Brain Areas Involved in Sound and Spoken Word Memory

Background: \- Studies have shown that animals such as monkeys and dogs have excellent sight and touch memory but perform poorly on sound memory tasks. Human brains have certain areas that are important for speaking and understanding language. These areas may be involved in sound and spoken word memory. Researchers want to study these areas of the brain to find out if the memory for sounds requires brain structures that are usually associated with language learning and are unique to humans. Objectives: \- To use magnetic resonance imaging to study areas of the brain involved in sound memory. Eligibility: \- Healthy right-handed volunteers between 18 and 50 years of age. They must be native English speakers and have completed high school. Design: * The study requires a screening visit and 1 or 2 study visits to the National Institutes of Health Clinical Center. * At the screening visit, volunteers will have a medical history taken. They will also have physical and neurological exams, and complete a questionnaire. Women of childbearing age will give a urine sample. Participants who have not had a magnetic resonance imaging (MRI) scan in the past year will have one at this visit. * At the second visit, participants will have tests of sound memory. They will listen to a set of nonsense words spoken through earphones and memorize the words. Then they will listen to the words again to judge if the words were part of the earlier list. Participants will have a 1 hour break, then do the sound memory test again. During the second test they will have repetitive transcranial magnetic stimulation (rTMS), which stimulates different regions of the brain. * If the group results from the testing sessions are positive, there will be a third visit. At this visit, participants will have a sound perception test. They will listen to words spoken through earphones and judge whether the words in the pair are the same or different. Participants will have rTMS during these tests as we