I've speculated for years about ways that blind people might use notation as an aid for comprehending the visual world or visual concepts. When I was in college, that speculation proved fruitful. On the advice of a friend, I started studying Lisp. By learning Lisp -- and more specifically, sexp notation -- I was finally able to really grok trees. I suspect there is a lot more gold to be mined from that idea of using notation as an adaptive technique.