Exploring (C)overt attention for multi-objective gaze-independent BCIs, visual angle not exceeding 1 degree

Studies had reported that the performance of multi-objective gaze-independent BCIs under covert attention conditions was lower than the matrix speller BCIs under overt attention conditions. However, no research has compared the performance of multi-objective gaze-independent BCIs under covert attention conditions with under overt attention conditions, when visual angle doesn't exceed 1°. For exploration of the above problem, two paradigms developed from Geometric Speller (GeoSpell) have been built. Ten healthy participants had participated in this study. Results show that the performance of the gaze-independent BCI is substantially higher when the participant could gaze directly at targets. However, the multi-objective gaze-independent BCIs under covert attention conditions are competitive in terms of evoking N200 (p<;0.05).