US: Thought alone can be used to manipulate a robotic arm. Researchers have wired a monkey's brain directly to a human-like mechanical limb, allowing the animal to feed itself without actually moving.
A new method for connecting the brain directly to a mechanical interface was described at the meeting of the American Association for the Advancement of Science, currently under way in Washington.
Prof Andrew Schwartz of the University of Pittsburgh explained his work in "neuroprosthetics", creating artificial limbs controlled by the brain simply by thinking.
The hope is that a similar device could be used in humans, allowing those incapacitated by disease or accident to exert a degree of control over their environment.
"What we want to be able to do is tap into information in the brain and map an intention to move," Prof Schwartz explained.
The result of these experiments is a monkey able to extend a three-jointed robotic arm, seize a tasty piece of courgette, and place it in its mouth.
The process begins by inserting a number of very fine probes into the monkey's brain, in the area involved in voluntary movement.
The probes do not harm the animal - nor do they have a lasting effect on its brain - but they do carry electrodes able to detect the firing of individual brain cells or neurons.
The monkey is first trained to make hand movements, and during this time the researchers record which neurons are firing and in which "direction" they preferentially fire.
The electrodes only tap into a few dozen of the millions of neurons actually required to move the arm.
Even so, the signal provides a sample of neuronal responses, enabling the researchers to approximate brain activity in a way similar to the way political polls can predict the intentions of voters by assessing only a few hundred votes.
The neuronal data is then fed into a complex mathematical formula that takes the sample and uses it to anticipate what hand movement the monkey is trying to achieve, Prof Schwartz explained.
The animal's hands are then restrained in plastic tubes but it very quickly learns that the robot arm will respond to its thoughts.
In a short time it abandons attempts to use its own arm to seize the proffered piece of courgette and instead uses the robot arm to take and eat the food.
Similar work in Brown University makes use of a cursor allowing a monkey to respond to its environment.
Prof Schwartz's system involves the direct manipulation of a robot arm, something that if found suitable for humans could transform quality of life for those with impaired movement.
Prof Schwartz hopes to be able to test the system in human subjects in about two years.