The purpose of this research study is to test whether or not researchers can alter or change
expectations on pain. The researchers will test whether there is an effect on the size of the
pupil and responses to thermal heat temperatures in subjects with osteoarthritis of the knee
or hip or healthy subjects for comparison.
One of 3 possible treatment groups will be administered to qualifying subjects: (1)
gabapentin, a medication that is commonly used to treat nerve pain, (2) modafinil, a
medication that is commonly used to treat people with narcolepsy (a disorder that causes
people to fall asleep) and (3) a placebo, which is an inactive substance, like a sugar pill,
that is not thought to have any effect on your disease or condition