Mechanisms of Affective Touch in Chronic Pain

Inclusion Criteria: 1. ages 18-65 2. fluent in English 3. physician diagnosis of Fibromyalgia but no other chronic pain conditions (patients) or no evidence of chronic pain (healthy volunteers) Exclusion Criteria: 1. Sensory, motor, or anatomic differences or injuries relevant to study procedures 2. Known anomalies of the central nervous system (including stroke, dementia, aneurysm, or personal history of psychosis) 3. Pregnancy 4. Inability to rate pain or sensations 5. Major medical conditions such as kidney, liver, cardiovascular (hypertension, preexisting cardiac arrhythmia), autonomic, pulmonary, or neurological problems (e.g., seizure disorder) or a chronic systemic disease (e.g., diabetes). 6. History of blood clots or first-degree family members with clotting disorders 7. Current use of opiate medication(s) 8. Contraindications to MRI if participating in pilot MRI study 9. Unable to identify a heat stimulus 50C or lower that generates a rating of a 7 on our VAS scale 10. History of fainting or seizures 11. History of frostbite 12. Open cut or sore on hand to be immersed in cold water bath 13. Fracture of limb to be immersed 14. History of Reynaud's phenomenon (hands get white, then blue on exposure to cold, then red on warming)