Multi-command SSVEP-based BCI system via single flickering frequency half-field stimulation pattern

This paper proposes a half-field steady state visual evoked potential (SSVEP)-based brain-computer interface (BCI) system to enhance the number of limited commands obtained from the existing SSVEP-based BCI methods. With the theory of vision perception and the concept of the existing half-field SSVEP-based BCI system, we propose the new stimulation pattern that, by using only one frequency, four commands can be generated with the average classification accuracy of approximately 77%. By using only one frequency, eye fatigue can be reduced. Furthermore, this method can be efficiently used to further increase the number of commands for the existing SSVEP-based BCI system.