whole research center dedicated to cracking the mystery of consciousness. And this book isn't some fringe theory; it was showered with 'Best Science Book of the Year' awards when it came out. He’s trying to take this incredibly complex, philosophical topic and ground it in actual science. Lucas: Alright, you have my attention. If a top neuroscientist is telling me I’m hallucinating, I’m at least willing to listen. Where do we even start with an idea that big? Christopher: We start with your own brain. Let me ask you, have you ever seen that famous optical illusion, Adelson's Checkerboard?

Lucas: Vaguely. The one with the green cylinder casting a shadow on a checkerboard, right? Christopher: That's the one. So you have this checkerboard pattern. There's a square in the light, labeled 'A', that looks dark gray. And there's a square in the shadow of the cylinder, labeled 'B', that looks like a very light gray. Which one is darker? Lucas: A, obviously. It's not even close. B is practically white. Christopher: And you'd bet money on it? Lucas: I would bet this possibly-not-real microphone on it. Christopher: Well, you'd lose the microphone. Squares A and B are the exact same shade of gray. Identical. If you took a color sampler in Photoshop, they would have the same RGB value. Lucas: No way. That's impossible. I’m looking at a picture of it right now, and my eyes are telling me you’re wrong. How can that be? Christopher: This is the core of Seth's argument. Your brain isn't a passive camera just recording light. It's a prediction machine. It sees the shadow being cast by the cylinder and it makes a guess. It says, "Okay, a light-colored square in a shadow would reflect less light, making it look darker. To see it as it truly is, I need to mentally brighten it." So your brain 'corrects' the image for you. It presents you with what it thinks is the most useful reality. Lucas: So my brain is basically running its own internal, automatic Photoshop filter on reality, all the time, without my permission? Christopher: Exactly! And it's not a bug; it's the fundamental feature of how we perceive anything. Seth calls it a 'controlled hallucination'. The 'hallucination' part is the brain's prediction—its best guess of what's out there. The 'controlled' part is the sensory data—the light waves actually hitting your retina—that reins the hallucination in and keeps it tethered to the world. Lucas: Huh. That makes the whole phenomenon of 'The Dress' make so much more sense. You know, the blue-and-black or white-and-gold dress that broke the internet a few years ago. Christopher: It's the perfect example. People weren't 'wrong' about the color. Their brains were just making different assumptions about the lighting in the photo. Was the dress in a shadow or in bright, direct light? Depending on your brain's unconscious guess, you experienced a completely different reality. Your brain was telling you a different story about the world. Lucas: Wow. Okay, I can sort of accept that my perception of the world is a bit of a construction, a story my brain tells me. But surely I am not a hallucination. My feelings, my memories, my sense of being Lucas... that's got to be real. That’s the one thing I can be sure of, right? Christopher: That is the most profound and challenging leap the book asks us to take. Seth argues that the self is also a perception. It’s another, more complex, controlled hallucination. And the most powerful way to understand this is to see what happens when the machinery that builds that hallucination breaks down.

Lucas: Breaks down how? Like in a brain injury? Christopher: Precisely. Seth brings up the devastating case of a British musicologist named Clive Wearing. In 1985, Wearing was at the peak of his career, a brilliant conductor and musician. Then he contracted a rare brain infection—herpes encephalitis—which completely destroyed his hippocampus, the part of the brain crucial for forming new memories. Lucas: Oh man. So he had amnesia? Christopher: The most profound case of amnesia ever recorded. Clive was left with a memory span of about 7 to 30 seconds. He was trapped in a permanent, looping present. He couldn't remember the question he was just asked, or the fact that he'd just had a sip of coffee. Lucas: That's just… I can't even imagine. What was that like for him? Christopher: He kept a diary. And in it, he would write the same entries over and over, sometimes just minutes apart. Things like: "8:31 AM: Now I am perfectly, completely awake." Then, a few minutes later: "9:06 AM: Now I am really, completely awake." He would cross out the previous entries, angry that anyone could think he was conscious before. To him, every moment of awareness was the very first. Lucas: Wow. So he had no past. Christopher: None. And because he had no past, he had no sense of a continuous self. His wife, Deborah, wrote that he would often say things like, "I haven't heard anything, seen anything, touched anything, smelled anything. It’s like being dead." He had lost what Seth calls the 'narrative self'—that story we tell ourselves that links our past, present, and future into a coherent identity. Lucas: That is both heartbreaking and absolutely fascinating. So without that story, that continuous narrative built from memory, his sense of 'Clive' just... evaporated. It really shows how much of our 'self' is a construct, a story we're constantly updating. Christopher: Exactly. The feeling of being a stable, continuous 'you' isn't a given. It's an active, biological process. Seth breaks the self down into different layers—the embodied self (the feeling of having a body), the perspectival self (seeing from a first-person point of view), the volitional self (the sense of agency), and this narrative self. For Clive, the narrative part was annihilated, but other parts remained. He still recognized his wife, Deborah, and would greet her with overwhelming love every time she entered the room, as if for the first time. He could still play the piano brilliantly. Lucas: So parts of his 'self' were still there, but the main character of his own life story was gone. It really drives home that the self isn't one single 'thing' in the brain. It's a bundle of different perceptions. Christopher: A bundle of controlled hallucinations, all working together to create the experience of 'Being You'. And the ultimate purpose of this construction, Seth argues, isn't for self-knowledge or philosophical pondering. It's for survival. The self is a tool the brain uses to regulate the body and keep it alive. Lucas: Which makes the self a biological phenomenon. It's tied to our bodies, to being a living, breathing organism. Christopher: He calls it the 'beast machine' theory. We are conscious selves because we are beast machines. Our minds are not separate from our biology; they are expressions of it. And if the self is tied to our specific biology, that opens up a wild question: what is it like to be a different kind of beast machine?

Lucas: You mean like an animal? How could we ever know what it's like to be, say, a dog or a bat? Christopher: That's the challenge. But Seth pushes us to think about an even more alien mind, one that evolved on a completely different branch of the evolutionary tree. He takes us into the world of the octopus. Lucas: Oh, I love that. Octopuses are so bizarrely intelligent. Christopher: They're like something from another planet. A human brain is centralized. An octopus's nervous system is highly distributed. It has more neurons in its eight arms than in its central brain. Each arm can act semi-autonomously. It can taste by touch. It can solve complex puzzles. Lucas: Hold on, so its arms are kind of thinking for themselves? That's wild. It's like having eight intelligent, feeling limbs that you have to coordinate. Christopher: And think about what that means for its sense of self. We have a very clear, unified sense of our body. An octopus, with its incredibly flexible, boneless body and distributed brain, might not experience 'body ownership' in the same way at all. Experiments have shown that a detached octopus arm will avoid grabbing another octopus arm with skin on it, but will happily grab a skinned one. It has a chemical, taste-based self-recognition system. Lucas: So it 'tastes' itself to know what's 'me' and what's 'not me'? That's so different from our visual and spatial sense of self. So, does Seth think an octopus is conscious? Christopher: He argues it's very likely, but in a way that is profoundly, fundamentally alien to our own experience. It's a consciousness without a unified, stable self at its core. It forces us to abandon our human-centric bias that consciousness has to look and feel like ours. Lucas: And what about machines? If an octopus can be conscious, what about a super-intelligent AI? Christopher: This is where Seth becomes more of a skeptic. He argues that intelligence and consciousness are not the same thing. You don't have to be smart to suffer, and you can be very smart without feeling anything at all. His 'beast machine' theory ties consciousness to the biological imperative of staying alive—regulating temperature, finding food, avoiding damage. It's about interoception, the sense of the body's internal state. Current AI, no matter how intelligent, doesn't have a body to keep alive. It doesn't have a biological stake in its own existence. Lucas: So for Seth, consciousness isn't about processing power, it's about being a living thing. A thing that can die. Christopher: That's the heart of it. It's a deep, biological anchor. Without that, he suggests, you might get incredibly sophisticated information processing, but you won't get genuine, subjective experience. You'll get a clever zombie, not a conscious mind.

Lucas: So, from the colors we see, to the person we think we are, to the minds of other creatures, it's all a construction. Our brain is a reality-generator, not a reality-detector. And its main job isn't to be accurate, but to be useful—to keep the beast machine running. Christopher: Exactly. We are all living inside a perceptual world created by our brains. It’s a world of controlled hallucinations, and that includes the hallucination of being a stable, continuous self. The science is revealing just how deeply our conscious minds are part of nature, not separate from it. Lucas: It’s a bit of a humbling thought, isn't it? It displaces us from the center of things. We're not just passive observers of an objective reality. We're active participants in a reality of our own making. Christopher: It is. And that leads to the ultimate question Seth leaves us with: If your reality is a controlled hallucination, what do you choose to do with it? Lucas: That's a huge idea to sit with. It almost gives you a sense of freedom, in a weird way. If it's all a construct, maybe we have more say in that construction than we think. Christopher: I think that's a perfect takeaway. We’d love to hear what our listeners think about this. Does this idea change how you see yourself, or the world? Find us on our socials and join the conversation. It’s a topic that really sticks with you. Lucas: It definitely does. This has been a mind-bending one. Christopher: This is Aibrary, signing off.