The Thatcher illusion: Are faces special?

Mind gamers: why was a picture of Margaret Thatcher so important for understanding the human visual system?What’s wrong with the picture above? Obviously, the two faces are upside down, but does something seem a little odd about one of them? When you show this to most people, they can tell there’s a difference, but it’s not immediately clear what the problem is.The Thatcher illusion was first reported by the University of York’s Professor Peter Thompson in 1980, and laid