Shifting stimuli for brain computer interface based on rapid serial visual presentation

Abstract

Most of event-related potential (ERP)-based brain-computer interface (BCI) spellers are limited practical value for paralyzed patients with severe oculomotor impairments. Recently, a gaze-independent BCI speller was proposed that uses rapid serial visual presentation (RSVP), but it is difficult to recognize targets because of the rapid presentation of characters. We developed two ERP-based BCI spellers using RSVP with motion, and non-motion stimulation. We evaluated the effect of the two different stimulus conditions on the performance of the speller system with eight participants. The stimulation methods that employ motion stimulation inside the foveal vision demonstrate not only gaze-independence but also higher performance than method that uses non-motion stimulation (88.9% for non-motion RSVP, 90.3% for motion RSVP). The performance of the different stimulation methods was susceptible to ERP latency and amplitudes. As a result, motion-type RSVP stimulation condition (i.e., motion RSVP) had shorter latency and higher amplitudes than the non-motion RSVP stimulation condition. It is expected that the proposed motion RSVP stimulation method could be used for developing a gaze independent BCI system with high performance.