Only components whose scalp maps had <15% residual variance from the best-fitting forward model scalp projection were considered for further analysis. Any remaining components that reflected muscle activity, electrocardiogram, or eye-movements, on the basis of their dipole location, spectra, and scalp maps, were considered artifacts and excluded from further analysis. From the remaining components, selection of the component that represented activity associated with visual perception was based on two criteria: (i) the back-projected time-course was required to show time-locked increase in amplitude between 100 and 170 ms after stimulus onset; and (ii) the estimated equivalent current dipole was required to be located in posterior cortex. In all cases the selected component accounted for a larger percentage of the variance of the total EEG than any other component between 100 and 170 ms. The mean percentage variance accounted for by the selected components in this time-window was 70%, indicating that the selected components contributed substantially to the VEP. The mean residual variance of the dipole fit for the selected independent components was reasonably low (6.5%), suggesting that the selected ICs reflect
