Lucy in the Sky
By modulating the centers on and off with different rates, Shapiro and Charles showed that different apparent rates of motion could be attributed to different elements of the figure to create undulating shape-changing effects
Shapiro and Emily Knight of Bucknell University placed in the Top Ten list of the 2008 Best Visual Illusion of the Year Contest with this variant that pits background- and edge-modulated rows of diamonds against each other in a perpetual collision that never connects.
Graphic designer Michael Pickard of Sunderland University built on these findings to create a spectacular artistic vision of wind-blown flowers, without a single moving object.
Thorsten Hansen, Kai Hamburger and Karl R. Gegenfurtner of Giessen University were also top ten finalists in the 2007 Best Visual Illusion of the Year Contest, with this entry that shows that direction, magnitude and speed of apparent motion in a grid of brains depends on all three: the color of the brains, the direction of the brightness gradient of the brains as a function of the background brightness, and the retinal position of the brains with respect to the viewer’s center of gaze.
Notice that if you focus your gaze at any one the brains, it moves less than the surrounding brains, and that if you step away from the screen, the brains move more than if you peer very closely at the image on the screen. Also, the relative speed and direction of the moving brains depends on their color and the direction of the brightness gradient they create with the background,
Knight and Shapiro combined the various effects of contrast modulation, shading, shape and color to create an unmoving image of illusory but biologically plausible motion, which placed among the top ten finalists of the 2007 Best Visual Illusion of the Year Contest. Notice that without the modulating background, the effect is lost.
Visual dissociations of Movement, Position and Stereo Depth: Some Phenomenal Phenomena. R.L. Gregory and P.F. Heard in Quart. J. Exp. Psychol., 35A, 217-237, 1983.
Visual Illusions Based on Single-Field Contrast Asynchronies. A.G. Shapiro, J.P. Charles and M. Shear-Heyman in Journal of Vision, 5(10):2, 764-782, 2005. http://journalofvision.org/5/10/2/, doi:10.1167/5.10.2.
The Neural Correlate Society’s Best Visual Illusion of the Year Contest Web site: http://illusioncontest.neuralcorrelate.com.