Investigating the robustness of constant and variable period graphics in eliciting steady state visual evoked potential signals using Emotiv EPOC, MATLAB, and Adobe after effects

This paper investigates the robustness of the EEG (electroencephalograph) signal produced by SSVEP (Steady State Visual Evoked Potential) method with constant and variable period visual graphics generated in Adobe After Effects motion graphics application. The investigation has been carried out in 8 test cases using 3 subjects, 2 computers and Emotiv EPOC headset. Several external factors such as impact of ambient noises and fluorescent lighting were also considered. Results indicated that both constant and variable period flickering graphics produced equally strong EEG amplitudes. However, constant period graphics elicited cleaner signals with more pronounced base frequencies while variable period graphics exhibited strong harmonics and sub-harmonics in their signals.