A P300-based brain-computer interface for people with amyotrophic lateral sclerosis.
OBJECTIVE
The current study evaluates the efficacy of a P300-based brain-computer interface (BCI) communication device for individuals with advanced ALS.


METHODS
Participants attended to one cell of a N x N matrix while the N rows and N columns flashed randomly. Each cell of the matrix contained one character. Every flash of an attended character served as a rare event in an oddball sequence and elicited a P300 response. Classification coefficients derived using a stepwise linear discriminant function were applied to the data after each set of flashes. The character receiving the highest discriminant score was presented as feedback.


RESULTS
In Phase I, six participants used a 6 x 6 matrix on 12 separate days with a mean rate of 1.2 selections/min and mean online and offline accuracies of 62% and 82%, respectively. In Phase II, four participants used either a 6 x 6 or a 7 x 7 matrix to produce novel and spontaneous statements with a mean online rate of 2.1 selections/min and online accuracy of 79%. The amplitude and latency of the P300 remained stable over 40 weeks.


CONCLUSIONS
Participants could communicate with the P300-based BCI and performance was stable over many months.


CONCLUSIONS
BCIs could provide an alternative communication and control technology in the daily lives of people severely disabled by ALS.
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany. Electronic address: femke.nijboer@uni-tuebingen.de.
F
F
Nijboer
Laboratory of Nervous System Disorders, Wadsworth Center, New York State Department of Health, Albany, USA.
E W
EW
Sellers
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
J
J
Mellinger
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
M A
MA
Jordan
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
T
T
Matuz
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
A
A
Furdea
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
S
S
Halder
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
U
U
Mochty
University of North Florida, Jacksonville, USA.
D J
DJ
Krusienski
Laboratory of Nervous System Disorders, Wadsworth Center, New York State Department of Health, Albany, USA.
T M
TM
Vaughan
Laboratory of Nervous System Disorders, Wadsworth Center, New York State Department of Health, Albany, USA.
J R
JR
Wolpaw
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany; National Institutes of Health (NIH), NINDS, Human Cortical Physiology Unit, Bethesda, USA.
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N
Birbaumer
Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Gartenstraße 29, 72074 Tübingen, Germany.
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A
Kübler
D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology* / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D016002:Discriminant Analysis; D004569:Electroencephalography / Q000379:methods; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D030141:Feedback, Psychological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time; D014584:User-Computer Interface