Anil Seth is a world-renowned neuroscientist, a best-selling author, with expertise in the science of consciousness, artificial intelligence, and art-science collaboration.

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How things seem is not how things are. Even when we realise how things are, they still seem the same way they always did. We know the earth rotates, but we still perceive that the sun rises in the East. The same applies to the rest of the world around us.

What does it mean to experience the world? When we wake up and take in our space, it’s as if it’s all there, and we’re just becoming aware of it. But we’re change blind. We often miss changes in our space. Perception of change is not the same as a change of perception.

Our experience of the world and our experiences of self within the world are forms of perception, a form of hallucination that’s incredibly useful in staying alive.

Colour is a hallucination

Take, for example, the experience of colour. It’s far from straightforward. Our eyes are sensitive to only a tiny slice of the electromagnetic spectrum. That slice of reality is where we live. Red, green and blue are just the three wavelengths we can perceive. We perceive both less than is there, and more than is there. And this applies to more than just colour.

The brain is a prediction machine: all we perceive is the brain’s best guess as to the source of the inputs it is receiving. There’s no light or sound in the brain, just electrical signals. To make sense of these signals, the brain has to make some informed guesswork as to what caused these signals. This is what we experience. The brain doesn’t read out the world, it creates it.

Every face that you’ve ever seen – and your ancestors saw – has pointed outwards. But an image of an inwards mask looks like it’s outwards-facing to us – because we’re trained to se it looking outwards.

Calibrating the brain’s predictions

Our sensory inputs are used to calibrate our brain’s predictions of the world around us. It’s more “I’ll see it when I believe it”, rather than “I believe it when I see it”. There’s a phenomenon called pareidolia – our brains see faces where there are no faces.

A hallucination is uncontrolled perception, but perception is a controlled hallucination.

So, what is self? It’s. Complex idea: there are many “selfs”, from our social self to our narrative self. The bodily self can be influenced by our perception – it’s the root of the mechanism that allows us to be hypnotised. A large part of our brain is devoted to regulating the body. We have far more than five senses because many of them are internal. But the brain is doing the same thing: interpreting electrical signals, based on prediction, and changing those predictions based on inputs.

Changing our perception of perception

What we consciously experience is based on our brain’s best guess of what sensory input is derived from. All of these experiences depend on the brian’s fundamental role of trying to keep us alive, rather than trying to see what’s really there.

What are the implications? AI is a big theme: consciousness has much more to do with being alive than being conscious. AI can only ever imitate that. And we don’t see people as they are, but as we are. There’s a huge perceptual diversity in people — and that’s valuable.

We don’t see the world as it really is, but how we think it is. That’s a form of echo chamber, and until you realise that, you can’t escape it.

Get involved

They have a project going on called The Perception Census, that you can do, which tracks your own perceptual view of the world.