Brain-computer interface (BCI) evaluation in people with amyotrophic lateral sclerosis

• Published in: Amyotrophic lateral sclerosis and frontotemporal degeneration Vol. 15; no. 3-4; pp. 207 - 215
• Main Authors: McCane, Lynn M., Sellers, Eric W., McFarland, Dennis J., Mak, Joseph N., Carmack, C. Steve, Zeitlin, Debra, Wolpaw, Jonathan R., Vaughan, Theresa M.
• Format: Journal Article
• Language: English
• Published: England Informa Healthcare 01.06.2014; Taylor & Francis
• Subjects: Adult; Aged; Amyotrophic lateral sclerosis (ALS); Amyotrophic Lateral Sclerosis - complications; Amyotrophic Lateral Sclerosis - diagnosis; augmentative and alternative communication (AAC); Biofeedback, Psychology; brain-computer interface (BCI); Brain-Computer Interfaces; Communication Disorders - etiology; Communication Disorders - rehabilitation; Electroencephalography; event-related potentials (ERP); Event-Related Potentials, P300 - physiology; Female; Humans; Male; Middle Aged; Online Systems; P300; Photic Stimulation; Psychomotor Performance - physiology; Reaction Time - physiology; rehabilitation; event-related potentials (ERP); augmentative and alternative communication (AAC); rehabilitation; Amyotrophic lateral sclerosis (ALS); P300; brain-computer interface (BCI)
• ISSN: 2167-8421; 2167-9223; 2167-9223
• DOI: 10.3109/21678421.2013.865750

Abstract Brain-computer interfaces (BCIs) might restore communication to people severely disabled by amyotrophic lateral sclerosis (ALS) or other disorders. We sought to: 1) define a protocol for determining whether a person with ALS can use a visual P300-based BCI; 2) determine what proportion of this population can use the BCI; and 3) identify factors affecting BCI performance. Twenty-five individuals with ALS completed an evaluation protocol using a standard 6 × 6 matrix and parameters selected by stepwise linear discrimination. With an 8-channel EEG montage, the subjects fell into two groups in BCI accuracy (chance accuracy 3%). Seventeen averaged 92 (± 3)% (range 71-100%), which is adequate for communication (G70 group). Eight averaged 12 (± 6)% (range 0-36%), inadequate for communication (L40 subject group). Performance did not correlate with disability: 11/17 (65%) of G70 subjects were severely disabled (i.e. ALSFRS-R < 5). All L40 subjects had visual impairments (e.g. nystagmus, diplopia, ptosis). P300 was larger and more anterior in G70 subjects. A 16-channel montage did not significantly improve accuracy. In conclusion, most people severely disabled by ALS could use a visual P300-based BCI for communication. In those who could not, visual impairment was the principal obstacle. For these individuals, auditory P300-based BCIs might be effective.