Demo of an ambigous motion stimuli first shown by Stuart Anstis. After a while the perception of 4 rotating pairs of dots ought to change into a perception of two squares rotating, or sometimes even a cube. For more information see psy2.ucsd.edu/~sanstis/SAGlobal.html and this book chapter: Anstis, S. (2003): Levels of motion perception. In: Harris, L. & Jenkin, M. (eds.): Levels of perception. New York, US: Springer-Verlag.

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