Inclusion Criteria  Healthy males and females 9-16 years old English speakers  Exclusion Criteria  Participants will not be enrolled if any of the following criteria exist and based on the investigator discretion:  Pregnancy Chronic Pain or frequent headaches (>5 headache /month) Psychiatric or neurological disorders Lack of sensation in the testable limb Disorders associated with pubertal maturation or usage of contraceptive pills that affect sex hormone levels Regular use of medications that affect the pain system (e.g., opioids, antidepressants).