The Ponzo Illusion: Inadequacy of Apparent Depth Explanations

1969 ◽  
Vol 28 (2) ◽  
pp. 423-433
Author(s):  
Robert L. Houck ◽  
Roy B. Mefferd ◽  
Betty A. Wieland
Keyword(s):  
Ponzo Illusion ◽  
Apparent Distance ◽  
Apparent Size ◽  
Vertical Line ◽  
Apparent Depth ◽  
Size Constancy ◽  
Constancy Scaling ◽  
Distance Relationship

Os viewing the Ponzo figure reported a series of sudden changes in its phenomenal organization and orientation. In none of these was the vertical line nearer the vertex of the figure reported to be smaller than the vertical line nearer the open end, i.e., the illusion occurred with all percepts except a rare one of a flat stimulus. In two of the most frequent and persistent percepts, the illusion could be explained on the basis of apparent size-apparent distance relationship among the elements. This was also the case with Gregory's theory of misapplied size-constancy scaling. However, with other percepts neither of these explanations was tenable.

The Role of Figure Orientation and Apparent Depth in the Perception of the Horizontal—Vertical Illusion

Perception ◽  
1975 ◽  
Vol 4 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Harvey R Schiffman ◽  
Jack G Thompson
Keyword(s):  
Stimulus Figure ◽  
Vertical Line ◽  
Apparent Depth ◽  
Horizontal Line ◽  
Size Constancy ◽  
Illusory Effect

An experiment was performed which examined the role of figural orientation directly, and the role of an inappropriately invoked size-constancy mechanism indirectly, in the actuation and magnitude of the horizontal—vertical illusion. When the vertical line of the stimulus figure was aligned above the horizontal line, the illusory effect was significant and positive; in contrast, when the vertical line was located below the horizontal line, the illusion was negative. Under the assumption that a vertical line can appear as a foreshortened line in depth, these findings support an explanation based on the operation of a misapplied size-constancy mechanism.

Apparent Size Contrasts of Retinal Images and Size Constancy as Determinants of the Moon Illusion

1978 ◽  
Vol 46 (3) ◽  
pp. 803-808 ◽  
Author(s):  
Olin W. Smith ◽  
Patricia C. Smith ◽  
Charles C. Geist ◽  
Robert R. Zimmermann
Keyword(s):  
Necessary Conditions ◽  
Apparent Distance ◽  
Framing Effect ◽  
Apparent Size ◽  
Visual Images ◽  
Retinal Images ◽  
Size Constancy ◽  
The Moon ◽  
Moon Illusion ◽  
The Earth

Kaufman and Rock (1962) and Rock and Kaufman (1962) concluded that the moon illusion is a function of and attributable to apparent distance. They also reported a large framing effect as an exception. Analysis of the effect suggests two components which can account for the illusion independently of apparent distance. These are apparent size contrasts of visual images of discriminable features or objects of the earth with the moon's image and size constancy of the features or objects plus the interactions of the two. Apparent distances to horizons are always a consequence of the necessary conditions for the illusion. They are related to the illusion but are not a determinant of it.

scholarly journals Influences of orientation on the Ponzo, contrast, and Craik-O’Brien-Cornsweet illusions

2019 ◽  
Vol 82 (4) ◽  
pp. 1896-1911
Author(s):  
Leo Poom
Keyword(s):  
Real World ◽  
Physical Environment ◽  
Ponzo Illusion ◽  
Simultaneous Contrast ◽  
Size Constancy ◽  
3D Object ◽  
Railway Tracks ◽  
Left Right Asymmetry ◽  
Prior Experiences

AbstractExplanations of the Ponzo size illusion, the simultaneous contrast illusion, and the Craik-O’Brien-Cornsweet brightness illusions involve either stimulus-driven processes (assimilation, enhanced contrast, and anchoring) or prior experiences. Real-world up-down asymmetries for typical direction of illumination and ground planes in our physical environment should influence these illusions if they are experience based, but not if they are stimulus driven. Results presented here demonstrate differences in illusion strengths between upright and inverted versions of all three illusions. A left-right asymmetry of the Cornsweet illusion was produced by manipulating the direction of illumination, providing further support for the involvement of an experience-based explanation. When the inducers were incompatible with the targets being located at the different distances, the Ponzo illusion persisted and so did the influence from orientation, providing evidence for involvement of processes other than size constancy. As defined here, upright for the brightness illusions is consistent with an interpretation of a shaded bulging surface and a 3D object resulting from a light-from-above assumption triggering compensation for varying illumination. Upright for the Ponzo illusion is consistent with the inducers in the form of converging lines being interpreted as railway tracks receding on the ground triggering size constancy effects. The implications of these results, and other results providing evidence against experience-based accounts of the illusions, are discussed.

The Role of Apparent Depth and Context in the Perception of the Ponzo Illusion

Perception ◽  
1978 ◽  
Vol 7 (1) ◽  
pp. 47-50 ◽  
Author(s):  
Harvey R Schiffman ◽  
Jack G Thompson
Keyword(s):  
Contextual Factors ◽  
Ponzo Illusion ◽  
Apparent Depth

The role of apparent depth features and the proximity of the test lines to the adjacent contours in the actuation of the Ponzo illusion was examined. Six versions of the Ponzo figure were employed: a standard Ponzo figure and five modified figures in which the test lines varied in orientation (horizontal or vertical) and in location (inside or outside the converging contours). Both manipulations resulted in a significant decrease in the magnitude of the illusion in comparison to the standard Ponzo figure. The results suggest that the Ponzo illusion is significantly affected by contextual factors.

Depth Location of Shafts Filling Half the Space between Mueller-Lyer Fins

1968 ◽  
Vol 27 (3) ◽  
pp. 1019-1022 ◽  
Author(s):  
B. G. Stacey ◽  
A. R. Pike
Keyword(s):  
Apparent Depth ◽  
Size Constancy ◽  
Lyer Illusion ◽  
Dark Room

Using luminous stimuli in a dark room, Ss were required to judge the apparent depth location of shafts filling half the space between the ingoing and outgoing fins of the Mueller-Lyer illusion. Under these conditions there is a reversal of the apparent depth location of the shafts as compared with the usual M-L illusion. This finding is contrary to a prediction derived from the misapplied size-constancy theory but can be interpreted in terms of the size-distance principle.

Apparent Depth and the Müller—Lyer Illusion

Perception ◽  
1973 ◽  
Vol 2 (2) ◽  
pp. 225-234 ◽  
Author(s):  
M A Georgeson ◽  
C Blakemore
Keyword(s):  
Three Dimensional ◽  
Apparent Depth ◽  
Size Constancy ◽  
Comparison Line ◽  
Perspective View ◽  
Lyer Illusion ◽  
Classical Size

The Müller–Lyer illusion was presented stereoscopically as either a flat or a three-dimensional figure. When the flat figure was made to appear closer or further than a comparison line, the illusion persisted along with large changes in overall size due to classical size constancy. When the fins of the figure were tilted in depth the illusion was somewhat reduced for both forward and backward tilts. It is argued that the size-constancy theory of illusions should predict an enhancement when stereopsis and the typical perspective view' reinforce each other, and abolition or reversal of the illusion when they are in opposition. These results therefore pose some problems for the theory.

The Size-Constancy of Underwater Swimmers

1965 ◽  
Vol 17 (4) ◽  
pp. 329-337 ◽  
Author(s):  
Helen E. Ross
Keyword(s):  
Apparent Distance ◽  
Suspended Particles ◽  
Size Constancy ◽  
Clear Water ◽  
Unequal Size

The size-constancy of divers was measured by requiring them to adjust the distance between two disks of unequal size so that they appeared phenomenally equal. In clear water divers showed greater constancy-ratios than on land. In murky water, where visibility was reduced by suspended particles, constancy-ratios were the same as, or less than, on land. It is suggested that these effects may be due to changes in apparent distance: in clear water objects appear nearer through refraction, but in murky water they appear further away because of the distance cues provided by the visibility gradient. The orientation of the display, or of the diver's body, did not affect constancy under water, though it does on land. It is argued that the effect on land is due to visual and proprioceptive cues which are absent in the water.

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

1966 ◽  
Vol 18 (1) ◽  
pp. 63-72 ◽  
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.

The Site of Size Constancy

Perception ◽  
1972 ◽  
Vol 1 (1) ◽  
pp. 111-119 ◽  
Author(s):  
C Blakemore ◽  
E T Garner ◽  
J A Sweet
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Neural Mechanism ◽  
Angular Width ◽  
Size Constancy ◽  
Depth Cues ◽  
Black And White ◽  
Maximum Elevation ◽  
Constancy Scaling ◽  
High Contrast Grating

Under appropriate conditions, with good depth cues, the perception of the bar width or spatial frequency of a pattern of black and white stripes (a grating) shows excellent size constancy. Two gratings at different distances look similar in spatial frequency when the actual width, not the angular width, of their stripes is the same. Adaptation to a high-contrast grating causes a rise in the threshold contrast for detecting gratings of similar orientation and spatial frequency. This aftereffect transfers from one eye to the other, so it probably depends on binocular orientation-selective neurones in the visual cortex. With the adapting grating at three times the distance of the test grating the maximum elevation of threshold occurs for exactly the same angular spatial frequency as that of the adapting pattern. Therefore the neural mechanism for size-constancy scaling probably occurs after the visual cortex, perhaps in the inferotemporal cortex.

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