2020 Volume 58 Issue 1 Pages 5-13
Cortical potential imaging has been proposed as a method of imaging brain electrical activity with high spatial resolution. In cortical potential imaging, the potential on the brain surface is estimated using an electroencephalogram (EEG) of the scalp. In order to visualize the electrical activity of the brain, this study proposed the use of a spatial inverse filter with optimal filter property considering transfer matrix error. Moreover, the spatial inverse filter was expanded into a spatio-temporal filter to visualize changes in brain activity dynamically with time. The simulation results showed that the proposed method provided cortical potential mapping with higher accuracy than the conventional inverse imaging techniques. This method was applied to actual human EEGs of visually evoked potentials. We confirmed that the pathway toward generation of visual information could be visualized by estimated cortical potential mapping. Stabilization may be further improved by restricting filter parameters according to the spatio-temporal noise information from the EEG.
