Detect visual field using eye tracking and Steady-state visual evoked potential

This paper makes the subjects' sight locked in a certain area using an eye tracker, getting Steady-state visual evoked potential (SSVEP) from flickering stimuli with a fixed frequency but at random positions, in order to observe the impact of stimulus at different positions and their distances on the electroencephalogram (EEG). The result suggests that if human have to select the positions of stimuli of SSVEP-BCI, it is an agreeable strategy to separate them at least 4 degrees for avoiding the possible mistakes. We hope that it could help in setting distances between stimuli or updating pattern selection algorithms in the future BCI system and other paradigms.