These claims by Musk and the FB exec are pretty outlandish. Any type of surgery is very high risk. Brain surgery is incredibly dangerous. There's a reason why so few surgeons specialise in it. The article even mentions one of the human trials which used implants was directed at people who were already paralysed.

But all that aside, developing sensor technology that could get accurate measures of brain activity in a non-invasive and non-destructive way would be quite a breakthrough (and really the first step to anything more substantial. Until we invent nano-robots, implants will simply be way too dangerous).

We have no real idea of how the brain works. It's so vastly different from any machine we've ever designed, filled with redundancy and not only electrical signals, but chemical signals that combine to create all kinds of inputs and feedback. Trying to read our stream of consciousness is not an easy task, as it may not be represented in the brain in a way we could recognise with instruments (or even in one discrete location in the brain at all).

Brain research is always amazing, but it also shows just how far humanity is lacking in our own understanding of the world. Advertising/Propaganda, the Stanley Milgram Experiments, conformity experiments all suggest brains may be more deterministic than we care to admit. We have hundreds of thousands of inputs (skin, eyes, internal pain/nerve cells, hearing) and there's no way we could raise twins in a lab and control all those inputs to see if we can get two humans to always do the same thing (ethically).

I wonder if we ever do create machines/AI that have connotative abilities and that can understand self-awareness; if they may end up telling us that they (and in turn us) don't actually have the free well we think we do.