The brains of monkeys who learned to control robotic arms rewired themselves to treat the arms as if they were real -- a finding scientists say has implications for developing limbs to assist handicapped humans. The findings build upon a 2003 study that found monkeys were able to control robotic arms using only signals from their brains and without moving their own arms. Miguel Nicolelis and colleagues at Duke University's Center for Neuroengineering analyzed the data to see what was happening to the primates' brain cells as they learned to use the robotic arm to position a cursor on a video screen. "The monkey's brain incorporates properties of the robotic arm as if it was another arm and changes to adapt to those properties," Nicolelis, a neurobiologist, told United Press International. "Basically, the brain extends the representation of the animal's body and enhances the sense of self. The animal can function using two arms but also can function as if he has a third arm."
This not only expands the limit of the brain's ability to adapt itself to new situations, it also "opens new venues for how to design prosthetics that can be more readily incorporated by the brain," he said. Such prosthetics, dubbed "neuroprosthetics" by Nicolelis, could give those needing artificial limbs the ability to control them as if they were the real thing. Experiments in Nicolelis' lab already are building on the neuroprosthetic concept. His team is developing ways patients can receive feedback sensation, either visually or by touch, from neuroprosthetic devices via electrodes running from the limb to the brain. This would make the appendages function more like real limbs by providing a perceptual image in the patients' minds, he said. Although neuroprosthetics probably are five years away at least, Nicolelis said, "It's becoming rapidly a new area of clinical research." |