"Reality": Construction, Deconstruction, and Reconstruction

Interactive Demonstration:

The interactive display below can be used to acquire the ability to see Hofstadter's Road Sign in at least four different ways. Controls to the left allow one to bias one's perception by adding apparent barriers and arrows. Controls to the right allow one to vary the color of the dots at various locations in ways that may help one see different patterns.

 http://serendip.brynmawr.edu/exchange/hofstadter/applet