As anyone who's studied psychology will know, much of it involves restating the bleeding obvious, adding a spice of jargon to make it sound as though some important insight has been achieved. Sometimes they don't even bother with the jargon, but devise an incomprehensible experiment. Here (via ArtsJournal) is a good example:
The mystery of why eyes in certain paintings and photographs appear to move has been solved: it has to do with how we perceive two and three dimensions, a new study finds.
According to a paper published in a recent issue of the journal Perception by James Todd, a professor of psychology at Ohio State University, and his colleagues, the optical illusion "is in the misleading information provided by the picture," Todd said.
No matter what angle you look at a painting from, the painting itself doesn't change, since it's on a flat surface. The patterns of light and dark remain the same.
But three-dimensional objects, in life, change with the way light falls on them as viewers move around the object.
"When observing real surfaces in the natural environment, the visual information that specifies near and far points varies when we change viewing direction," Todd said.
He added, "When we observe a picture on the wall, on the other hand, the visual information that defines near and far points is unaffected by viewing direction. Still we interpret this perceptually as if it were a real object. That is why the eyes appear to follow you as you change your viewing direction."
So now we know.