The volunteers were each given a 3D high-resolution virtual reality helmet that displayed an avatar that represented a standard human figure. The scientists then used robots to stroke the back or leg of the subjects while the helmet displayed a red dot that moved on the same areas of the avatar. In order to get an idea of how these volunteers perceived their bodies, researchers then asked them to imagine dropping a ball and speaking up when that imaginary ball would hit the floor. Researchers followed this by asking research participants about their experience with the avatar, as well as where they perceived the touch to have come from. Finally, the scientists measured the temperature of the volunteers' skin on various points across their backs and legs.