> ### Scientists Study Brain Implants to Control PCs, Artificial Limbs

> By Paul Eng March 13

> Tired of monkeying around with a mouse in order to work with your computer? The good news: One day, you may be able to control your PC just by thinking.

> Researchers have pursued such futuristic man-to-machine connections for years in the hopes they could allow paralyzed people to more easily control computers or other complex devices such as artificial limbs.

> And scientists at Brown University in Providence, R.I., say the results of their latest research, to be published in this week's Nature journal, may help bring such possibilities closer to reality.

> In order to study just how the brain controls hand movements, researchers at Brown implanted tiny electrodes into the brains of three rhesus monkeys. The monkeys were trained to manipulate a joystick to move a cursor to a target on the computer screen. Each time they were successful, they were given a treat.

> #### Monkey See, Monkey Do

> The implants recorded the brain signals generated as the monkeys manipulated the joystick. Those signals were converted into a mathematical program, a so-called linear filter, that mimics the appropriate control signals needed to move the cursor to a particular point on the screen.

> Once the signals were properly encoded or "learned" by the filter, the scientists disconnected the joysticks from the computer displaying the cursor. The implants continued to pick up the monkeys' mental patterns produced by moving the joystick, which were then translated by the linear filters into the signals to move the cursor to the correct spot.

> Majail Serruya, a graduate student and one of the researchers who conducted the Brown experiments, says other researchers have conducted similar studies with "wired" monkey brains — and even humans.

> Last year, researchers at Duke University in North Carolina wired monkey brains to control robotic arms that mimicked the motions of their real arms. And in 1998, Dr. Philip R. Kennedy, an clinical assistant professor of neurology at Emory University in Georgia, reported that a paralyzed man was able to control a cursor with a cone-shaped, glass implant.

> #### Fewer Mind Taps

> But Serruya says his team's research advances those previous works by reducing the number of brain cells that need to be tapped. "We didn't have to implant thousands of electrodes in the monkey's brain to get our results," says Seruuya.

> The Brown researchers were able to mimic the brain's control signals by recording from as few as six of the brain's neurons. And that may make it much easier to adopt for use in humans.

> "Our results demonstrate that a simple mathematical approach, coupled with a biological system, can provide effective decoding for brain-machine interfacing, which may help to restore function to neurologically impaired humans," the researchers said in their report.

> #### Years of Research Remain

> "I think it's a step forward in an important area of research," says Sandro Mussa-Ivaldi, a professor of physiology and biomedical engineering at Northwestern University in Illinois. "But there is a lot of work ahead."

> For one, Mussa-Ivaldi says researchers still don't understand how information is processed in the brain or how to send information back to the brain implants. "When you carry a glass of water, your brain is constantly being informed about the cup," he says. "We understand how to get the signal out from brain to control the device but to carry info back so we can close the loop is something we have yet to figure out."

> And while the implants used in the Brown experiment are smaller than previous implants, they still used wires to connect to the computer. "We need to develop better connections between the devices and the brain," says Mussa-Ivaldi. "We have to develop less invasive ways [to monitor the brain]."

> The researchers at Brown University admit that it will be quite some time before handicapped people could be thinking their way to greater functionality.

> For example, Surreya says the research still needs to be confirmed by other studies — including those conducted by researchers at other universities. And of course, the techniques would need to be approved by the Food and Drug Administration before any testing could be conducted with human subjects.

> Still, Serruya and several other Brown researchers have recently started a private company called Cyberkinetics on the premise that the technology could be added in medical devices.

> "This implant is potentially one that is very suitable for humans," Serruya says. "It shows enough promise that we think it could ultimately be hooked up via a computer to a paralyzed patient to restore that individual's interaction with the environment. "

> > Scientists study how implants may one day allow paralyzed people to use brain waves to directly control computers and artificial limbs.

> ABCNEWS.com