Kaleidoscopic
motion and velocity illusions
Peter A. van der
Helm
Abstract.
A novel class of vivid motion and velocity illusions for
contrast-defined shapes is presented and discussed. The illusions
concern a starlike wheel that, physically, rotates with constant
velocity between stationary starlike inner and outer shapes but that,
perceptually, shows pulsations, jolts backwards, jolts forwards, and
accelerations, each time it aligns with the inner and outer shapes.
These dynamic effects turn from one into another when contrasts in the
image change gradually, and seem to be caused by colour
assimilation and ambiguous figure-ground segregation.
Peter
A. van der Helm 