There was an interesting article in the New Scientist from 2 November last year. It describes a Halloween party trick that involves quite simply looking at your face in the mirror.
As I prepare the room, it feels as if I’m getting ready for a seance. I close the curtains to block out most of the light and place two chairs about a metre apart. I prop up a large mirror on one and sit in the other so that I can just see my reflection in the near darkness. Then I set a timer for 10 minutes and wait patiently for the faces to appear.
When they do, it is startling. At first the distortions in the mirror are small: a lifted eyebrow, a twitch of the mouth. But after seven minutes my reflection suddenly looks fake, like a waxwork. And then it is no longer my face. For a few seconds an old man with a thickly wrinkled brow and down-turned mouth stares back at me.
Apparently these visual illusions are quite common. Giovanni Caputo, a psychologist from the University of Urbano in Italy came across the phenomenon by accident when conducting an experiment looking at self-identity in a room entirely enclosed with mirrors. The experiment was usually conducted in normal lighting, but one day he decided to dim the lighting, and found that many people experienced a distortion in what they saw after about 10 minutes.
Since his chance discovery, Caputo has found that most people perceive some degree of eerie distortion to their face if they stare into a mirror in low light for at least 10 minutes. “Usually, after about 1 minute of mirror-gazing, the eys start to move or shine, the mouth opens, or the nose becomes very large,” he says. “If you continue to gaze there are very big changes, until completely new faces appear.” And it’s not just human faces that are seen-” some report seeing animals and others fantastical or monstrous beings….You are suddenly conscious that there is another person behind the mirror.”
The article offers a number of explanations for the phenomenon. One is that the incomplete view of the image disrupts the way that the brain binds together features to make a recognizable face, and so it patches together a ‘photo fit’ of features. Another suggestion is that it is a form of dissociation, which is apparently heightened by looking in mirrors.
I must confess to being a little frightened to try it myself. But it did bring to mind many of the those Victorian horror-stories and reports of seances conducted in dimly lit rooms. Of course, darkness hides a plethora of tricks and manipulations by unscrupulous shysters, but it’s an interesting thought that perhaps some of the effects are generated within the brain of the perceiver as well.
Source: “Mirror, mirror” by Douglas Heaven. New Scientist, 2 November 2013