Oscillatory Contributions to Working Memory and Attention

Eligibility Details: Inclusion Criteria: - Age of # 18 <36. - Right-handed. - Be in good health determined by the investigator on basis of medical history, physical and neurological exam; for "EEG-only" sessions no physical or neurological exams will be performed; - Female subjects must be two years past menopause, surgically sterile or practicing a medically acceptable method of birth control (does not apply to "EEG-only" sessions); - Female subjects must not be pregnant. - Able to understand and speak English. - Able to provide written consent prior to admission Exclusion Criteria: - History of epilepsy, stroke, brain surgery, cranial metal implants, structural brain lesion, devices that may be affected by TMS or tCS(pacemaker, medication pump, cochlear implant, implanted brain stimulator); - Women who are breast-feeding (self report)*; - History of head trauma with loss of consciousness for greater than 5 minutes; - Any history of seizures; - Any family history of seizures*; - Diabetes requiring insulin treatment*; - A serious heart disorder or subjects who have had a heart attack within the last 3 months; - Subjects who meet DSM-IV criteria for alcohol /drug abuse problems within the last six months; - Any current Axis I or II diagnoses or past Axis I diagnoses; - Required use of medication that affects CNS function; - A subject with metallic implants, such as prostheses, shrapnel or aneurysm clip-S, or persons with electronic implants, such as cardiac pacemakers. The magnetic field generated by the MR machine can cause a displacement or malfunctioning of these devices*; - The female subject who is pregnant or planning to become pregnant; or a female subject of child-bearing potential who is not practicing a medically acceptable form of birth control*; - The subject has had a diagnosis of cancer in the past 3 years and/or has active neoplastic disease; - The investigator anticipates that the subject will be unable to comply with the protocol. - Prohibited Concomitant Treatment: Any investigational medication; antipsychotic, antidepressant; or ECT; Other psychotropic medications including sedative hypnotics (excluding chloral hydrate zaleplon); sumatriptan (and similar agents); anxiolytics and herbals (e.g., St. John's Wort, Kava Kava); an introduction or change in intensity of psychotherapy; any nonpsychopharmacologic drug with psychotropic effects (e.g., antihistamines, beta blockers). - Colorblindness - Poor or Uncorrected Vision - History of fainting/syncope