A novel motion coupling coding method for brain-computer interfaces

Objectives The best frequency response band for the steady-state visual evoked potential (SSVEP) stimulus for humans is limited. This results in a reduced number of encoded targets. Methods To circumvent these limitations, we propose a motion-coupled, steady-state motion visual evoked potential (SSMVEP) method. We designed a stimulus paradigm that couples both sinusoidal and square wave motions. The paradigm performs a spiral motion with a higher frequency in the form of sinusoidal wave, and alters the size of the lower frequency via the square wave form. Results The motion-coupled SSMVEP method could simultaneously induce stable motion frequency and coupling frequency, and there was no loss of frequency component. Conclusions The proposed method has been evaluated to have substantial potential for increasing the number of coding targets, which is an effective supplement to the existing studies.