The findings, part of an ongoing funded research endeavor in brain-computer interface (BCI) at Albany Med, were presented earlier this month at the 63rd meeting of the American Epilepsy Society in Boston.
The research team was led by Gerwin Schalk, Ph.D., associate professor of neurology at Albany Medical College and research scientist at the Wadsworth Center of the New York State Department of Health, and Anthony Ritaccio, M.D., the J. Spencer Standish professor of neurology and neurosurgery and director of the Epilepsy and Human Brain Mapping Program at Albany Med. The first author was Peter Brunner, a doctoral candidate working on the project. Using a software platform called BCI2000, they recorded electrical activity directly from the brain’s surface. Signals were detected using platinum electrodes that were implanted in epileptic patients directly on the surface of the brain for clinical evaluations prior to epilepsy surgery.
The goal of a BCI system is to allow people with or without disabilities to use their brain signals to communicate or to manipulate their environment. Because BCIs use brain signals rather than muscles for communication and control, they can be operated by people who are severely paralyzed, even “locked-in,” by amyotrophic lateral sclerosis (ALS), brainstem stroke, severe cerebral palsy, or other devastating disorders.
In the study, the subject looked at a monitor that displayed a 6×6 matrix containing alphabetic and numeric characters, and space and backspace commands. Each row and column of the matrix was illuminated randomly and rapidly, i.e., 16 times per second. The subject’s task was to pay attention to each of the characters she wanted spell. The computer learned the desired character by interpreting and recording the brain’s responses to the illuminated row and column that commonly contained the desired character.
The subject was able to make character selections at rates of more than 20 characters per minute at or close to 100 percent accuracy. “These results could further extend communication options, such as email or instant messaging, for people with severe motor disabilities to connect with the outside world,” said Dr. Ritaccio. Past studies have used electroencephalography (EEG), the recording of electrical activity from electrodes placed on the scalp, to engage in computer assisted spelling. “In our method, which used electrodes placed on the surface of the brain, spelling rates were as up to three times faster when compared to using signals from the scalp,” according to Dr. Ritaccio. “The subject in this study was able to spell with her mind faster than some people can type.”
Over the past decade at Wadsworth, Dr. Schalk has led an international effort to develop a general-purpose software platform for BCIs and brain monitoring. This software is becoming the standard software for BCI research in hundreds of labs around the world. Moreover, Dr. Ritaccio has established a nationally ranked epilepsy center at Albany Med and has integrated the use of electrode grids to locate seizure foci and map important brain functions, including language.
Albany Medical Center is northeastern New York’s only academic health sciences center. It consists of Albany Medical College, Albany Medical Center Hospital and the Albany Medical Center Foundation, Inc. Additional information about Albany Medical Center can be found at www.amc.edu.
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