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Journalism of Courage
Scientists in North Carolina have built a brain implant that lets monkeys control a robotic arm with their thoughts, marking the first time that mental intentions have been harnessed to move a mechanical object. The technology could someday allow people with paralysing spinal cord injuries to operate machines with thoughts as naturally as others do with their hands. It may allow them to move their arms or legs again, by transmitting the brain8217;s directions not to a machine but directly to the muscles. The brain implants could also allow scientists to control, hands-free, small robots that could perform tasks in inhospitable environments.
In the experiments, monkeys with wires running from their brains to a robotic arm were able to use their thoughts to make the arm perform tasks. Before long, scientists said, they will upgrade the monkeys so they can transmit the commands to machines wirelessly. 8216;8216;It8217;s a major advance,8217;8217; University of Washington neuroscientist Eberhard E. Fetz said of the studies.
The device relies on tiny electrodes, each resembling a wire thinner than human hair. After removing patches of skull from two monkeys to expose the outer surface of their brains, Nicolelis and his colleagues stuck 96 of these wires, about a millimetre deep, in one monkey8217;s brain and 320 of them in the other animal8217;s brain. The surgeries were painstaking, taking about 10 hours.
Then came the training, with the monkeys first learning to move the robot arm with a joystick. The arm was kept in a separate room. While the monkeys trained, a computer tracked the patterns of bioelectrical activity in the animals8217; brains. The computer figured out that certain patterns amounted to a command to 8216;8216;reach8217;8217;. Others meant 8216;8216;grasp8217;8217;. Gradually, the computer learned to 8216;8216;read8217;8217; the monkeys8217; minds. Then the researchers did something radical: They unplugged the joystick so the robotic arm8217;s movements depended completely on a monkey8217;s brain activity.In effect, the computer was now serving as an interpreter.
At first, Nicolelis said, the monkey kept moving the joystick, not realising her brain was now solely in charge of the arm8217;s movements. Then, he said, an amazing thing happened. 8216;8216;We8217;re looking, and she stops moving her arm,8217;8217; he said, 8216;8216;but the cursor keeps playing the game and the robot arm is moving around.8217;8217; The animal was controlling the robot with its thoughts. 8216;8216;We couldn8217;t speak. It was dead silence,8217;8217; he said.LAT-WP
