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
What I find so fascinating about this illusion is how our mind can’t “undo” it. With many of the other illusions presented in this class (and in other places), I find that I can see the alternative. Even though top-down processing seems to be the immediate and default way of receiving something, one can often refocus the eyes (and the mind) in order to use only bottom-up processing. For example, many of the examples of Gestalt Law’s can be undone by simply looking at it a different way. The Olympic Rings illustration of the law of Pragnanz (from the textbook) can be seen a different way when you mentally break them apart. We can shift our attention between the candlestick and the faces or the witch and the beautiful woman in those popular illustrations of illusion.
What sets this illusion apart from the others is that it can’t be “undone”. No matter how hard I try to simply use bottom-up processing on this one, my mind can only fathom the face coming out and not the reality of the hollowed out mask. Our conventional thought and top-down processing is simply too strong to be overcome in this case. Faces wouldn’t make sense if they were concave. Even while watching the video of the mask rotating – where we clearly see what it is the whole time – the moment that it reaches the point in its revolution where out mind can’t perceive it as it is, we see something completely different. In addition to what it looks like, it also seems to reverse direction. I spent way too much time focusing on it, trying to see it as hollow and rotating clockwise. I guess Gestalt and top-down processing win this battle.
Goldstein, E. B. (2011). Using Knowledge: Top-Down Processing. In Cognitive psychology: Mind, research and everyday experience (3rd ed., p. 60). 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
I couldn’t agree more. I haven’t been to Haunted House in Disneyland , but I have a similar experiment about the top down Processing Illusion when I first saw a 3D street art in Macau, China.
What I saw is a 3D 4th floor shopping center on the floor. I can barely step in to that picture area. Beacause my top down processing the that space is three or four floors lower. I would all and broke my leg if I step in.
The perspective of 3D street art is very important. The aritis’s design always relate the painting to the distance or heights illusion. This is how they are using our top down processing to be amazed my the work. Sometimes it require the viewer to stand at a certain vantage point in order to see the three-dimensional image.
Referrence
http://www.huffingtonpost.com/2012/08/08/3d-street-art-optical-illusions-chalk-artists_n_1757390.html
I find it fascinating how our minds perceive visual input through top-down processing. I, myself, have never been to Disneyland, but I have had similar experiences with museum and “fun house” displays in other vacation spots. One place in particular is the Ripley’s museum in Niagara Falls, Canada. While it has been several years since I visited, I vaguely recall a similar experience with two white columns against a black backdrop. From a distance, they appeared to be two faces looking at each other but as I got closer, the definition of columns became clearer.
I remember spending countless hours of my childhood summers laying in the grass, watching clouds with my sister. We were always able to see shapes and figures in those clouds, such as elephants, angels, puppies, and faces. In our minds, these clouds were in shapes of familiar things, but in actuality they were just condensation caught up in air. Now my daughter and I do the same in the summer, with her young mind finding zoo animals and my older mind still seeing what my mind relates the clouds to, but also with the knowledge that things aren’t what they seem. I’ve been told that “you only see what you want to see” and that “you only hear what you want to hear” when faced with an unfamiliar situation. Perhaps a better way to say these things is to emphasize that you only see/hear what your mind wants you to. Top-down processing has effects on our minds without our conscious consent, which, in my opinion, makes the processes of our minds all the more fascinating.