According to an article in Nature Magazine, autistic people may not daydream as much as the rest of us. A study conducted by Daniel Kennedy of the University of California at San Diego, La Jolla, and his colleagues studied 15 adults with some form of autism and 14 healthy controls. They used scanning technology to image the part of the brain which controls daydreaming and certain emotional responses. Ordinarily, this part of the brain becomes most active when the person is relaxed. But among autistic subjects, "Their daydreaming network seemed permanently dampened; it did not show increased activity during rest and was not roused by emotional words." This difference, researchers suggest, may explain why it is so difficult for autistic people to have a mental picture of themselves in relationship to the world -- and may also explain differences in emotional response.