The classic: Thinking the Way Animals Do: Unique insights from a person with a singular understanding. By Temple Grandin, Ph.D.
https://www.grandin.com/references/thinking.animals.html>I have no language-based thoughts at all. My thoughts are in pictures, like videotapes in my mind. When I recall something from my memory, I see only pictures. I used to think that everybody thought this way until I started talking to people on how they thought. I learned that there is a whole continuum of thinking styles, from totally visual thinkers like me, to the totally verbal thinkers. Artists, engineers, and good animal trainers are often highly visual thinkers, and accountants, bankers, and people who trade in the futures market tend to be highly verbal thinkers with few pictures in their minds. (...) A horse trainer once said to me, "Animals don't think, they just make associations." I responded to that by saying, "If making associations is not thinking, then I would have to conclude that I do not think."
I have internal monologue but not as much as before, sometimes significantly less or completely absent. First time my monologue stopped during long meditation retreats. It seems reasonable because I didn't use verbal thinking during meditation. You don't use it, you lose it. I'm surprised how little the inner monologue has to do with abstract thinking. You don't have to have sentences in your head to do stuff unless it's writing or reading related. Decisions, no need. Math or programming, no need at all. Logical thinking, no need or very little.
Totally verbal thinkers are often aggressively against even considering my experience: "That's impossible", "You can't think without words". Maybe these kind of people are the opposite end of 'spectrum' from visual thinker autistic like Temple Grandin.