“In handwriting the brain is mediated by the drawing hand, in typewriting by the fingers hitting the keyboard, in dictation by the idea of a vocal style, in word processing by touching the keyboard and by the screen’s feedback. The fact seems to be that each of these methods produces a different syntactic result from the same brain. Maybe the crucial element in handwriting is that the hand is simultaneously drawing. I know I’m very conscious of hidden imagery in handwriting—a subtext of a rudimentary picture language. Perhaps that tends to enforce more cooperation from the other side of the brain. And perhaps that extra load of right brain suggestions prompts a different succession of words and ideas.”
— Ted Hughes, from this highly informative interview in Paris Review