title: Voluntary brain regulation and communication with electrocorticogram signals.
abstract: 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.
authors.affiliation: Institute of Environmental Medicine and Clinical Hygiene, University Medical Center Freiburg, Freiburg, Germany. Thilo.Hinterberger@Uniklinik-Freiburg.de
authors.forename: Thilo
authors.initials: T
authors.lastname: Hinterberger
authors.forename: Guido
authors.initials: G
authors.lastname: Widman
authors.forename: Thomas Navin
authors.initials: TN
authors.lastname: Lal
authors.forename: Jeremy
authors.initials: J
authors.lastname: Hill
authors.forename: Michael
authors.initials: M
authors.lastname: Tangermann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rosenstiel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schölkopf
authors.forename: Christian
authors.initials: C
authors.lastname: Elger
authors.forename: Niels
authors.initials: N
authors.lastname: Birbaumer
mesh_terms: 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