Magnetic resonance imaging (MRI) is a diagnostic tool that creates high quality images of the human body without the use of X-ray (radiation). MRI is especially useful when studying the brain, because it can provide information about certain brain functions. In addition, MRI is much better than standard X-rays at showing areas of the brain close to the skull and detecting changes in the brain associated with neurological diseases. In this study researchers will use MRI to gather information about the processes that control human movement and sensory processing.