Cyber monkeys to take over world?

Two monkeys have been taught to move an object around a computer screen in 3D simply by imagining it, scientists disclosed today.

The extraordinary experiment could be a step towards providing disabled human patients with thought-controlled artificial limbs.

The macaque monkeys had their brains linked to a computer which displayed a cursor that could move in three dimensions.By picking up the activity of individual neurons in the motor cortex part of the monkeys' brains, the computer caused the cursor to move within an imaginary square.The monkeys could make the cursor go where they wanted, "virtual reality" fashion, by moving their arms.But then their arms were restrained and they were asked to direct the cursor by thought alone.

At first they pushed against the restraints, but after several days learned they could move the cursor simply using their imagination.

When this was done, the cursor moved with almost as much accuracy and speed as it did when controlled by arm movements, the researchers reported in the journal Science.

"This indicates that it is possible to develop effective brain control modulation patterns in the absence of physical limb movements or normal muscle activation patterns," wrote the scientists, led by Dawn Taylor at Arizona State University in Tempe, in the United States.Allowing the monkeys to watch the cursor during the brain-controlled movements seemed to fine-tune their motor cortex neurons.

The researchers found that a surprisingly small number of cells - only about 18 - was enough to carry out the thought-control task.