Abstract
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 × 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 × 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 × 6 or a 7 × 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. Significance: BCIs could provide an alternative communication and control technology in the daily lives of people severely disabled by ALS.
Original language | English |
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Pages (from-to) | 1909-1916 |
Number of pages | 8 |
Journal | Clinical Neurophysiology |
Volume | 119 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 2008 |
Keywords
- Amyotrophic lateral sclerosis
- Brain-computer interface
- Electroencephalogram
- Event-related potentials
- P300
- Rehabilitation
ASJC Scopus subject areas
- Clinical Neurology
- Radiology Nuclear Medicine and imaging
- Neurology
- Sensory Systems
- Physiology (medical)