Monkeys have successfully operated robotic arms to feed themselves with human-like precision, activating a mechanical device with signals from their brain. Researchers say the technique could eventually be used to help people who are paralyzed or suffer from neurological disorders like Lou Gehrig's disease. VOA's Jessica Berman reports.

Researchers at the University of Pittsburgh have done what until now has only been on the drawing board. They have made it possible for a monkey to move a robotic arm with brain signals.

Experts say the technology could help individuals who are paralyzed due to spinal cord injuries or who are unable to move to due conditions such as Lou Gehrig's disease.

In a study published this week in the journal Nature, researchers report they have made it possible for two monkeys to feed themselves marshmallows and chunks of fruit with human-like precision using a robotic arm activated by signals from a region of the brain known as the cerebral cortex.

During the experiments, the monkeys' arms were tied to their sides and the robotic arm was placed at the shoulder.

Senior study author Andrew Schwartz of the University of Pittsburgh's School of Medicine says thin wires placed in the animals' brains detected movement signals given off by about one hundred neurons or nerve cells in the motor cortex.

Schwartz says the signals were then fed into a computer, which generates movement in the robot arm that is extremely life-like.

"Using this in a really natural way, the movement is smooth," said Andrew Schwartz. "It has the same kind of velocity profile and movement characteristics as a real movement would."

Schwartz says researchers can only speculate how the primates learn to use the robotic arm. "It's hard to ask the monkeys what they are feeling," he said. "But it seems to me that it would be like the kind of skill that you have when you work a mouse and look at the cursor on your computer screen. It doesn't take very long before you are just thinking about the cursor and you are not considering about what your hand is doing at all.

"In fact, your hand is moving on the table top and your cursor is moving on the screen, which is perpendicular, but you don't make that transformation consciously," he concluded.

Schwartz says researchers are working to increase the flexibility of the robotic prosthetic by adding wrist and finger joint movements.