An fMRI Study on the Spectral and Spatial Properties of Steady-State Visual Evoked Response
Jie Pan, Xiaorong Gao, Shangkai Gao · 2009
Steady-state visual evoked response (SSVER) has been widely used in cognitive research and engineering applications due to its high signal-to-noise ratio (SNR). Previous studies on SSVER explored its properties in the low and medium frequency bands (< 40 Hz), without any concern of the high frequency band (40-60 Hz). High-frequency SSVER has a considerable potential in BCI applications for its comfort and minimal visual fatigue caused. In this study, the spatial and spectral properties of SSVER were comprehensively investigated via functional MRI (fMRI). Two methods, GLM (general linear model) and spatial ICA (independent component analysis) were employed for the analysis of fMRI data. It was consistently found by the two methods that SSVER of the three frequency bands were located primarily in the visual cortex, with weaker activities occasionally detected in the parietal and frontal cortices. No differences in spatial distribution were found among the three frequency bands.