Activating and Identifying Neural Responses to Social Rejection: a Combined tDCS and fMRI Study

Inclusion Criteria: 1. Healthy males or females between 18 and 25 years old 2. No diagnosis on Axis I by Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders IV. No current, or within the past 5 years. 3. Not currently in a romantic relationship 4. Ability to understand and follow instructions and oriented to name, time, and place. 5. No additional neurologic or psychiatric disorders 6. No current use of psychotropic drugs or during past 3 months (except marijuana and alcohol) 7. No current use of marijuana or during past 3 weeks 8. Not currently abusing alcohol 9. No history of alcohol or drug dependence within past 5 years 10. A negative urine pregnancy and toxicology screen. Verbal affirmation will be obtained (i.e., "not pregnant" and "not currently using psychotropic drugs or during the past 3 months") during the Screening Visit (Day 1). Urine screen will be obtained on Days 2 and 3. If subject reports that there is a "possibility that she is pregnant" on Day 1 (Screening Visit) a urine pregnancy screen will be performed on that day. 11. (Women): If stopped or started oral contraceptives recently, at least 60 days on/off oral contraceptives. Exclusion Criteria: 1. Left-handed or ambidextrous 2. Metallic dental implants 3. Metallic objects in the brain/skull 4. Medical device implants 5. Implanted electronic devices 6. History of seizures 7. History of strokes 8. Unexplained loss of consciousness 9. Frequent or severe headaches or neck pain 10. Clinically significant, uncontrolled liver, kidney, cardiac, or pulmonary disease 11. Terminal medical diagnosis consistent with survival \< 1 year 12. Pregnancy; childbirth or miscarriage within 6 months, breastfeeding within 6 months of recruitment 13. Serious mental impairment. Mini mental state exam of \< 23/30 14. Chronic skin disease 15. Previous experience with transcranial direct current stimulation (tDCS) 16. Regular tobacco use or tobacco use within past month 17. If using hormonal birth control, taking progestin-only pills (e.g., Cerazette, Ovrette), or Intrauterine devices (Mirena, Skyla), since progestin-only birth controls are more likely to cause mood swings. Addition Exclusion Criteria for participating in fMRI: 1. Metal anywhere in the body 2. Weight over 250 pounds, or girth size incompatible for scanner bore.