On diversity within operators EEG responses to LED-produced alternate stimulus in SSVEP BCI

This work is an attempt to identify causes of the widely observed fact that performance of Brain-Computer Interface systems based on Steady-State Visual Evoked Potentials varies between different users. The efficient LED-produced alternate stimulus systems are taken into account. The effect of stimulus color and flickering frequency on measured SSVEP response at first and second harmonics is investigated for 10 women and 11 men. The experimental setup is described, measurement procedure, signal processing and analysis algorithms are outlined. The results are presented and discussed. One of the early conclusions drawn from this extensive research is that the promising strategy of SSVEP-based BCI system optimization for best performance can be through stimulus adjustment to each individual user.