[CNN.com] [/TECH] MAIN PAGE Study: Monkey brains move cursor WORLD U.S. Technique still a long way from human use WEATHER BUSINESS [photo] WASHINGTON SPORTS (Reuters) -- POLITICS Scientists say brain Monkeys LAW experiments carried out implanted with [Click Here] SCI-TECH on rhesus monkeys could special SPACE one day help paralyzed electrodes moved HEALTH people work a computer a cursor on a ENTERTAINMENT using only their computer screen TRAVEL thoughts. just by thinking EDUCATION about it, and IN-DEPTH ----------------------------learned how to ----------------------------do it better [Click Here] with practice, scientists reported on Thursday. QUICK NEWS LOCAL The experiment could eventually lead to the COMMUNITY development of better prosthetic limbs for MULTIMEDIA amputees and might even offer a way for E-MAIL SERVICES paralyzed patients to move again. CNNtoGO ABOUT US/HELP "They were able to move balls around, by thinking about it, in three-dimensional CNN TV space," said Andrew Schwartz, a neural what's on physiologist at Arizona State University who show transcripts led the study. CNN Headline News CNN International The new field, called neuroprosthetics, is askCNN small but active. In March, a team at Brown University in Rhode Island reported similar EDITIONS research in the journal Nature. CNN.com Asia CNN.com Europe In Schwartz's experiment, each tiny CNNenEspanol.com electrode was attached to a single neuron in CNNArabic.com the motor cortex, the part of the brain set your edition where movement is controlled. Two rhesus macaque monkeys were fitted with 50 to 100 electrodes, which consisted of minuscule wires about half the width of a human hair. [Click here for our advertiser] The monkeys had been trained to play a computer game, at first using their arms, in which they had to move virtual balls around a three-dimensional virtual space. After the appropriate neurons were mapped, they were fitted with electrodes that sent signals to the computer. "We basically strapped the animals' arms down so they couldn't use their arms," Schwartz said. At first the monkeys strained to use their arms but as they learned their thoughts alone could move the cursor on the screen, they stopped trying to move. Writing in the journal Science, Schwartz's team said what was new in the latest experiment was the addition of a "feedback loop" that helped the monkeys, and the computers, learn how to make the virtual movements more accurate. "They learn to get better and better at this," Schwartz said. This means fewer electrodes are needed to achieve more precise movement. "Their performance is approaching that of what we can get when they move their own arms," Schwartz said. Monkeys feel no pain Schwartz said the monkeys do not feel pain from the electrodes and have been trained to work in return for a simple drink of water. "They get used to it and they work at it until they get tired. (Then) they stop working and just sit there," Schwartz said. Schwartz said it will be a long time before the technique can be tried out in people. "Right now the electrodes we are using are not really appropriate for human use," Schwartz said. "They don't work every time." The electrodes also cause some scarring that may eventually affect their performance. Although patients likely to want to try the method first may be desperate, Schwartz said regulators would not be willing to approve major brain surgery unless it was clear it was safe. If he were paralyzed, Schwartz said, he would overlook the risk. "If I had my druthers, I'd do it," he said. At least one person has. Dr. Phil Kennedy, chief executive officer of Neural Signals in Atlanta, Georgia, implanted two glass electrodes into the brain of a quadriplegic man. The patient was able to move a cursor across a computer screen. But it took great effort and weeks of training. Copyright 2002 Reuters. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. RELATED STORIES: • Dr. Sanjay Gupta: Eye on brain's 'cheerleader' June 4, 2002 • Study: Babies can 'tune in' faces May 21, 2002 • Study: Origin clues from 'dawn mother' April 25, 2002 RELATED SITES: • Arizona State University • Brown University • Nature • Neural Signals Note: Pages will open in a new browser window External sites are not endorsed by CNN Interactive. TECHNOLOGY TOP STORIES: • 'Millipede' stores massive data • Device detects phone bugs • Roll credits on Film88.com • Cryo3 may spot 'dirty bombs' • Virtual 'Black Hawk Down'? (More) Search Back to the top © 2002 Cable News Network LP, LLLP. An AOL Time Warner Company. All Rights Reserved. Terms under which this service is provided to you. Read our privacy guidelines. Contact us.