VB-ECD solution illustrated here on EEG data from the multimodal face perception experiment available from the SPM website. A symmetric dipole pair was fitted to the topography of the difference between faces and scrambled faces averaged between 170 and 180 ms. (a) The upper part shows the dipole location through the transparent cortical mesh; the middle part shows the correspondence between observed and predicted scalp data in two ways (topographies and dot plot); the bottom part shows the free energy, the explained variance, and the estimated dipole amplitude (from left to right) obtained from each of the ten repetitions of the procedure with different initial locations. Results correspond to the one with highest free energy (red point). (b) Orthogonal views of the brain with dipole locations obtained from the solution with highest free energy. (c) Enlarged fragment of the axial image shown by white square in (b). The ellipse shows the 95% confidence volume for dipole location.
