In a big step towards making humans more bionic, scientists have trained monkeys to control not just one, but two virtual arms by thoughts alone. The work could someday be a boon to double amputees or quadriplegics.
In 2011, researchers led by Duke University neuroscientist Miguel Nicolelis demonstrated a unique two-way interface between mind and machine. The team began by recording activity from up to 200 neurons in the brains of monkeys. Once computer algorithms understood how different neuronal patterns led to specific arm motions, the researchers transposed those movement commands into a virtual world, allowing the monkeys to control a virtual arm. Next, by adding in a technique called intracortical microstimulation, which electrically stimulates sensory neurons in the brain, the researchers gave the monkeys the ability to "feel" the virtual objects they manipulated.