Objective Steady-state visual evoked potential (SSVEP) is the response of brain elicited by periodic visual stimulation, and is widely used in electroencephalography (EEG) based brain-computer interface (BCI) . SSVEP frequency-response functions are usually obtained by using a light emitting diode (LED) as a visual stimulator. Recently, the computer monitor is widely used for producing flickering stimuli.However, there are few existing studies that have attempted to investigate computer monitor-based SSVEP frequency-response functions. Therefore, this study investigated computer monitor-based SSVEP frequencyresponse characteristic. Methods We used the sampled sinusoidal encoded method to realize 42 stimulation frequencies ranging from 4 Hz to 45 Hz on a conventional LCD screen. We collected an EEG dataset from 10 healthy subjects and investigated the relationship between SSVEP amplitude/signal-to-noise ratio (SNR) and stimulation frequencies. Results Strong SSVEPs were observed over occipital area. The SSVEP amplitude of the fundamental frequency exhibited strong peak at 10 Hz and weaker secondary maximum at 20 Hz. The SSVEPamplitude of the second harmonic was maximal for the stimulation frequency of 6 Hz and smaller for higher stimulation frequencies. The SSVEP SNR of the fundamental frequency in the low-and medium-frequency bands was comparable. Conclusions These results could provide a basis for frequency selection of computer screenbased SSVEP-BCIs.
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