It is a mystery that has vexed the art world for centuries: Is Mona Lisa's famous smile happy? The answer is overwhelmingly "yes," according to a new study. German researchers report that nearly everyone shown altered images of Leonardo da Vinci's famous brunette perceived the original as happy. "We really were astonished," neuroscientist Juergen Kornmeier tells AFP. The point of the analysis was to determine how people respond to visual clues such as facial expressions. Researchers from the University of Freiburg report in Nature that they chose to study reactions to the 16th-century masterpiece because of the "emotional ambiguity" of her expression. To some observers, they note, Mona Lisa's slight smile appears to dissolve into a sneer the longer you stare at it. To test that theory, the team manipulated a black-and-white copy of the tableau, creating eight altered images.
Four curved her mouth upward in progressively "happier" images, and four curled her lips down to seem "sadder." Then they displayed the images in random blocks of nine to 12 people, repeating 30 times, per Phys.org. On a happy-to-sad scale, researchers expected the original to be judged the most ambiguous, but in fact 97% deemed her "happy." In a second round presenting eight "sadder" versions with more curve to the lips, the original Mona Lisa was still rated happy, but the other images "were perceived as a little sadder." The results show that context is important as the brain scans an image using past sensory experiences, Kornmeier tells AFP. He said the findings could aid the study of psychiatric disorders. (Is another woman lurking beneath Mona Lisa?)