Primarily visual-spatial (spatial concepts can exist as a separate thing without specific images....it's hard to explain), with varying amounts of other sensory information.
My thought processes seem to be fundamentally associative or formed around patterns (visual and auditory......a lot of it is more of a background thing than a conscious thing).
I do not think in words.....they have no use for me beyond communicating with others, and I wish I didn't need to use them at all.
After my first post I began to observe my thinking process more trying to understand it. What you said about images, concepts, associative processes feels like it is similar to or a part of my thinking process. Yes hard to describe, but you did better than I did.
I'm finding that I really don't have any idea how I think. All this descriptive stuff is conjecture.
I'm reminded of the tv broadcast where the interviewer homed in on a young chess master. He asked, "You're playing 14 matches at the same time just moving up the line of opponents quickly and beating each one. How do you do that? How do you remember all 14 matches and moves at the same time."
The chess master paused for 3 or 4 seconds and said, "I don't know. I just do it."
Students used to ask me how I knew so much and could connect things together like that (meaningfully and logically). Even though I tried to give them a practical answer I couldn't, because I just did it.
Maybe because we are inside the process we really can't see it. We are the centers around which this thinking is happening. I can't control it all. Most often I can tap in when and where I need to, but by no means do I have a macro understanding of what's going on.
Sorry I can't add some more meaningful thoughts to this. I put in substantial time and effort, but I'm stymied.
