I very definitely don't see pictures in my mind, but then I'm self-diagnosed with Aphantasia - essentially, the inability to picture things in my head.
There's a test for it here:
http://www.bbc.com/news/health-34039054
I can recall in grade 2, we were doing exercises where the teacher told us to close our eyes and picture such and such, and getting frustrated that I couldn't "see" what I was supposed to be picturing. Then, eventually, I decided that when the teacher told us to "picture" something, she actually meant that we should imagine it, that actually seeing it in our mind wasn't what she meant. And I went on thinking that "picturing" something had nothing to do with seeing it in my mind until last year.
Then last year I did this test, and didn't really understand what the questions meant. The questions are asking how clearly I can see something when I picture it. I can imagine something, but how can I describe how clearly I see what I'm imagining?
Anyway, I blundered through the test, basically answering the questions randomly and got an average score. But then, after doing further reading, I found out that sometime people with Aphantasia
do see pictures in their mind, they just can't do it at will. And I can recall that sometimes I
have, in fact, involuntarily seen real pictures in my mind, but never voluntarily. When I imagine something, or close my eyes and try to "picture" something, I'm not actually seeing any pictures in my mind at all.
So then I took the test again, taking the questions much more literally, actually trying to see images in my mind. And I score 8/40, the lowest possible score, very much consistent with having Aphantasia.
That said, despite being both officially diagnosed with ASD and self-diagnosed with Aphantasia, I
do consider myself to have an imagination.Given the right conditions, I'm perfectly capable of coming up with very entertaining stories or performing other imaginative activities.