Image:Duck-Rabbit illusion.jpg

The famous duck-rabbit ambiguous image. Is it a duck? Is it a rabbit?

"The subject of a gestalt demonstration knows that his perception has shifted because he can make it shift back and forth repeatedly while he holds the same book or piece of paper in his hands. Aware that nothing in his environment has changed, he directs his attention increasingly not to the figure (duck or rabbit) but to the lines of the paper he is looking at. Ultimately he may even learn to see those lines without seeing either of the figures, and he may then say (what he could not legitimately have said earlier) that it is these lines that he really sees but that he sees them alternately as a duck and as a rabbit. ...As in all similar psychological experiments, the effectiveness of the demonstration depends upon its being analyzable in this way. Unless there were an external standard with respect to which a switch of vision could be demonstrated, no conclusion about alternate perceptual possibilities could be drawn." -- Thomas Kuhn, The Structure of Scientific Revolutions (3rd edn., p. 114).

[edit] License

• Source: Jastrow, J. (1899). The mind's eye. Popular Science Monthly, 54, 299-312.

	This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1923. See this page for further explanation.
	Deutsch | English | Español | Français | Gaeilge | Galego | Italiano | Nederlands | ‪中文(简体)‬ | +/-
	This image might not be in the public domain outside of the United States (this especially applies in Canada, China (not Hong Kong, Macao, or Taiwan Area), Germany, Mexico, and Switzerland). The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.

Les pages ci-dessous contiennent cette image :

• La Structure des révolutions scientifiques
• Joseph Jastrow
• Canard-lapin