What the Tech?: These Monkeys Have Mind Control Powers
Researchers at Mass. General figured out how to make primates manipulate each other’s movements using microchips.
Researchers at Massachusetts General Hospital aren’t monkeying around: scientists are working on ways to one day allow people with paralysis to regain control of their limbs using specialized internal sensors, and they’re successfully testing the process using primates.
Using a microchip implanted in a Rhesus monkey’s brain and a second set of transmitters implanted in a separate sedated monkey’s spinal cord, Ziv Williams, an assistant professor of surgery at Harvard Medical School and attending neurosurgeon at Mass. General, said a team of scientists were able to get one animal’s arms to move based on the thoughts of the other.
“The general concept of the thesis was, basically we had one microchip in the brain of the ‘master,’ and what we did was select specific electrodes in the spinal cord of the ‘avatar’ to produce limited movements. The trick was to do this in real-time,” said Williams.
The study, which used a computer to process and transmit the thoughts and actions between the primates, was published Tuesday in the journal Nature Communications.
Williams said they struggled with how to test this theory in a state of paralysis without having to actually paralyze a monkey. So instead of relying on cruelty to cripple their subject, they used the two primates and sedated one of them. “That was something we really did not want to do for a lot of ethical reasons,” he said. “So the way we approached the problem was to use two separate animals.”
The monkey that acted as the “master” was responsible for controlling or thinking about the movements, and a second, sedated monkey was the “avatar,” who was responsible for generating the movement, he said. This was done using electrodes connecting the brain of the master to the spinal cord of the avatar through the computer.
Williams said the way they got the master to move the limbs of the avatar was by placing a target on a screen in front of him. In order to get a cursor on the screen into that target, the master would have to use his thoughts to control the movements of the avatar’s arms, which were attached to a joystick in a separate room.
The master’s thoughts would be transferred through the electrodes and translated into movements read by the microchip in the avatar’s body. Once the joystick moved, it would shift the cursor into the target on the screen, and the master would get a reward—a squirt of juice. “We did this over and over again. The master would see a target at the top of the screen and think, ‘I need to make a movement to the top of the screen.’ And based on that thought, it would now get translated to an actual movement,” he said.
Only two monkeys were used throughout the research, and their roles in the study were interchanged, which produced the same results. For now, the novel idea is merely a “proof of concept.”
But don’t fear: Williams and his team aren’t concerned about creating an army of primates to take over the world. They are focused on helping people with serious medical problems. “The goal of the project was to help people with spinal cord injury, or people that are paraplegic or injured from strokes and not able to move bypass their injuries,” said Williams. “[We would like] to translate this into a clinical practice. The only difference would be in an individual that’s paralyzed, instead of putting the microchip in another person’s body, which isn’t the goal of this project, the microchips would be in their own spine below the site of the injury.”
He said the patient would have another microchip in their brain, and would then be able to move their lifeless body parts. “The goal would really be to animate your own paralyzed arm.”
Admitting that their research was partly inspired by science fiction—the original concept came before the movie “Avatar” ever hit theaters—Williams believes the relation between the Hollywood film and the team’s research helps people better understand what they are working on. “We already had the idea. But I think the name connotes a very specific thing in people’s minds, and helps in conveying the general idea of what we did,” said Williams.
Being able to make a movement isn’t the whole picture, however. Williams said a big part of this project is being able to feel or sense movements, and there has been recent progress in that field that’s been studied by other researchers. “The different elements are starting to come together to a point where I think you can actually start combining these different thought processes into something that may be a potentially useful neural prosthesis.”
He said it’s a complex process, however, and it involves a lot of moving parts that need to work together simultaneously. Researchers want to get to a point where it’s practically useable in the medical field, and hope that can happen in the next decade. “The next steps we are hoping to accomplish is to try and perform these movements at a finer resolution … and being able to produce movements where you’re not just reaching for something, but where you could grab it or point to it. But there are several technical things that need to be done to get to that point,” said Williams. “That’s an active point of what we are doing right now.”