Slog News & Arts

Line Out

Music & Nightlife

« Should Gay Marriage Be Legal i... | Whose Side Is Billo On? »

Thursday, May 29, 2008

Why Cyborg Monkeys Are Cool

posted by on May 29 at 16:26 PM

RobotMonkey.jpg (From the current edition of the journal Nature.)

Thanks to our continuing success in Iraq, you might have noticed distinctly fewer limbs in today’s America. Hence this recent work published in the journal Nature is quite encouraging:

Here we describe a system that permits embodied prosthetic control; we show how monkeys (Macaca mulatta) use their motor cortical activity to control a mechanized arm replica in a self-feeding task. In addition to the three dimensions of movement, the subjects’ cortical signals also proportionally controlled a gripper on the end of the arm. Owing to the physical interaction between the monkey, the robotic arm and objects in the workspace, this new task presented a higher level of difficulty than previous virtual (cursor-control) experiments. Apart from an example of simple one-dimensional control, previous experiments have lacked physical interaction even in cases where a robotic arm or hand was included in the control loop, because the subjects did not use it to interact with physical objects—an interaction that cannot be fully simulated. This demonstration of multi-degree-of-freedom embodied prosthetic control paves the way towards the development of dexterous prosthetic devices that could ultimately achieve arm and hand function at a near-natural level.

The big plan here? Brain cells make electrical currents when doing their jobs. By listening for these electrical spikes with electrodes, we can eavesdrop. Using a map of the brain, giving us a clue which part of the brain controls (or controlled) the limb, we can put the electrodes over the right spot. When we detect a change in the brain cells in this spot, we can move a robot arm. Enjoy your new cyborg limb!

Well, Meel Velliste et al. got a monkey to move a robotic arm just by thinking. Nifty. Many groups, including my buddy Kai Miller right here in Seattle, have gotten people to play video games just by thinking. This brings us one step closer to replacing all those lost limbs.

Still, we really don’t have the best idea of exactly what these brain cells must say to one another when they want to move a limb or a finger. The better we understand this language, the better we can program the computer sitting between the electrodes on the brain and the robotic limb. Back to my friend’s thesis defense this week.

Listening to the brain with these electrodes, that read millions of brain cells at a time, is a bit like listening to the crowd at a stadium. You can hear large groups chanting in unison, horns or general roar; trying to pick out an individual conversation in all of this is next to impossible.

Still, we can figure a lot out at this level. When parts of the brain are at rest, they’re subject to regular gonging. The idea is somewhat like the best scene in Blazing Saddles (“Dag namit. The sheriff is a n{GONG}…”) Every time the part of the brain starts getting an idea to activate out of turn, the gonging from deeper levels interrupts the planning. So, the absence of this gonging is one way to detect when a part of the brain is activated. The problem is, this happens over a huge area of the brain. We need to figure a way to listen in on the planning among the brain cells that can now proceed uninhibited. A good old-fashioned scientific knife fight emerged in the field. One camp figured this planning would be synchronized—like a section in the stadium starting to chant, “Wave! Wave! Wave!” The other camp figured it’s hard to plan anything by only chanting in unison. Any meaningful planning would be the brain cells taking to one another, out of sync, and thus just sound like a bit louder roar from a small section. Screw listening for chants, listen for an increase in crowd noise and you’ll figure out when the brain is trying to, say, wiggle a finger.

My friend, sifting through recordings from human brains and using complex mathematical earplugs to separate the raw data from the electrodes into manageable pieces, figured out the second camp is probably right. Listen for the roar!

Two fun advances in science at a timely moment.

RSS icon Comments


Holy crap, did you just explain monkey cybernetics with a Blazing Saddles reference? You, sir, rock.

Posted by flamingbanjo | May 29, 2008 4:58 PM

And even better, the Government will eventually have a simulacrum for each of us tuned to our particular brain frequency to let them know what we're up to at any given time. Fab indeed.

Posted by Smade | May 29, 2008 5:01 PM

Has nobody clued in that this is the start of the Police State that the Red Bushies want us to be living in?

"I know what you were thinking of doing, citizen comrade!"

Posted by Will in Seattle | May 29, 2008 5:11 PM

Thank you, flamingbanjo. I was waiting all week to use that reference.

Posted by Jonathan Golob | May 29, 2008 6:27 PM

Your tinfoil will keep on working against this, too, Will, same as it does for the radio transmissions. Rest easy.

The Blazing Saddles reference was indeed masterful, Jonathan. Can it also be used to make the monkeys do my bidding?

Posted by elenchos | May 29, 2008 6:31 PM

Mind control is a *much* more difficult task.

To continue my metaphor, you'd need to be able to interject in the conversations between all the individual brain cells. All we can hear now is crowd roar; we don't even really understand the language the neurons use to talk with one another. Somebody needs to go back and get a shitload of microphones to even start at that task.

Still, DARPA has grants to do just that. And unlike the NSF or NIH, they're paying out. ;p

Posted by Jonathan Golob | May 29, 2008 6:38 PM


Say... the language of the crowd of neurons that we don't understand... inside the brains of a primate ... if the technology successfully transfers to human brains, which I hear they'll be working on in the next year or two... doesn't this GO AGAINST GOD?

Hasn't anybody cleared this with the simple farmers? The people of the land... The common clay of the new West? You know... morons?

Sounds like a Darwinian plot to me.

I say we use this technology only to aid injured monkeys and great apes, but going no further up the ladder than Beppo.

Posted by CP | May 29, 2008 9:49 PM

Actually, tin foil hats are useful for basic faraday shielding.

But it's best to use recycled tin foil.

Posted by Will in Seattle | May 30, 2008 12:23 AM

Are these monkeys that were born without limbs or were they removed? did they already have neural pathways that were coded for movement of those limbs?

Posted by inkweary | May 30, 2008 11:46 AM

Comments Closed

Comments are closed on this post.