To accomplish our Specific Aims, we propose to conduct a two-session fMRI experiment in up to 30 patients with fibromyalgia (FM) and up to 30 healthy controls. All subjects will be invited to complete the second, identical fMRI session about 3 months following completion of the first session. Fibromyalgia subjects will complete their scans before and after a 12-week Tai Chi intervention in collaboration with Tufts Medical Center.

Criteria for fibromyalgia patients.

Inclusion Criteria:

• Volunteers 18-50 years of age.
• Fibromyalgia for at least the past 3 months, as determined by the referring physician.
• At least a 10th grade English-reading level; English can be a second language provided that the patients feel they understand all the questions used in the assessment measures.

Exclusion Criteria:

• Specific causes of pain (e.g., cancer, fractures, spinal stenosis, infections)
• History of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcome.
• Presence of any contraindications to fMRI scanning. For example: cardiac pacemaker, metal implants, fear of closed spaces, pregnancy.

Criteria for healthy adults.

Inclusion Criteria:

• Volunteers 18-50 years of age.
• At least a 10th grade English-reading level; English can be a second language provided that the patients feel they understand all the questions used in the assessment measures.

Exclusion Criteria:

• Chronic and acute pain (ex. Fibromyalgia).
• History of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcome.
• Presence of any contraindications to fMRI scanning. For example: cardiac pacemaker, metal implants, fear of closed spaces, pregnancy.