Voluntary brain regulation and communication with electrocorticogram signals.
Brain-computer interfaces (BCIs) can be used for communication in writing without muscular activity or for learning to control seizures by voluntary regulation of brain signals such as the electroencephalogram (EEG). Three of five patients with epilepsy were able to spell their names with electrocorticogram (ECoG) signals derived from motor-related areas within only one or two training sessions. Imagery of finger or tongue movements was classified with support-vector classification of autoregressive coefficients derived from the ECoG signals. After training of the classifier, binary classification responses were used to select letters from a computer-generated menu. Offline analysis showed increased theta activity in the unsuccessful patients, whereas the successful patients exhibited dominant sensorimotor rhythms that they could control. The high spatial resolution and increased signal-to-noise ratio in ECoG signals, combined with short training periods, may offer an alternative for communication in complete paralysis, locked-in syndrome, and motor restoration.
Hinterberger
Thilo
T
Institute of Environmental Medicine and Clinical Hygiene, University Medical Center Freiburg, Freiburg, Germany. Thilo.Hinterberger@Uniklinik-Freiburg.de
Widman
Guido
G
Lal
Thomas Navin
TN
Hill
Jeremy
J
Tangermann
Michael
M
Rosenstiel
Wolfgang
W
Schölkopf
Bernhard
B
Elger
Christian
C
Birbaumer
Niels
N
D000328:Adult; D001676:Biofeedback, Psychology / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology*; D003143:Communication Devices for People with Disabilities; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000503:physiopathology / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000503:physiopathology; D012815:Signal Processing, Computer-Assisted; D012984:Software; D013003:Somatosensory Cortex / Q000503:physiopathology; D013826:Theta Rhythm; D014584:User-Computer Interface; D014956:Writing