UK site DO THE TEST has a short video that will test your visual perception. It’s a must for every motorcyclist who wants to understand more about how the mind processes what we see.
I believe that video is derived from some of the excellent work done at the University of Illinois Visual Cognition Lab. You’ll find a lot more examples of similar work there. (And a surprisingly stern and crappy copyright notice on that page; so much for the spirit of collaboration and knowledge sharing in academic research.)