Two monkeys have been trained to eat morsels of food using a robotic arm controlled by thoughts that are relayed through a set of electrodes connecting the animal's brain to a computer, scientists have announced.
The astonishing feat is being seen as a major breakthrough in the development of robotic prosthetic limbs and other automated devices that can be manipulated by paralysed patients using mind control alone.
Scientists eventually plan to use the technology in the development of prosthetics for people with spinal cord injuries or conditions such as motor neurone disease, where total paralysis leaves few other options for controlling artificial limbs or wheelchairs. They hope one day to develop robotic machines that feel like a natural extension of the human body, which would enable the technology to be adapted for a wide variety of purposes, from driving a car to operating a fork-lift truck.
The monkey learns by first observing the movement, which activates the brain cells as if he were doing it. It's a lot like sports training, where trainers have athletes first imagine that they are performing the movements they desire.
One encouraging finding was how readily the monkeys learnt to control the robot... Equally encouraging was how naturally the monkeys controlled and interacted with the robot.
They made curved trajectories of the gripper through space to avoid obstacles, made rapid corrections in the trajectory when the experimenter unexpectedly changed the location of the food morsel, and even used the gripper as a prop to push a loose treat from their lips into their mouth.
The next task was to develop a way of sending sensory information back to the monkey through the robotic arm so that the animal knows how hard to grip an object, which is essential for human interactions.
For physical interactions with the environment, the subject must also be able to sense and control the forces exerted by the robot on any object or surface so that, for instance, they can pick up an object with a strong enough grip to prevent it slipping from the robotic hand but not so strong as to crush it. These and other technical issues are challenging, but not insurmountable.