I watched the entire 2h48min presentation last night, was pretty interesting. Here are some of the cool bits.
https://www.youtube.com/watch?v=YreDYmXTYi4
You can only read/control areas of the brain that have the neuralink threads in them, so if you wanted to make someone see, you'd need to put the threads into the visual cortex part of the brain, if you wanted to make them walk, it needs to go in the motor cortex of the brain.
It wont be easy to control people memories with this type of device, because of how the brain is designed, memories are deeper in the brain, and this region is harder to get to with the needles and electrodes. There are limited electrode threads on each neuralink, so they have to be choosy about the location, they are nowhere near reading a whole brain.
They have these monkeys with the neuralinks control mouse cursors with their minds. When the monkey thinks "up" the mouse goes up, when the monkey thinks "down" it goes down etc. The strange thing the mouse control ability changes every day, different neurons fire the next day when the monkey thinks "up", and this causes the mouse to move with a bias. It's like if I thought about "banana" on Monday, the neuralink might read which neurons were activated, and interpret this as "banana." If I did this same thing again on Thursday, and thought again about "banana," things would fire slightly differently, and the neuralink would have some difficulty interpreting things. They need to figure out a way to compensate for this constant change.
There is this layer under you skull called the dura, a tough membrane, they remove this and it lets their surgical robot jab the electrodes into the brain. This happens faster than im comfortable with, but apparently the brain moves so much it needs to be quick. The robot can see blood vessels and avoids them when putting in the electrodes.
The one issue with removing the dura layer is that the body will replace it with scar tissue, and this can be a problem when they want to remove it, as there is all this tissue growing around the device. They want to do the surgery right through the dura in the future, and not remove it, but this poses a problem, because now they cant see the blood vessels as easily.
They have
an entire team that just works on needle prototyping, and they use lasers to ablate the metal and make different needle shapes to test how well they insert the electrodes.
They have a pig and they can control it's leg movements. They added another neuralink device into the pig's spine, and this lets them do things with the pigs leg muscles. all remotely. Seen here:
This is promising because they could use two neuralinks, one in the head and one after the part where the break in the spinal cord is, and
potentially let people walk again. Over time moisture actually diffuses through the polymer material into the neuralink, and eventually cause the electronics to fail, so replacement has to be easy. Could be around the 5 year mark, but more testing is needed in this area. They device monitors it's internal humidity. The motor cortex (controls movement) is on the outside of the brain, so it's easier to access.
I hope Musk waits 10 years before doing elective brain surgery, he has an important mind, and I don't think the shareholders would like it if he gets poking around in that area. I'm not sure the upside of faster computer control is worth the downside, like a stroke or some other brain issue. He's going to probably run head first (heh) into getting this done, and his engineering side might not appreciate that the human body isn't quite like lego, even though he seems to think it is.
