Delboeuf illusion

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A few words

Delboeuf illusion

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This kind of assimilation illusion is associated with the name of Franz Joseph Delboeuf, a Belgian philosopher. The copies of the same shape - circles and rings in our case - appear to inherit properties of their environment. Two equal circles - one inside a bigger circle, the other containing a smaller circle - seem to have different sizes.

References

The Mind's Eye, Readings from SCIENTIFIC AMERICAN, W. H. Freeman and Company, 1986

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