Monkeys Control Robotic Arm With Brain Implants: The details are fascinating (emphases mine): "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 new work is the first in which any animal has learned to use its brain to move a robotic device in all directions in space and to perform a mixture of interrelated movements -- such as reaching toward an object, grasping it and adjusting the grip strength depending on how heavy the object is. ..
The device relies on tiny electrodes, each one resembling a wire thinner than a 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 those tiny wires about a millimeter deep in one monkey's brain and 320 of them in the other animal's brain.
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 -- "If you put a 50-kilogram robot in front of them, they get very nervous," Nicolelis said -- but the monkeys could track their progress by watching a schematic representation of the arm and its motions on a video screen. The monkeys quickly learned how to use the joystick to make the arm reach and grasp for objects, and how to adjust their grip on the joystick to vary the robotic hand's grip strength. They could see on the monitor when they missed their target or dropped it for having too light a grip, and they were rewarded with sips of juice when they performed their tasks successfully.
While the monkeys trained, a computer tracked the patterns of bioelectrical activity in the animals' brains. The computer figured out that certain patterns amounted to a command to "reach." Others, it became clear, meant "grasp." Gradually, the computer learned to "read" the monkeys' minds.
Then the researchers did something radical: They unplugged the joystick so the robotic arm's movements depended completely on a monkey's brain activity. In effect, the computer that had been studying the animal's neural firing patterns was now serving as an interpreter, decoding the brain signals according to what it had learned from the joystick games and then sending the appropriate instructions to the mechanical arm.
At first, Nicolelis said, the monkey kept moving the joystick, not realizing that her own brain was now solely in charge of the arm's movements. Then, he said, an amazing thing happened. "We're looking, and she stops moving her arm," he said, "but the cursor keeps playing the game and the robot arm is moving around." The animal was controlling the robot with its thoughts.
"We couldn't speak. It was dead silence," Nicolelis said. "No one wanted to verbalize what was happening. And she continued to do that for almost an hour."
At first, the animals' performance declined compared to the sessions on the joystick. But after just a day or so, the control was so smooth it seemed the animals had accepted the mechanical arm as their own. "It's quite plausible that the perception is you're extended into the robot arm, or the arm is an extension of you," agreed the University of Washington's Fetz, a pioneer in the field of brain-controlled devices.
"Once you have an output signal out of the brain that you can interpret, the possibilities of what you can do with those signals are immense," said Donoghue, who recently co-founded a company, Cyberkinetics Inc. of Foxboro, Mass., to capitalize on the technology. ..
Asked if the monkeys seemed to mind the experiments, Nicolelis answered with an emphatic "No." "If anything, they're enjoying themselves playing these games. It enriches their lives," he said. "You don't have to do anything to get these guys into their chair. They go right there. That's play time." 1:44:10 AM