An intriguing article has just been published in the journal Perception about a never-before-described visual illusion where your own reflection in the mirror seems to become distorted and shifts identity.

To trigger the illusion you need to stare at your own reflection in a dimly lit room. The author, Italian psychologist Giovanni Caputo, describes his set up which seems to reliably trigger the illusion: you need a room lit only by a dim lamp (he suggests a 25W bulb) that is placed behind the sitter, while the participant stares into a large mirror placed about 40 cm in front.

The participant just has to gaze at his or her reflected face within the mirror and usually “after less than a minute, the observer began to perceive the strange-face illusion”.

The set-up was tried out on 50 people, and the effects they describe are quite striking:

At the end of a 10 min session of mirror gazing, the participant was asked to write what he or she saw in the mirror. The descriptions differed greatly across individuals and included: (a) huge deformations of one’s own face (reported by 66% of the fifty participants); (b) a parent’s face with traits changed (18%), of whom 8% were still alive and 10% were deceased; (c) an unknown person (28%); (d) an archetypal face, such as that of an old woman, a child, or a portrait of an ancestor (28%); (e) an animal face such as that of a cat, pig, or lion (18%); (f ) fantastical and monstrous beings (48%).

Caputo suggests that the dramatic effects might be caused by a combination of basic visual distortions affecting the face-specific interpretation system.

The visual system starts to adapt after we receive the same information over time (this is why you can experience visual changes by staring at anything for a long time) but we also have a system that interprets faces very easily.

This is why we can ‘see’ faces in clouds, trees, or even from just two dots and a line. The brain is always ‘looking for faces’ and it is likely that we have a specialised face detection system to allow us to recognise individuals whose faces actually only differ a small amount in statistical terms from other people’s.

According to Caputo’s suggestion, the illusion might be caused by low level fluctuations in the stability of edges, shading and outlines affecting the perceived definition of the face, which gets over-interpreted as ‘someone else’ by the face recognition system.

More mysterious, however, were the participants’ emotional reactions to the changes:

The participants reported that apparition of new faces in the mirror caused sensations of otherness when the new face appeared to be that of another, unknown person or strange `other’ looking at him/her from within or beyond the mirror. All fifty participants experienced some form of this dissociative identity effect, at least for some apparition of strange faces and often reported strong emotional responses in these instances. For example, some observers felt that the `other’ watched them with an enigmatic expression – situation that they found astonishing. Some participants saw a malign expression on the ‘other’ face and became anxious. Other participants felt that the `other’ was smiling or cheerful, and experienced positive emotions in response. The apparition of deceased parents or of archetypal portraits produced feelings of silent query. Apparition of monstrous beings produced fear or disturbance. Dynamic deformations of new faces (like pulsations or shrinking, smiling or grinding) produced an overall sense of inquietude for things out of control.

If any Mind Hacks readers try the illusion out for themselves, I’d be fascinated to hear about your experiences in the comments.



Link to full-text of article.

Link to PubMed entry for study.