Twenty CLBP patients (10 females, 10 males, mean age, 46.5 years), half of whom on long-term opioid regimen, underwent BOLD functional MRI scan while performing a cognitive control task. Briefly, patients received acute thermal pain in the lower back inside a 3T scanner and were asked to reframe their pain by re-interpreting the meaning of the situation to make it less aversive. Following image preprocessing in SPM12, seed-to-voxel analysis was performed to assess functional connectivity between selected seed regions (left DLPFC, and left insula), and all other voxels in the brain.