In one condition, subjects drank some splenda sweetened lemonade and in another condition, they drank sugar end lemonade. The idea is that if self control is a limited resource, maybe it runs on sugar because we know the brain essentially does run on glucos. Only the subjects who drank the sugar-sweetened lemonade ended up having this kind of bounce back in their ability to exert self control on a subsequent task. "I think roy balmister stands by his original proposition," he says.