I've discussed the topic of "aphantasia" (the inability to form mental images [0]) with programmers at various jobs as well as with non-developer friends. It's certainly anecdata, but it's always been curious to me that I've only ever heard engineers identify with this condition -- and more frequently than the understood likelihood of it within the general population would lead me to expect.
So, again, not a known neurological effect of programming, but an interesting correlation I've observed between many of the best programmers I've known and the condition of aphantasia.