Figure 6.

Variation of functional connectivity in the high gamma band (60–120 Hz) as measured with PLV index at the IED peak with respect to baseline (-1 to−0.5 s) for two illustrative patients. The variation index was computed for each electrode contact then interpolated over the underlying cortical surface using an in-house algorithm. The resection site targeted by a later surgery is overlaid as a thick contour. The first patient (upper row) had 2 surgeries; the first one targeted mainly the anterior insula (white contour line) while the maximal decrease of PLV was found in the lateral inferior frontal gyrus. The second surgery (orange contour line) targeted left orbitofrontal and frontal lateral regions, which was concordant with the sites of maximal PLV variation. For the second patient, the resected site (orange contour line) overlaps with the two sites with maximal PLV variation. The PLV projection onto the modeled cortex was threshold; only points on the projection of the cortex which account for 95% of the variance were kept.