title: A covert attention P300-based brain-computer interface: Geospell.
abstract: The Farwell and Donchin P300 speller interface is one of the most widely used brain-computer interface (BCI) paradigms for writing text. Recent studies have shown that the recognition accuracy of the P300 speller decreases significantly when eye movement is impaired. This report introduces the GeoSpell interface (Geometric Speller), which implements a stimulation framework for a P300-based BCI that has been optimised for operation in covert visual attention. We compared the Geospell with the P300 speller interface under overt attention conditions with regard to effectiveness, efficiency and user satisfaction. Ten healthy subjects participated in the study. The performance of the GeoSpell interface in covert attention was comparable with that of the P300 speller in overt attention. As expected, the effectiveness of the spelling decreased with the new interface in covert attention. The NASA task load index (TLX) for workload assessment did not differ significantly between the two modalities.
  This study introduces and evaluates a gaze-independent, P300-based brain-computer interface, the efficacy and user satisfaction of which were comparable with those off the classical P300 speller. Despite a decrease in effectiveness due to the use of covert attention, the performance of the GeoSpell far exceeded the threshold of accuracy with regard to effective spelling.
authors.affiliation: Neuroelectrical Imaging and BCI Lab, Fondazione Santa Lucia IRCCS, Rome, Italy. f.aloise@hsantalucia.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Aloise
authors.forename: Pietro
authors.initials: P
authors.lastname: Aricò
authors.forename: Francesca
authors.initials: F
authors.lastname: Schettini
authors.forename: Angela
authors.initials: A
authors.lastname: Riccio
authors.forename: Serenella
authors.initials: S
authors.lastname: Salinari
authors.forename: Donatella
authors.initials: D
authors.lastname: Mattia
authors.forename: Fabio
authors.initials: F
authors.lastname: Babiloni
authors.forename: Febo
authors.initials: F
authors.lastname: Cincotti
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D003143:Communication Devices for People with Disabilities; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D012984:Software; D014584:User-Computer Interface; D014956:Writing; D055815:Young Adult