We ask volunteers to sit completely motionless in front of a computer screen and view pictures of animals, flowers, babies, food, money, guns, surfers, skydivers, car crashes, and other objects and scenes. These pictures impact their body budget; heart rates go up, blood pressures change, blood vessels dilate. These budgetary changes, which prepare the body to fight or flee, occur even though the volunteers are not moving and have no conscious plan to move.
