
Using thought to control machines - pmuk
https://www.economist.com/news/leaders/21733983-brain-computer-interfaces-may-change-what-it-means-be-human-using-thought-control-machines
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simon_acca
I am working on such a BCI for with my girlfriend who's a graduate student in
cognitive neuroscience.

It's actually based on a very simple concept that most people here will have
stumbled upon in algorithms 101: binary search.

The subject is put in an fMRI machine and is looking at a screen like this[0]
where the middle word of the dictionary is presented.

The subject can then perform either "inner speech" (singing or reciting in
your head) if the word s/he wants to spell is before the one currently
displayed, or "mental imagery" (imagining drawing some figure in space)
otherwise.

As you probably know the time complexity of binary search is
O(log(dictionary_length)) instead of a classic letter speller which would be
O(alphabet_length*word_length) so this method is much quicker in most cases.

I would love some HN input on this!

This is a demo that you can play around with:
[https://sophia.science/biword/](https://sophia.science/biword/) [0]

And this is a complete explanation of the paradigm:
[https://sophia.science/biword/Biword_poster.pdf](https://sophia.science/biword/Biword_poster.pdf)

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yorwba
From the description, it sounds like you are not taking the difference in
frequency between words into account. I think you might be able to improve the
average number of choices by splitting at the median position, such that the
correct word is equally likely to be before or after it in the dictionary.

Edit: You could also combine that with a language model to condition the
probability of words on the preceding context, similar to how a phone keyboard
recommends completions. Maybe the gains aren't big when you're still limited
to selection by dictionary order, but it might be worth trying out.

~~~
simon_acca
> From the description...

Thanks, that is an interesting hypothesis, I had not considered it. The number
of choices you have to go trough though should grow with the inverse of the
frequency of the word, that means you could have to go trough an inordinate
amount of choices to get to an unlikely word... luckily with such "stateless"
paradigms I can just simulate it for every single word!

> Edit: You could also...

This is exactly the improvement we are currently working on!

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yoz-y
One thing not mentioned in the article is that we can not currently make
implants that work after a few years because of scarification. ECOG devices
might work but those have worse properties than implants.

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Razengan
Pretty much the basis of "magic" in the hyper-sci-fi RPG Numenera [0], set a
billion years in a post-post-post-apocalyptic future, where "mages" are called
"nanos" (you can guess why.)

[0] [http://numenera.com](http://numenera.com)

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YokoZar
The line in the article about VR-brain interfaces is I believe a reference to
[http://www.neurable.com/](http://www.neurable.com/)

This tech is exciting. Imagine a wizard game where you literally meditate to
recover mana.

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roscoebeezie
I once had the exact same idea as these guys.

~~~
RepressedEmu
They were probably listening...

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jradd
Suggest anyone interested to check out some related material:

Hope 2016 - Hacking the brain [0]

Semantic Maps showing models used to predict brain activity using "Voxels" [1]

0:
[https://www.youtube.com/watch?v=-1JPnHtLYCQ&index=75&list=PL...](https://www.youtube.com/watch?v=-1JPnHtLYCQ&index=75&list=PLcajvRZA8E099SG5JGAaS56NMHPTbuHIV)

1: [http://gallantlab.org/huth2016/](http://gallantlab.org/huth2016/)

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krisives
Is this similar to what Emotiv is developing?

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fapjacks
Word of warning: Hardware from Emotiv (e.g. Insight) is just complete garbage,
and the company clearly does not care much about anything beyond moving as
many devices as possible. The hardware is crap, the app is crap, and for
example the electrodes in the hardware have like max a couple months' worth of
life in them. You can't even buy replacements for all the electrodes you need.
Just complete garbage.

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Pete_D
Thanks for the tip. Do you have any recommendations for good hardware?

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fapjacks
Hey, I apologize but I don't have any recommendations unfortunately. Honestly
the $400 I traded for complete trash just put me off the whole industry. I'll
try again in another ten years or something. I wish you good luck in your
search, though.

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myaso
Pay walled, but I don't even need to read the article. If you have a working
proposal for consuming information faster than my eyes and ears can do it and
also a working proposal for controlling a computer faster than I can do it
with a keyboard; with the constraint that the method that does this doesn't
kill me immediately or eventually, then you have my attention. Until that day
happens, I do not care and I will focus my time and attention on things that
are actually possible.

