The Difference of SSVEP Resulted by Different Pulse Duty-cycle
Objective: Assess the influence of the pulse duty cycle on the steady-state visual evoked potential (SSVEP) via the frequency spectrum. Method: A single LED was flashed at 10 Hz with varying duty cycle from 10％--90％. The maximum luminance was kept constant. The SSVEP was recorded with 128 channels and the time series was analyzed after applying a FFT. Results: the amplitude of the first harmonic depends on the duty cycle in an inverted-U fashion, with the highest value around 50％. The relationship between amplitude of the higher harmonics and duty cycle of stimulus is like that of the fundamental frequency. In some subjects, the amplitude of the second harmonic can exceed that of the first harmonic. Conclusion: The duty cycle influences the steady-state visual evoked potential. Most of this influence can be traced to the duty-cycle dependence of that of the stimulus spectrum.
Zhenghua Wu
School of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China
国际会议
2009国际通信电路与系统学术会议(ICCCAS 2009)(2009 International Conference on Communications，Circuits and Systems)
成都
英文
605-607
2009-07-23（万方平台首次上网日期，不代表论文的发表时间）