As the brain uses more fuel it produces more waste products, carbon dioxide and water.
Blood carries fuel to the brain and waste products away from the brain.
As brain activity increases, blood flow to and from the area of activity also increases. The activities are designed to stimulate the areas of the brain responsible for voluntary motor activity and sensation. By comparing the results of PET scans performed in different conditions, researchers can locate regions of the brain responsible for specific tasks. This study should provide new information about voluntary movements in humans and the preparation involved in controlling them. Bethesda, Maryland 20892.