I wonder if this could be induced in people who suffer from hallucinations to reduce or eliminate their symptoms? Maybe their system is rigged into overdrive the other way. It says on wikipedia that there are 'cases reported of acquired aphantasia'.
I don’t think hallucinations and having a “minds eye” are the same thing. A minds eye is different in the sense that it’s entirely separate from the “visual feed” you get from your eyes, they’re not combined so you can’t really mistake them as a hallucination; hallucinations trick you into seeing things that are not really there such as when people with schizophrenia can see people who are not actually with them — I remember seeing this guy on Instagram with a proper schizophrenia diagnosis that showcased this very phenomenon in action and the way he dealt with it is by using his phones camera to check whether the person they are perceiving is real or not. You never have to do that if you have hyperphantasia (the opposite of aphantasia) because it’s very easy to tell whats real and what’s not, and more importantly, it takes mental effort to create and maintain these imaginations in your mind and you can have total control over them.
I also found this study asking a similar question about many different types of mental illnesses, though some of it is about making people that have aphantasia better able to visualize to treat things like PTSD:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9614338/
I think adults with hyperphantasia can easily tell what's real and what's not, but I had a lot of trouble with it as a child. My parents were afraid I was hallucinating, so took me to see a child psychologist, but it turned out I was just pulling things from my extremely acute mind's eye into reality while awake like many people do while dreaming, and I hadn't figured out that didn't make them "real" in a way other people could see like it did in my dreams.
(I shudder to think how differently things could have gone if I had been misdiagnosed with a severe mental illness when all I actually have is an unusually powerful imaginative ability.)
