4. Certain condition that intervene with Quantitative Sensory Testing (QST) and fMRI procedures (e.g., Peripheral neuropathy, implanted ferrous metal, claustrophobia etc) or any impairment, activity or situation would prevent satisfactory completion of the study protocol (e.g unreliable, or inconsistent pain scores). This includes unreliable, or inconsistent pain scores as deemed by the principal investigator.