Though there are many ideas relating to causative factors, even current research seems to be lacking in a conclusive explanation for why the Ternus effect occurs and has not yet discovered exactly which mechanisms are responsible. Petersik and his team in 2006 suggested that intensive brain-imaging research on each percept is the way forward and is the most likely way to discover the answer. On the other hand, Grossberg and Rudd (1992, Psychol. Rev., 99, 78–121) have developed a neural model of motion perception that simulates many examples of long-range apparent motion, including both the Ternus and reverse-contrast Ternus illusions <http://cns.bu.edu/~steve>.