Power of Thought Could Help Paralyzed Move
The technique developed by the Duke researchers allowed large numbers of single neurons to be recorded separately, then the information was combined using a computer. The researchers implanted as many as 96 electrodes, each smaller than the diameter of a human hair, into five regions of the monkeys' brains including the motor cortex, which controls body movement. They then recorded the output of these electrodes as the animals were taught tasks, such as reaching for small pieces of food.
The extensive signaling data generated during many repetitions of these tasks were then fed into a computer designed to analyze the brain signals, in an effort to predict the trajectory, or path, of the monkey's hand. The researchers devised mathematical methods to predict hand movements in real-time as the monkeys learned different hand movements.
Once the researchers determined that the computer analysis could reliably predict hand trajectory from brain signal patterns, they used the brain signals from the monkeys as processed by the computer to allow the animals to control a robot arm.
"The basic science question we are asking is, how is it that from an electrical pattern of activity we obtain a particular behavior or a particular sensation?'' Duke researcher Miguel Nicolelis, MD, PhD, tells WebMD. "We are beginning to learn the answer to this question, but it is a slow process. My most optimistic prediction is that we could see human trials within the next 10 years."
Nicolelis says the Duke team plans to spend the next five years conducting further primate studies, designed to investigate how the brain processes information. ""Eventually," he says, "we should be able to establish a reciprocal interaction whereby the brain controls the movements of the robot, and the robot sends information to tell the brain what it is doing."