[beardyw]

It seems that no one properly understands how information is stored in the brain. I think that needs to be solved first.

[approaching236]

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)

Spikes: Exploring the Neural Code

[bognition]

This is definitely a huge problem, but we also need a viable interface to write information.

[analognoise]

How do you write if you don't even know how to read the storage media?

[pjc50]

Write-only memory! In a very literal sense.