A monkey has shown the ability to use its brainwaves to control the hand of another sleeping primate, giving hope of a cure for paralysis in the future.
Scientists from Harvard Medical School and Cornell University showed how a monkey could transfer its thoughts through electrodes to manipulate the movements of a sleeping monkey to make it control a joystick.
Published in Nature Communications, researchers had a Rhesus monkey fully sedated to simulate full paralysis, where the brain is disconnected from the muscle it normally commands.
Neuroscientists and engineers attached electrodes to the brain of one monkey to the spinal cord of another through a computer. They then decoded and relayed the neural information being sent out.
The 'master' monkey, controlling the movement, was able to move a cursor towards one of two spots by making the paralysed monkey's hand move a joystick. The 'master monkey' was able to hit the target about 84% of the time.
Maryam Sanaechi from Cornell University told AFP: "We demonstrate that a subject can control a paralysed limb purely with its thoughts."
The researchers believe this is the first time an animal has been given control of another's limb movements.
They say their findings indicate subjects can move a limb just by thinking, even without a connection between the brain and muscle.
Ziv Williams, from Massachusetts General Hospital of Harvard Medical School, told Live Science: "The benefit there is that you are using your own body as opposed to a mechanical device, which can need a lot of support and is not always practical to carry around with you.
"The hope is to create a functional bypass for the damaged spinal cord or brainstem so that patients can control their own bodies.
"I was inspired a little by the movie Avatar. Probably the biggest challenge we had was having this happen in real-time. In theory, you can record neuronal activity any time, analyse it offline, and use those signals to stimulate the spinal cord or muscles.
"The trick is being able to figure out what the monkey is intending in real-time and then stimulating the spinal cord or muscles to create the desired movements."
Speaking to the BBC, he added: "The goal is to take people with brain stem or spinal cord paralysis and bypass the injury. The hope is ultimately to get completely natural movement, I think it's theoretically possible, but it will require an exponential additional effort to get to that point."