Pink Dots Illusion

("Lilac Chaser")

Stare at the cross in the center for a few minutes. Try not to move your eyes. What do you see?


 

After you have observed the illusion and answered the discussion questions, scroll down for more information.

 

 

 

 

 

 

 


The stimulus itself, the thing that is presented on the screen, is composed of a series of 12 still frames of 11 pink dots on a gray background, which flash in succession. The ring of dots contains a gap, whose location changes by one dot in each successive image. The first few frames are made of the following images, which are shown one after another. In the remaining frames, the position of the gap moves by one dot in each frame.
Frame 1 Frame 2 Frame 3 Frame 4

The only colors in the picture are pink (dots), gray (background) and black (center cross). If you see any other colors, thery are "all in your head," generated by the way your visual system operates.

This illusion was designed by Jeremy Hinton.

For more information:

An interactive version of this illusion can be seen at

http://www.michaelbach.de/ot/col_lilacChaser/index.html ,

where it is called "Lilac Chaser." On this page, you can vary the color of the dots, the color of the background, the color intensity, and the speed at which the frames change.

There are a lot more fun illusions on the same site; its home page is
http://www.michaelbach.de/ot/

Psychology 105
C. Furchner