Slashdot Mirror


Brain Interface Lets Monkeys Control Prosthetic Limbs

himicos was one of many readers to point out one recent success of scientists working to develop working brain-machine interfaces, writing "A team at the university of Pittsburgh has finally advanced a 2002 technology enough for use in prosthetic limbs, the targeted application all along. Training computer models to the firing patterns of the neurons in the parts of the brain that control motion, they are able to project the intentions of a monkey to a robotic arm, which follows the will of the animal. The sad thing about the articles is that the beauty of the mathematics used to create and train the models is totally ignored." Reader phpmysqldev adds a link to coverage at the BBC, and writes "This of course brings significant hope to amputees and other other people with physical disabilities." (Note that this research has been going on for quite some time.)

16 of 208 comments (clear)

  1. And just like that... by oahazmatt · · Score: 5, Funny

    Brain Interface Lets Monkeys Control Prosthetic Limbs And just like that, a SciFi channel original movie is conceived.
    --
    Those who believe the Internet is private,
    find their privates are on the Internet.
    1. Re:And just like that... by mpeskett · · Score: 5, Insightful

      You'd prefer they started out by sticking electrodes into humans with no idea what they were doing?

      Of course some experimentation will be needed when they move to human subjects, but a monkey's brain is similar enough to ours that they can get a starting point to experiment around, rather than working blind on a human subject.

      One other thing to note, there are no touch/pain receptors within the brain itself - people have brain surgery done while awake so the doctors can keep them talking and know they aren't accidentally removing something important. Once you've got an opening into the skull (which would be done under anaesthetic) you can poke and prod at the brain all you want without the subject feeling a thing.

      Oh, and its on the news because its interesting and something of a step forward scientifically. Quit it with the conspiracy theories please.

  2. Forget Replacement Limbs... by crymeph0 · · Score: 5, Insightful

    How about custom appendages? If the brain can be trained to independently control a new arm, why couldn't it learn to control a genuine Doctor Octopus suit?

    --
    It should be illegal to say that freedom of speech should be limited.
    1. Re:Forget Replacement Limbs... by PachmanP · · Score: 4, Insightful

      How about custom appendages? If the brain can be trained to independently control a new arm, why couldn't it learn to control a genuine Doctor Octopus suit?
      Speaking from experience, it is because the grant money is better. If you say you need money to research brain/machine interfaces for prothetic limbs to help disabled people, you are more likely to get it than when you say you need the research to give yourself/your_cyborg_army superhuman appendages to be used for world domination.
      --
      You're thinking small. Why miniaturize the laser, when we could instead enlarge the sharks? -John Searle
    2. Re:Forget Replacement Limbs... by khayman80 · · Score: 4, Insightful
      I would imagine the mental map we have of our bodies has four limbs. This would mean that, for purposes of sensation, motor control and proprioception, we can't operate more than four limbs at once. Why would we evolve the ability to control limbs that we don't even have? I mean, brains are flexible, but I would guess that trying to push the "body control/sensation/proprioception" map past four limbs may have some unintended (and possibly bad) consequences.

      An alternative might be the use muscles in the face to control extra limbs. Frowning would perform one action with the prosthetics, smiling another, etc. But this would be considerably more clumsy than the intended use- replacing a limb that doesn't exist on the physical body, but does have a designated place in the brain that controls it.

    3. Re:Forget Replacement Limbs... by crymeph0 · · Score: 4, Interesting

      But in this case, the monkey was trained to use the robotic arm not as a replacement for a missing arm, but as an entirely new arm. That is, even though the apparatus was similar to an existing limb, the brain still had to learn to control a brand new limb independently from the old ones. If nothing else, this means we can give ourselves at least a third arm, and probably more. The brain is fairly malleable, and I bet with training, we could adapt ourselves to a wide variety of "appendage upgrades".

      Of course, because of the "abomination before God" factor, nobody in the medical establishment will ask this question officially for years, if ever. But I'm sure some geek amputee will start playing around with modding his new arm/leg/ear, and if he doesn't turn into a bloodthirsty cyborg, or get lynched by fundamentalists, he'll become very rich and famous by enabling us to reach way beyond what we thought our full potential was.

      --
      It should be illegal to say that freedom of speech should be limited.
  3. Adapting the technology by utnapistim · · Score: 4, Funny

    So ... I realize that this will ultimately be adapted to humans, but could it be adapted to something else?

    Specifically, I'm thinking of adapting a laser prosthetic arm, to be used by the poor, armless sharks ...

    It's just an idea ...

    --
    Tie two birds together: although they have four wings, they cannot fly. (The blind man)
  4. hope to amputees by Paul+Rose · · Score: 5, Funny

    >>This of course brings significant hope to amputees
    As long as they don't mind carrying a monkey to control their prosthetic arm...

  5. Re:Explain the beauty? by kalirion · · Score: 4, Insightful

    How would you explain the beauty of a sunset to the blind?

  6. Monkey's opinion by nategoose · · Score: 4, Insightful

    The monkey in the pictures had his own arms restrained within tubes so that he/she would be forced to use the mechanical arm in order to get the marshmallow, and the mechanical arm isn't oriented so that the monkey could possibly mistake it for his/her own arm. I can't help but wonder what the monkey's opinion of all this is. It's got to be more than a little confusing.

    1. Re:Monkey's opinion by nategoose · · Score: 5, Funny

      He/she might be thinking "I wish this @#$@ing robot arm thing would quit stuffing those @%#$ed marshmallows in my mouth!"

  7. Not impressed. by JoeD · · Score: 5, Funny

    Get back to me when they can use the robotic arm to fling poo.

  8. Re:Explain the beauty? by hansraj · · Score: 5, Insightful

    I am amazed at the number of responses being just smug and claiming how you need to do math to appreciate the beauty. Reminds me of a guy doing PhD is Chemistry about effects of certain chiral isomer of nicotine on cancer. His first response when I asked what he worked on was "You won't get it". I am a PhD student in computational geometry and I frequently have to explain my work to relatives who have no idea about geometry. When I pestered the guy that whether or not he can explain his work to a layman reflects his understanding about his work, he agreed to try. Of course I could understand the central part once he replaced the technical name of the molecule with "a chiral isomer of nicotine". I am sure it could have been further simplified as "mirror image molecule of the stuff in tobacco" in case I didn't remember what "chiral" and "nicotine" are.

    On the topic, I am not entirely sure about the exact math used in the said experiment but based on the fact that the link points to the notion of "information content", here is my guess how it should work (at least in principle). I will try just because no one else seems to. Feel free to correct me.

    The state of the neurons of the relevant area of the brain (relevant for the goal in the experiment - say pick marshmallows or open the door) could be modeled as a random variable. The first problem when trying to figure out what a certain electrical activity in brain represents would be to figure out whether you are looking at a random electrical activity (brain doing lots of background work maybe) or some order (brain trying to focus and activate the subroutine for "move hand and open door"). This difference between order and chaos is captured in a neat formula describing the entropy or the information content of the random variable. Naturally, the less the entropy the more the order. I have no idea what possibly goes on after this step.

    In any case, now coming to the "beauty" part. Of course you need an eye to appreciate beauty for the notion is quite subjective. The remarkable thing is that a simple formula captures the vague notion of "order" that we all have. The formula might not be the most beautiful thing because as I understood from the article, the log term is somewhat forced to make sure different things add up nicely. But then, one could think of this very fact (the extra log term) as a neat mathematical representation of the notion that disorder should be able to be combined with another disorder to create something bigger.

    I hope my response is better than "drop whatever you are doing and go do a PhD in math before you can understand the beauty of math".

  9. Re:How long until.... ? by 117 · · Score: 4, Funny

    How long until one of these monkeys kills the scientists with his robotic arm, in retaliation for them removing his perfectly good arm? If they keep interrupting me whilst I'm trying to post on /. , then not much longer....
  10. Re:Explain the beauty? by dezert_fox · · Score: 5, Informative

    Shannon entropy has been a standard tool in data communications for a very long time--telcos use this math to make your phones work. It's effectively a way of quantifying the informational content of a signal, which can be used to determine exactly what kind of bandwidth you need in a bandwidth-limited environment. I'm uncertain what it's used for in the context of a brain-machine interface.
    Any good data communications textbook would have some nice examples in it, and actually that wikipedia article posted is very readable and informative.

  11. Re:Explain the beauty? by Hognoxious · · Score: 4, Funny

    Showing all the math that needs to be done. or Show a picture of a monkey with a robotic arm.
    It's just the same here. Consider:
    • I for one welcome our very hard mathematics doing overlords
    • I for one welcome our new bionic monkey overlords
    In Soviet Russia the same league isn't even in THEM!!!!
    --
    Confucius say, "Find worm in apple - bad. Find half a worm - worse."