Figure 10.

Typical behaviors of SEEG correlates of STW. A, Clustering of SEEG channel according to HF and LF changes during STW. The figure shows the typical behavior of three automatically determined groups of channels. The grouping was done in 514 of the 544 channels, after excluding channels with outliers in one or more of the bands that would render the clustering algorithm inefficient. The choice of three groups was arbitrary. The main behaviors were an increase in the z score in LF and HF, an increase in HF only, and no change. In most channels (61%), the correlate to scalp STW is weak. These three groups of channels are usually present in all brain regions, and the difference in the average correlate in each region is to some degree because of the difference in the proportion of these three groups of channels. B, Spatial heterogeneity in SEEG correlates of STW. The distribution of channels showing the three previously determined pattern (LF and HF, HF, and none) in each brain region is presented as a percentage. In most brain areas, channel involvement in LF and HF is not homogeneous. Abbreviations: g, gyrus.