Research study of pain related to osteoarthritis of the knee.    You are being asked to participate in this study because you have chronic pain as the result of osteoarthritis, or you represent a similar person in age and gender and you do not have osteoarthritis pain.  The purpose of this research study is to look at how the body senses pain, how the brain processes that information, and how the body responds. 

Diagnosis of chronic osteoarthritic pain (pain of 6 months or more duration) in one or both knees.
1. Is able to read and speak English and provide informed consent.
2. Has no severe or unmanaged psychiatric disturbance (e.g. psychotic, substance dependent, clear secondary gain).
3. Has no severe ongoing or unaddressed medical conditions.
4. If female, is not pregnant or breast feeding, and not currently attempting to conceive.

Compensation is $25