SNR analysis of high-frequency steady-state visual evoked potentials from the foveal and extrafoveal regions of Human Retina

• Published in: 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society Vol. 2012; pp. 1810 - 1814
• Main Authors: Lin, Fang-Cheng, Zao, John K., Tu, Kuan-Chung, Wang, Yijun, Huang, Yi-Pai, Chuang, Che-Wei, Kuo, Hen-Yuan, Chien, Yu-Yi, Chou, Ching-Chi, Jung, Tzyy-Ping
• Format: Conference Proceeding Journal Article
• Language: English
• Published: United States IEEE 01.01.2012
• Subjects: Adult; Correlation; Electroencephalography; Evoked Potentials, Visual - physiology; Female; Fourier Analysis; Fovea Centralis - physiology; Humans; Male; Middle Aged; Photic Stimulation; Retina; Retinal Cone Photoreceptor Cells - physiology; Retinal Rod Photoreceptor Cells - physiology; Signal Processing, Computer-Assisted; Signal to noise ratio; Steady-state; Visual Perception - physiology; Visualization; Young Adult
• ISBN: 1424441196; 9781424441198
• ISSN: 1094-687X; 1557-170X; 1558-4615
• DOI: 10.1109/EMBC.2012.6346302

With brain-computer interface (BCI) applications in mind, we analyzed the amplitudes and the signal-to-noise ratios (SNR) of steady-state visual evoked potentials (SSVEP) induced in the foveal and extra-foveal regions of human retina. Eight subjects (age 20-55) have been exposed to 2° circular and 16°-18° annular visual stimulation produced by white LED lights flickering between 5Hz and 65Hz in 5Hz increments. Their EEG signals were recorded using a 64-channel NeuroScan system and analyzed using non-parametric spectral and canonical convolution techniques. Subjects' perception of flickering and their levels of comfort towards the visual stimulation were also noted. Almost all subjects showed distinctively higher SNR in their foveal SSVEP responses between 25Hz and 45Hz. They also noticed less flickering and felt more comfortable with the visual stimulation between 30Hz and 45Hz. These empirical evidences suggest that lights flashing above the critical flicker fusion rates (CFF) of human vision may be used as effective and comfortable stimuli in SSVEP BCI applications.