Here’s an interesting optical illusion — by focusing on the center point of the image and using peripheral vision to observe the faces, the perception of the faces changes drastically, making what we culturally consider “beautiful people” into grotesque masks. In particular, watch the eyes. The eyes seem to grow in size and in proportion to the face. The effect in more pronounced with brown eyes.
Harvard Vision Lab created a few experiments that feature Attention Controls Errors and Perceptual Blindness. Below is one of their optical illusions. Directions: concentrate on the central white dot. Did the colors of the outside dots continue to shift throughout the video? If they stopped when the dots were rotating, then you’ve just experienced Silencing—the lab’s vocabulary for individual’s inability to pay attention to both motion and color shift at the same time. Here, we mostly call it Perceptual Blindness. My Personal Experience with this Illusion: The first time I watched the video, I think the colors stopped shifting…but I don’t really remember—I wasn’t paying attention! The second time, I saw the shift. When I showed the illusion to a colorblind individual, he saw the shift from the first viewing. To read about the complete experiment and to view more illusion videos, please visit the lab: http://visionlab.harvard.edu/silencing/
Our minds play tricks on us all the time. Once the information has entered our cognition via our senses, it still has to get processed to be understood. Like any other data, it’s all about context. For interesting examples of optical illusions, please visit http://www.lottolab.org/articles/illusionsoflight.asp. R. Beau Lotto has put together a few interesting examples of mis-processing! Or watch him deliver a talk at TED.