These figures consist of repetitive patterns like Escher's works but include illusion!


Vertical or horizontal edges appear to tilt.

Copyright A.Kitaoka 1999

"Cultured turtles"

Vertical or horizontal edges appear to be distorted.

Copyright A.Kitaoka 2002


*Green turtle.

The inset appears to move.

Copyright A.Kitaoka 2000

"Ascending and descending turtles"

Vertical edges appear to tilt.

Copyright A.Kitaoka 2002

"Kame wa mannen"*

*In Japan, they say turtles live for ten thousand years and they bring us long life.

The concentric arrays appear to be a spiral.

Kitaoka, A., Pinna, B., and Brelstaff, G. (2001). Last but not least: New variations of spiral illusions. Perception, 30, 637-646. (p. 642, Figure 6c)

Copyright Pion Ltd 2001

(Originally illustrated by A.Kitaoka 1999)

Attention: This work is published in an academic journal "Perception" (see above), which shows papers of studies on perception. I have never explicitly transfered the copyright to the Pion Ltd, which publishes Perception, but it is naturally accepted that the Pion Ltd has the copyright of this work. Therefore, it is strongly recommended that those who would like to use this figure in their papers or books should also obtain the permission from the Pion Ltd. In my opinion, although this work might be artful, this is no more than a spiral-illusion version of the illusion of "fringed edges" (Kitaoka et al., 2001). That is, this work can be a basic figure like the Zollner figure or the Cafe Wall figure. I thus hope the free use of this work for research or educational purposes.

Most of the figures shown in this homepage are GIF files, which are bitmap ones. This mean oblique lines or edges should be jaggy. For those who need vector files (Microsoft Word files or Corel Draw files), please feel free to contact me.

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