Fig. 4. Group × time images (two-factorial model with two main factors; analysis of covariance, group: [sham and incision; two levels] and time [preincision, postincisions 1, 2, and 3; four levels]). The NRS scores at incision were added as cofactors in the model to reduce the impact of pain sensitivities on the results (uncorrected for multiple comparisons, P = 0.001, 10 voxels). There were mainly temporal activation profile differences between both groups (sham and incision procedure) for somatosensory areas (SI and SII), the cingulated gyrus (BA 24, BA 31, and BA 32), and medial frontal cortices (BA 5, BA 6). NRS = numerical rating scale; BA = Brodman area.