A Novel Auditory-tactile P300-based BCI Paradigm

Spelling is an important application of braincomputer interface (BCI). However, the visual saccade-independent P300 BCI spellers generally are not suited for widespread use by people who have lost voluntary eye movement due to their poor performance. In this study, we propose a novel P300 BCI paradigm for spelling through auditory-tactile bimodal stimuli. The target number of speller is increased and thus the information transfer rate (ITR) is improved. Specifically, a BCI speller with 36 selectable items was developed by simultaneously and randomly presenting auditory and tactile stimuli from same one of six directions. With six participants, the average simulated online ITR of the bimodal-stimulus-BCI system increased by 30% and 34% compared with the auditory and tactile approach, respectively. These findings suggest the proposed bimodal BCI paradigm is exceedingly efficient, which is promising for achieving quick spelling in visual saccade-independent P300-BCI application.