High-Frequency Steady-State Visual Evoked Potentials from the Foveal and Extrafoveal Regions of Human Retina
碩士 === 國立交通大學 === 生醫工程研究所 === 100 === To understanding the brain functions via the brain-computer interface (BCI), here, we studied the steady-state visual evoked potentials (SSVEP) from retinal fovea and extrafoveal in response to a 2牵 circular and a 16牵–18牵 annular white light stimuli flickering b...
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| Format: | Others |
| Language: | en_US |
| Published: |
2012
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| Online Access: | http://ndltd.ncl.edu.tw/handle/51077796994713969738 |
| Summary: | 碩士 === 國立交通大學 === 生醫工程研究所 === 100 === To understanding the brain functions via the brain-computer interface (BCI), here, we studied the steady-state visual evoked potentials (SSVEP) from retinal fovea and extrafoveal in response to a 2牵 circular and a 16牵–18牵 annular white light stimuli flickering between 5 and 65 Hz by 5 Hz increments. Eight subjects (age 20~55 years old) participated in this experiment. Their EEG signals were recorded using a commercial 64-channel NeuroScan system. Their flickering perception and comfort levels were also studied. Spectral and canonical correlation analyses of SSVEP signals collected from nine EEG channels in the occipital area showed distinctively higher signal-to-noise ratios (SNR) in the foveal responses between 25 and 45 Hz. The findings from the subjects also indicate that the less flickering and felt are more comfortable with stimulation flickering between 30 and 45 Hz. These empirical evidences suggest that lights flashing above human vision flicker fusion thresholds can be potentially used as an effective visual stimuli tool in SSVEP BCI applications.
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