Anil Seth is a prominent neuroscientist and professor at the University of Sussex, and has made significant contributions to the field of consciousness studies. His research and ideas, particularly the concept of human consciousness as a "controlled hallucination," offer a new perspective on understanding the human mind. Anil Seth's work combines neuroscience, psychology, and computational science. He is known for his study of the biological basis of consciousness and has become a leading figure in this field. Dr. Seth is also the author of the book Being You: A New Science of Consciousness.
Human Consciousness as a Hallucination
Seth's central idea is that our perception of reality is about active prediction and interpretation rather than passively receiving information. He suggests that the brain is continuously making predictions about the sensory input it receives, and these predictions form the basis of our perception. In essence, what we perceive is the brain's best guess of what's out there in the world, based on incomplete sensory information.
Seth argues that the brain is a prediction machine that constantly generates models or hypotheses about the world. These predictions are then compared with actual sensory input. When there is a match, our perception is confirmed; when there's a mismatch, the brain updates its model. This process is continuous and forms the basis of our conscious experience. This is similar to how scientific models work, except that our brain does it in real time.
Hallucinations vs. Perception
A key aspect of Seth's theory is the comparison between hallucinations and normal perception. In hallucinations, the predictions of the brain are not adequately checked against or corrected by incoming sensory information, leading to a distorted perception of reality. There is no feedback loop. In normal perception however, these predictions are constantly being updated and refined based on real-world sensory inputs, leading to a more accurate understanding of the world.
Neurological Basis
Seth's work is grounded in studies of the brain's neural mechanisms. He explores how different brain regions are involved in creating predictions and how they are adjusted. This approach also explains why, when certain brain areas are damaged or when sensory inputs are disrupted, individuals might experience hallucinations or altered states of consciousness.
Implications for Understanding Human Consciousness
This perspective has profound implications for understanding human consciousness. It suggests that our experience of being conscious is not a direct reading of the world but a constantly updated simulation created by the brain. Consciousness, in Seth's view, is a deeply personal, private experience, generated by the brain's predictions and interpretations.
The "Best Guess" Approach to Perception
Seth's theory proposes that all perceptions are internal constructions, a kind of 'best guess' of the world. This means that different individuals might perceive the same stimulus differently, based on their brains' unique predictive models. These models are shaped by a person's previous experiences, biology, and even mood, leading to a highly subjective experience of reality.
Attention plays a crucial role in this model. Seth suggests that what we pay attention to shapes the predictions our brain makes, influencing our perception. This idea aligns with how focusing on certain aspects of our environment can change how we perceive it.
Consciousness and Self
An important extension of Seth's theory is how it accounts for the sense of self. He proposes that the way the brain predicts and interprets external sensory information is also how it creates our perception of the self. This self-model is a controlled hallucination of sorts, providing a coherent narrative and sense of agency.
While Seth's theory is influential, it is not without its critics. Some argue that while the model explains the mechanics of perception, it doesn't fully address the deeper philosophical questions of why consciousness feels the way it does – the so-called "hard problem" of consciousness.
Future Directions
Seth's ongoing research aims to further unravel the neural mechanisms behind conscious experience. He is also interested in how artificial intelligence and machine learning might provide new insights into the workings of the brain and consciousness.
Anil Seth's view of consciousness as a controlled hallucination offers a fascinating lens through which to understand the mind. By framing consciousness as the brain's best guess at interpreting a complex and ambiguous world, Seth's work challenges our notions of objective reality and subjective experience. His theory not only advances our understanding of the human brain but also provides a framework for exploring the nature of consciousness itself, a mystery that has intrigued thinkers for centuries.
Seth Answers Some Questions
In a recent interview by Steve Strogatz on the Joy of Why podcast, Seth answers some questions concerning the mystery of consciousness. Here are a few excerpts:
Strogatz: 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: 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.
Strogatz: 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: ...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...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...consciousness in general is...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. 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...
So the idea behind the concept of controlled hallucination is that our experiences of the world and indeed of the self, they’re not direct readouts of what’s actually there, even though it may seem that way in our experience. You open your eyes in the morning, and there’s just a world. And it seems as though the world is just pouring itself into your mind through the transparent windows of your eyes and your other senses. But this is not what is going on...That perception, what we experience, is an active interpretation of the sensory information that comes in. And this sensory information, it doesn’t come with labels on, like: “I’m from a cat or a coffee cup,” or “I’m red or green,” or “I’m from the back of a mug,” or even “I’m from the heart or the stomach.” From the brain’s perspective, it’s electrical impulses. It’s just activity. So the idea is that the brain is always trying to figure out the most likely cause of the sensory information that it gets. It can’t directly know what the world is like. I mean, who knows what the world is really like? That’s really a question for a physicist. It’s certainly not something that is reflected directly in our experience. And the brain is always then trying to make its best guess about the causes of the sensory signals that it gets.
How does it do that? Well, here comes the modern gloss on this. It’s a theory called predictive processing or predictive coding, or active inference in another recent guise. And the idea is quite simple. It’s that the brain is always generating predictions about the way the world is or the way the body is. And it uses the sensory signals to just update, calibrate these predictions to keep them tied to the world, in ways that are not necessarily titrated by accuracy, but by their utility for the organism. So we see the world not as it is, but as we are.
But there’s a really provocative flip here, which is to realize — or at least this is the hypothesis — that what we perceive is not just sort of modulated by the brain’s expectations, but it’s built from them. So that the world we experience really does come from the inside out, rather than from the outside in. And the sensory signals, they’re just reporting what we call prediction errors, the difference between what the brain is expecting and what it’s getting at every level of processing...
So this is why I use the word “controlled hallucination,” because it shares with the common understanding of hallucination that it’s an experience that comes from within. But the control is equally important. I’m certainly not saying that our experience is arbitrary, or that the real world doesn’t exist or anything like that. No, the world exists. But our experience of it is always a construction, always an act of interpretation. And it is controlled by sensory signals coming from the world. And evolution has made damn sure of that, that our perceptual experiences work in service of our behavior. And of course, they can go wrong. And that’s when we get fun illusions, and why magic tricks work and all this wonderful stuff...
And I think the same sort of weird mapping holds in all other aspects of our experience too. It’s not just a filter of what’s there. It’s a construction that uses sensory signals to build this experience, this subjective experience of a world with all sorts of properties that help us behave. But these properties, they exist. Where do they exist? They’re in the continuing interaction between the brain, the body and the world. They’re not just out there in the world, or just in the brain.
Strogatz: I’m reminded of expressions that you have been using earlier in this conversation where you say things like, “the brain’s best guess,” or “the brain is trying to make sense of…” It almost makes me picture what people used to call the homunculus. Like, there’s a little person inside your head who’s looking out through your eyes, trying to make sense of the world. It’s sort of: the self, what is it? I mean, who’s in there? Who is it that’s trying to make sense?
Seth: Yeah, I mean, so this is why when I say the brain believes this, or the brain predicts this, I tried to be careful to say the brain rather than you. Because I think the experience of being you, the experience of self, is another kind of controlled hallucination. It’s another kind of brain-based best guess, OK? And this is another challenge to this sort of naive how-things-seem view of perception. Now, just as it seems as though there’s a real world out there that just pours itself into our minds, it might also seem to us that the self is the thing that does the perceiving. This quiddity, this essence of you or me, maybe the soul that resides somewhere homunculus-like inside the skull, doing all the perceiving and then deciding what to do and then pulling various meat strings in the body to make actions happen. And I think this is fundamentally mistaken...It’s not the thing that does the perceiving. It’s another kind of perception, but this time based at least in part on the body. So just as the brain, in trying to make sense of what’s out there in the world, is making predictions about the causes of signals that come into the eyes and the ears and so on, it’s also trying to figure out what’s happening inside the body and trying to also control the body too. And this also happens, in my view anyway, through a process of the brain creating predictions and using them to update sensory signals, but in this case from the body. Or when making actions to use predictions to actually, you know, overwhelm sensory data so they become self-fulfilling predictions, so that if I move my arm to pick up the cup again, now that’s a kind of self-fulfilling prediction about where my arm will be.
But the key point is that there’s a common principle here underlying experiences of the world, and experiences of the self. They’re both forms of perceptual prediction. Neither of them reflect things as they really are. And both can be subject to illusions — they can both go awry in various ways.
Links to Anil Seth's work can be found at AnilSeth.com
