When I was a little girl, I loved going to Disneyland. My family only went about once a year, but each time I went, I just had to ride the Haunted House! Filled with flying ghosts, stretching pictures and singing statues, the Haunted House was as much magical as it was terrifying for me. One particular illusion I found fascinating was of two, white statue heads that stared at me as I walked through the hall of portraits. Each year, I would linger a little longer, staring back at those statues, wondering how they were staring at me at the same time other people claimed that the statues were staring at them. One year, I was bold enough to take a closer look and, to my surprise, they were not statues at all! In fact, instead of being convex, they were actually concave. This fascinated me even more, especially because they continued to look like rounded, white statues even after I knew that they weren’t. Recently, I learned that an illusion like this is achieved by something called top-down processing (Goldstein, 2011).

Top-down processing occurs when we look at something and our previous knowledge or expectations influence how we perceive what we are looking at (Goldstein, 2011). In the case of the two statues in the hall of portraits of Disneyland’s Haunted House, previous experience with looking at a statue of a person’s head, as well as the innumerable amount of times I had looked at a person’s face, would cause me to expect that the statues and their faces were convex. Therefore, when I looked at the concave, white molds of statue heads, lit up in a dark room and surrounded by a thick black border, I perceived them as curving outward toward me.

You may be wondering why Disney didn’t just choose to use normal, rounded statues. I thought the same thing. The park is filled with mechanical dolls and puppets, so why wouldn’t they just do the same for these statues and make them mechanically follow people as they walk by? They could have, but then they would not have been able to achieve the illusion that the statues were staring back at every individual at the same time. Again, because of top-down processing that happens in our brains, each person is experiencing the illusion based on their own prior experiences and expectations (Goldstein, 2011). The statues would appear to follow me as I walked past them because the part of the faces that got cut off, from my point of view, due to them being concave and not convex, is what I’d expect a person’s facial features to look like, according to my past experience, when looking at me from that angle. Meanwhile, another person could be walking in the opposite direction of me and for the same reasons the statues would look as if they were looking at them.

Finally, you may be wondering why the illusion continued to work, even after acquiring the knowledge that the statues were actually concave molds facing away from me. As the narrator of the video “Hollow Face Optical Illusion – VisualFunHouse.com” states, we have such a large amount of knowledge containing faces with noses that stick out, that the top-down processing overrides any signals from the receptors in our visual senses that says otherwise.

So the next time you get a chance to visit Disneyland or Disneyworld or maybe even a nearby haunted house during Halloween, make sure to take a closer look at what kinds of illusions you may be experiencing due to top-down processing. It’s amazing the way our brains work! To experience the illusion now, check out the following two videos…

Hollow Face Optical Illusion – VisualFunHouse.com

and

Hollow face illusion by John Kubie, author of “Depth Perception and The Hollow Face Illusion” on BrainFacts.org.

Reference

Goldstein, E. B. (2011). Beyond bottom-up processing. In Cognitive psychology: Mind, research and everyday experience (3rd ed., pp. 52-56). Belmont, CA: Wadsworth Cengage Learning.

Hollow face optical illusion – visualfunhouse.com. (2008, March 29). YouTube. Retrieved February 2, 2014, from http://www.youtube.com/watch?v=OHuStlT1RM8

Kubie, J. (2013, July 28). Depth Perception and the Hollow Face Illusion. Retrieved February 1, 2014, from http://blog.brainfacts.org/2013/07/depth-perception-and-the-hollow-face-illusion/#.Uu9LnvuorzO