Transcripts of our episodes are made available as soon as possible. They are not fully edited for grammar or spelling.

Dr. Seth is a Professor of Cognitive and Computational Neuroscience at the University of Sussex in the United Kingdom. The author of over 200 research papers, Anil integrates psychology, philosophy, computer science, and neuroscience to explore how our brains generate subjective experiences. Outside the laboratory, Anil has a knack for communication, too. His TED Talk has reached nearly 15 million viewers, and his bestselling book Being You: A New Science of Consciousness takes a baffling topic and makes it relatable and engaging for general readers. Anil joins the podcast to explain why animals may be conscious, but artificial intelligence is not, and why, despite the potential for technological dystopias, he is optimistic about the future.

Tom: Anil, welcome to the show.

Anil: Thanks for having me; it’s a pleasure.

Tom: I want to start by asking you a few personal questions. Can you tell me first where you grew up and what some of your best memories from childhood are?

Anil: I grew up in a small village called Letcombe Regis, in Oxfordshire, in the south of England. It’s a very rural area, and I just have these Memories of an unrestricted childhood, being able to ramble around the countryside in ways that I guess children generally don’t enjoy these days.

Tom: As you were a child patrolling and exploring the world, finding your own things to play with and, experiment with, what kind of dreams do you cultivate as a young person imagining what your future would look like?

Anil: I didn’t have a vision of what it was I wanted to do. I was interested in consciousness, in the brain, and in science in general. I had this vague idea that that’s, what I wanted to be involved in. But a lot of people have these interests in who they are, and then they get educated into doing things that are more sensible and lining up with job opportunities better. So it was, one of these cases where life makes sense when looked at backwards. But when I was moving through it forward, there was no grand strategic plan.

Tom: Who are some of your mentors, people you look up to, and who had a big influence on you as you were growing up?

Anil: A person that comes to mind now is a person who sadly died a few weeks ago, the philosopher Daniel Dennett. Now, I read his book on consciousness when I was an undergraduate, 17 years old, I’d just started at Cambridge University. And reading his book on consciousness, called Consciousness Explained, gave me the sense that there’s a there, you know, there is exciting stuff to do here. And that’s given me a North Star ever since and I was lucky to get to know Daniel Dennett over the last eight years or so. And He’s been a great influence both before I knew him and after I knew him.

I was very lucky to go to Cambridge and to study natural sciences. And the great thing about that course was it was an antidote to this pressure to specialize. I had to study three or four different sciences to start with and could only specialize really in the third and final year. I started off doing physics and I was really getting to grips with some of these things that had fascinated me earlier, things like relativity and quantum mechanics. But in the back of my mind already was this idea that what I was really interested in now was the mind and the brain, how that worked.

And it felt to me at that time, for, for me, better or worse, that physics was not going to get me there. And frankly, it also got hard. You know, physics and math are easy up until a point, and then they become impossible. And I felt like I hit a wall.

But at that time, I was also doing molecular biology, and just became fascinated by the details of how cells work, and how genes work, and how proteins work. And this just seemed marvelous. But also, you know, we started studying psychology, and at Cambridge you get tutored in these very small groups. Maybe two or three students go and see a professor, which is an enormous privilege. my professor there, another mentor really, Nicholas McIntosh, was one of the 20th century’s leading behaviorist psychologists, which means that for him, studying consciousness was out there in the fringes and not what psychology should be about. But he was a great mentor because he encouraged me to think critically about consciousness while at the same time learning what was then the standard background for experimental psychology, how animals learn, conditioning, these kinds of things.

Tom: Well, it sounds like you got exposed to a great breadth of scientific disciplines as an undergraduate. And at least in the United States, choosing doctoral studies, taking the next step down the line requires incredibly narrowed, specialized focus. What did you do, on that next step of the academic path? And was it obvious that that was the next thing to do for you?

Anil: It wasn’t obvious. So, I think the next step came about because after my first degree, I wasn’t quite ready to just go and get a job outside of academia, not that I could have got a secretly interesting one anyway, but I, was also a little dissatisfied with how the psychology training at Cambridge had ended. We were learning about the brain in terms of all these boxes and arrows, old-school cognitive psychology. But the brain is not like that. You open a brain up; you don’t see neat boxes and arrows. You see just this mess of neurons. So, I became fascinated by the idea of neural networks. And this was long before they’ve become at the frontiers of AI.

That’s when I first came to Sussex University. Another mentor of mine, a philosopher named Andy Clark, had written some of the earliest papers and books exploring how thinking of the brain in terms of neural networks could help make sense of how we perceive, understand, and learn. So, I wanted to do a course that introduced me to some of these ideas and taught me some computer science and how to program.

So, I did a master’s course in that stuff at Sussex and stayed on to do a PhD. And the PhD, became, uh, much more specialized as PhDs must do. And I was working then on topics in what became known as artificial life. So, I kind of left the brain behind and I was interested now in how very simple systems could generate complex behavior. And we were using methods, like evolutionary algorithms, evolving neural networks to control little robots to do interesting things, and then trying to break down how and why. And the work I was doing there was more relevant to things like ecology and, robotics than it was to an understanding of consciousness. And at the end of that PhD, part of me thought, I’ve gone too far away and I need to get back to this, North Star, this idea of, you know, Uh, it later turned out that a lot of the concepts and ideas that I picked up during the PhD have been very, very useful because they have given me a distinctive perspective on the brain and on the mind.

Tom: This is a good segue to talking specifically about consciousness research. To get us started, tell me a little bit about what you mean by consciousness. Just as a layman, I’m wondering, is consciousness the same as self-awareness?

Anil: I don’t think consciousness is the same as self-awareness. For me, consciousness is something more basic. The philosopher Thomas Nagel defines it, I think, very nicely as for a conscious organism, there is something it is like to be that organism. and what he’s getting at here is that it feels like something to be me. I’m not just an object. You’re not just an object. Other animals, at least some other animals, are not just objects. It feels like something to be a bat, but for a table or a chair, it doesn’t feel like anything. They’re just objects. Another good definition of consciousness for me is what goes away. in general anesthesia and what comes back when you come around

Tom: Okay, that is helpful. So, some kind of interior experience.,

Anil: I think that’s right. The key thing is that some is experiencing going on and for us human beings’ part of that is normally the experience of self, So I’m aware that I am Anil Seth. I’m aware that I’m talking to you right now but that’s It’s not necessarily true for consciousness in general. It may not even be true for humans all the time. People in deep meditation or ego dissolution can be conscious but might lack this higher level of self-awareness entirely.

Tom: Hmm. Yeah.

Anil: Well, along these lines I hear Quite a few public intellectuals, maybe even other neuroscientists, say that consciousness doesn’t exist or it’s not real. Could you just help me understand? To me, consciousness seems self-evident as a given. maybe I read too much Descartes. But when you hear about people denying the very subject that you study and have put decades of your life into, what is it you think they’re saying when they say that consciousness doesn’t exist?

It’s a very good question. In philosophy, this position is called illusionism, and there are variants of it. Firstly, I think they can’t mean what we think they mean. It seems strange to completely deny the fact that we are conscious. And I think if you press people who say this, that’s not quite what they mean.

In one sense, it’s trying to push the idea that there’s Nothing supernatural, nothing extra special. Once we understand how the brain works and how all its functions are implemented, then we’ll have understood everything that we need to understand about consciousness, too.

I find this idea interesting up to a point. I think my starting point is very much not. That, my starting point, is that consciousness is real, conscious experiences exist, and there is something distinctive and interesting about how our brains do more than just process information. There is an experiential, a phenomenal dimension to it.

When I open my eyes, there are colors, shapes, sounds, smells, tastes, and touches. But I’m also open to the idea that consciousness is not what we might think it is. If we’re looking for some sort of red mental paint inside the brain or the mind when we have an experience of red, well, we’re not going to find it.

And if we’re looking for free will in some uncaused cause that pulls strings in the brain and makes things happen that wouldn’t otherwise happen, well, we’re not going to find that either. One of the great hopes, I think, of consciousness research is that it’s not only the answers change, but the questions change, too,

Tom: Mm hmm.

Anil: for me, that’s a more productive way to think of what illusionism might mean. Consciousness exists, but it might not be what we think it is.

Tom: Okay. Is consciousness one sort of unified, irreducible thing or is consciousness. made of parts? science often progresses by taking something that’s complicated, figuring out what the parts? are, and studying the parts tell me, how does this relate to consciousness

Anil: if we treat consciousness as a single irreducible thing, one big scary mystery, we’re tempted to try and find a single eureka solution to it. I mean, this sometimes works, but it often doesn’t work.

Now, in the history of studying life, instead of Treating life as one big scary mystery, the divide and conquer approach worked very well there. And so, in consciousness, maybe the same thing will apply. And we can try to treat it as a big mystery. But there are many parts.

There’s the experience of the world. There’s the experience of the self within the world. There are different kinds of perceptual experiences. There’s free will. And by separating it out, I think the sense that it’s an intractable mystery will begin to dissolve whether it disappears entirely or not, it is too early to say.

Tom: One thing I found fascinating in your book is how you described levels of consciousness. What are the levels of consciousness that a human can experience?

Anil: Looking at levels is a simplification of consciousness, right? I don’t think consciousness is Along a single dimension, like something such as temperature is, but there are still some broad differences where you would say there’s consciousness. When we’re under general anesthesia, we can say it’s gone away entirely.

Other states of sedation, maybe consciousness has gone away to some extent. Then there are various stages of sleep, that, again, very complex, but we can simplify and treat them, at least as a first approximation, as lying along a spectrum. And then we have normal waking consciousness.

There’s a kind of open question whether we can have a higher state of consciousness than the normal waking state. Now, colloquially, people talk about this all the time, but is there something that really is the opposite to anesthesia or sleep? That to me is a little, unclear.

Tom: Yeah, I was fascinated by your Description of trying to understand People who have a severe brain injury, who are in a coma, who are non-responsive; a doctor might want to know, is this person, though they’re nonresponsive, consciousness? Do they have an interior life? Are they aware of what’s going on?

They cannot tell me there is a way of using any instruments, measurements, or tools that can help a doctor detect whether a patient perhaps is still with us or not with us.

Anil: Yes, there is now, and I think this underscores how studying consciousness an armchair luxury is not just where we try and wrestle with the philosophical problems of the old, but it’s making an important difference already in the clinic, and this is one context where we see this.

People with traumatic brain injury, other kinds of brain injury, they sometimes enter these states where They do seem behaviorally unresponsive. They seem from the outside to lack any consciousness because they don’t respond to commands when you talk to them. They don’t do anything voluntarily. So, it’s easy to conclude that they’re unconscious. And the classic ways of assessing these patients is based on their behavior. And if they don’t behave in a way consistent with consciousness, then you say they’re not conscious. But this could just be because They can’t express the fact that they’re conscious.

The brain damage may have prevented them from, saying anything or behaving in, the right way. So, it’s important to look at the brain too. And there are now these emerging methods that are getting very, very useful in detecting consciousness that’s not apparent on the outside. The most well-known of these is something called the perturbation complexity index.

Basically, it amounts to sending a pulse of energy into the brain using a magnetic coil and then listening to the echo. If the echo is quite complex, this pulse of energy bounces around the brain a lot. You can measure how complex that is. And that number gives you an indication of whether that person is still conscious.

You can even open communication channels. You can even actually have people Talk to you through their brain activity when they’re unable to talk to you using their mouth, hands, or body.

This was another approach, another study done by a colleague and friend of mine, Adrian Owen, and his group in Canada. They had the idea that they could put patients in a brain imaging machine and ask them to imagine one of two things: playing tennis or walking around the rooms of their house.

We know from many previous studies that imagining playing tennis activates different brain regions than imagining wandering around your house. The reason they chose those two things was that the brain regions involved are very easy to distinguish—they’re very different in different places.

And so, the logic was that if you ask. patients these questions and you see the same patterns of brain activity, well that’s a really, strong indication that they’re conscious because it seems almost impossible that people would follow these instructions and not be aware.

But then the next thing you can do, take someone who does pass it, well then you can say, now I’m going to ask you a question and if you want to answer yes, Imagine playing tennis.

And if you want to answer no, imagine walking around your house. So yes, these conversations can take quite a while because they’re the kind of 20-question, yes and no, but any kind of communication channel with a person who otherwise is completely isolated from the environment—well, that’s priceless.

Tom: I want to pivot from measuring consciousness to another line of questions here. What would you say is the purpose of consciousness, like what is consciousness for? Humans have it, maybe other kinds of animals, it’s a peculiar, powerful, amazing thing. We have all these organs in our bodies doing various things. What about consciousness?

Anil: One of the most perplexing views in philosophy, I think, is the idea that consciousness is epiphenomenal, that it has no function. it’s quite an old idea, been talked about since Darwin’s days of consciousness just being, the whistle of this steam engine, not having any purpose.

That seems in direct contradiction to what conscious experience is. If we think about what’s going on in any experience, it seems beautifully designed to be useful for us as organisms, especially for complex organisms like human beings and many other animals, who have a certain flexibility in how they respond to the challenges of their environment.

So, any experience that we have and what it does is it brings together a large amount of relevant information about our immediate environment. We see things, we hear things, we can taste, touch things. Brings all this information together in a unified, way

That suggests opportunities for what we do next. We see a door; we might open it. And these are affordances that the psychologist William Gibson talked about. So, for me, purpose of consciousness is to condense a huge amount of organism relevant information in a way that’s. constructed to best guide our behavior that’s going to make us more likely to survive.

Tom: I want to turn next to the relationship between Consciousness and intelligence, I think a lot of times we either equate or conflate the two. what does consciousness have to do with intelligence?

Anil: Consciousness and intelligence, conceptually, are two different things.

Consciousness, we defined at the beginning, is any kind of experiencing whatsoever. It doesn’t have to involve language or complex thought or anything. It’s just being stabbed by a knife and feeling pain. Intelligence, conceptually, is different. Conceptually, it’s very broadly doing the right thing at the right time, or you could be a bit more specific and say it’s achieving goals through flexible means, and they are different.

I think being high on some scale of intelligence might give you more ways of being conscious. For example, I could be sad if something bad is happening, but to feel regret, which is a more subtle kind of conscious experience, then I need to have the cognitive capacity to imagine alternative courses of action, the path not taken. Otherwise, regret doesn’t mean anything.

Tom: Hmm.

Anil: So, there’s a correlation there, I think, that the more cognitive states you can enter, the more conscious states you might be able to enter. But they are not the same thing. I think using intelligence as a benchmark for consciousness is a mistake. you can have systems that are conscious, maybe some non-human animals may score low by our questionable standards of human intelligence, but still be conscious in their own way and perhaps have a more vivid conscious experience of the present than we do because we’re always distracted by the past and the future.

And it’s possible that we could have systems like AI or other technologies that are intelligent, but that are not conscious at all. And our tendency to link the two together, I think, says more about our human psychological biases, that we know we’re conscious and we think we’re intelligent, so we put the two together.

And then it says about how, these systems or these properties must go together in the real world.

Tom: Hmm. Yeah,

Anil: Seems like there’s a lot of public conversation now about the possibility of consciousness and maybe in octopus, birds, maybe even insects.

Tom: How might you go about trying to somehow measure or detect consciousness in some objective way that isn’t just hopeful or an expression of someone’s preference. Where does the measurement come in, in terms of non-human consciousness? Yeah.

Anil: problem. One of the challenges is these. measures that we have that have been used on human patients. We can’t just apply them to non-human animals or other systems and interpret the data. it doesn’t mean anything. the measures that we have, they’re not like measures of temperature that, we can apply to the sun or to deep space or to the volcano and, know what we’re talking about.

We don’t have the benchmarks. So, I think we’ve, got to be very cautious. we’ve got to recognize that we’ve got these countervailing pressures. You know, on the one hand, it’s clearly wrong to be human exceptionalist about this and say, oh, you know, only humans are conscious because can talk to each other and tell us about consciousness, so nothing else qualifies.

That seems very likely to be wrong. But on the other hand, we’ve got to be very careful when we generalize. So, for me, it’s just this cautious, incremental, cautious, process a bit like walking out onto a frozen lake and just checking the ice beneath your feet at every step to make sure it’s, solid.

So, the more we know about human consciousness, the more we can see what those mechanisms are. presence in other animals and if they are and all the evidence lines up and we can think well How would we adapt a test that we’re using in humans to a non-human animal?

Tom: A lot of what we know about human consciousness comes from studying the brains of monkeys. And other mammals too. For the ethically debatable reason that we’re prepared to do experiments on non-human primates that we are not prepared to do on, humans.

Anil: so, it does go both ways. Of course, the assumption there is that the brains of, non-human primates are sufficiently similar that they will shed light on human consciousness. And, we’re assuming, of course, that consciousness is one of those shared properties.

And here, I think neuroscience in general faces a unique challenge. Now, the brain is not on the other side of the universe. It’s not at the tiny scale of quantum mechanics.

It’s human size, obviously, because we all have one inside our heads. And there are many of them. So, studying the brain is easy compared to, the mysteries of cosmology or of particle physics. But the key challenge for the brain is complexity. 86 billion neurons, each one connected to a thousand neurons. We need both the ability to measure systems of that complexity and to develop theories about their behavior. So, we need a James Webb telescope for the brain, but one that’s suited to complexity rather than distance.

Tom: Yeah. Let’s turn then, too, non-biological entities. And you and I were at TED several weeks ago, and there was a lot of talk about artificial intelligence, assumptions, maybe justified that artificial intelligence is going to get better and better. We may sooner or later reach, artificial general intelligence, which, if I understand it correctly, is when, an AI system can approximate or exceed anything that a human can do.

I felt like there’s often a built-in assumption that, an AI system that can beat or exceed us in everything that we do, we could infer is conscious or, that a certain level of intelligence must yield consciousness. But I hear you saying that we should really be cautious about attributing consciousness to things.

What are some circumstances in which you think might be justified to attribute consciousness to an artificial agent?

Anil: For that to be possible, I would need to be convinced of an assumption that computation of some kind is sufficient for consciousness. And this is the assumption underlying all of these, claims. And we see these claims a lot. You’re right.

In the media, in the tech industry, and then some of the academic commentary as well, that AI will get smarter. And at a certain point, Consciousness just comes along for the ride, and the inner lights come on. And revealingly, this is often taken to be this moment of AGI, or perhaps a singularity, or some other threshold at which AI bootstraps itself beyond our understanding and control.

And again, this to me reveals more about our psychological biases than it does about what’s likely to happen. We think conscious AI is around the corner because we associate it with intelligence in this anthropocentric way, and we think we’re at this major point of transition on this exponential curve.

But there is this deeper question. Is consciousness, in principle, something a computer could have? Even if it doesn’t come along for free with extra intelligence, what if you programmed a computer to, be conscious, took our best theories of consciousness and simulated them on a supercomputer. Would that be enough?

Well, it still rests on this assumption that consciousness is a form of computation. And for me, this is a very, very strong claim. It might be right. But to just assume that it is, I think is a very dangerous assumption. And it’s dangerous because the more you look at a brain, the more you realize how different it is from a computer.

Even the claim that brains process information or do computation, well that is very questionable. And in a brain, you just can’t separate what it does, whether that’s computation or something else, from what it is. there’s no sharp distinction between mindware and wetware as you find between hardware and software.

In a computer. So I’m a bit on the fringe here,, but I, think that it’s more likely that consciousness is a property of life, of our nature as living creatures, than that it’s a property of computation. don’t know if that’s true. I can’t prove that. Frustratingly, it’s very difficult to think of an experimental test for it, but you can at least make a case for that being possible.

And if that’s on track, then we’ll see. We won’t get conscious AI. What we will get, of course, and we already have, we have computers that do a very good job of convincing us that they’re conscious. Because we are susceptible to these biases, we project these qualities in. So that’s going to be challenging enough as it is, living in a world Interacting with systems, large language models juiced up by deep fakes and perhaps robotics, where we’re unable to resist attributing consciousness, even if we’re unsure or sure that consciousness is not there.

Tom: To me, it’s just an imperative that, okay, look, we’re going to be in this situation. So, we need to, urgently discover more about consciousness in those situations where we know it exists. The more we know about the biology of consciousness in human beings and other animals, The better placed we’ll be to make informed inferences about whether it’s present in other systems.

I want to ask you A couple last personal questions to, tie things back to where we started. So, I wonder How has your study of consciousness shaped the way you see yourself and your relationships?

Anil: It’s hard to say because I don’t have the control condition of a different me that didn’t do this. But I, I do think about this, a bit, and I think it has made a difference. I can’t study consciousness during the day and then put it away in a drawer and go home and not think about it because we’re conscious all the time.

So, I do find myself walking around the world and it’s almost there in the background is just this mental habit of Not taking my experience at face value, not taking it for granted. On the one hand, just recognizing what a miracle it is that we have conscious experiences. What a privilege. And it didn’t have to be this way.

People talk about life out there on other planets and how amazing it would be if we found life on other planets. We probably will find life, but it may well just be some boring slime mold or something. The difference between a universe with life elsewhere and one suffused by consciousness or awareness, I mean, that It’s an astronomical difference.

It’s consciousness that is this beautiful gift that allows us to not just live but experience. So, I do find myself reflecting on that, but then more prosaically as well. When I’m just opening my eyes and looking at the sunset, something like that, then I do think, well, what’s happening?

What’s out there? How is my brain creating this experience? When it comes to emotions, it’s the same principle.

And that bit of distance can be, I think , quiet and helpful. Maybe it’s what meditation would give you in a different way for people who have the discipline, unlike myself, have the discipline to meditate for thousands and thousands of hours. And the fun thing to say here is I do think it changes relationships too.

Tom: Mm

Anil: If you understand that your own experience is a kind of construction, a controlled hallucination in the words I’ve used in the book and elsewhere, then you have a recognition that other people’s experiences might be different from your own, even in the same shared objective reality. There’s a bit of humility that you can cultivate about your own way of seeing, way of hearing, that my hope is provides a platform for understanding, for compassion.

I have no idea whether that’s reflected in my personal life, but I think it’s, something that’s relevant in wider society. We have this project going on now called the Perception Census, which is trying to measure how unique, perceptual experience is, how much it varies from person to person.

This is scientifically interesting, but there is also this Kind slightly below the surface social agenda here, that if we can bed in this recognition, that the way I see things, the way you see things is unique, is different. that might help us all realize that we, live in perceptual echo chambers, just as much as we live in social media echo chambers. And of course, then we’ve got a chance of getting out of them.

Tom: Yeah. The last question I got for you. The fields of neuroscience, artificial intelligence, robotics are blazing forward. There is a lot of optimism. There’s also a lot of, dystopian scenarios that people have, Devised and worry about what gives you hope about the future?

Anil: Well, every development, I think, in this rapidly changing environment, scientific and technological, has two faces. Technology can be incredibly powerful for the benefit of humanity. It can also be dangerous. these methods in AI are extremely powerful. We have new fields of medicine opening, but we also have challenges to our social fabric, which are going to be difficult.

To deal with. Are we up to navigating them? I think we are, but I don’t think we can take it for granted. And

when it comes to consciousness research, what gives me hope here is not that I think we’re going to finally solve the problem. I would love. for there to suddenly be an explanation that makes perfect sense.

And, we understand yes, that’s how and why consciousness happens. That may be a pipe dream still, but what gives me hope is that the very process back to an earlier part of our chat, this divide and conquer approach, doing it piecemeal, even if we don’t solve the fundamental mystery, we still make a lot of progress, and that progress can be extremely beneficial for each of us individually and for society.

Ultimately, it’s a humanizing enterprise. The more we understand about ourselves, I think the more we see ourselves as part of nature and less as apart from nature. And that’s always been empowering and humbling in equal measure. For us as a species.