If you’ve ever undergone general anaesthetic then you have experienced oblivion, an interruption of consciousness more complete than even the deepest sleep. Whole hours or days can pass in a millisecond; it’s proof – if you need it – that you can cease to be, that the world will go on without you. Some people find this terrifying. The neuroscientist Anil Seth finds it reassuring.
In 2017 Seth gave a Ted talk that has since been viewed more than 12 million times, a mind-blowing, 15-minute distillation of his three decades of research, which ended with Seth paraphrasing Julian Barnes: ‘When the end of consciousness comes, there’s nothing to be afraid of – nothing at all.’ It’s a sentiment he returned to in his bestselling 2021 book, Being You, and when we met recently in Falmer, East Sussex, he told me why: ‘When you see how fragile and precarious our unified consciousness is, of ourselves and of the world, when you see how many ways it can go wrong or just be abolished completely, you can either take that as a scary thing or a reminder to be very glad to be where you are.’ He chooses the latter.
Seth, 49, was casually dressed in jeans, beige trainers and a blue jumper. His close-shaven head and quiet intensity lent him a monkish air, which he periodically punctured with a joke. We spoke in his office at the University of Sussex, where he is co-director of the Sackler Centre for Consciousness Science. (As the university will no longer be receiving new funding from the Dr Mortimer and Theresa Sackler Foundation, the centre is due to be renamed.) On the bookshelves were works on psychology, philosophy, informatics, physics, a Zadie Smith novel, poetry anthologies. Tacked to the wall was a print-out headlined ‘12 fucking rules of success”’. (1. Do the fucking work. Don’t be lazy.)
Seth began studying consciousness in the mid-Nineties, a time when advances in computing and brain imaging were giving scientists new tools for understanding the mind. In 1994, the Australian philosopher David Chalmers outlined the challenge ahead: in a talk at the inaugural Science of Consciousness Conference in Tuscon, Arizona, Chalmers set out what he described as ‘the hard problem of consciousness’. How can objective, physical matter give rise to the unique, subjective experience of consciousness? How could anyone adequately describe the inimitable feeling of being you, with reference only to your brain and biology?
Philosophers and scientists have tried to tackle this hard problem in different ways. Panpsychists argue that consciousness is a fundamental quality of all matter – that a deckchair exhibits a different kind of consciousness from you or I, but is conscious nonetheless. At the other extreme, illusionists argue that consciousness is only imaginary. Seth, whose academic background spans physics, psychology, computing and neuroscience, says he has come to another, more satisfying conclusion.
His research has led him to radical positions: the way you see yourself and the world is a controlled hallucination, Seth argues. Rather than passively perceiving our surroundings, our brains are constantly making and refining predictions about what we expect to see; in this way, we create our world. He points to the example of #TheDress, the viral photo of a cocktail dress that to some people appears gold-and-white, and to others as blue-and-black. In his Ted talk, Seth twice plays an audio clip of a high-pitched, distorted voice that is so incomprehensible it could be speaking any language or none at all. Then he primes his audience with the sentence: ‘I think Brexit is a terrible idea.’
When he plays the clip again, the words are so immediately discernible it’s hard to imagine how they couldn’t have been.
Sometimes the term hallucination confuses people (Seth wishes there were a better word): it might suggest that perception is arbitrary, or that things don’t exist. In fact, if our brains are working properly, we’re constantly updating our predictions based on feedback from our senses – which is why ordinary perception is a ‘controlled hallucination’, not a fever-dream. That said, Seth told me as we strolled across campus in search of a sandwich, he’s open to the idea that the physical world doesn’t exist in the manner we think it does. That’s a ‘question for a physicist, someone like Carlo Rovelli. Who knows what’s actually out there? But let’s assume things are out there and things exist,’ he said. Reality, Seth believes, is the hallucination we can all agree on.
Some aspects of perception are more illusory than others. Our experience of ourselves, as having an enduring, stable identity over time, is a useful illusion. As is our perception of free will: we believe we are acting freely when we follow our own beliefs, goals or desires – but we can’t freely choose those beliefs, goals or desires. The purpose of consciousness, of all these hallucinations, is to keep us alive. When we die, it will be extinguished. Seth believes other animals are conscious, but doesn’t think artificial intelligence ever will be.
As for the ‘hard problem’, Seth believes that the better we understand our brains – the more precisely we can measure, manipulate and track consciousness – the less intractable the problem becomes. This theory doesn’t satisfy everyone: when I interviewed him for the New Statesman, Chalmers told me he disagreed that the hard problem can be solved this way – you still need to account for the mechanism by which objective matter produces subjective experiences. But he also emphasised their common ground: Seth’s approach of mapping conscious states on to brain states (identifying, for instance, which neurons correspond to ‘seeing red’ or ‘thinking about dinner’) is ‘pretty much the same approach I would recommend’. The New Statesman article 26 February 2022, ‘Is Reality an Hallucination?’