Fig. 7

Effect of location of reference-electrodes on dPLV across eight sets of SSI parameters in 64 (top) and 128 channel data (bottom). The p-values of repeated-measure ANOVAs testing significance of LOC_ref effect as well as the effect size (η ²) of LOC_ref are shown in each error-bar plot of the corresponding conditions. The eight SSI parameter conditions were sorted so that the amount of dPLV decreases from right to left. Note that the order of SSI sets were the same between 64 and 128 channel data although the patterns of dPLV variation across the 11 reference-electrodes are different between them. Importantly, PLV inflation by SSI was close to zero in both 64 and 128 channel data when the best set of SSI parameters was used (i.e., m = 3, n = 50, and λ = 1e-8)