Robots can be controlled using a brain interface already. MIT researchers are exploring the idea of reading brainwaves using an EEG cap to correct errors made by robots as a person watches. The system simply captures and analyzes error-related signal from the brain, enabling the robot to recognize when it is making a mistake.
The robot relies on a corrective system that works in real-time to classify brainwaves in 10-30ms. More info is available here.