"This is science Americans sixty seconds science. I'm Christopher Dodd Yata. Davinci's most famous painting also has an optical illusion named for it. The Mona Lisa affect. It's the feeling that the subject of a painting is following you with her gaze to continuously fuel being looked at despite moving to the left of moving to the right paps, even rotating picture Sebastian law is a psychologist at the university of Bielfeld in Germany, and while he doesn't dispute that the illusion itself exists. He probably also seen it in the Sam army recruitment. Poster he says, there's a problem with the phenomenon's name a construct your son, so many papers on what people have literally started to introduction with. We all know that of these looks at you. And so on the full, and then he would go into our argument, whatever it is. But actually, she disposition picture doesn't look at you. He and his colleague horsemen conducted a scientific investigation of this claim by sitting twenty four volunteers in front of a computer screen, which displayed various magnification of the Mona Lisa. They placed rulers at two. Distances between the subjects and the screen, and then ask the subjects to indicate where on the rulers the Mona Lisa's gays intersected, and then you can compute a line that specically school mathematics here. And then you can figure out the angle what came out was fifteen degrees to right. So the Mona Lisa actually stairs over the viewers, right shoulder. He says not straight out of the canvas the key to creating her namesake allusion. The right up is in the journal. I percents in Las says affects like these can have modern implications too. For example, when building virtual assistance on computers, which might need to speak to and make eye contact with more than one person in a room as for davinci's masterpiece. There's still another illusion. That remains the mysterious ambiguity of the Mona Lisa's smile. Thanks for listening for scientific American sixty seconds science. I'm Christopher Don. Yata?"