[russelldc]

> Whenever I read about this phenomenon, there doesn't seem to be a good quasi-objective metric of this subjective capability to visualize -- there's no test or questionnaire I can use to see how my abilities rate against others'.

There certainly is. The Vividness of Visual Imagery questionnaire, or VVIQ [1]. It's been referenced in most of the recent aphantasia research I've looked at.

[1] https://wh.snapsurveys.com/s.asp?k=148940557153

[Al-Khwarizmi]

It looks like a good try, but I wouldn't call that "quasi-objective". The answers are highly subjective in my view. I just don't know how vivid the so-called mind images are supposed to be, so I don't know what the "scale" of the answers is.

[mherdeg]

This is interesting, thanks!