“There are things in that [wall]paper that nobody knows but me, or ever will. Behind that outside pattern the dim shapes get clearer every day. It is always the same shape, only very numerous. And it is like a woman stooping down and creeping about behind that pattern.”
—Charlotte Perkins Gilman,
“The Yellow Wallpaper,” 1892
The protagonist in Charlotte Perkins Gilman's short story “The Yellow Wallpaper” suffers from the most notable case of pareidolia in fiction. Pareidolia, the misperception of an accidental or vague stimulus as distinct and meaningful, explains many supposedly paranormal and mystical phenomena, including UFO and Bigfoot sightings and other visions. In Gilman's story, the heroine, secluded in her hideously wallpapered bedroom and having nothing with which to occupy herself, is driven to insanity>—full-blown paranoid schizophrenia>—by the woman behind the yellow pattern. As she descends into madness, she comes to believe that she is imprisoned by the wallpaper.
Mental disease can aggravate pareidolia, as can fatigue and sleepiness. After a recent surgery, one of us (Martinez-Conde) noticed faces everywhere, in places as unlikely as the ultrasound images of her left arm during an examination of potential postsurgical blood clots. She realized at once that the ubiquitous faces were the product of lack of sleep and the high titer of pain medication in her bloodstream, so she was more fascinated than concerned. Her doctor agreed but made a note in her file for a different drug regime in the future. Just in case. Luckily, the hospital room's walls were bare, and there was no yellow wallpaper in sight.
Our brain is wired to find meaning. Our aptitude to identify structure and order around us, combined with our superior talent for face detection, can lead to spectacular cases of pareidolia, with significant effects in society and in culture.
Satan in the Smoke
Photojournalist Mark D. Phillips captured the World Trade Center, engulfed in smoke and flames, seconds after the second plane attack on 9/11. Unknown to Phillips at the time, the picture, distributed by Associated Press and published on the front pages of several newspapers, contained the face of none other than the Prince of Darkness. A media frenzy ensued, and Phillips, who retired from photojournalism that same day, received more than 30,000 messages related to the “face of evil” in the murky cloud and the feelings it brought forth in the viewers.
One year later computer scientists Vladik Kreinovich and Dima Iourinski of the University of Texas at El Paso published a geometric analysis of the face in the photograph, also seen in a different image from CNN. The analysis showed that perturbations in the smoke can consist of horizontal lines (such as the “eyes” and “mouth”), and vertical lines (such as the “nose”) overlaid on a conic surface (the “head”). The scientists concluded that both the background shape (the cone) and the features on the background (horizontal and vertical lines) are naturally explained by the physics and geometry of smoke plumes emanating from fire.
The Face from Space
In 1976, as NASA's Viking 1 circled Mars looking for possible landing sites for its sister ship Viking 2, it spotted the likeness of a mile-wide human (or maybe Martian?) face, staring back from the Red Planet's region of Cydonia. Scientists believed that the Martian “sphinx” was one of numerous mesas around Cydonia and that unusual shadows made it look like a humongous head. Conspiracy theorists favored the alternative explanation of a government cover-up, however, and criticized NASA's unsuccessful attempts to hide the remnants of an ancient Martian civilization. Eighteen years later obtaining high-resolution images of Cydonia was a priority for NASA. “We felt this was important to taxpayers,” says Jim Garvin, chief scientist for NASA's Mars Exploration Program. “We photographed the Face as soon as we could get a good shot at it.” In April 1998 the Mars Orbiter Camera team snapped a picture 10 times sharper than the original Viking photos, revealing the mystifying Face on Mars to be ... a mesa.