Long ago, the accuracy would decline as scar tissue formed around implanted electrodes. Not sure if that's changed in recent years as techniques improved.

How long ago is long ago? 7 years ago I took a course on the then-current state of the art for neural interfacing, and this was nowhere near a solved problem then. There was research going into emulating sea cucumbers, so the electrode could be stiff enough to penetrate the brain but then soften to avoid the build up of scar tissue. I think that research is still ongoing.

I remember reading about the problem in an article posted on HN a couple of months ago, so I don't think it's solved yet.

The article mentions that

> electrodes implanted in his motor cortex recorded signals of his brain activity

so I'm assuming other thoughts and interactions had little to no effect.

This makes me wonder if "thinking about writing letters" is really an accurate description of what's happening. Was the subject merely thinking about writing letters, or was he actually trying to write them, such that if he weren't paralyzed his muscles would be moving to perform that task?

The subject was instructed to actually try and write the letters; the AI they trained on the electrode outputs attempted to return pen stroke velocities.

My hypothesis would be yes.

You need to establish the initial feedback loop somehow and imagining writing is a good way to do it. But once you have it I’d suspect you could get faster doing what you’re describing.

I agree, and I'm a bit excited/worried if brain interfaces turn out to be kinda like smart handheld devices, years of failures until the essential "recipe" is discovered like the iPhone, followed by a tsunami of innovation, functionality, and power - some realized, some not.

Do we have adequate wisdom to wield the powers we are granting ourselves?

I’d be interested to compare this to an adult who is brand new to typing on a keyboard (if you could find one!).

What’s the typing speed and error rates over time as the subject practices? How do these compare to the progress with the BCI?

Conversely, T5 is 65 years old and just adapting to a completely new way of communicating at retirement age. Comparing that to the neuroplasticity of a far younger subject, I can see a high chance of this outperforming mobile typing. 10 fingers, I'm not so sure.

i wonder how this would have performed on recognizing hanzi