Thammasat University students interested in the allied health sciences, philosophy, psychology, psychiatry, neuroscience, and related subjects may find it useful to participate in a free 17 January Zoom webinar on neuroscience and human perception.

The event, on Tuesday, 17 January 2023 at 9pm Bangkok time, is organized by the Department of Psychiatry, the University of Oxford.

The TU Library collection includes books about different aspects of neuroscience.

The presentation, titled From beast machines to dreamachines, will be given by Professor Anil Seth, Professor of Cognitive and Computational Neuroscience at the University of Sussex, the United Kingdom, codirector of the Sackler Centre for Consciousness Science and codirector of the Canadian Institute for Advanced Research (CIFAR) Program on Brain, Mind, and Consciousness, and of the Leverhulme Doctoral Scholarship Programme: From Sensation and Perception to Awareness. He is interviewed in a book in the TU Library collection on consciousness. 

Students are invited to join remotely with details at the following link, with no preregistration required:

https://talks.ox.ac.uk/talks/id/f72e3eba-adc0-4e3f-a795-8853741f9428/

During a recent TED talk, Professor Seth explained how human brains invent identity:

Who am I? Who is anyone, really?

When I wake up in the morning and open my eyes, a world appears. These days, since I’ve hardly been anywhere, it’s a very familiar world: there’s the wardrobe beyond the end of the bed, the shuttered windows and the shrieking of seagulls, which drives Brighton residents like me absolutely crazy. But even more familiar is the experience of being a self, of being me, that glides into existence at almost the same time.

Now this experience of selfhood is so mundane that its appearance, usually, just happens without us noticing at all. We take our selves for granted, but we shouldn’t. How things seem is not how they are. For most of us, most of the time, it seems as though the self, your self, is an enduring and unified entity — in essence, a unique identity. Perhaps it seems as though the self is the recipient of wave upon wave of perceptions, as if the world just pours itself into the mind through the transparent windows of the senses. Perhaps it seems as though the self is the decision-maker in chief, deciding what to do next and then doing it, or, as the case may be, doing something else. We sense, we think and we act. This is how things seem.

How things are is very different, and the story of how and why this is so is what I want to give you a flavor of today. In this story, the self is not the thing that does the perceiving. The self is a perception too, or rather, it’s the collection of related perceptions. Experiences of the self and of the world turn out to be kinds of controlled hallucinations, brain-based best guesses that remain tied to the world and the body in ways determined not by their accuracy, but by their utility, by their usefulness for the organism in the business of staying alive…

Now the upshot of all this is that perceptual experience is what I’ve come to call, drawing on the words of others, a “controlled hallucination.” Now this is a tricky term, prone to misunderstandings, so let me be clear. What I mean is that the brain is continuously generating predictions about the causes of sensory signals, whether these come from the world or from the body, and the sensory signals themselves serve as prediction errors, reporting a difference between what the brain expects and what it gets, so that the predictions can be continuously updated. Perception isn’t a process of reading out sensory signals in a bottom-up or outside-in direction. It’s always an active construction, an inside-out, top-down neuronal fantasy that is yoked to reality in a never-ending dance of prediction and prediction error. Now I call this process controlled hallucination to emphasize just this point. All of our experiences are active constructions arising from within, and there’s a continuity here, between normal perception and what we typically call hallucination, where, for example, people might see or hear things that others don’t. But in normal perception, the control is just as important as the hallucination. Our perceptual experiences are not arbitrary. The mind doesn’t make up reality. While experienced colors need a mind to exist, physical things, like the coffee cup itself, exist in the world whether we’re perceiving them or not — it’s the way in which these things appear in our conscious experience that is always a construction, always a creative act of brain-based best guessing.

And because we all have different brains, we will each inhabit our own distinctive, personalized inner universe.

In a podcast from 2020 on How Our Minds Predict Our Reality, he stated:

There’s so many metaphors that people bring to bear when they try to understand the brain. It’s an enormously complex object, it defies any kind of intuition. It’s 90-odd billion neurons, 1000 times more connections. We don’t know the fine wiring diagram of the brain. We just know it’s important for a lot of things. People have always reached for kind of dominant technology as the metaphor — a system of complex plumbing, a computer, and more recently, maybe the internet.

I’ve always found the computer metaphor a bit off-putting, a bit misleading, it de-emphasizes consciousness. It de-emphasizes the role of the body, and the brain just is not a computer. Computers you can use to simulate all kinds of things, but the brain isn’t a computer. The way I started to think about it — and it certainly was not original idea, as I later realized, it’s built on a very long tradition in philosophy and in psychology — is to think from a starting point more of, what is the problem that the brain is trying to solve? It’s like a functional perspective on it. And if we start with perception, so one of the main jobs of the brain is to perceive both the body and the world so that the body can act, the organism can act within the world. And the problem with perception, it’s tempting to think in a lot of classical models of perception, think of it as this kind of bottom up process, where the sensory data comes in through the senses and is then read out by the self, which sits somewhere inside the skull.

But that’s a pretty unsatisfying view because the world that we perceive is only indirectly related to what, if anything, is actually out there in the world. There are no colors actually out there in the world, colors are something that’s constructed by the brain. So I started to think… There was a literature already on perception as a predictive act. And I don’t mean predicting the future. I mean, prediction in the sense of making a best guess about what caused sensory inputs. So  in this sense is more like filling in missing data or making an inference. And we get all the sensory data, but it doesn’t come with labels about where it’s from, or even what kind of sensory data it is. But we end up perceiving this world full of structured objects with particular properties.

So the idea is that perception really depends on these top-down predictions, that the brain is always bringing to bear, to give shape and form to the sensory data that comes in. Now, this idea goes way back to Plato, even, in the shadows on the cave and people thinking those are real. And then there’s an Arabian scholar in about the 11th century who started talking about perception inference. And then in the 19th century, the German scientist Herman Von Helmholtz was the first to really articulate this idea of perception as inference…

(All images courtesy of Wikimedia Commons)