JASTROW'S DUCKRABBIT

Also referred to asduck-rabbit, rabbit-duck, Jastrow's duck-rabbit illusion, andrabbit-duck illusion. The eponym Jastrow's duck-rabbit refers to the Polish-American psychologist Joseph Jastrow (1863-1944), who in 1899 published a drawing depicting an ambiguous figure that can be interpreted either as a duck or a rabbit. Jas-trow used the drawing to illustrate the notion that sense perception depends on perceptual stimuli as well as mental activity. Jastrow's duck-rabbit is designated as an ambiguous, or reversible, or bistable figure. It has been argued that it is not an " illusion proper, on the grounds that it does not operate primarily on the brain's (or mind's) unconscious inferences about the external environment, but on expectations, knowledge, and the direction of attention. Nevertheless, Jastrow's duck-rabbit tends to be classified as a "cognitive illusion, or, more specifically, an "ambiguous illusion. In the past, it has been erroneously assumed that the duck-rabbit was borrowed from a popular German weekly calledFliegende Blätterand introduced into the scientific discourse by the Austrian philosopher Ludwig Wittgenstein (1889-1951). However, Wittgenstein himself recognized Jastrow as the duck-rabbit's original creator.

Brugger, P. (1999). One hundred years of an ambiguous figure: Happy birthday, duck/ rabbit!Perceptual&Motor Skills, 89(3 Pt 1), 973977.

Gregory, R.L., Gombrich, E.H., eds. (1973).Illusion in nature and art. London: Gerald Duckworth & Company.