It used to be hip thing to talk about right versus left side, and in fact a Nobel prize was awarded for research that led to this thinking. I believe Roger Sperry was the recipient. Now you hear that all of this has been debunked. I haven't picked a side in this, but it sounds like one of those things where the pendulum swings first one way, then the other. It is very popular in "science" today to shoot holes in older theories. It is important to not "throw the baby out with the bathwater" as these ideas come to balance.
So leaving all of that behind, I think that we can talk about two "modes" of thinking. What used to be called the "left brain" mode was verbal and analytical, whereas the "right brain" mode is visual and perceptual.
Recognizing that these two modes exist, however we might want to label or try to explain them has great merit. And recognizing them in our own selves, particularly in this case in the context of drawing can be of great value. I am quite willing to take the "right side" book on these terms. Given that it works, gives it merit above all other considerations.
This sort of thinking has diverse applications. Consider martial arts and various athletic activities where people talk about getting in the zone and switching off your analytical mind.
Tom's Pen Info / tom@mmto.org