Figure 6.

Seed‐based connectivity analysis. Functional connectivity, as measured by the PLV, was computed using voxels in the contralateral primary somatosensory cortices as seeds (MNI_xyz = [30/−30, −30, 60] [Bradley et al., 2017]). T‐maps of the seed‐based connectivity contrasts between pain and control conditions are depicted (left and right side). Warm and cold colors indicate enhanced and reduced functional connectivity in the pain condition as compared to the control condition, respectively. In both pain conditions, we observed increased connectivity between the somatosensory seed voxel and the medial prefrontal cortex and the frontal cortex contralateral to the stimulation side in the alpha frequency band. Moreover, a positive effect at beta frequencies was revealed in the pain left condition. As shown by the conjunction analysis (middle), increased alpha connectivity overlapped in the medial prefrontal cortex which indicates its involvement in the processing of tonic pain independent of the stimulation side. Topographies without significant cluster are presented with reduced opacity. PLV, phase locking value