Impact of stimulus configuration on steady state visual evoked potentials (SSVEP) response

We investigate the impact of configuration of multistimuli presented in computer monitor to steady-state visual evoked potential response. The configuration of stimuli is defined by three parameters-the size of stimuli, the separation distance between the stimuli and the layout. Two 4 by 4 checkerboards in twelve configurations were presented to the subjects. 9 subjects participated in this study. Subjects’ electroencephalography (EEG) data was off-line analyzed by using Fast Fourier Transform (FFT). The mean classification rates of configuration with bigger size and larger separation distance is higher than those configurations with smaller size and shorter separation distance. These results suggest that the stimulus size is the most important parameter of three, followed by the separation distance and layout.