7 ms·

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 c

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 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.

teaearlgraycold 3y ago
I think then VR headsets will become medical devices soon enough
drzzhan 3y ago
What is it noise-to-signal ratio? Sorry I don't know much about the field but that sounds like something can shutdown ideas like "we can put eeg into transformer and it will work". So may I ask what reference papers that I need to know on this?
- IshKebab 3y ago
  Signal to noise ratio is a very basic thing; you can Google it.
  - phanimahesh 3y ago
    They weren't asking what SNR is, but what the typical SNR for eegs in realworld circumstances is. Even if they were, count them among the lucky 10000 [1] and explaining is nicer. Soon with ai generated spam it feels like searching for anything is going to be worse than useless. 1: https://xkcd.com/1053/ https://xkcd.com/1053/
- southerntofu 3y ago
  Not from that field, but "reading" the brain means electromagnetism. In real life, EM interference is everywhere from lights, electric devices, cellphone towers... EVERYWHERE. Parent meant brain waves are weak to detect compared to all surrounding interference, except when a lab faraday cage blocks outside interference then the brain becomes "loud" enough to be read. https://en.wikipedia.org/wiki/Signal-to-noise_ratio https://en.wikipedia.org/wiki/Signal-to-noise_ratio https://en.wikipedia.org/wiki/Faraday_cage https://en.wikipedia.org/wiki/Faraday_cage
  - blharr 3y ago
    I don't think electronic interference is the problem. Cellphone towers and electronics operate at GHz and MHz, which are different frequencies than brainwaves. Interference seems to typically be labeled by a "Signal to Interference" ratio rather than signal to noise. From my understanding, noise is still inherently present even in a faraday cage, through things like thermal noise and amplifier noise, which is why the poster mentioned you still have to perform signal processing over very long intervals to remove noise.
daniel_iversen 3y ago
What’s your thoughts of Elon’s NeuraLink? Also, do you have an opinion on whether good AI algorithms (like in the article) can help filter out or parse a lot of the noise?
- dsr_ 3y ago
  It was a little bundle of what looked like thin, glisteningly blue threads, lying in a shallow bowl; a net, like something you'd put on the end of a stick and go fishing for little fish in a stream. She tried to pick it up; it was impossibly slinky and the material slipped through her fingers like oil; the holes in the net were just too small to put a finger-tip through. Eventually she had to tip the bowl up and pour the blue mesh into her palm. It was very light. Something about it stirred a vague memory in her, but she couldn't recall what it was. She asked the ship what it was, via her neural lace. That is a neural lace, it informed her. ~ A more exquisite and economical method of torturing creatures such as yourself has yet to be invented.
  - wizzwizz4 3y ago
    Excession, by Iain M. Banks.
- laserbeam 3y ago
  In my understanding, NeuraLink is just a research project thaf musk invested into and did some PR for. I wouldn't read into it more than that. Like any other similar BCI research project feel free to ignore it until papers are published. That is, unless you are involved in the field.
  - yreg 3y ago
    In my understanding it is a research project that has a lot more funding than others in the field and therefore it might be better positioned for a breakthrough. Am I mistaken?
    - burning_hamster 3y ago
AndrewKemendo 3y ago
I just did a two day ambulatory eeg and noted anytime I did anything that would be electrically noisy. For example going through a metal detector or handling a phone. Unsurprisingly one of their biggest sources of noise is handling a plugged in phone. I think something like an EEG faraday beanie would actually work and adding accessory egocentric video would allow doctors to filter a lot of the noise out.
- deleted 3y ago
  [deleted]
- caycep 3y ago
  also, just blinking or tensing muscles on your scalp
logtempo 3y ago
Recently, a Swiss-French team made the communication between the brain and the legs possible, and the device looked relatively mature. I think patient had nerves damaged in the vertebral column. What do you think about it ? Looked like a promising development. https://actu.epfl.ch/news/thought-controlled-walking-again-after-spinal-co-3/ https://actu.epfl.ch/news/thought-controlled-walking-again-a...
- fragmede 3y ago
  Not OP, but Ttat article's use of the word "implant" implies a much more invasive device, which means a way better signal. Additionally, the output, while still complex, is far from the level of decoding of thought presented here. Thus, while still impressive, it is less of a leap from existing technology, and much more within the realm of what we know is very much possible.
  - logtempo 3y ago
    Yes, there is a part that is under the skull, if I understand it correctly ("at the surface of the cortex"). It claims to be the first success in the world, so it is indeed impressive! https://youtu.be/6Ee3kZIW5fk https://youtu.be/6Ee3kZIW5fk
bbor 3y ago
...This seems really, really confidently dismissing a new technology as impossible, which of course this forum loves (b/c GPT). This very paper seems like pretty damn strong evidence that prehaps the signal-to-noise ratio of EEG might be coming down as we get better algorithms.
kromem 3y ago
While I believe you that the signal to noise is terrible, I have strong suspicions that given enough data we'll still be seeing surprising advancements in spite of that. The ability of deep learning to tease back out signal from noise, such as reversing what's being typed from room audio with a keyboard in it, shouldn't be underestimated. The biggest challenge may be that EEG data correlated with signals is relatively expensive to generate, so there's not going to be anything like millions of hours of people looking at or processing known things to throw into a model. Whereas we're about to have massive increases in eye tracking data as it becomes a central component to new consumer hardware.

teaearlgraycold 3y ago

I think then VR headsets will become medical devices soon enough

drzzhan 3y ago

What is it noise-to-signal ratio? Sorry I don't know much about the field but that sounds like something can shutdown ideas like "we can put eeg into transformer and it will work". So may I ask what reference papers that I need to know on this?

IshKebab 3y ago
Signal to noise ratio is a very basic thing; you can Google it.
- phanimahesh 3y ago
  They weren't asking what SNR is, but what the typical SNR for eegs in realworld circumstances is. Even if they were, count them among the lucky 10000 [1] and explaining is nicer. Soon with ai generated spam it feels like searching for anything is going to be worse than useless. 1: https://xkcd.com/1053/ https://xkcd.com/1053/
southerntofu 3y ago
Not from that field, but "reading" the brain means electromagnetism. In real life, EM interference is everywhere from lights, electric devices, cellphone towers... EVERYWHERE. Parent meant brain waves are weak to detect compared to all surrounding interference, except when a lab faraday cage blocks outside interference then the brain becomes "loud" enough to be read. https://en.wikipedia.org/wiki/Signal-to-noise_ratio https://en.wikipedia.org/wiki/Signal-to-noise_ratio https://en.wikipedia.org/wiki/Faraday_cage https://en.wikipedia.org/wiki/Faraday_cage
- blharr 3y ago
  I don't think electronic interference is the problem. Cellphone towers and electronics operate at GHz and MHz, which are different frequencies than brainwaves. Interference seems to typically be labeled by a "Signal to Interference" ratio rather than signal to noise. From my understanding, noise is still inherently present even in a faraday cage, through things like thermal noise and amplifier noise, which is why the poster mentioned you still have to perform signal processing over very long intervals to remove noise.

daniel_iversen 3y ago

What’s your thoughts of Elon’s NeuraLink? Also, do you have an opinion on whether good AI algorithms (like in the article) can help filter out or parse a lot of the noise?

dsr_ 3y ago
It was a little bundle of what looked like thin, glisteningly blue threads, lying in a shallow bowl; a net, like something you'd put on the end of a stick and go fishing for little fish in a stream. She tried to pick it up; it was impossibly slinky and the material slipped through her fingers like oil; the holes in the net were just too small to put a finger-tip through. Eventually she had to tip the bowl up and pour the blue mesh into her palm. It was very light. Something about it stirred a vague memory in her, but she couldn't recall what it was. She asked the ship what it was, via her neural lace. That is a neural lace, it informed her. ~ A more exquisite and economical method of torturing creatures such as yourself has yet to be invented.
- wizzwizz4 3y ago
  Excession, by Iain M. Banks.
laserbeam 3y ago
In my understanding, NeuraLink is just a research project thaf musk invested into and did some PR for. I wouldn't read into it more than that. Like any other similar BCI research project feel free to ignore it until papers are published. That is, unless you are involved in the field.
- yreg 3y ago
  In my understanding it is a research project that has a lot more funding than others in the field and therefore it might be better positioned for a breakthrough. Am I mistaken?
  - burning_hamster 3y ago

AndrewKemendo 3y ago

I just did a two day ambulatory eeg and noted anytime I did anything that would be electrically noisy. For example going through a metal detector or handling a phone. Unsurprisingly one of their biggest sources of noise is handling a plugged in phone. I think something like an EEG faraday beanie would actually work and adding accessory egocentric video would allow doctors to filter a lot of the noise out.

deleted 3y ago
[deleted]
caycep 3y ago
also, just blinking or tensing muscles on your scalp

logtempo 3y ago

Recently, a Swiss-French team made the communication between the brain and the legs possible, and the device looked relatively mature. I think patient had nerves damaged in the vertebral column. What do you think about it ? Looked like a promising development. https://actu.epfl.ch/news/thought-controlled-walking-again-after-spinal-co-3/ https://actu.epfl.ch/news/thought-controlled-walking-again-a...

fragmede 3y ago
Not OP, but Ttat article's use of the word "implant" implies a much more invasive device, which means a way better signal. Additionally, the output, while still complex, is far from the level of decoding of thought presented here. Thus, while still impressive, it is less of a leap from existing technology, and much more within the realm of what we know is very much possible.
- logtempo 3y ago
  Yes, there is a part that is under the skull, if I understand it correctly ("at the surface of the cortex"). It claims to be the first success in the world, so it is indeed impressive! https://youtu.be/6Ee3kZIW5fk https://youtu.be/6Ee3kZIW5fk

bbor 3y ago

...This seems really, really confidently dismissing a new technology as impossible, which of course this forum loves (b/c GPT). This very paper seems like pretty damn strong evidence that prehaps the signal-to-noise ratio of EEG might be coming down as we get better algorithms.

kromem 3y ago

While I believe you that the signal to noise is terrible, I have strong suspicions that given enough data we'll still be seeing surprising advancements in spite of that. The ability of deep learning to tease back out signal from noise, such as reversing what's being typed from room audio with a keyboard in it, shouldn't be underestimated. The biggest challenge may be that EEG data correlated with signals is relatively expensive to generate, so there's not going to be anything like millions of hours of people looking at or processing known things to throw into a model. Whereas we're about to have massive increases in eye tracking data as it becomes a central component to new consumer hardware.