Entrained path deflection in apparent motion.
A dot jumping back and forth between two positions would normally appear to jump along a straight line. But when surrounded by dots which jumped through three positions arranged in a V, it also appeared to jump along a V-shaped trajectory.
D005133:Eye Movements; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008027:Light; D009039:Motion Perception / Q000502:physiology*; D009903:Optical Illusions / Q000502:physiology*; D013997:Time Factors