Comparison of stimulus types in visual P300 speller of brain-computer interfaces

This study proposes several categories of stimulus types under the visual oddball speller paradigm with application to brain-computer interface (BCI). Motion (including translation and rotation), zoom in/out, pattern rotation and sharpening types are tested and analysed. Results show that rotation and zooming type could obtain comparative or higher accuracies as well as information transfer rates compared with classic color type. Spatio-temporal distributions of the weighted event related potentials evoked by different stimulus types show respective patterns, and subject specific configuration of stimulus type is suggested.