From Ari N. Shulman at Big Questions Online:
Is human perception a controlled hallucination? That was the claim advanced in a pair of talks at the Human Mind Conference in Cambridge, England in June, one by Anil Seth, a neuroscientist at the University of Sussex, the other by Andy Clark, a philosopher at the University of Edinburgh. They were not advancing the radical thesis, made by some overeager neuro-philosophers, that all experience is an illusion. Rather, Seth and Clark made the case that there is no bright dividing line between hallucination and ordinary perception.
The terms “controlled hallucination,” and related ones like “inferred fantasy” and “virtual reality,” are useful rhetorical devices for illustrating what is distinctive about the theory of predictive processing. But Clark is resistant to adopting these terms in full. For none of them quite describes what the theory says about the nature of our perceptual contact with the world. Perception, on Clark’s view, “doesn’t cut us off from the world…instead, it opens us up to the world as it matters to a creature like us.” More.
There was a reason that scientists used to be more modest in their claims.
See also: Researcher: Never mind the “hard problem of consciousness”: The real one is… “Our experiences of being and having a body are ‘controlled hallucinations’ of a very distinctive kind”
Post-modern science: The illusion of consciousness sees through itself