Your Brain: A Controlled Hallucination Explained #shorts

Added: 2026-05-16

[00:00:00]This explains a lot why you are the way you are, why you keep walking into rooms expecting them to feel differently, why you keep hearing the same things from different people. Your brain is layering an entire history into a single moment, and you're experiencing the layered version. There's a phrase that has gotten really popular, and that is the phrase reality is a controlled hallucination. This comes from Anil Seth, who's a professor of cognitive and computational neuroscience at the University of Sussex in the UK. He's been on the Clarivate Highly Cited Researchers list, the international list of the top 1% of researchers in this field for 5 years running, and he's published over 200 peer-reviewed papers.

[00:00:42]And the phrase controlled hallucination comes from his 2021 popular science book Being You, not from a single peer-reviewed paper. I want to be very transparent about that. The neuroscience he's describing is well supported by his peer-reviewed work and by the broader predictive processing literature. But the phrase itself is his interpretive framing, his way of putting it. And as we will see in a minute, it's a phrase philosophers have a lot of pushback on.

[00:01:09]Now, here's what the phrase controlled hallucination is trying to capture.

[00:01:13]Hallucination because your brain is generating the experience, not receiving it. And controlled because the sensory data coming in keeps the hallucination tethered to something real. It's why ambiguous images can flip differently for different people. The most direct demonstration of this is a 2021 paper in Nature Communications, at a lab in NYU School of Medicine. They used intracranial recordings in human patients, actually measuring electrical activity inside the brain, to show that long-term prior expectations shape what you see through long-range feedbacks from higher brain regions down to early visual areas. I want to mention that Nature Communications is one of the top general science journals and the finding has been replicated and extended. The broader evidence that what your brain expects shapes what your eyes effectively see was put together in a 2013 review in Frontiers in Human Neuroscience at the University of Edinburgh. The same image can look like one thing to one person and something completely different to another one depending on what their brain was primed to expect. Your prior knowledge is part of the input. Reality is a controlled hallucination is a popular framing for predictive processing as we mentioned.

[00:02:28]It's not a settled scientific fact.

[00:02:30]Predictive processing itself is well supported by research, but the slogan has a few critics and they're worth taking seriously.