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W H Ittelson

Publications and source records attributed to W H Ittelson.

5 recordsLinked to original sources
PubMed1993

Mirror reversals: real and perceived.

A mirror optically reverses the axis perpendicular to its surface, but apparent reversals (eg right-left) can be seen parallel to the surface. This poses a perceptual problem which Ittelson, Mowafy, and Magid resolved by concluding that an object appears to differ from its mirror image by an apparent reversal along its axis of greatest symmetry. Three papers--two included in this discussion (by Haig and by Morris), and an earlier one by Gregory--that disagree with this conclusion are examined, and arguments advanced in them are shown to be unconvincing. The question of apparent mirror reversals is then discussed in more detail.

Attention↗
PubMed1991

The perception of mirror-reflected objects.

In what ways and under what conditions does an object appear to differ from its enantiomorph (its mirror reflection)? This 'mirror question' or its popular counterpart, "Why does a mirror reverse left and right but not up and down?" is frequently encountered, but an acceptable answer is not to be found in the literature. The question is approached as an experimental problem in visual psychophysics. A mirror optically reverses the axis perpendicular to its surface. What are the perceptual consequences of this stimulus transformation? This question is examined in four experiments by using stimuli of varying complexity and familiarity. Apparent reversals are demonstrated along right-left, front-back, top-bottom, and oblique axes, depending on the perceived asymmetries of the stimulus object. Perceived asymmetry is shown to depend both on structural asymmetries and on canonical axes and orientations defined by social convention. It is concluded that an object appears to differ from its enantiomorph by an apparent reversal along the axis of least perceived asymmetry. Implications for perceptual frames of reference and for the perception of symmetry are discussed.

Adult↗