When I was a kid growing up in Far Rockaway, I had a friend named Bernie Walker.
We both had "labs" at home, and we would do various "experiments".
One time, we were discussing something - we must have been 11 or 12 at the time -
and I said, "But thinking is nothing but talking to yourself inside."
"Oh yeah?" Bernie said. "Do you know the crazy shape of the crankshaft in a car?”
"Yeah, what of it?"
"Good. Now tell me: how did you describe it when you were talking to yourself?"
So I learned from Bernie that thoughts can be visual as well as verbal.
-- Richard Feynman