The Site of Size Constancy

Blakemore, Colin; Garner, E T; Sweet, Jacqueline

doi:10.1068/p010111

Cited by 23 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This suggests that visual inferences of material properties are more likely to be based on estimated material spatial frequencies than on retinal frequencies. This finding is in accordance with data from experiments investigating spatial-frequency discrimination (Burbeck, 1987), spatial frequency memory masking (Bennett & Cortese, 1996), size constancy (Blakemore, Garner, & Sweet, 1972), recognition memory for shapes (Milliken & Jolicoeur, 1992), and for the extraction of upper case letters from noise (Parish & Sperling, 1991). It also seems to be in line with our everyday experience where material properties do not change massively with viewing distance.…”

Section: Discussionsupporting

confidence: 89%

Frequency-based heuristics for material perception

Giesel

Zaidi

2013

Journal of Vision

View full text Add to dashboard Cite

People often make rapid visual judgments of the properties of surfaces they are going to walk on or touch. How do they do this when the interactions of illumination geometry with 3-D material structure and object shape result in images that inverse optics algorithms cannot resolve without externally imposed constraints? A possibly effective strategy would be to use heuristics based on information that can be gleaned rapidly from retinal images. By using perceptual scaling of a large sample of images, combined with correspondence and canonical correlation analyses, we discovered that material properties, such as roughness, thickness, and undulations, are characterized by specific scales of luminance variations. Using movies, we demonstrate that observers' percepts of these 3-D qualities vary continuously as a function of the relative energy in corresponding 2-D frequency bands. In addition, we show that judgments of roughness, thickness, and undulations are predictably altered by adaptation to dynamic noise at the corresponding scales. These results establish that the scale of local 3-D structure is critical in perceiving material properties, and that relative contrast at particular spatial frequencies is important for perceiving the critical 3-D structure from shading cues, so that cortical mechanisms for estimating material properties could be constructed by combining the parallel outputs of sets of frequency-selective neurons. These results also provide methods for remote sensing of material properties in machine vision, and rapid synthesis, editing and transfer of material properties for computer graphics and animation.

show abstract

Section: Discussionsupporting

confidence: 89%

Frequency-based heuristics for material perception

Giesel

Zaidi

2013

Journal of Vision

View full text Add to dashboard Cite

show abstract

“…But this argument cannot explain the periodic function measured with a grating as the test target, nor the uniform effect after monocular adaptation (Fig. 6), and, in any case, Blakemore, Garner and Sweet (1972) have found that size constancy does not operate before the site of the threshold elevation.…”

Section: Disparity Detection In Manmentioning

confidence: 77%

Evidence for disparity detecting neurones in the human visual system

Blakemore

Hague

1972

The Journal of Physiology

View full text Add to dashboard Cite

1. It is known that adaptation to a grating pattern causes a rise in the contrast threshold for test gratings of similar spatial frequency and orientation. 2. We find this after‐effect also to be disparity‐specific. Adaptation to a grating at zero horizontal disparity (at the same distance as the fixation point) causes a greater elevation of threshold for patterns at the same disparity than for those at nearby disparities, closer or more distant than the fixation point. 3. Adaptation to a grating at some disparity other than zero causes a disparity‐specific elevation of threshold centred on the adapting disparity. 4. This finding also applies if the observer adapts to a grating but single bright bars are used as the test stimuli. 5. The disparity‐specific ‘tuning curves’ revealed by these techniques are quite broad, having a half‐width at half‐amplitude of several min of disparity. 6. Adaptation to a grating at one disparity causes an apparent change in the distance of test gratings at nearby disparities. 7. We compare these psychophysical experiments with the properties of disparity‐selective binocular neurones in the visual cortex of cats and monkeys.

show abstract

“…It is perhaps the most primitive process shown so far to do so. 1 Spatial frequency coding, for example, is based upon retinal, rather than distal, spatial frequency as shown by the failure of adaptation to a specific spatial frequency to generalize to the same gratings presented at different distances (Blakemore, Garner, & Sweet, 1972). Recognition of a configuration seems, however, to depend at least approximately on size ratios within the figure and to be indifferent to its absolute size (Sutherland, 1968).…”

Section: Discussionmentioning

confidence: 99%