Figure 1.

Topography of alpha asymmetry factor scores depicted separately for mastoids-referenced and CSD-transformed data

Note. FAAf = frontal alpha asymmetry factor; PAAf = parietal alpha asymmetry factor; CAAf = central alpha asymmetry factor; EAAf = external alpha asymmetry factor. Dashed line indicates separation of factors; channels colored with dark grey showed an average factor loading across frequencies >.700 (e.g., alpha asymmetry score of F7/8 at 8, 9, 10, 11, 12, 13 Hz on FAA); channels colored with light grey showed an average factor loading across frequencies >.600; channels Fp1/2 and Tp9/10 were excluded from the PCA.