Well this is very interesting. I had never heard of it. I took the survey, I guess I am on the dim side. Because I don't see any great amount of detail in my images in my head. But I do have images.

I have never visualized the fret board or tried and if I try to picture a C Major fingering in my head that isn't too clear either. Hmmm. 

Also, I cannot mentally "hear" a note. I am thinking of an "A" right now but I cannot hear it. I have friends who can call it if they hear it, but that also escapes me. Maybe in time I can develop that type of ear. But what you are talking about is in the mind, and mine, while not blacked out, is pretty dim.