Scientists at ASU have developed a device that allows monkeys to move a cursor on a computer screen by thought alone. This research has raised hopes that paralyzed people may one day be able to control artificial limbs with their minds.
Stephen Tillery, a doctoral candidate at ASU, said he and several other scientists have implanted tiny electrodes into the brains of rhesus monkeys to record their brain activity.
"The main research is called neuroprosthetics, and the idea is to have some way to measure brain activity to control a device," Tillery said. "For example, someone who is paralyzed to run a robotic arm to get themselves food."
Bundles of electrode implants were implanted into the cerebral cortex of several monkeys. The implants then record signals from the monkey's motor cortex, an area of the brain that controls movement, as the monkeys try to move a cursor on a computer screen.
Neurons fire as the monkey's hand moves through space, and the researchers were then able to create a mathematical model that simply related the firing of neurons to the cursor's position.
Researchers found that the activity of neurons in the brain's motor cortex could be decoded into a signal capable of moving the computer cursor via thin cables that connect the implant to the computer.
Tillery said that he was able to predict where the monkeys were going to move the cursor. He said there is a correlation between the way neurons transpire and the way the monkeys move.
"You can read a monkey's mind by looking at its brain activity," Tillery said.
Tillery said the electrode brain implants do not cause any harmful side effects to the brain.
"The implants are very fine -- the brain is pretty robust," Tillery said. "We have not tried this in humans, but others have."
Tillery said after awhile the monkeys begin to reject the implants and scar tissue builds around the wires.
Andrew Schwartz, a bioengineering professor at ASU, said the implants are not very reliable. He said in order to have humans moving artificial limbs via thought, they must have electrodes permanently implanted.
Schwartz said the implants last three to six months on average.
He said he is working towards having the monkeys use thought control to move a robotic arm in order to retrieve things by using their brain.
"Right now we have monkeys moving objects in 3-Dimensional space with brain control," Schwartz said.
Tillery said he hopes to have monkeys feeding themselves with robotic arms within a few weeks.
Reach the reporter at erin.hawksworth@asu.edu.
