Inclusion Criteria:  a) adults (ages 22 to 60) who understand all procedures and have the ability to provide informed consent, with a score on the Mini-Mental Status Exam of at least 24; b) participants experiencing chronic pain, with ongoing pain symptoms, and score on the Brief Pain Inventory of > 5 on question #3 (which asks about maximal pain in the past 24 hours) or > 5 on question #5 (which asks about average pain in the past 24 hours); c) a diagnosis of chronic postoperative pain, low back pain, musculoskeletal pain, fibromyalgia, visceral pain or neuropathic pain, including complex regional pain syndrome or peripheral neuropathy; and d) no significant changes in pain medications for at least one month prior to study entry.