This is a popular thing to say but is too superficial, we obviously have interfaces that operate mechanical arms and other things with a computer interface interpreting signals from the brain and other nerves. We actually know quite a bit about what kind of signals get sent from some parts of our bodies to other parts and these patterns hold within the brain as well. It just gets microscopic and -very- complicated. Check out these books:
Dayan & Abbott theoretical neuroscience (I found a pdf)
This book Nonzero by Robert write isbn:9780679758945 was pretty enlightening for me