No, I've talked about this with a friend with aphantasia, and that's not it.
While I'm willing to concede there's probably different degrees of visualization (which in my mind also explains why some people are able to draw "from memory" and others are less apt), there's also people who absolutely cannot visualize at all.
My friend:
- Cannot visualize AT ALL. If you ask him to picture a red circle, he cannot do it. He cannot visualize the color red.
- If you ask him to picture the face of his mother, he cannot do it. All he sees is darkness. (We've wondered about this, how can he tell it's his mother when he sees her? He has no difficulty identifying faces, he just cannot visualize them at all if they are not in front of him. Not "not close enough" -- AT ALL).
- He cannot mentally reproduce music, no matter how imperfectly. I can "hear" the opening soundtrack of Star Wars (with reasonable fidelity), he cannot.
- He cannot taste in anticipation something he enjoys, like flavorful coffee. I can anticipate drinking a good coffee, and get some sort of sensorial stimulation/anticipation even before I get the coffee. He cannot, at all. And he does enjoy good coffee.
It's not about a difference in terminology, he really cannot visualize/mentally experience anything if it's not actually happening.
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Finally:
> I don't think anybody is "literally" envisioning things, as in hallucination
I am. It's not exactly a hallucination because there's no confusion about what's real and what's not, but "hallucination" is pretty close to what actually happens in my mind. I can visualize pretty much anything I've experienced, and some things I haven't too, like green elves dancing on my keyboard. I've always been a visual person.
I can draw things "from memory" and it's pretty much putting into paper what I'm seeing in my mind.