Monkeying around with the Brain: Scientists Turn an Animal's Thoughts into Action. Will the New Research Help Humans?

Article excerpt

In a lab in North Carolina, an owl monkey thinks about grabbing a piece of fruit. His brain sends electric messages to his muscles. He lifts his furry arm, aiming for the fruit--and a nearby robot arm simultaneously mimics the movement. With this small gesture, the monkey has proved something crucial: primate brainwaves can control complex robotic motion. It's not an isolated accomplishment; scientists hope that this work will one day help paralyzed people operate prosthetic limbs. And it could also deepen our understanding of how the brain works, says Duke University's Miguel Nicolelis, who reported the owl monkey research in last week's issue of the journal Nature. His lab and others are trying to find out what brain cells say when they talk to each other, racing to solve what scientists call the "decoding problem."

Nicolelis and his colleagues tackled the question by implanting electrodes in a monkey's brain. These electrodes eavesdropped on dozens of brain cells, called neurons. The researchers then created a computer model that predicted how the monkey would move every time those neurons fired. Once they hooked the computer model up to a robot arm, the researchers could tell how well the model was working. When monkey and robot moved the same way, the model was accurate. It wasn't an easy task. John Donoghue, chair of the neuroscience department at Brown University, explains that scientists have only recently learned to "listen" to many neurons at once. "We used to listen to one neuron at a time," he says. "But that's like trying to understand an entire symphony by listening to the second violinist."

Donoghue's lab is one of several working with models that translate brainwaves into movement. …