Anecdata to add to this:
In the third grade I took the phrase "voices in your head mean you're crazy" so I actively suppressed my internal monologue (previously expressed in language) and now my thinking is mostly abstract and/or visual. There are two exceptions: imagining a hypothetical conversation or reviewing a previous conversation in my head. Those are the only cases of language in my head. When I read I experience a combination of the two.
I tend to use hypothetical conversations in my head to analyse my thoughts, but otherwise feel my thinking is more abstract than verbal. So I'm not sure I agree with the dichotomy this article is presenting.
