A gaze independent spelling based on rapid serial visual presentation.
An event-related potential (ERP) speller is a brain computer interface (BCI) based on the detection on ERPs that can be used as spelling device for those people deprived of other means of communication. In the present online study we investigated in twelve participants the performance of an ERP speller based on the rapid serial visual presentation paradigm (RSVP). Three variants of the RSVP speller have been investigated regarding chromaticism and speed of stimulus presentation. All the subjects were able to successfully operate the RSVP speller and high mean symbol selection accuracies were reached in all conditions, (93.6% to 94.8%). Offline analysis revealed a possible mean spelling speed of about 2 symb/min for an optimized number of stimulus sequences. The RSVP speller is intuitive to use and it is gaze independent, which makes it suitable for patients with deterioration of oculomotor control.