"Nao, for something completely different."



1.) Perceived motion due to the juxtaposition of contrasting colors (or tonal values) is known as the Peripheral Drift illusion. Faubert, J. & Herbert, A. M. (1999) Perception, 28, 617 - 622; Kitaoka. A., Ashida. H. (2003). Vision, 15, 261-262.

2.) Apparent bending and or tilting of lines is a variation of the café wall illusion. Gregory R.L. & Heard P. (1979) Perception 8:365–380.

3.) Judgment of the relative tonal values of objects is affected by the conception of a 3-dimensional scene with light and shadowed areas. Adelson E.H. (1993)
Science 262:2042–2044

5.) Circles appearing as spirals is related to the “Fraser’s Spiral” illusion. Fraser J. (1908),Brit. J. Psych. 2:307–320

6.) Colored edges appear to“bleed” into adjacent areas. This is known as the Watercolor Illusion. Pinna, B. (1987). XXI Congresso degli Psicologi Italiani, 158.; Pinna, B., Brelstaff, G., & Spillmann, L. (2001). Vision Research, 41, 2669−2676.; Pinna, B., Werner J.S., & Spillmann, L. (2003). Vision Research, 43, 43−52.

7. Twisted cord illusion. Coren, S. and J. S. Girgus, (1978)

8.) Perception of bright spots at the intersection of grid lines is an example of the Hermann Grid illusion. Hermann L (1870) Physiologie 3:13–15.

9.) Scintillating Grid illusion is a variation of the Hermann Grid illusion (see ref. 8), Schrauf M; Lingelbach B, Lingelbach E & Wist ER (1995) ,Perception 24: suppl. A, 88–89.

10.) The perceived gray area in the lightest nodes of this image is an illusion.

11.) Overlayed images, one composed of high frequency components and the other of the low frequency components leads to different perceptions when viewed from close and far. Schyns P.G., Oliva A. (1994), Psychol Sci 5:195–200.

12.) Variation of the peripheral drift illusion with high to low contrast shapes. Kitaoka, A.and Ashida, H. Presented in the 2004 winter meeting of the Vision Society of Japan, (January 26 - 28, 2004) (http://www.psy.ritsumei.ac.jp/ akitaoka/VSJ04w.html) The authors called this effect 'central drift' illusion because this illusion is observed in the center of the visual field as well as in the periphery. No explanation has been given to this illusion.

14.) This impossible figure is related to the well-known Penrose Triangle.

15.) The appearance of motion in the flow from the faucet is the Leviant Illusion which was made famous by the 1981 painting by 'Enigma' by artist Isia Leviant in 1981

16.) The fugitive dots are an example of "blanking". McAnany, J., & Levine, M. W. (2004)Vision Research Volume 44, 993–1001 2004