Ed Catmull, former head of Pixar, also has aphantasia[0] and had the staff take the only real diagnostic that exists (the Vividness of Visual Imagery Questionnaire[1]) and found that, on average, the animators had less ability to visualize than the production managers. Obviously they varied significantly - the article mentions one that could play the entire movie in their mind - but lack of mental imagery clearly does not preclude professional level artistry.
[0] https://www.bbc.com/news/health-47830256 [1] https://en.wikipedia.org/wiki/Vividness_of_Visual_Imagery_Qu...
Someone with the condition you describe (zero mental imagery) would, constantly, feel like they are seeing basic objects for the very first time, you wouldn't recognize anything at all, this would be a highly debilitating condition just like severe amnesia.
I totally get that you, having lived a life where mental imagery is such an integral part of your baseline experience, assume that many of the things you rely on it for require it. However, the human brain is impressively adaptable, and it turns out many, many aspects that people assume are linked (and may well be for them as individuals) are not globally so.
This thread is full of such realizations - people assuming ability at chess, art, tetris, spatial reasoning, abstract reasoning, architectural design, conceptualizing of DB schemas, etc. must be correlated with facets of thought like strength of mental imagery, presence of an inner monologue, ability to dream, etc. In all of those cases, people have chimed in with (anecdotal, to be sure) counterexamples. It turns out brains are generally capable of doing a lot of different things in a lot of different ways.
“I’m sitting in a room with a dog and a TV. Then someone says ‘visualize a stop sign.’ And, so then I’m sitting in a room with a dog, a TV and a stop sign. I’m know the stop sign isn’t real. It might be fuzzy or even black & white. But, I can see it between the dog and the TV.”
Well… I know exactly what a stop sign looks like. But, there’s no stop sign in the room with me and my dog. It’s not there at all.
So clearly, there is some encoding process going on here, and the comparison is done on the basis of this encoding. This can be much more efficient than comparing the actual thing. Think of it has taking the hash of a picture, and performing comparisons using the hash, not the picture itself.
I guess I must have the condition. I closed my eyes and tried to see a red apple, which the article uses as the diagnostic test. Nope, all I saw was black. Could I think of what a red apple looks like? Of course. If the test is to actually, truly see an apple while your eyes are closed, my guess is everyone would fail.
In the 1-5 guide, I'd probabably rate myself a 99 or something silly. I feel like the equipment is capable of visualising, but I just don't know how to operate it.
However, I do have involuntary visualizations. My dreams are images, very unlike thought. And in the last 5 or so years I can recall 2 occasions where I was in a relaxed state and pictured things without really trying, so I know it's possible to have dream like images when awake.
My wife says she can just perfect recall stuff. I entirly believe she can visualise, but I believe she confuses what happened with what she can see. She also states she can visualise the apple, or pretty much anything else she wants.