Andre said:
How could you draw a picture without visual thinking?
Kids do. Ask them to draw a house and they will draw it as a list of words - a door, a roof, a chimney, a couple of windows, the sun overhead.
It is a verbal portrait, a collection of named attributes, rather than a visual representation.
Learning to draw what the eyes actually see is a more difficult skill.
If you really want to get into the issue of thought processes, Vygtoskian psychology is the best approach. It is all about how human language scaffolds natural mental imagery thinking (or anticipation - the first half of the perceptual cycle, as Ulric Neisser so neatly put it).
And observing the developmental stages in the drawings of children is a classic way of seeing how the tool of language and the brain's natural capacities for mental imagery become a seamlessly integrated dyadic process.
Introspection is also a learned skill, and as with the hoary old questions about dreams (do you dream, do you dream in colour, do you dream of smells and tastes?), most people have not learned to observe the structure of their own thinking and so cannot even answer basic questions about their use of an inner voice to shape their imagery.