Test Retest Reliability of OA and OH

Exclusion Criteria

• •History of chronic pain
• •Current significant pain disorder
• •Active ongoing pain every day that is acute or chronic in duration
• •Recent history of migraine (1 attack in last 24 months)
• •Lifetime history mood disorders (anxiety, depression, bipolar) or psychotic disorders.
• •Subjects taking psychotropics (e.g. benzodiazepines, antidepressants), or medications known to affect the autonomic nervous system (e.g. beta-receptor agonists or antagonists) will be excluded.
• •Cognitive impairment affecting the ability to provide informed consent, understand directions, and participate in study procedures
• •Uncontrolled or unstable medical disorder preventing participation in study procedures
• •Pregnancy
• •Tattoos on forearm
• •History of brain surgery
• •Nonambulatory status
• •Heart problems such as an irregular heart beat or coronary artery disease
• •Neurological problems such as seizure, fainting spells, recurrent severe headache, stroke, transient ischemic attack
• •High blood pressure
• •Severe liver disease
• •Severe gastrointestinal disease
• •Chronic severe infectious disease (e.g. HIV/AIDS)