Now you see sadness, now you don't.

A new study has found that removing just the tears out of pictures of people crying reduces the sadness that viewers perceive in the photos, even though the rest of the expression remains intact. The research subjects said when the tears were digitally erased, the faces' emotional content became ambiguous, ranging from awe-filled to puzzlement. 

"One of the startling things is that the faces not only look less sad but they don't look sad at all. They look neutral," said Robert Provine, the University of Maryland-Baltimore County neuroscientist who led the work. "Any photograph you see, you can put your finger on the screen and block out the tears. It's like the face is transformed."