Comparisons of stimulus paradigms for SSVEP-based brain-computer interfaces.

Abstract

<i>Objective.</i>With the recent development of visual evoked potential (VEP) based brain-computer interfaces (BCIs), the stimulus paradigm has been continuously innovated, in which the pursuit of higher BCI performance and better user experience has become indispensable.<i>Approach.</i>To optimize the stimulus paradigm, a 12-target online BCI system was designed in this study by adopting flicker for steady-state VEPs, Newton's ring for steady-state motion VEP, and frame rate based video stimulus, respectively. The signal characteristics of VEP, classification accuracy, and user experience of the three stimulus paradigms were quantitatively evaluated and compared.<i>Main results.</i>The online information transfer rates for the three stimulus paradigms were 53.77 bits min^-1, 51.41 ± 3.55 bits min^-1, and 52.07 ± 3.09 bits min^-1, respectively. The video stimulus had a significantly better user experience, while the flicker stimulus showed the worst.<i>Significance.</i>These results demonstrate the advantage of the proposed video stimulus paradigm and have significant theoretical and applied implications for developing VEP-based BCI systems.