I think this was also the spirit of the GP's post: there is obviously a lot of pre-wiring at least in the perception area of the brain. If there weren't, it wou

I think this was also the spirit of the GP's post: there is obviously a lot of pre-wiring at least in the perception area of the brain. If there weren't, it would be impossible for the neurons to learn how to control and interpret the extremely complex input from the eye in the mere days it takes. Also, if there weren't pre-built wiring of some kind, you would not expect to see the same arbitrary definitions of objects develop in all people (I realize object perception comes a little later than simple sight). Of course, just as you say, like almost any other physiological process, if you do not expose those pre-built structures to enough stimuli, they will atrophy. This is especially true in the early developmental period.