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.