title: Usability and Workload of Access Technology for People With Severe Motor Impairment: A Comparison of Brain-Computer Interfacing and Eye Tracking.
abstract: BACKGROUND
  Eye trackers are widely used among people with amyotrophic lateral sclerosis, and their benefits to quality of life have been previously shown. On the contrary, Brain-computer interfaces (BCIs) are still quite a novel technology, which also serves as an access technology for people with severe motor impairment.
  
  
  OBJECTIVE
  To compare a visual P300-based BCI and an eye tracker in terms of information transfer rate (ITR), usability, and cognitive workload in users with motor impairments.
  
  
  METHODS
  Each participant performed 3 spelling tasks, over 4 total sessions, using an Internet browser, which was controlled by a spelling interface that was suitable for use with either the BCI or the eye tracker. At the end of each session, participants evaluated usability and cognitive workload of the system.
  
  
  RESULTS
  ITR and System Usability Scale (SUS) score were higher for the eye tracker (Wilcoxon signed-rank test: ITR T = 9, P = .016; SUS T = 12.50, P = .035). Cognitive workload was higher for the BCI (T = 4; P = .003).
  
  
  CONCLUSIONS
  Although BCIs could be potentially useful for people with severe physical disabilities, we showed that the usability of BCIs based on the visual P300 remains inferior to eye tracking. We suggest that future research on visual BCIs should use eye tracking-based control as a comparison to evaluate performance or focus on nonvisual paradigms for persons who have lost gaze control.
authors.affiliation: Université Catholique de Louvain, Louvain-la-Neuve, Belgium emanuele.pasqualotto@uclouvain.be.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pasqualotto
authors.affiliation: Eberhard Karls Universität, Tübingen, Germany.
authors.forename: Tamara
authors.initials: T
authors.lastname: Matuz
authors.affiliation: University of Perugia, Perugia, Italy Sapienza Università di Roma, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Federici
authors.affiliation: Eberhard Karls Universität, Tübingen, Germany.
authors.forename: Carolin A
authors.initials: CA
authors.lastname: Ruf
authors.affiliation: Eberhard Karls Universität, Tübingen, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Bartl
authors.affiliation: Sapienza Università di Roma, Rome, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Olivetti Belardinelli
authors.affiliation: Eberhard Karls Universität, Tübingen, Germany Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Venezia Lido, Italy.
authors.forename: Niels
authors.initials: N
authors.lastname: Birbaumer
authors.affiliation: Universität Würzburg, Würzburg, Germany National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Halder
mesh_terms: D000328:Adult; D000368:Aged; D062207:Brain-Computer Interfaces; D004185:Disability Evaluation; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000068079:Motor Disorders / Q000150:complications* / Q000175:diagnosis*; D009483:Neuropsychological Tests; D018709:Statistics, Nonparametric; D014584:User-Computer Interface; D016526:Workload
keywords: ALS; BCI; assistive technology; brain-computer interface; cognitive workload; eye tracking; usability