Fig. 4.  The mean changes in rCBF in the activation clusters across all sessions. For the clinical maneuvers session in the CLBP subjects, these areas had a 17–25% increase in rCBF. For all comparisons to the clinical maneuvers session, P < 0.01. aINS = anterior insula, ASL = arterial spin labeling, BIL = bilateral, CLBP = chronic low back pain, CTRL = control, gr = grams, HC = healthy controls, L = left side, M1 = primary motor cortex, MFG = medial frontal gyrus, MPFC = medial prefrontal cortex, preSMA = presupplementary motor area, R = right side, rCBF = regional cerebral blood flow, S1 = primary somatosensory cortex, S2 = secondary somatosensory cortex, SMG = superior marginal gyrus, SPL = superior parietal lobule.