Miguel Nicolelis: A monkey that controls a robot with its thoughts. No, really.

247,580 views ・ 2013-02-18

TED


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Translator: Timothy Covell Reviewer: Morton Bast
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The kind of neuroscience that I do and my colleagues do
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is almost like the weatherman.
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We are always chasing storms.
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We want to see and measure storms -- brainstorms, that is.
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And we all talk about brainstorms in our daily lives,
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but we rarely see or listen to one.
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So I always like to start these talks
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by actually introducing you to one of them.
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Actually, the first time we recorded more than one neuron --
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a hundred brain cells simultaneously --
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we could measure the electrical sparks
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of a hundred cells in the same animal,
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this is the first image we got,
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the first 10 seconds of this recording.
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So we got a little snippet of a thought,
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and we could see it in front of us.
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I always tell the students
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that we could also call neuroscientists some sort of astronomer,
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because we are dealing with a system
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that is only comparable in terms of number of cells
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to the number of galaxies that we have in the universe.
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And here we are, out of billions of neurons,
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just recording, 10 years ago, a hundred.
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We are doing a thousand now.
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And we hope to understand something fundamental about our human nature.
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Because, if you don't know yet,
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everything that we use to define what human nature is comes from these storms,
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comes from these storms that roll over the hills and valleys of our brains
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and define our memories, our beliefs,
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our feelings, our plans for the future.
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Everything that we ever do,
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everything that every human has ever done, do or will do,
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requires the toil of populations of neurons producing these kinds of storms.
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And the sound of a brainstorm, if you've never heard one,
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is somewhat like this.
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You can put it louder if you can.
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My son calls this "making popcorn while listening to a badly-tuned A.M. station."
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This is a brain.
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This is what happens when you route these electrical storms to a loudspeaker
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and you listen to a hundred brain cells firing,
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your brain will sound like this -- my brain, any brain.
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And what we want to do as neuroscientists in this time
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is to actually listen to these symphonies, these brain symphonies,
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and try to extract from them the messages they carry.
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In particular, about 12 years ago
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we created a preparation that we named brain-machine interfaces.
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And you have a scheme here that describes how it works.
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The idea is, let's have some sensors that listen to these storms, this electrical firing,
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and see if you can, in the same time that it takes
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for this storm to leave the brain and reach the legs or the arms of an animal --
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about half a second --
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let's see if we can read these signals,
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extract the motor messages that are embedded in it,
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translate it into digital commands
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and send it to an artificial device
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that will reproduce the voluntary motor wheel of that brain in real time.
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And see if we can measure how well we can translate that message
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when we compare to the way the body does that.
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And if we can actually provide feedback,
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sensory signals that go back from this robotic, mechanical, computational actuator
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that is now under the control of the brain,
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back to the brain,
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how the brain deals with that,
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of receiving messages from an artificial piece of machinery.
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And that's exactly what we did 10 years ago.
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We started with a superstar monkey called Aurora
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that became one of the superstars of this field.
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And Aurora liked to play video games.
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As you can see here,
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she likes to use a joystick, like any one of us, any of our kids, to play this game.
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And as a good primate, she even tries to cheat before she gets the right answer.
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So even before a target appears that she's supposed to cross
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with the cursor that she's controlling with this joystick,
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Aurora is trying to find the target, no matter where it is.
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And if she's doing that,
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because every time she crosses that target with the little cursor,
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she gets a drop of Brazilian orange juice.
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And I can tell you, any monkey will do anything for you
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if you get a little drop of Brazilian orange juice.
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Actually any primate will do that.
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Think about that.
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Well, while Aurora was playing this game, as you saw,
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and doing a thousand trials a day
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and getting 97 percent correct and 350 milliliters of orange juice,
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we are recording the brainstorms that are produced in her head
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and sending them to a robotic arm
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that was learning to reproduce the movements that Aurora was making.
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Because the idea was to actually turn on this brain-machine interface
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and have Aurora play the game just by thinking,
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without interference of her body.
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Her brainstorms would control an arm
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that would move the cursor and cross the target.
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And to our shock, that's exactly what Aurora did.
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She played the game without moving her body.
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So every trajectory that you see of the cursor now,
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this is the exact first moment she got that.
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That's the exact first moment
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a brain intention was liberated from the physical domains of a body of a primate
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and could act outside, in that outside world,
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just by controlling an artificial device.
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And Aurora kept playing the game, kept finding the little target
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and getting the orange juice that she wanted to get, that she craved for.
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Well, she did that because she, at that time, had acquired a new arm.
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The robotic arm that you see moving here 30 days later,
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after the first video that I showed to you,
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is under the control of Aurora's brain
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and is moving the cursor to get to the target.
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And Aurora now knows that she can play the game with this robotic arm,
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but she has not lost the ability to use her biological arms to do what she pleases.
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She can scratch her back, she can scratch one of us, she can play another game.
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By all purposes and means,
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Aurora's brain has incorporated that artificial device
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as an extension of her body.
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The model of the self that Aurora had in her mind
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has been expanded to get one more arm.
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Well, we did that 10 years ago.
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Just fast forward 10 years.
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Just last year we realized that you don't even need to have a robotic device.
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You can just build a computational body, an avatar, a monkey avatar.
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And you can actually use it for our monkeys to either interact with them,
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or you can train them to assume in a virtual world
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the first-person perspective of that avatar
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and use her brain activity to control the movements of the avatar's arms or legs.
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And what we did basically was to train the animals
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to learn how to control these avatars
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and explore objects that appear in the virtual world.
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And these objects are visually identical,
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but when the avatar crosses the surface of these objects,
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they send an electrical message that is proportional to the microtactile texture of the object
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that goes back directly to the monkey's brain,
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informing the brain what it is the avatar is touching.
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And in just four weeks, the brain learns to process this new sensation
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and acquires a new sensory pathway -- like a new sense.
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And you truly liberate the brain now
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because you are allowing the brain to send motor commands to move this avatar.
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And the feedback that comes from the avatar is being processed directly by the brain
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without the interference of the skin.
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So what you see here is this is the design of the task.
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You're going to see an animal basically touching these three targets.
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And he has to select one because only one carries the reward,
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the orange juice that they want to get.
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And he has to select it by touch using a virtual arm, an arm that doesn't exist.
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And that's exactly what they do.
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This is a complete liberation of the brain
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from the physical constraints of the body and the motor in a perceptual task.
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The animal is controlling the avatar to touch the targets.
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And he's sensing the texture by receiving an electrical message directly in the brain.
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And the brain is deciding what is the texture associated with the reward.
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The legends that you see in the movie don't appear for the monkey.
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And by the way, they don't read English anyway,
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so they are here just for you to know that the correct target is shifting position.
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And yet, they can find them by tactile discrimination,
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and they can press it and select it.
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So when we look at the brains of these animals,
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on the top panel you see the alignment of 125 cells
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showing what happens with the brain activity, the electrical storms,
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of this sample of neurons in the brain
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when the animal is using a joystick.
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And that's a picture that every neurophysiologist knows.
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The basic alignment shows that these cells are coding for all possible directions.
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The bottom picture is what happens when the body stops moving
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and the animal starts controlling either a robotic device or a computational avatar.
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As fast as we can reset our computers,
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the brain activity shifts to start representing this new tool,
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as if this too was a part of that primate's body.
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The brain is assimilating that too, as fast as we can measure.
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So that suggests to us that our sense of self
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does not end at the last layer of the epithelium of our bodies,
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but it ends at the last layer of electrons of the tools that we're commanding with our brains.
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Our violins, our cars, our bicycles, our soccer balls, our clothing --
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they all become assimilated by this voracious, amazing, dynamic system called the brain.
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How far can we take it?
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Well, in an experiment that we ran a few years ago, we took this to the limit.
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We had an animal running on a treadmill
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at Duke University on the East Coast of the United States,
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producing the brainstorms necessary to move.
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And we had a robotic device, a humanoid robot,
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in Kyoto, Japan at ATR Laboratories
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that was dreaming its entire life to be controlled by a brain,
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a human brain, or a primate brain.
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What happens here is that the brain activity that generated the movements in the monkey
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was transmitted to Japan and made this robot walk
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while footage of this walking was sent back to Duke,
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so that the monkey could see the legs of this robot walking in front of her.
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So she could be rewarded, not by what her body was doing
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but for every correct step of the robot on the other side of the planet
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controlled by her brain activity.
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Funny thing, that round trip around the globe took 20 milliseconds less
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than it takes for that brainstorm to leave its head, the head of the monkey,
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and reach its own muscle.
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The monkey was moving a robot that was six times bigger, across the planet.
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This is one of the experiments in which that robot was able to walk autonomously.
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This is CB1 fulfilling its dream in Japan
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under the control of the brain activity of a primate.
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So where are we taking all this?
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What are we going to do with all this research,
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besides studying the properties of this dynamic universe that we have between our ears?
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Well the idea is to take all this knowledge and technology
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and try to restore one of the most severe neurological problems that we have in the world.
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Millions of people have lost the ability to translate these brainstorms
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into action, into movement.
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Although their brains continue to produce those storms and code for movements,
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they cannot cross a barrier that was created by a lesion on the spinal cord.
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So our idea is to create a bypass,
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is to use these brain-machine interfaces to read these signals,
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larger-scale brainstorms that contain the desire to move again,
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bypass the lesion using computational microengineering
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and send it to a new body, a whole body called an exoskeleton,
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a whole robotic suit that will become the new body of these patients.
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And you can see an image produced by this consortium.
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This is a nonprofit consortium called the Walk Again Project
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that is putting together scientists from Europe,
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from here in the United States, and in Brazil
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together to work to actually get this new body built --
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a body that we believe, through the same plastic mechanisms
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that allow Aurora and other monkeys to use these tools through a brain-machine interface
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and that allows us to incorporate the tools that we produce and use in our daily life.
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This same mechanism, we hope, will allow these patients,
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not only to imagine again the movements that they want to make
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and translate them into movements of this new body,
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but for this body to be assimilated as the new body that the brain controls.
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So I was told about 10 years ago
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that this would never happen, that this was close to impossible.
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And I can only tell you that as a scientist,
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I grew up in southern Brazil in the mid-'60s
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watching a few crazy guys telling [us] that they would go to the Moon.
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And I was five years old,
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and I never understood why NASA didn't hire Captain Kirk and Spock to do the job;
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after all, they were very proficient --
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but just seeing that as a kid
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made me believe, as my grandmother used to tell me,
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that "impossible is just the possible
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that someone has not put in enough effort to make it come true."
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So they told me that it's impossible to make someone walk.
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I think I'm going to follow my grandmother's advice.
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Thank you.
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(Applause)
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