There are two orders of motion. The first order of motion is two or more stimuli that are switched on and off in alternation can produce two different motion percepts. An example of this concept is depicted from things like billboards and signs that make the viewer originally perceive the object as moving but in fact it is just stationary shapes that are turned on and off to make the allusion that they are in fact moving. This is also call apparent motion.The second order of motion is motion in which the moving contour is defined by contrast, texture, flicker or some other quality that does not result in an increase in luminance or motion energy in the spectrum of the stimulus. These pictures are all examples of Motion Perception.http://www.youtube.com/watch?v=WZ3Q82ZmgTQ - This video shows a Las Vegas sign that appears to be very motion like, when in fact not at all.