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Kobayashi Y. Asymmetric Brightness Effects With Dark Versus Light Glare-Like Stimuli. Iperception 2021; 12:2041669521993144. [PMID: 33738087 PMCID: PMC7934062 DOI: 10.1177/2041669521993144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 01/04/2021] [Indexed: 11/16/2022] Open
Abstract
The glare effect is a brightness illusion that has captured the attention of the vision community since its discovery. However, its photometrical reversal, which we refer to here as photometrical reversed glare (PRG) stimuli, remained relatively unexplored. We presented three experiments that sought to examine the perceived brightness of a target area surrounded by luminance gradients in PRG stimuli and compare them with conventional glare effect configurations. Experiment 1 measured the brightness of the central target area of PRG stimuli through an adjustment task; the results showed that the target appeared brighter than similar, comparative areas not surrounded by luminance gradients. This finding was unexpected given the recent report that PRG stimuli cause pupil dilation. Meanwhile, Experiments 2 and 3 implemented a rating task to further test the findings in Experiment 1. Again, the study found a robust brightening illusion in the target area of PRG stimuli in a wide range of target and background luminance. The results are discussed in comparison with the brightness enhancement of the glare effect.
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Affiliation(s)
- Yuki Kobayashi
- Yuki Kobayashi, Ritsumeikan University, 2-150, Iwakuracho, Ibaraki, Osaka 567-8570, Japan.
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2
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Soranzo A, Acaster S, Taroyan N, Reidy J. Depth Plane Separation Affects Both Lightness Contrast and Assimilation. Front Psychol 2020; 11:2114. [PMID: 32982864 PMCID: PMC7490546 DOI: 10.3389/fpsyg.2020.02114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/29/2020] [Indexed: 11/13/2022] Open
Abstract
Lightness contrast and assimilation are two opposite phenomena: contrast occurs when a gray target perceptually acquires a complementary color than the bordering, inducing, surfaces; assimilation is when a gray target perceptually acquires the same color component as the inducers. Previous research has shown that both phenomena are affected by the manipulation of depth between the inducers and target. However, different results have been reported; it is not clear whether contrast persists when inducers are non-coplanar with the target. Previous studies differ for the spatial configuration of the stimuli and the technique adopted to manipulate depth. The aim of this research was to measure the effects of manipulating the depth between inducers and target in comparable conditions. Results show that contrast persists, but largely reduces, after depth manipulation while assimilation reverses to contrast. Furthermore, interesting asymmetries between white and black inducers emerged with white inducers favoring contrast and black inducers favoring assimilation. These results provide further evidence that high-level processes of visual processing are involved in both phenomena, with important consequences for lightness theories.
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Affiliation(s)
- Alessandro Soranzo
- Department of Psychology, Sociology and Politics, Faculty of Social Sciences and Humanities, Sheffield Hallam University, Sheffield, United Kingdom
| | - Steph Acaster
- Department of Psychology, Sociology and Politics, Faculty of Social Sciences and Humanities, Sheffield Hallam University, Sheffield, United Kingdom
| | - Naira Taroyan
- Department of Psychology, Sociology and Politics, Faculty of Social Sciences and Humanities, Sheffield Hallam University, Sheffield, United Kingdom
| | - John Reidy
- Department of Psychology, Sociology and Politics, Faculty of Social Sciences and Humanities, Sheffield Hallam University, Sheffield, United Kingdom
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3
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Zavagno D. The Influence of Physical Illumination on Lightness Perception in Simultaneous Contrast Displays. Iperception 2018; 9:2041669518787212. [PMID: 30046432 PMCID: PMC6055112 DOI: 10.1177/2041669518787212] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 06/13/2018] [Indexed: 11/16/2022] Open
Abstract
Three experiments investigated the role of physical illumination on lightness perception in simultaneous lightness contrast (SLC). Four configurations were employed: the classic textbook version of the illusion and three configurations that produced either enhanced or reduced SLC. Experiment 1 tested the effect of ambient illumination on lightness perception. It simulated very dark environmental conditions that nevertheless still allowed perception of different shades of gray. Experiment 2 tested the effect of the intensity of Gelb lighting on lightness perception. Experiment 3 presented two conditions that integrated illumination conditions from Experiments 1 and 2. Our results demonstrated an illumination effect on both lightness matching and perceived SLC contrast: As the intensity of illumination increased, the target on the black background appeared lighter, while the target on the white background was little affected. We hypothesize the existence of two illumination ranges that affect lightness perception differently: low and normal. In the low range, the SLC contrast was reduced and targets appeared darker. In the normal range, the SLC contrast and lightness matchings for each background were little changed across illumination intensities.
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Affiliation(s)
- Daniele Zavagno
- Department of Psychology, University of Milano-Bicocca, Italy
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4
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Abstract
Lightness constancy is the ability to perceive surface reflectance correctly despite substantial changes in lighting intensity. A classic view is that lightness constancy is the result of a "discounting" of lighting intensity, and this continues to be a prominent view today. Logvinenko and Maloney (2006) have proposed an alternative approach to understanding lightness constancy, in which observers do not make explicit estimates of reflectance, and lightness constancy is instead based on a perceptual similarity metric that depends on both the reflectance and the illuminance of surfaces viewed under different lighting conditions. Here we compare these two views using a novel, free-adjustment reflectance-matching task. We test whether observers can match reflectance in a task where they are free to adjust both the illuminance and the reflectance of the match stimulus over a wide range. We find that observers can match reflectance under these conditions, which supports the view that observers make explicit estimates of reflectance. We also compare performance in this free adjustment task using physical objects and computer-rendered images as stimuli. We find that lightness constancy is good in both cases, but with some evidence of a glow-related artifact with computer-rendered stimuli.
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Affiliation(s)
- Khushbu Y Patel
- Department of Psychology and Centre for Vision Research, York University, Toronto, Canada
| | - Anudhi P Munasinghe
- Department of Psychology and Centre for Vision Research, York University, Toronto, Canada.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, USA
| | - Richard F Murray
- Department of Psychology and Centre for Vision Research, York University, Toronto, Canada
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5
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Affiliation(s)
- Alan Gilchrist
- Psychology Department, Rutgers University, Newark, NJ, USA
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6
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Radonjic A, Pearce B, Aston S, Krieger A, Dubin H, Cottaris NP, Brainard DH, Hurlbert AC. Illumination discrimination in real and simulated scenes. J Vis 2016; 16:2. [PMID: 28558392 PMCID: PMC5024666 DOI: 10.1167/16.11.2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Indexed: 11/24/2022] Open
Abstract
Characterizing humans' ability to discriminate changes in illumination provides information about the visual system's representation of the distal stimulus. We have previously shown that humans are able to discriminate illumination changes and that sensitivity to such changes depends on their chromatic direction. Probing illumination discrimination further would be facilitated by the use of computer-graphics simulations, which would, in practice, enable a wider range of stimulus manipulations. There is no a priori guarantee, however, that results obtained with simulated scenes generalize to real illuminated scenes. To investigate this question, we measured illumination discrimination in real and simulated scenes that were well-matched in mean chromaticity and scene geometry. Illumination discrimination thresholds were essentially identical for the two stimulus types. As in our previous work, these thresholds varied with illumination change direction. We exploited the flexibility offered by the use of graphics simulations to investigate whether the differences across direction are preserved when the surfaces in the scene are varied. We show that varying the scene's surface ensemble in a manner that also changes mean scene chromaticity modulates the relative sensitivity to illumination changes along different chromatic directions. Thus, any characterization of sensitivity to changes in illumination must be defined relative to the set of surfaces in the scene.
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Affiliation(s)
- Ana Radonjic
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, ://www.sas.upenn.edu/~radonjic/
| | - Bradley Pearce
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne,
| | - Stacey Aston
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, ://staceyaston.com/
| | - Avery Krieger
- Department of Psychology, University of Pennsylvania, Philadelphia, PA,
| | - Hilary Dubin
- Department of Psychology, University of Pennsylvania, Philadelphia, PA,
| | - Nicolas P Cottaris
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, ://color.psych.upenn.edu/people/nicolas-p-cottaris
| | - David H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, ://color.psych.upenn.edu/people/brainard
| | - Anya C Hurlbert
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, ://www.ncl.ac.uk/ion/staff/profile/anyahurlbert.html
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7
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Abstract
What determines an object's lightness remains unclear, but it is generally thought that the ratios of its luminance to the luminance of other objects in a scene play a crucial role because these ratios allow the relative reflectance of each object to be estimated, providing all the objects are under the same illumination. Because objects that lie in the same plane are typically illuminated equally, it has been suggested that it is the luminance ratios between coplanar objects that primarily determine lightness (Gilchrist, 1977 Science195 185–187; Gilchrist et al, 1999 Psychological Review106 795–834). An alternative hypothesis is that perceived illumination differences can affect lightness directly. As the studies that provided evidence for the coplanar ratio hypothesis always varied the illumination and the coplanar relationships simultaneously, it is unclear which hypothesis is correct. I measured the influence of each factor separately and found that the perceived illumination differences have a greater effect on lightness.
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Affiliation(s)
- Piers D L Howe
- Harvard Medical School, 220 Longwood Avenue WAB 232, Boston, MA 02115, USA.
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8
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Abstract
Illusions of lightness offer valuable clues to how lightness values are computed by the visual system. The traditional domain of lightness illusions must be expanded to include failures of constancy, as there is no distinction between these categories. Just as lightness is (relatively) constant in the face of changes in illumination level, so it is equally constant in the face of changes in background reflectance. Simultaneous lightness contrast, the most familiar lightness illusion, is fairly weak, and represents a failure of background-independent lightness constancy. It is argued that a combination of the highest-luminance rule of anchoring plus the Kardos idea of codetermination can account for most lightness illusions. Kardos suggested that the lightness value of a target surface is partly determined relative to the field of illumination (or framework) in which it is embedded, and partly relative to the neighboring field of illumination. Although Kardos did not apply his principle of codetermination to failures of background-independent constancy such as the simultaneous contrast illusion, this can be done rather easily by defining a framework as a perceptual group instead of identifying it strictly with an objective field of illumination.
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Affiliation(s)
- Alan Gilchrist
- Department of Psychology, Rutgers University, 101 Warren Street, Newark, NJ 07102, USA
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9
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Catarci T, de Leoni M, Marrella A, Mecella M, Russo A, Steinmann R, Bortenschlager M. WORKPAD. ACTA ACUST UNITED AC 2011. [DOI: 10.4018/jiscrm.2011010103] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In complex emergency/disaster scenarios, persons from teams from various emergency-response organizations collaborate to achieve a common goal. In these scenarios, the use of smart mobile devices and applications can improve the collaboration dynamically. The lack of basic interaction principles can be dangerous, as it could increase the level of disaster or can make the efforts ineffective. This paper examines the main results of the project WORKPAD finished in December 2009. WORKPAD worked on a two-level architecture to support rescue operators during emergency management. The use of a user-centered design methodology during the entire development cycle has guaranteed that the architecture and resulting system meet end-user requirements. The feasibility of its use in real emergencies is also proven by a demonstration showcased with real operators. The paper includes qualitative and quantitative results and presents guidelines that can be useful in developing emergency-management systems.
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10
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Hedrich M, Bloj M. Basic colour names for 2D samples: effects of presentation media and illuminants. Ophthalmic Physiol Opt 2010; 30:638-45. [PMID: 20883349 DOI: 10.1111/j.1475-1313.2010.00757.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have previously shown (Bloj et al., 2008; Abstracts Materials & Sensations 2008) that under particular conditions colour memory is independent of presentation media, and of the illuminants under which colours are viewed. In the present study we investigate whether colour naming is also unaffected by these two factors. Forty-eight colour samples from the Natural Colour System (NCS) collection were presented as real paper samples or as accurate computer simulations displayed on a calibrated monitor. The colour swatches could be presented under a daylight illuminant - two intensities, 85 ('D1') or 60 cd m(-2) ('D2') - or a purple illuminant, 45 cd m(-2) ('Lily'). The colour samples were shown in arrays of 16 (4 × 4 layout) and the observer's task was to assign one of the eleven basic colour terms to each of the samples. Six observers repeated this colour naming task five times for each presentation medium and illuminant. On average, in 73% of the cases the same colour term was assigned to surface and display colours. This level of agreement was highest for colour samples under daylight (D1-82%, D2-73%) and poor for Lily (65%). Although colour memory is unaffected by the nature of the colour stimulus, here we show that there are limitations to cross-media agreement in colour naming.
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Affiliation(s)
- Monika Hedrich
- Bradford School of Optometry and Vision Science, University of Bradford, Bradford, UK.
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11
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Blakeslee B, Reetz D, McCourt ME. Spatial filtering versus anchoring accounts of brightness/lightness perception in staircase and simultaneous brightness/lightness contrast stimuli. J Vis 2009; 9:22.1-17. [PMID: 19757961 DOI: 10.1167/9.3.22] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
J. Cataliotti and A. Gilchrist (1995) reported that, consistent with anchoring theory, the lightness of a black step in a reflectance staircase was not altered by moving a white step from a remote to an adjacent location. Recently, E. Economou, S. Zdravkovic, and A. Gilchrist (2007) reported data supporting three additional predictions of the anchoring model (A. Gilchrist et al., 1999): 1) equiluminant incremental targets in staircase simultaneous lightness contrast stimuli appeared equally light; 2) the simultaneous lightness contrast effect was due mainly to the lightening of the target on the black surround; and 3) the strength of lightness induction was greatest for darker targets. We investigated similar stimuli using brightness/lightness matching and found, contrary to these reports, that: 1) the relative position of the steps in a luminance staircase significantly influenced their brightness/lightness; 2) equiluminant incremental targets in staircase simultaneous brightness/lightness contrast stimuli did not all appear equally bright/light; 3) an asymmetry due to a greater brightening/lightening of the target on the black surround was not general; and 4) darker targets produced larger effects only when plotted on a log scale. In addition, the ODOG model (B. Blakeslee & M. E. McCourt, 1999) did an excellent job of accounting for brightness/lightness matching in these stimuli.
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Affiliation(s)
- Barbara Blakeslee
- Center for Visual Neuroscience, Department of Psychology, North Dakota State University, Fargo, ND 58108-6050, USA.
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12
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Metacontrast masking and the cortical representation of surface color: dynamical aspects of edge integration and contrast gain control. Adv Cogn Psychol 2008; 3:327-47. [PMID: 20517518 PMCID: PMC2864963 DOI: 10.2478/v10053-008-0034-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Accepted: 09/30/2006] [Indexed: 11/20/2022] Open
Abstract
This paper reviews recent theoretical and experimental work supporting the idea
that brightness is computed in a series of neural stages involving edge
integration and contrast gain control. It is proposed here that metacontrast and
paracontrast masking occur as byproducts of the dynamical properties of these
neural mechanisms. The brightness computation model assumes, more specifically,
that early visual neurons in the retina, and cortical areas V1 and V2, encode
local edge signals whose magnitudes are proportional to the logarithms of the
luminance ratios at luminance edges within the retinal image. These local edge
signals give rise to secondary neural lightness and darkness spatial induction
signals, which are summed at a later stage of cortical processing to produce a
neural representation of surface color, or achromatic color, in the case of the
chromatically neutral stimuli considered here. Prior to the spatial summation of
these edge-based induction signals, the weights assigned to local edge contrast
are adjusted by cortical gain mechanisms involving both lateral interactions
between neural edge detectors and top-down attentional control. We have
previously constructed and computer-simulated a neural model of achromatic color
perception based on these principles and have shown that our model gives a good
quantitative account of the results of several brightness matching experiments.
Adding to this model the realistic dynamical assumptions that 1) the neurons
that encode local contrast exhibit transient firing rate enhancement at the
onset of an edge, and 2) that the effects of contrast gain control take time to
spread between edges, results in a dynamic model of brightness computation that
predicts the existence Broca-Sulzer transient brightness enhancement of the
target, Type B metacontrast masking, and a form of paracontrast masking in which
the target brightness is enhanced when the mask precedes the target in time.
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13
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Rudd ME, Zemach IK. Contrast polarity and edge integration in achromatic color perception. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2007; 24:2134-56. [PMID: 17621319 DOI: 10.1364/josaa.24.002134] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Previous work has shown that the achromatic color of a target patch embedded in simple two-dimensional display depends not only on the luminance contrast between the target and its immediate surround but also on the contrasts of other nearby edges. Quantitative models have been proposed in which the target color is modeled as a spatially weighted sum of edge contrasts in which the target edge receives the largest weight. Rudd and Arrington [Vision Res.41, 3649 (2001)] elaborated on this idea to include an additional mechanism whereby effects of individual color-inducing edges are "partially blocked" by edges lying along the path between the inducing edge and the target. We tested the blockage model in appearance matching experiments performed with disk-and-single-ring stimuli having all four possible combinations of inner and outer ring edge contrast polarities. Evidence was obtained for both "blockage" (attenuation) and "antiblockage" (amplification) of achromatic color induction signals, depending on the contrast polarities of the inner and outer ring edges. A neural model is proposed to account for our data on the basis of the contrast gain control occurring between cortical edge detector neurons.
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Affiliation(s)
- Michael E Rudd
- Howard Hughes Medical Institute and Department of Physiology and Biophysics, University of Washington, Seattle, Washington, USA.
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14
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Zemach IK, Rudd ME. Effects of surround articulation on lightness depend on the spatial arrangement of the articulated region. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2007; 24:1830-41. [PMID: 17728806 DOI: 10.1364/josaa.24.001830] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We investigated the effect of surround articulation on the perceived lightness of a target disk. Surround articulation was manipulated by varying either the number of wedges in a surround consisting of wedges of alternating luminance or the number of checks in a surround consisting of a radial checkerboard pattern. In most conditions, increased articulation caused incremental targets to appear lighter and decremental targets to appear darker. But increasing the surround articulation in a way that did not increase the number of target-coaligned edges in the display did not affect the target lightness. We propose that the effects of surround articulation depend on the relationship between the orientations and contrast polarities of the target edges and those of edges present within the surround.
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Affiliation(s)
- Iris K Zemach
- Department of Psychology, University of Washington, Seattle 98195-1525, USA.
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15
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Zdravković S, Economou E, Gilchrist A. Lightness of an object under two illumination levels. Perception 2007; 35:1185-201. [PMID: 17120840 DOI: 10.1068/p5446] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Anchoring theory (Gilchrist et al, 1999 Psychological Review 106 795-834) predicts a wide range of lightness errors, including failures of constancy in multi-illumination scenes and a long list of well-known lightness illusions seen under homogeneous illumination. Lightness values are computed both locally and globally and then averaged together. Local values are computed within a given region of homogeneous illumination. Thus, for an object that extends through two different illumination levels, anchoring theory produces two values, one for the patch in brighter illumination and one for the patch in dimmer illumination. Observers can give matches for these patches separately, but they can also give a single match for the whole object. Anchoring theory in its current form is unable to predict these object matches. We report eight experiments in which we studied the relationship between patch matches and object matches. The results show that the object match represents a compromise between the match for the patch in the field of highest illumination and the patch in the largest field of illumination. These two principles are parallel to the rules found for anchoring lightness: highest luminance rule and area rule.
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Affiliation(s)
- Suncica Zdravković
- Department of Psychology, University of Novi Sad, Stevana Musica 24, 21000 Novi Sad, Serbia.
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16
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Bressan P, Actis-Grosso R. Simultaneous lightness contrast on plain and articulated surrounds. Perception 2006; 35:445-52. [PMID: 16700287 DOI: 10.1068/p5247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Simultaneous lightness contrast is stronger when the dark and light backgrounds of the classic display (where one of the targets is an increment and the other is a decrement) are replaced by articulated fields of equivalent average luminances. Although routinely attributed to articulation per se, this effect may simply result from the increase in highest luminance in the light articulated, vs plain, background; by locally darkening the decremental target, such an increase would amplify the difference between the targets. We disentangled the effects of highest luminance and articulation by measuring, separately, the magnitude of lightness contrast on dark and light plain and articulated backgrounds. We found that highest luminance and articulation contribute separately to the final illusion.
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Affiliation(s)
- Paola Bressan
- Dipartimento di Psicologia Generale, Università di Padova, via Venezia 8, I 35131 Padua, Italy.
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17
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Chien SHL, Bronson-Castain K, Palmer J, Teller DY. Lightness constancy in 4-month-old infants. Vision Res 2006; 46:2139-48. [PMID: 16427110 DOI: 10.1016/j.visres.2005.11.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Revised: 11/22/2005] [Accepted: 11/29/2005] [Indexed: 11/24/2022]
Abstract
In the present study, discrete trial familiarization/novelty techniques were used to study lightness constancy in 4-month-old infants. The test stimuli were real objects (paper smiley faces) of two different reflectances, dark gray (17% reflectance) and light gray (54% reflectance). In Experiment 1, the test stimuli were viewed against a white (90% reflectance) surround, and in Experiment 2, against a black (4.6% reflectance) surround. In Experiments 1 and 2, the illumination was changed between familiarization and test phases of each trial. In Experiment 3, the reflectance of the surround was changed from white to mid gray (28.5% reflectance) between familiarization and test phases of each trial. With the white surround, the infants preferred the face with the novel reflectance, consistent with the presence of lightness constancy. With the black surround, the infants showed no preference between faces with novel reflectance vs. novel luminance. With the changing surround, the infants showed a small preference for the stimulus with the novel ratio, as opposed to the stimulus with the novel reflectance and the novel luminance. The results are discussed in the context of adult cues for lightness constancy, including white anchor points and local luminance ratios.
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18
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Bonato F, Cataliotti J. A vision research apparatus for broad luminance range displays. ACTA ACUST UNITED AC 2004; 36:77-82. [PMID: 15190701 DOI: 10.3758/bf03195551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lightness, the perceived gray shade of a surface, and the perception of self-luminous surfaces--that is, surfaces that appear to glow--have most often been studied with paper displays and computer-generated stimuli presented on CRT monitors. Although both methods are often effective, experiments that require a wide range of luminance values in the same display are often difficult to conduct with paper and computer displays alone. Also, color mode appearance is often an issue when surface color perception is the topic of research; CRT monitors are essentially light sources themselves and often appear in the luminous mode of color appearance. Here, we describe an apparatus in which the target is an undetected aperture whose luminance is adjustable. Whereas a typical CRT monitor offers a luminance range of about 100:1, much broader luminance ranges are possible with the described apparatus. Unlike a CRT monitor, the stimulus background will always appear in the surface mode of color perception, and the target(s) can appear as either surface colors or luminous colors. Apparatus modifications are possible, including the addition of a stereoscope or an embedded CRT for creating an adjustable region that is computer controlled.
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Affiliation(s)
- Frederick Bonato
- Department of Psychology, Saint Peter's College, 2641 Kennedy Boulevard, Jersey City, NJ 07306, USA.
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19
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Jandó G, Agostini T, Galmonte A, Bruno N. Measuring surface achromatic color: toward a common measure for increments and decrements. BEHAVIOR RESEARCH METHODS, INSTRUMENTS, & COMPUTERS : A JOURNAL OF THE PSYCHONOMIC SOCIETY, INC 2003; 35:70-81. [PMID: 12723781 DOI: 10.3758/bf03195498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Surface color is traditionally measured by matching methods. However, in some conditions, the color of certain surfaces cannot be measured: The surface simply looks brighter or darker than all the patches on a matching scale. We studied the reliability, validity, and range of application of three different types of simulated Munsell scales (white-, black-, and split-surrounded) as methods for measuring surface colors in simple disk-ring displays. All the scales were equally reliablefor matching both increments and decrements, but about 2096 of the increments were unmatchable on the white-surrounded scale, about 1396 of the decrements were unmatchable on the black-surrounded scale, and about 9% of the increments were unmatchable on the split-surrounded scale. However, matches on all the scales were linearly related. Therefore, it is possible to convert them to common units, using regression parameters. These units provide an extended metric for measuring all increments and decrements in the stimulus space, effectively removing ceiling and floor effects, and providing measures even for surfaces that were perceived as out of range on some of the scales.
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20
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Agostini T, Galmonte A. A new effect of luminance gradient on achromatic simultaneous contrast. Psychon Bull Rev 2002; 9:264-9. [PMID: 12120788 DOI: 10.3758/bf03196281] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A new effect in the domain of achromatic simultaneous contrast has been observed. A middle gray region placed at the center of an area filled by a linear achromatic gradient from black (outer part) to white (inner part) is perceived as being much darker than an identical middle gray region surrounded by a reversed gradient. By using a matching task in two experiments, it has been shown that this phenomenon is much stronger than the classical achromatic simultaneous contrast effect. The new effect is interpreted in terms of the albedo hypothesis.
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21
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Abstract
Lightness induction, or simultaneous lightness contrast (we prefer the term lightness induction since contrast has another meaning in the visual literature, namely, the relative intensity of the stimulation), was studied for a 3-D object (Adelson's wall of blocks) and its 2-D pictorial representations. A statistically significant lightness induction effect was found only for the pictures but not for the 3-D object. No lightness induction effect was found for the 3-D object under either monocular or binocular viewing conditions.
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22
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Kraft JM, Maloney SI, Brainard DH. Surface-illuminant ambiguity and color constancy: effects of scene complexity and depth cues. Perception 2002; 31:247-63. [PMID: 11922136 DOI: 10.1068/p08sp] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Two experiments were conducted to study how scene complexity and cues to depth affect human color constancy. Specifically, two levels of scene complexity were compared. The low-complexity scene contained two walls with the same surface reflectance and a test patch which provided no information about the illuminant. In addition to the surfaces visible in the low-complexity scene, the high-complexity scene contained two rectangular solid objects and 24 paper samples with diverse surface reflectances. Observers viewed illuminated objects in an experimental chamber and adjusted the test patch until it appeared achromatic. Achromatic settings made tinder two different illuminants were used to compute an index that quantified the degree of constancy. Two experiments were conducted: one in which observers viewed the stimuli directly, and one in which they viewed the scenes through an optical system that reduced cues to depth. In each experiment, constancy was assessed for two conditions. In the valid-cue condition, many cues provided valid information about the illuminant change. In the invalid-cue condition, some image cues provided invalid information. Four broad conclusions are drawn from the data: (a) constancy is generally better in the valid-cue condition than in the invalid-cue condition: (b) for the stimulus configuration used, increasing image complexity has little effect in the valid-cue condition but leads to increased constancy in the invalid-cue condition; (c) for the stimulus configuration used, reducing cues to depth has little effect for either constancy condition: and (d) there is moderate individual variation in the degree of constancy exhibited, particularly in the degree to which the complexity manipulation affects performance.
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Affiliation(s)
- James M Kraft
- Department of Psychology, University of California at Santa Barbara, 93106, USA.
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Agostini T, Galmonte A. Perceptual organization overcomes the effects of local surround in determining simultaneous lightness contrast. Psychol Sci 2002; 13:89-93. [PMID: 11892786 DOI: 10.1111/1467-9280.00417] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Lightness induction can occur on the basis of the immediate surround of a region (local interactions) and also on the basis of global factors of perceptual organization. The experiments reported in this article used novel displays that made it possible to differentiate the contributions of these two kinds offactors. The experiments demonstrated, for the first time, that when higher-level factors act contemporaneously with lower-level factors, the contrast effect induced by the global-organization principle of perceptual belongingness overcomes the effect due to retinal lateral inhibition.
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24
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Abstract
In this paper we demonstrate the existence of simultaneous lightness contrast in displays in which the target patches are both more luminant than their surrounds. These effects are not predicted by theories of lightness that assume that the highest luminance in a scene is perceived as white, and anchors all the other luminances. We show that the strength of double-increment illusions depends crucially on the luminance of both the surrounds and the target patches. Such luminance prerequisites were not met in previous studies, which explains why simultaneous contrast with incremental targets has so far been regarded as extremely weak or nonexistent.
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Affiliation(s)
- P Bressan
- Dipartimento di Psicologia Generale, Università di Padova, Italy.
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25
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Yamauchi Y, Uchikawa K. Upper-limit luminance for the surface-color mode appearance. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2000; 17:1933-1941. [PMID: 11059587 DOI: 10.1364/josaa.17.001933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A series of experiments were carried out to reveal determinants for the mode of color appearance by measuring the upper-limit luminance of a color chip for the surface-color mode. We used a CRT color monitor to present test and surround stimuli in the surface-color mode. The stimuli were composed of a three-by-three array of color chips on a gray background with a white frame. The observer increased the luminance of a center test color until it just ceased to appear in the surface-color mode. Our results show that this upper-limit luminance was different among test colors, but their brightnesses, calculated from the luminance and brightness/ luminance values, were almost the same and were slightly below the brightness of the white frame. The existence of the surrounding color chips affected the results, but their sizes and spatial arrangements did not. When all of the luminances of the surrounds changed equally, the upper-limit luminances of the test colors for the surface-color mode appearance changed by the same ratio. This result indicates that the brightness of a target was a determinant for selecting the mode of color appearance and that the brightest surround stimulus acted as a cue for determining the judgment.
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Affiliation(s)
- Y Yamauchi
- Imaging Science and Engineering Laboratory, Tokyo Institute of Technology, Yokohama, Japan
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26
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Krantz JH. Tell me, what did you see? The stimulus on computers. BEHAVIOR RESEARCH METHODS, INSTRUMENTS, & COMPUTERS : A JOURNAL OF THE PSYCHONOMIC SOCIETY, INC 2000; 32:221-9. [PMID: 10875166 DOI: 10.3758/bf03207787] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Most psychology experiments start with a stimulus, and, for an increasing number of studies, the stimulus is presented on a computer monitor. Usually, that monitor is a CRT, although other technologies are becoming available. The monitor is a sampling device; the sampling occurs in four dimensions: spatial, temporal, luminance, and chromatic. This paper reviews some of the important issues in each of these sampling dimensions and gives some recommendations for how to use the monitor effectively to present the stimulus. In general, the position is taken that to understand what the stimulus actually is requires a clear specification of the physical properties of the stimulus, since the actual experience of the stimulus is determined both by the physical variables and by the psychophysical variables of how the stimulus is handled by our sensory systems.
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27
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Agostini T, Galmonte A. Spatial articulation affects lightness. PERCEPTION & PSYCHOPHYSICS 1999; 61:1345-55. [PMID: 10572463 DOI: 10.3758/bf03206185] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In a recent paper, Agostini and Bruno (1996) showed that the size of simultaneous lightness contrast increases under Gelb lighting. To extend Agostini and Bruno's work, we applied their methodology to a set of more spatially articulated displays. In four experiments, we investigated the role of spatial articulation on the size of the simultaneous lightness contrast effect. In the first experiment, we found a decrease of the simultaneous lightness contrast effect as the spatial articulation increased. In the second experiment (the control experiment), performed under homogeneous illumination, we found that the effect of spatial articulation is not detectable, even though the data seem to show the same trend as that in the previous experiment. In the third experiment, we found that spatial articulation affects not only the middle reflectance region, but also the lowest one. As the spatial articulation increases, the effect on the lightnesses of both regions decreases. In the last experiment, performed with a reduced range of reflectances, we found a lightening effect for all the reflectances and, again, an effect of spatial articulation. The results of these experiments are interpreted according to the model proposed by Gilchrist et al. (in press).
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Affiliation(s)
- T Agostini
- Dipartimento di Psicologia, University of Trieste, Italy.
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28
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Brainard DH. Color constancy in the nearly natural image. 2. Achromatic loci. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 1998; 15:307-325. [PMID: 9457790 DOI: 10.1364/josaa.15.000307] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Most empirical work on color constancy is based on simple laboratory models of natural viewing conditions. These typically consist of spots seen against uniform backgrounds or computer simulations of flat surfaces seen under spatially uniform illumination. In this study measurements were made under more natural viewing conditions. Observers used a projection colorimeter to adjust the appearance of a test patch until it appeared achromatic. Observers made such achromatic settings under a variety of illuminants and when the test surface was viewed against a number of different backgrounds. An analysis of the achromatic settings reveals that observers show good color constancy when the illumination is varied. Changing the background surface against which the test patch is seen, on the other hand, has a relatively small effect on the achromatic loci. The results thus indicate that constancy is not achieved by a simple comparison between the test surface and its local surround.
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Affiliation(s)
- D H Brainard
- Department of Psychology, University of California, Santa Barbara 93106, USA
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29
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Bruno N, Bernardis P, Schirillo J. Lightness, equivalent backgrounds, and anchoring. PERCEPTION & PSYCHOPHYSICS 1997; 59:643-54. [PMID: 9259633 DOI: 10.3758/bf03206012] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Observers compared two center/surround configurations haploscopically. One configuration consisted of a standard surface surrounded by two, three, or four surfaces, each with a different luminance. The other configuration consisted of a comparison surface surrounded by a single annulus that varied in luminance. Center surfaces always had the same luminance but only appeared to have the same lightness with certain annuli (equivalent backgrounds). For most displays, the luminance needed to obtain an equivalent background was close to the highest luminance in the standards surround configuration. Models based on the space-average luminance or the space-average contrast of the standard surround configuration yielded poorer fits. Implications for computational models of lightness and for candidate solutions to the anchoring problem are discussed.
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Affiliation(s)
- N Bruno
- Dipartimento di Psicologia, Università di Trieste, Italy.
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