-->
Home Store Project Ideas Project Guide Ask An Expert Blog Careers Teachers Parents Students

Visual Illusions: When What You See Is... Not What's There?

Exploring the science behind what we see and what we think we see. It's not always the same thing!


When you watch the animation above, focus on the white dot in the center. As the surrounding dots begin to spin, do they seem to stop changing colors until the spinning ends? In fact, they continue to change, but the motion of the overall outer ring makes it appear that they stop blinking until the ring stops spinning. If you watch it again and focus on the outer ring, you will see that the colored dots continue to blink and shift color even when the ring spins.

This animation recently won the seventh annual "Best Visual Illusion of the Year" contest , organized by the Neural Correlate Society and associated with the annual Vision Sciences Society meeting. The winning illusion by Jordan Suchow and George Alvarez, a Harvard graduate student and assistant professor of psychology, respectively, is titled "Silencing awareness of change by background motion." It's a simple title for a sensory perception that may also seem simple. But what's simple about the fact that we can think we are seeing something we are not? Nothing!

From studying visual illusions, and the ways in which the brain controls what we perceive, scientists learn more about sensory perception, about the brain, and about vision.


The Science of Visual Illusion

Research in visual illusion and sensory perception involves psychology, physiology, and neuroscience of vision and image processing. Students who are interested in these fields or who simply enjoy the "wow" factor of visual illusions can get more hands-on with the following science projects:


illusion-HumBeh-200px.jpg

Sleight of Eye
The image above lets you quickly test a non-animated visual illusion. To give it a try, look first at the airplane image. Do you see that the two halves are differently colored? Now, stare at the dot between the blue and yellow rectangles for 20 seconds. Then shift your gaze to the dot in the airplane image. How do the two halves appear now? As you continue to watch, the effect will disappear. (See full project.)

Taking it Farther


To view the other 2011 winning illusions (as well as winners from previous years), visit the Best Illusion Contest of the Year website.

Science Buddies Science Activities

Science Buddies Summer Science Roundup


thumbnail
School and family science weekly spotlight: make a solar oven from household and recycled materials.

thumbnail
With different kinds of dried beans, plastic cups, and water, kids can model rocks and observe the way different sized particles in rocks affect how much water a rock can hold.

thumbnail
Students can experiment with the engineering design process by trying to improve the durability of a simple handheld device.

thumbnail
School and family science weekly spotlight: melting ice chemistry.

thumbnail
For families living in drought conditions, careful monitoring of water usage is especially important. With hands-on science and engineering projects, students can investigate water-saving strategies and science and engineering related to water conservation. Above: The effect of drought can be...

thumbnail
City parklets provide interesting challenges for engineers, designers, and planners. With software from Autodesk and a fun Digital STEAM Workshop challenge, students can design their own parklets and see what is involved in reimagining a few parking spots as a social space.



Your Science!
What will you explore for your science project this year? What is your favorite classroom science activity? Email us a short (one to three sentences) summary of your science project or teaching tip. You might end up featured in an upcoming Science Buddies newsletter!



You may print and distribute up to 200 copies of this document annually, at no charge, for personal and classroom educational use. When printing this document, you may NOT modify it in any way. For any other use, please contact Science Buddies.