We have performed the first clinical study (IRB study #05121504) to investigate the change in brain activity associated with significant postoperative pain (6). This was an IRB-approved study with just one patient to establish that the methods we have developed will be sensitive enough for a more complete randomized clinical trial. We determined that postsurgical pain is associated with increased activity in the contralateral primary somatosensory cortex. Other brain regions showing increased postsurgical activity were the contralateral parietal cortex, bilateral pulvinar and ipsilateral medial dorsal nucleus of the thalamus, contralateral putamen, contralateral superior temporal gyrus, ipsilateral fusiform gyrus, ipsilateral posterior lobe and contralateral anterior cerebellar lobe. We have received permission from the IRB to perform a larger study with 21 patients (IRB study #07050273).