Very much insanely expensive and only experimental. The man I met had a team of like five people needed just to set the thing up and calibrate it for his "brain waves" that day (they had to constantly fine tune the neural net he used to control it because the human brain is so plastic it would change every day and become unusable after a couple days) - plus more researchers running the experiments he was doing. The team had a portable supercomputer running the neural net (this thing was maybe a two or three server cabinets on wheels) that they brought around with them. They had a safety managers to make sure the arm didn't hurt anyone and make sure he was medically okay. This was not a device he used around the house, he was an employee of the research lab and using it for experiments was his full time job.

The risks of these devices are also significant: you have to get risky brain surgery to install them and then you might still reject the implants and have to get them removed.

A very limited number of people have these - the lab this guy worked at had I think about a dozen people, all with BMIs installed using different surgery techniques (some had the implants on the areas where the brain met the nerves going to the muscles so the output to the neural net was a more "direct" representation of movement whereas others had implants on motion planning areas on the brain giving a more "high level" output to the neural net). There are several such labs in the world. My best guess is there are less than one hundred BMIs installed on people today, as well as quite a few more on animals.

Not trying to be funny here: lunch with those guys must’ve been absolutely fascinating. When I worked at Microsoft a couple of decades ago we all loved the job and we talked about work even on breaks. To see the staff of the place you’re describing just hanging out must have been extraordinary.

It was! The guy with the implant did his undergrad in nanotechnology and had pretty much became an expert in BMI stuff so they were a very cohesive team. They had a lot of funny stories too - like when they accidentally put the mind control monkeys in the cage with the cocaine addiction research monkeys and got to see how cocaine affected the brain interface (it didn’t).

IIRC this is only experimental. The most reliable/interesting stuff are relying on ECoG (== put electrodes on the surface of the brain), and this means you have to perform a surgery.

For human applications, most of the time the researchers are using patients that requires several brains surgery (e.g severe epilepsy) so that they can do some sort of fly-by experiments (several surgery are needed so that they can also remove the electrodes).

I studied this at uni; my knowledge is probably not up to date.

Thanks - so it seems like it's actually the ease-of-implant part that Neuralink is really doing most interesting development on then, rather than the actual abilities it gives (so far at least)

Out of my range here, but I bet they have a deeper and wider base to draw on for the AI interface with the brain than most other organizations through their CEO.