Figure 2.

(Left) each electrode is paired with six nearby electrodes for computation of phase synchronization indices. There are 21 possible combinations. Few of them are shown by arrows. (Middle) average of phase synchronization indices over 21 combinations of electrode pairs. The phase synchronization index of the white noise is shown with a dashed line. (Right) montage layout of 256 electrodes above the head for plotting purposes. The nose is on the top. The ellipse encloses the area covered by electrodes above the eye level but excludes the electrodes on the forehead.