> Now that the researchers have shown that the optrode method works in vivo, they will shortly publish research that shows the optrode technology is bidirectional – that it can not only read neural signals, but can write them too.

Woah, that is a huge deal. That's the advantage of a neural implant (other than permanent connections); the ability to write feedback to the brain just like muscles do. That allows controlling prosthetics without looking at them and much faster learning in theory.