In February, Duke scientists announced a brain-machine interface that allowed a rhesus monkey to control a single robotic arm more than 7000 miles away. Today, they've expanded on the previous experiment, announcing an improved interface that allows for independent control of two arms, assimilating both mechanical arms into the monkeys' existing motor control systems.

Similar to the previous experiments, the experiment set up two rhesus monkeys in front of a remote video link, while implants monitored nearly 500 neurons to pick up motion signals. After some training, the monkeys were trained to cover targets on the screen with the arms, proving the subjects had control over the remote robotic appendages. This latest experiment is only an incremental improvement over February's trials, but it shows the basic brain-machine link holds steady through more complex setups that demand more and more of the brain. Scientists hope that future interfaces modeled on this one will someday help paralysis victims or amputees, although and human testing on the interface is still years in the future.