Even after a person has been told of this phenomenon, they will continue to perform the same mistake. See figures 5-7: When given instructions to add “cross-contour lines” to figure 5, the typical subject will produce figure 7, not figure 6. Once again, the tendency to make the lines 'increasingly perpendicular' is evident.
Compared to a quadrilateral on its own, judgments of the acute and obtuse angles in the cube drawings were biased towards 90 degrees.Angle illusion on a picture’s surface
Of interest, the judgments are attracted only to 90
degrees, not to 0 degrees or 180 degrees, 45 degrees and 135 degrees,other possible components of good form.
...an angle illusion could be a top-down, Gestalt effect. When physical conditions approach a ‘simpler’ shape, a percept with symmetry, equality, parallels, and orthogonality is favoured, Gestaltists argue.
If the V means 90 degrees, it is seen as 90 degrees, in a strong version of this theory.
Peterson and Gibson (1993) argue perceptual input and cognitive information are processed in parallel. If recognition influences perception, angles close to 90 degrees on the page might indeed be seen as 90 degrees.
SHERIEF HAMMAD, JOHN M. KENNEDY, IGOR JURICEVIC and SHAZMA RAJANI
University of Toronto at Scarborough, 1265 Military Trail, Toronto ON M1C1A4, Canada
Received 28 August 2006; accepted 15 March 2007
Spatial Vision, Vol. 21, No. 3–5, pp. 451– 462 (2008)
Koninklijke Brill NV, Leiden, 2008.
Also available online - www.brill.nl/sv
Peterson, M. A. and Gibson, B. S. (1993). Shape recognition contributions to figure-ground organization in three-dimensional displays, Cognit. Psychol. 25, 383–429.