massimilianogoi on 11/12/2009 at 17:50
Quote Posted by Koki
We do? I'm not a neurologist, but isn't this just a case of reading an electrical impulse in a nerve ending? It has nothing to do with the brain, they're not reading his brain waves, only electrical impulses being sent through his nervous system.
And that's like marveling at the fact a lightbulb starts emitting light when you connect it to a battery.
And what about the signal disturbs? How can you purify the signal from them? And the tactile feedback? How can you build it, like a lightbulb? :p
SubJeff on 11/12/2009 at 18:01
Yeah, I'm with massi on this one. Its many, many times more complicated to read and send signals via nerves that make sense. For starters there are multiple types of nerve fibers, each type has specific characteristics and different functions and some of them you definitely don't want to stimulate by accident (except in you Koki, then it would be a desirable side effect). Then there is the issue of stimulus grading, both up and downstream, and noise reduction/signal leak in and out of your system.
To compare it to a lightbulb is like comparing a scientific calculator to an abacus.
demagogue on 11/12/2009 at 18:03
Quote Posted by Koki
only electrical impulses being sent through his nervous system.
My god you're right. And here I was the whole time thinking brain-waves were neural chemical-electrical impulses. But now you imply they're something much more! How exciting. What... what were they again?
Anyway, signals are signals; there's nothing magic about them. This hand does shit like open and close individual fingers; that's *not* just plugging it into a power-source, but encoding at a pretty discrete level of signal. Your post makes it sound like you're not giving this arm stuff enough credit and you're giving brain-waves too much credit.
Whatever... I've been reading a lot of Glimcher lately and was thinking mostly about the studies where they've cracked parts of the LIP area and found it encoding relative-expected-utility of various decision-choices, making a link between physiology and concrete economic equations. That's functional computation at the neural level. That's cool. This arm thing is something happening on the side that's interesting for its own sake and is just emblematic of the direction things are going, so I took the occasion to say what I did. But I might agree with your sentiment in the sense that I think the stuff Glimcher is doing is more enlightening and interesting than this as far as deciphering actual, useful "brain-code" goes.
SubJeff on 12/12/2009 at 11:15
Most of the concepts are all there atm. Its just the tech to exploit them that is lacking. Conceptually this bionic stuff is far easier to get working than anything that would need to communicate directly with the brain, and I mean even with the motor areas of the brain, nevermind decision making or higher thought areas. Heck, even communicating at a spinal level is way complex compared to peripheral nerves.
Once the ability to make the tech is there though...
massimilianogoi on 12/12/2009 at 19:06
I agree. But in this sector they will do progresses step by step, so we can be hopeful: one day there could surely be good replacement parts for our body, maybe not of metal, but in something near the flesh, like in the Blade Runner movie, or also with the own flesh too, replicated by staminal cells multiplications. :thumb:
catbarf on 12/12/2009 at 19:36
Quote Posted by demagogue
My god you're right. And here I was the whole time thinking brain-waves were neural chemical-electrical impulses. But now you imply they're something much more! How exciting. What... what were they again?
Dismissive as he is, he's right. This isn't a computer reading your brain, interpreting the electrochemical signals, and then moving your arm. Heck, when we learn to do that, we'll be able to manipulate anything with our thoughts. The prosthetic 'just' picks up on electrical signals sent through the nervous system and sends them to the motor. The distinction is important. I think this is an incredible achievement, but the applications are limited to just limb replacement. There's not much more that can be done with it.
SubJeff on 12/12/2009 at 19:52
Yeah, so basically you've said he's right and then explained how he's not right. It may not be as complex as picking up signals directly from the brain but the "analogy" he gave is waaaaaaay off base.
catbarf on 12/12/2009 at 21:48
Quote Posted by Subjective Effect
Yeah, so basically you've said he's right and then explained how he's not right. It may not be as complex as picking up signals directly from the brain but the "analogy" he gave is waaaaaaay off base.
Agreed. I just think there is an important distinction to be made between 'manipulate mechanical objects with your thoughts' and 'manipulate mechanical objects by moving nonexistent limbs'.
demagogue on 12/12/2009 at 22:04
I was just taking the piss in that paragraph anyway, so I'm not going to disagree that there's a big difference. And I already explained what was most interesting to me with the Glimcher work, which as I understood it is pretty sophisticated interpretation of individual signals in functional brain areas (he wrote a whole book about it, Neuroeconomics, anyway). I like to read about anything coming out of this field, though; so I'm pretty liberal in my enthusiasm for better or worse.
massimilianogoi on 13/12/2009 at 05:23
Quote Posted by catbarf
Dismissive as he is, he's right. This isn't a computer reading your brain, interpreting the electrochemical signals, and then moving your arm. Heck, when we learn to do that, we'll be able to manipulate anything with our thoughts. The prosthetic 'just' picks up on electrical signals sent through the nervous system and sends them to the motor. The distinction is important. I think this is an incredible achievement, but the applications are limited to just limb replacement. There's not much more that can be done with it.
No, it doesn't just that, the prothesys has also a primitive tactile system that returns feedback impulses to the brain. The boy, in the interview, tells that he is able to feel something when the robotic hand touches something. Awesome!
