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by dewarrn1 1026 days ago
EEG recording is an alternative that would outlast the potential disease-related degradation of eye movements. Manny Donchin gave a brown bag at UIUC about the possibilities of using this approach to support communication by ALS patients many years ago. It's clever: they use the P300 marker to index attention/intention. I do not recall whether he and his colleagues ever commercialized the tech. I believe that this publication is representative: https://doi.org/10.1016/j.clinph.2005.06.027
3 comments

I did a PhD in brain-computer interfaces, including EEG and implanted electrodes. BCI research to a big extent focuses on helping paralyzed individuals regain communication.

Unfortunately, EEG (including P300) doesn’t provide sufficient signal-to-noise ratio to support good communication speeds outside of the lab with Faraday cages and days/weeks of de-noising including removing eye-movement artifacts in the recordings. This is a physical limit due to attenuation of brain’s electrical fields outside of the skull, which is hard to overcome. For example, all commercial “mind-reading” toys are actually working based off head and eye muscle signals.

Implanted electrodes provide better signal but are many iterations away from becoming viable commercially. Signal degrades over months as the brain builds scar tissue around electrodes and the brain surgery is obviously pretty dangerous. Iteration cycles are very slow because of the need for government approval for testing in humans (for a good reason).

If I wanted to help a paralyzed friend, who could only move his/her eyes, I would definitely focus on the eye-tracking tech. It hands-down beat all BCIs I’ve heard of.

+1 from a fellow BCI PhD. EEG tech is not ready for this application yet.
+1 +1 from another fellow BCI PhD. EOG over EEG at the moment (likely forever, non-invasively).
++ with mere MA in cog sci and psychology. If you really wanted to get EEG to work for typing, maybe you could train someone to map thinking about specific kinds of things to the keyboard, but that would be an extremely weird experience. Eyeball is going to have the best signal about eyeball-related motor cortex we can access.
This! Eye tracking is slow and not good - but does that just mean we need to “faster horse” it or is there another option for bridging the communication gap for people with ALS and similar diseases? I have to believe there are better answers with other tech - likely EEG (+ AI).

My family is one of the unlucky ones that has genes for ALS so I’ve watched enough family members struggle. (I’m lucky, selfishly, because I dodged the gene but I still care deeply about this).

I had this thought, but then I thought about if my friend was struggling with a problem had had practical but imperfect solutions, would I better serve them by funding highly feasible solutions that they're already familiar with, or experimental moonshots that are more likely to fail, will take longer to implement, and my friend may not even care for at all...