Constancy scaling theory and the Mueller-Lyer illusion: More disconfirming evidence

Gregory's Inappropriate Constancy Scaling explanation for visual illusion was investigated. If perceptual experience with real-life edges and angles, near and far, leads to constancy scaling which is inappropriately applied to the Mueller-Lyer configuration, then configurations which are based upon angles of regard in between the two extreme field patterns would produce illusory effects between the two conventional Mueller-Lyer effects. A model representing one edge of a cubic figure, i.e., one vertical and four horizontal lines, was constructed of wooden dowel rods and photographed at predetermined angles. Transparencies based on the photographed images were then used to determine the PSE at each of these angles. Generally, we interpret our results as supportive of the theory, since PSEs increase as a function of angular change from 0° to 180°. The linear trend is complicated by an unexpected cubic trend, but an explanation is proposed.

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Illusion-Destruction by Appropriate Scaling

Perception ◽

10.1068/p040203 ◽

1975 ◽

Vol 4 (2) ◽

pp. 203-220 ◽

Cited By ~ 40

Author(s):

Richard L Gregory ◽

John P Harris

Keyword(s):

Scaling Theory ◽

Visual Distortion ◽

Lyer Illusion ◽

Constancy Scaling

The inappropriate constancy scaling theory of visual distortion illusions is tested by optically projecting typical models giving these figures by perspective. Appropriate or inappropriate stereoscopic disparities are then added–with the prediction that when perspective and stereo are geometrically correct the distortion should vanish. This is confirmed with measurements for the Müller-Lyer illusion and by observation of several other classical examples. It is suggested that much previous work has investigated ‘end stop’ conditions, given by angles too extreme to be generated as perspective. Conditions for appropriate scaling, giving zero or small distortions, are found to be critical but readily attainable.

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Reversal of the Müller-Lyer Illusion with Changes in the Length of the Inter-Fins Line

Quarterly Journal of Experimental Psychology ◽

10.1080/14640746708400094 ◽

1967 ◽

Vol 19 (3) ◽

pp. 208-214 ◽

Cited By ~ 37

Author(s):

Brian J. Fellows

Keyword(s):

Scaling Theory ◽

Lyer Illusion ◽

Constancy Scaling ◽

Expansion Effect

Subjects were asked to judge the relative lengths of lines placed between the ingoing and the outgoing fins of a Müller-Lyer figure. It was found that with the gap between the fins constant at 160 mm. there was a reversal of the normal Müller-Lyer illusion when the inter-fins line was between 40 and 100 mm. long. This effect was maximal when the line was 80 mm. The normal illusion returned when the line was increased in length to 120 mm. These findings do not support Gregory's inappropriate constancy scaling theory. They seem to suggest the operation of two distinct illusory forces in the Müller-Lyer situation. The reverse illusion may be due to the greater expansion effect upon the line between the ingoing fins, caused by the greater “enclosing” nature of these fins.

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Gregory's theory of illusions: Some disconfirming evidence in the case of the Muller-Lyer illusion.

Psychological Review ◽

10.1037/h0033466 ◽

1972 ◽

Vol 79 (6) ◽

pp. 538-539 ◽

Cited By ~ 6

Author(s):

Lester E. Krueger

Keyword(s):

Lyer Illusion ◽

Disconfirming Evidence

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Triangles and Squares Look Smaller Than They are: Some New Illusions of Extent

Perception ◽

10.1068/p120701 ◽

1983 ◽

Vol 12 (6) ◽

pp. 701-705 ◽

Cited By ~ 1

Author(s):

Michel Treisman

Keyword(s):

Local Scale ◽

Lyer Illusion ◽

Scaling Hypothesis ◽

Constancy Scaling ◽

Configurations Of Lines

Some new illusions of extent are described, and they are discussed in relation to the Müller-Lyer illusion and the constancy-scaling hypothesis. It is concluded that they support a minimal version of this hypothesis in which certain configurations of lines cause changes in local scale in certain directions, independently of whether or not these configurations are incorporated in larger patterns in a way which supports and receives a depth interpretation.

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Susceptibility to the Müller-Lyer Illusion and its Relationship to Differences in Size Constancy

Quarterly Journal of Experimental Psychology ◽

10.1080/14640746608400008 ◽

1966 ◽

Vol 18 (1) ◽

pp. 63-72 ◽

Cited By ~ 6

Author(s):

Vernon Hamilton

Keyword(s):

Individual Differences ◽

Size Constancy ◽

Direct Test ◽

Perceptual Inference ◽

Lyer Illusion ◽

Perceptual Style ◽

Constancy Scaling

The hypothesis that susceptibility to the Müller-Lyer illusion is the result of normal constancy scaling, misapplied, was submitted to direct test. No significant correlations between illusion error and size constancy estimates were obtained. Also invalidated were hypotheses that under-constancy is correlated with non-susceptibility to the illusion, and that over-constancy is correlated with greater illusion error. The results suggest that an approach to the explanation of illusion effects by means of analysing individual differences in size constancy, in intelligence and preferred “perceptual style,” might be fruitful. Some tentative suggestions are made concerning the role of perceptual inference, abstraction and analysing.

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