Optimizing and Exploring TMS-EEG Techniques

Background: Transcranial magnetic stimulation (TMS) activates brain cells. When this happens, the cells produce brain waves. These can be recorded with electrodes on the scalp. This can tell us about how TMS works and how the brain functions. Researchers want to learn more about the technique by testing healthy adults. Objective: To better understand how to use transcranial magnetic stimulation plus electroencephalography (EEG) to study the brain of healthy adults. Eligibility: Healthy adults ages 18 35 Design: Participants will be screened with a neurological exam. Participants will have 2-3 visits for a total duration of about 7/8 hours. Women of childbearing age must have a negative pregnancy test before each MRI scan. Visits may include: Physical exam Tests of attention, and thinking TMS. A brief electrical current will pass through a wire coil on the scalp. Participants will hear a click and may feel a pull. They may be asked to tense muscles or do tasks. Magnetic resonance imaging (MRI) scan for a maximum of 1 hour. Participants will lie on a table that slides into a cylinder in a strong magnetic field. They will do tasks on a computer screen or lie still. They will get earplugs for loud noise. EEG for no longer than 5 hours, with most lasting 3 hours. Gel and a cap with electrodes will be placed on the scalp. They will record brain waves while the participant gets TMS or does nothing. Questions about participants dominant hand and about the MRI.