Illusionist theories of consciousness say that people do not actually ever experience phenomenal qualities; we just have the very deep delusion that phenomenal qualities are a thing.
Whether it's a hallucination or not doesn't matter. Either way, our delusion tells us that we're perceiving things as "qualities", as "feels", even though all we are really perceiving is data. If I'm looking at something, then I am acquiring data that tells me, for instance, that there's a certain dark red shape at a certain location in my visual field, and a different reddish-orange shape near it, and whatever else. I'm acquiring the knowledge, the concept, of certain colors and brightnesses being in certain locations in my visual field. But I mistakenly think I am experiencing a dark red quality, and a reddish-orange quality, and the qualities of bright and dark and in-between, etc. I think I'm getting my visual input in the form of a subjective experience.
This paper that I'm linking clears up several important points about the Attention Schema Theory. Graziano admits that "Illusionist theories emphasize how subjective awareness does not really exist – the brain tricks itself into thinking it has it. Obviously, AST aligns with that perspective." But he says he doesn't think the word "illusion" is a helpful word for expressing this, and illusionism should have been called something else, and I think he's probably right. (It seems like it's too late to change it now, though.)
I really like Graziano's Attention Schema Theory. Even more because it's essentially an illusionist theory.
My piano teacher told me this about practicing the piano, when I was around 7 years old. I always remembered it, but I never actually have the patience to do it.
A friend of mine has not-quite-complete-aphantasia, meaning he cannot "see" visual images in his "mind's eye", except for some rare occasions. When he remembers things he saw, or imagines what hypothetical things might look like, he almost never has mental imagery. But he can still recall information about what he saw, including stuff like "how many items were there", even though he did not consciously count the items when he was looking at them, and is only counting them by examining the memory when asked. I asked him how he was doing it, and he said it was like examining concepts about what he saw, and somehow using those concepts to figure out how many he remembers seeing.
For me to do the same thing, I would have to bring a mental image from my memory into my "mind's eye", and count how many items I "see".
But maybe this mental imagery of mine is just something I'm convinced I experience, rather than something I actually experience? Maybe having aphantasia is nothing more than lacking a certain delusion when it comes to remembered or imagined sights? After all, I haven't found anything that my mental images can figure out, which his concepts cannot. Or vice versa.
In any case, aphantasia only applies to mental images. When my friend is actually looking at something with his eyes (not remembering or imagining), then just like me, he's convinced that what he's experiencing is something more than just concepts.