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

Amyotroph Lateral Scler Frontotemporal Degener. 2014 Jun;15(3-4):207-15. doi: 10.3109/21678421.2013.865750. Epub 2014 Feb 20.


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.

Keywords: Amyotrophic lateral sclerosis (ALS); P300; augmentative and alternative communication (AAC); brain-computer interface (BCI); event-related potentials (ERP); rehabilitation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Amyotrophic Lateral Sclerosis / complications*
  • Amyotrophic Lateral Sclerosis / diagnosis*
  • Biofeedback, Psychology*
  • Brain-Computer Interfaces*
  • Communication Disorders / etiology*
  • Communication Disorders / rehabilitation*
  • Electroencephalography
  • Event-Related Potentials, P300 / physiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Online Systems
  • Photic Stimulation
  • Psychomotor Performance / physiology
  • Reaction Time / physiology