One of the most incredible TED talks I’ve seen is about a monkey that controls an avatar, and later, a robotic arm, with its thoughts, demonstrating increasingly awesome uses of brain-machine interfaces. Sure, people who are paralyzed have demonstrated this ability too, but there’s something even more amazing about a monkey doing it, given that it doesn’t understand the point of the exercise or the implications of its own success (or failure). The monkey also can’t receive detailed written or spoken instructions — it has to learn by doing, by trial and error, encouraged by tasty rewards, which makes the science all the more impressive. Recently, brain-machine interfaces have taken another step forward, as demonstrated when one rhesus monkey was able to control the body of another.
The study author Ziv Williams, a Harvard-based neurosurgeon and neuroscientist, said he was inspired by the movie Avatar (I guess that movie was good for something after all). He wanted to see if someone who’s paralyzed could control his limbs via brain activity, like in the movie, rather than via actual muscle movement, effectively bypassing physical damage or limitations caused the paralysis.
Williams and his team connected two rhesus monkeys with a brain-spinal cord device they created. Electrodes were wired to the controlling monkey’s brain, and to the would-be paralyzed monkey’s spine. That monkey wasn’t actually paralyzed, but was sedated to the extent that he couldn’t control his own body for the purposes of the study. Researchers put his hand on a joystick connected to a screen visible to the controlling monkey.
Signals from the controlling monkey’s brain were translated and sent to the sedated monkey. The controlling monkey was able to move the cursor on the screen by moving the sedated monkey’s hand. When the controlling monkey successfully guided the cursor to a target, he received some orange juice as a reward. One of the big advancements — and challenges — of the study was getting this to happen in real time. The controlling monkey had to want the cursor to move in a specific way in order for its brain to send the signals to the other monkey. One strategy that helped was the researchers’ decision not to try to have the monkey control all the individual muscles necessary to perform the movements, but rather to focus on the goal of the movement: hitting the target with the cursor (and, of course, getting the juice).
Eventually, researchers hope they can use this technique to treat quadriplegics by designing a microchip that could be implanted in the brain that could record the signals that comprise a person’s intent or will to move, and then send those signals to a second microchip implanted in the spinal cord or injury site.
If you’re thinking that this could become a great strategy for mind control, you’ll probably be a bit disappointed. A brain-brain interface did recently allow one colleague to move the finger of another colleague across campus, but body-snatching has a long way to go before it becomes a useful tool for world domination.