Neuroscience has made progress in deciphering how our brains think and perceive our surroundings, but a central feature of cognition is still deeply mysterious: namely, that many of our perceptions and thoughts are accompanied by the subjective experience of having them. Consciousness, the name we give to that experience, can’t yet be explained — but science is at least beginning to understand it. In this episode, the consciousness researcher Anil Seth and host Steven Strogatz discuss why our perceptions can be described as a “controlled hallucination,” how consciousness played into the internet sensation known as “the dress,” and how people at home can help researchers catalog the full range of ways that we experience the world.
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Transcript
Steven Strogatz (00:03): I’m Steve Strogatz, and this is The Joy of Why, a podcast from Quanta Magazine that takes you into some of the biggest unanswered questions in math and science today. In this episode, we’re going to be discussing the mystery of consciousness. The mystery being that when your brain cells fire in certain patterns, it actually feels like something. It might feel like jealousy, or a toothache, or the memory of your mother’s face, or the scent of her favorite perfume. But other patterns of brain activity don’t really feel like anything at all. Right now, for instance, I’m probably forming some memories somewhere deep in my brain. But the process of that memory formation is imperceptible to me. I can’t feel it. It doesn’t give rise to any sort of internal subjective experience at all. In other words, I’m not conscious of it.
(00:54) So how does consciousness happen? How is it related to physics and biology? Are animals conscious? What about plants? Or computers, could they ever be conscious? And what is consciousness exactly? My guest today, Dr. Anil Seth, studies consciousness in his role as the co-director of the Sussex Center for Consciousness Science at the University of Sussex, near Brighton, England. The Center brings together all sorts of disciplinary specialists, from neuroscientists to mathematicians to experts in virtual reality, to study the conscious experience. Dr. Seth is also the author of the book Being You: A New Science of Consciousness. He joins us from studios in Brighton, England. Anil, thanks for being here.
Anil Seth (01:42): Thanks for having me. It’s a pleasure to be on with you.
Strogatz (01:44): Well, this is, I have to say, one of my favorite and most perplexing things to think about. I don’t really know where to start with it. I mean, consciousness is so mysterious. I sometimes have this uncanny sensation, maybe like once or twice a year. I’ll be looking in the bathroom mirror, shaving. And then I get this creepy feeling like: What is this lump of matter looking back at me in the mirror? Like, who’s in there?
Seth (02:11): Yeah, welcome to my world. This sounds like a description of my every day. Now, in one sense, you leave the mystery behind when you go and make dinner and leave your normal life. But it does have this habit of going everywhere with you. And most days, I’ll have a moment like that. And I will try and train myself also just to continually reflect and meditate on this everyday miracle that we have this electrified pâté inside our skull. And that somehow, in conjunction with the body and its interaction with the world, there isn’t just complicated biological machinery chugging away: There is subjective experience. It feels like something to be me, and it feels like something to be you — to use a definition that comes from the philosopher Thomas Nagel.
(02:58) And that is really still quite astounding. It doesn’t feel like anything to be a table or a chair. But this is the fundamental mystery of consciousness. And it’s both a deep scientific and philosophical mystery, but also a very personal mystery. Because part of the “feeling like” is the feeling of being a particular person. Being the individual that you are. Being you or being me.
Strogatz (03:22): You have just introduced the word “self.” You can be conscious of various things; you can also be conscious of having a self. Should we start to try to tease apart the different concepts related to consciousness? What is consciousness? How is it different from self-consciousness?
Seth (03:39): I think that’s a good idea. There’s always this problem with definition when it comes to a poorly understood phenomenon. Looking back at the history of science, I think we both know that definitions aren’t sort of written in stone and you settle on one and then you just try and figure out what the underlying science is. The definitions always evolve along with our understanding.
(04:00) And so for consciousness, the place I start is with this definition from philosopher Thomas Nagel, who simply said, for a conscious organism, there is something it is like to be that organism. It feels like something to be. Yeah, that’s fairly circular. But I like it because it hits the bullseye that it’s just talking about experience, and it’s useful for what it leaves out. It’s often tempting — and this has happened before in many other examples — of associating consciousness implicitly with something else, whether that’s intelligence, or having language or behaving in a particular way. Or knowing who I am in an explicit, reflective sense of self.
(04:40) All of these things may be aspects of human consciousness. But consciousness in general is not the same as any of these other things. It’s just the raw fact of that experiencing. But then within that, there are indeed further divisions that you can make. And I think this is heuristically useful in dividing up the problem so we can get at consciousness from a kind of divide-and-conquer strategy.
(05:03) And there are three ways that I like to do it. There’s the level of being conscious at all. You lose it when you’re under general anesthesia or in dreamless sleep. Then you are conscious of what’s around you, the world. And then within that, there’s the experience of being yourself, of being the person that you are.
Strogatz (05:20): I thought that was a terrific aspect of your book, as far as helpfulness to me as a reader, to be able to think about chopping up the problem in various ways. You mentioned four levels: the level of consciousness; the issue of what you call the content or contents of consciousness — what we’re conscious of or what we perceive; consciousness of self; and then the fourth one, you say, is this really profound mystery of being you?
Seth (05:47): Well, I actually think the third and the fourth are rather the same.
Strogatz: OK, fine.
Seth (05:49): But there are many ways of experiencing being yourself. So we can have experiences of self without knowing that we’re having these experiences. I can experience being associated with this object that’s my body, and I can have emotions and moods. And all of that can in principle unfold without attaching a name and a set of memories to it.
(06:13) So there are, within each of these areas of content and level and self, there are of course more fine-grained distinctions that we can make. And we can ask whether these finer-grained distinctions have any traction in the laboratory or the clinic — do they pick out joins in nature? Or do they not? Are they things we just sort of make up? And that’s part of, I think, the game of consciousness research. We can figure out which of our distinctions have traction in the real world.
Strogatz (06:20): Great, I do appreciate that, because on this podcast, we try to talk about science, especially big mysteries in science. But I would want to underline the word science. That there are things we can ponder that are outside the realm of science, not even testable or refutable in principle. And I take it that you really are focused on the scientific side of consciousness — I’m sure your philosophical side likes pondering the unanswerables as well.
Seth (06:41): Well, I don’t think philosophy is just pondering the unanswerables. I think science and philosophy really work together in understanding something for which it’s not clear what a satisfactory understanding would look like. Now, we don’t necessarily need philosophy if we are at the stage of the Human Genome Project, where we know exactly what we’re doing and it’s just a sort of engineering problem of how we do it. But when it comes to consciousness, there’s still a mystery not only about how it happens, but about what a successful answer would even look like.
Strogatz (07:08): I appreciate your use of the word “explain” here because I’d like to get into the question of what you have sometimes called the “real problem” of consciousness as opposed to the “easy problem.” So what is the real problem?
Seth (07:39): So science and philosophy really still need each other. You know, with the one, science without philosophy is a bit blind, and philosophy without science is a bit lame. So I’ve never formally studied philosophy, but it’s always been in my environment. And I’ve benefited enormously from talking to and collaborating with philosophers and even trying out some philosophy ideas myself. I think we need it. It keeps science honest, and it helps guide it to the right kinds of questions.
(08:16) But I think there’s still approaches to consciousness which I find less appealing, which are those that are in principle non-testable, which may be purely philosophical positions. There’s a position that’s becoming quite popular these days called panpsychism, which is this idea that consciousness isn’t something that brains generate, or that is identical to particular kinds of brain processes or biological processes, but that it’s fundamental and ubiquitous. That it’s somehow everywhere and in everything like charge or mass-energy. This is maybe superficially an appealing idea, because if you just say consciousness is there from the get-go, then you don’t have to explain how it comes about in certain places and not others.
(08:16) But it doesn’t really explain anything. And it’s not only that it’s not testable; it doesn’t lead to anything that could be testable. And it’s that that I find off-putting. I think philosophical perspectives, they’re rarely themselves testable. Like materialism — the view that I sort of work with, the idea that consciousness is a natural phenomenon and is somehow a property of material things like brains and bodies. That itself is probably not testable. But what it does do is it leads to things that are testable, and over time allows us to explain things about consciousness that we would otherwise not be able to explain.
(09:47) The real problem is how to explain, predict and maybe even control properties of consciousness in terms of their underlying mechanisms in the brain and the body. And that sounds like sort of an obvious thing that we should be trying to do, right? But it’s actually not so much, because these properties of consciousness that I’m talking about that we should try to explain, they are primarily experiential, or what we would call phenomenological properties. Which is an incredibly long word, but what it really just means is the way in which conscious experiences appear as experiences — not what they allow us to do so much, or what functions they might have in terms of the cognitive architecture of the brain.
(10:30) Like, why is a visual experience the way it is and different from an emotional experience? Visual experiences, they have spatial character, they have objects, and things move. An emotional experience doesn’t have these sorts of things, right? It has valence: Things are good or bad. So the real problem is about connecting mechanisms in the brain to these kinds of properties of phenomenology.
(10:54) The reason I called it the “real problem” was as a bit of a bit of a pushback — a kindly, friendly pushback against this “hard/easy problem” distinction from David Chalmers that has really dominated a lot of the contemporary science and philosophy of consciousness. And the reason it’s different is because the hard problem of consciousness is this big, scary mystery. It’s the problem that we mentioned at the start of this conversation. How is it that consciousness happens at all? What is it about matter arranged in a particular way that makes experience happen? I mean, Chalmers puts it like this himself, he said: “It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does.” And that’s a hard problem. It’s not just like, difficult. It’s hard in this conceptual sense of nobody even really knows what a good answer would look like.
(11:59) And then Chalmers separates that from the easy problems. And by the easy problems, basically, these are all the problems about how brains work, for which you don’t really need to bring consciousness into the picture at all. You know, how the brain transforms sensory signals into actions and making decisions and so on.
(12:17) And my worry with that approach was either you focus on this incredibly challenging hard problem, or you don’t really focus on consciousness at all. And I think there’s a middle ground, which is very productive, which is in fact what a lot of people are already doing, which is: Yes, you accept consciousness exists, and that it’s intimately related to the brain and the body, and you just try to explain its properties. And the hope is that as you do this, then the apparent mystery of the hard problem will bit by bit begin to lessen. And you won’t necessarily solve the hard problem this way, but you might dissolve it. So that it eventually disappears into a puff of metaphysical smoke. And we realize that even though we haven’t started out to solve this big question, we’ve actually got a very good naturalistic explanation that tells us so many things about consciousness in terms of their underlying mechanisms. And that’s all that a scientific explanation in the end is supposed to do.
Strogatz (13:19): If we could give a concrete example of these distinctions, I think it might help. So you mentioned earlier the visual experiences that we have. For instance, if I see something that’s red, you might naively say, “Well, I understand that that’s going to be diffe
