Time-frequency analysis of duty cycle changing on steady-state visual evoked potential: EEG recording

The purpose of this paper is to investigate the applicability of duty cycle for steady-state visual evoked potential (SSVEP)-based application. For this, the time-frequency analysis of SSVEP during visual stimuli presentation with different duty cycles was performed. The commercial wireless EEG headset with O1 and O2 channels was utilized to record the associated brain activity. The experimental paradigm, in this experiment, we mainly focus on instantaneously changes of duty cycle of SSVEP in the four principal frequency bands, i.e., theta (3-7 Hz), alpha (8-12 Hz), beta (13-30 Hz), and gamma (30-40 Hz). Peak magnitude, peak frequency, and spectral coherence of SSVEP were measured. Results showed that coherences measured in the theta and alpha bands differed significantly with p <; 0.001. Thus, the present results suggest that the duty cycle is recommended as a feature for potential multicommand SSVEP-based applications.