Researchers say these findings represent progress toward a mind-machine interface that may, one day, help people with a variety of disorders control devices, such as prosthetic arms and legs. The study’s lead investigator, neurologist Jerry Shih, says: “This study constitutes a baby step on the road toward that future, but it represents tangible progress in using brain waves to do certain tasks.”
The study was conducted in two patients with epilepsy. These patients were already being monitored for seizure activity using electrocorticography (ECoG), in which electrodes are placed directly on the surface of the brain to record electrical activity produced by the firing of nerve cells. In the study, the two patients sat in front of a monitor that was hooked to a computer running the researchers’ software, which was designed to interpret electrical signals coming from the electrodes.
The patients were asked to look at the screen, which contained a 6-by-6 matrix with a single alphanumeric character inside each square. Every time the square with a certain letter flashed, and the patient focused on it, the computer recorded the brain’s response to the flashing letter. The patients were then asked to focus on specific letters, and the computer software recorded the information. The computer then calibrated the system with the individual patient’s specific brain wave, and when the patient then focused on a letter, the letter appeared on the screen.
“We were able to consistently predict the desired letters for our patients at or near 100 percent accuracy,” Shih says. “While this is comparable to other researchers’ results with EEGs, this approach is more localized and can potentially provide a faster communication rate.”
The use of this technique would require patients to have a craniotomy to implant the electrodes. And software would have to calibrate each person’s brain waves to the action that is desired, such as movement of a prosthetic arm, Shih says. “These patients would have to use a computer to interpret their brain waves, but these devices are getting so small, there is a possibility that they could be implanted at some point,” he says.
MEDICA.de; Source: Mayo Clinic