By focusing on images of letters, people with electrodes in their brains can type with just their minds, scientists now reveal.
These findings make up one more step on the road to mind-machine interfaces that may one day help people communicate with just their thoughts. Researchers have recently employed brain scans to see numbers and maybe even pull videos from inside people's heads.
The neuroscientists were monitoring two patients with epilepsy for seizure activity with electrodes placed directly on the surface of their brains to record electrical activity generated by the firing of nerve cells. This kind of procedure requires a craniotomy, a surgical incision into the skull.
How it works
Lead investigator Jerry Shih, a neurologist at the Mayo Clinic campus in Jacksonville, Fla., wanted to test how well their fledgling mind-machine interface functioned in these patients. He reasoned it would perform better when electrodes were placed directly on the brain instead of when placed on the scalp, as is done with electroencephalography, or EEG.
After the system was calibrated to each patient's specific brain waves, when the patient 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 said. "While this is comparable to other researchers' results with EEGs, this approach is more localized and can potentially provide a faster communication rate. Our goal is to find a way to effectively and consistently use a patient's brain waves to perform certain tasks."