All participants will undergo MRI scanning of the brain while performing a task designed to test a language skill, such as identifying a picture or listening to or reading a word. The MRI detects changes in blood properties in the areas of the brain that perform each task. Before the MRI, children will be rehearsed for the tests and will have a session in the scanner to know what to expect and feel more at ease during the actual test. The time in the MRI machine is usually between 15 and 20 minutes, but will be no more than 40 minutes for children 8 to 12 years old, and not more than 20 minutes for younger children. Children may be requested to have up to five MRI sessions to test different brain functions or confirm findings.