Study of Brain Function During Cognitive Tasks

This study will use magnetic resonance imaging (MRI) to examine which areas of the brain are involved in performing certain cognitive tasks. MRI uses a strong magnetic field and radio waves to produce images of body tissues and organs that provide information about structure and function of tissues. Healthy normal volunteers between 21 and 40 years of age may be eligible for this study. Candidates must be native English speakers and must be right-handed. They must have no history of nervous system disease or psychiatric disorder. Candidates are screened with questionnaires and a neurological examination. Participants undergo functional MRI scanning. For this procedure, the subject lies on a stretcher that moves into the scanner - a metal cylinder surrounded by a strong magnetic field. During the scan, he or she is asked to make various decisions about whether words are related or not. Two words are presented visually, separated by a variable time delay. The subject reads both words, decides as quickly and accurately as possible whether the two words are related or not, and indicates the answer by pressing a button. The test takes about 2 hours. When it is completed, the subject completes a written questionnaire concerning his or her experience in the scanner. ...