Copyright Akiyoshi Kitaoka 2006
Illusion A) When observers approach the image keeping their eyes fixed on the central river, the outer rivers appear to approach the central one.
Illusion B) Each river appears to expand laterally.
Illusion C) The image sometimes appears to move horizontally (swinging-motion illusion).
Illusion D) Illusory orange streaks appear to run across the rivers parallel to bridges.
via psy.ritsumei.ac.jp
