sciencehabit writes "Researchers have for the first time devised a setup that allows monkeys to control two virtual arms with their thoughts. Two monkeys had electrodes implanted into its right and left brain hemisphere, which recorded the activity of up to 500 neurons acting together—the highest number of neurons yet used in such an experiment. The animal's task was to control the movement of two avatar arms on a computer monitor: To get a fruit juice reward, it had to place both hands over two circles and hold them there for 100 milliseconds. A computer algorithm processed the monkey's brain activity, homing in on patterns of neurons firing as it learned to do the task. Both animals' performances improved over time, and the researchers noticed that their neuronal firing patterns changed as this happened, suggesting that their brains were adapting to the brain-machine interfaces. This could be because the monkeys came to consider the virtual arms as part of their own bodies, the lead researcher suggests. 'The animals literally incorporate the avatar as if the avatar was them.'"