Journal articles: 'Object constancy'

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Kenyon, Robert V., Daniel Sandin, Randall C. Smith, Richard Pawlicki, and Thomas Defanti. "Size-Constancy in the CAVE." Presence: Teleoperators and Virtual Environments 16, no. 2 (April 1, 2007): 172–87. http://dx.doi.org/10.1162/pres.16.2.172.

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The use of virtual environments (VE) for many research and commercial purposes relies on its ability to generate environments that faithfully reproduce the physical world. However, due to its limitations the VE can have a number of flaws that adversely affect its use and believability. One of the more important aspects of this problem is whether the size of an object in the VE is perceived as it would be in the physical world. One of the fundamental phenomena for correct size is size-constancy, that is, an object is perceived to be the same size regardless of its distance from the observer. This is in spite of the fact that the retinal size of the object shrinks with increasing distance from the observer. We examined size-constancy in the CAVE and found that size-constancy is a strong and dominant perception in our subject population when the test object is accompanied by surrounding environmental objects. Furthermore, size-constancy changes to a visual angle performance (i.e., object size changed with distance from the subject) when these surrounding objects are removed from the scene. As previously described for the physical world, our results suggest that it is necessary to provide surrounding objects to aid in the determination of an object's depth and to elicit size-constancy in VE. These results are discussed regarding their implications for viewing objects in projection-based VE and the environments that play a role in the perception of object size in the CAVE.

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Ellis, R., D. A. Allport, G. W. Humphreys, and J. Collis. "Varieties of Object Constancy." Quarterly Journal of Experimental Psychology Section A 41, no. 4 (November 1989): 775–96. http://dx.doi.org/10.1080/14640748908402393.

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Three experiments are described in which two pictures of isolated man-made objects were presented in succession. The subjects’ task was to decide, as rapidly as possible, whether the two pictured objects had the same name. With a stimulus-onset asynchrony (SOA) of above 200 msec two types of facilitation were observed: (1) the response latency was reduced if the pictures showed the same object, even though seen from different viewpoints (object benefit); (2) decision time was reduced further if the pictures showed the same object from the same angle of view (viewpoint benefit). These facilitation effects were not affected by projecting the pictures to different retinal locations. Significant benefits of both types were also obtained when the projected images differed in size. However, in these circumstances there was a small but significant performance decrement in matching two similar views of a single object, but not if the views were different. Conversely, the object benefit, but not the viewpoint benefit, was reduced when the SOA was only 100 msec. The data suggest the existence of (at least) two different visual codes, one non-retinotopic but viewer-centred, the other object-centred.

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Wong, J. H., A. P. Hillstrom, and Y. C. Chai. "What changes to objects disrupt object constancy?" Journal of Vision 5, no. 8 (September 1, 2005): 1042. http://dx.doi.org/10.1167/5.8.1042.

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FRAYN, DOUGLAS H. "Grief and Object Constancy." American Journal of Psychiatry 153, no. 2 (February 1996): 297—a—297. http://dx.doi.org/10.1176/ajp.153.2.297-a.

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Jaekl, Philip, and Laurence Harris. "Space Constancy vs Shape Constancy." Seeing and Perceiving 23, no. 5 (2010): 385–99. http://dx.doi.org/10.1163/187847510x541153.

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AbstractThe perceived distance between objects has been found to decrease over time in memory, demonstrating a partial failure of space constancy. Such mislocalization has been attributed to a generalized compression effect in memory. We confirmed this drift with a pair of remembered dot positions but did not find a compression of perceived distance when the space between the dots was filled with a connecting line. When the dot pairs were viewed eccentrically the compression in memory was substantially less. These results are in line with a combination of factors previously demonstrated to cause distortion in spatial memory — foveal bias and memory averaging — rather than a general compression of remembered visual space. Our findings indicate that object shape does not appear to be vulnerable to failures of space constancy observed with remembered positions.

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FINLAYSON, GRAHAM D., and GUI YUN TIAN. "COLOR NORMALIZATION FOR COLOR OBJECT RECOGNITION." International Journal of Pattern Recognition and Artificial Intelligence 13, no. 08 (December 1999): 1271–85. http://dx.doi.org/10.1142/s0218001499000720.

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Color images depend on the color of the capture illuminant and object reflectance. As such image colors are not stable features for object recognition, however stability is necessary since perceived colors (the colors we see) are illuminant independent and do correlate with object identity. Before the colors in images can be compared, they must first be preprocessed to remove the effect of illumination. Two types of preprocessing have been proposed: first, run a color constancy algorithm or second apply an invariant normalization. In color constancy preprocessing the illuminant color is estimated and then, at a second stage, the image colors are corrected to remove color bias due to illumination. In color invariant normalization image RGBs are redescribed, in an illuminant independent way, relative to the context in which they are seen (e.g. RGBs might be divided by a local RGB average). In theory the color constancy approach is superior since it works in a scene independently: color invariant normalization can be calculated post-color constancy but the converse is not true. However, in practice color invariant normalization usually supports better indexing. In this paper we ask whether color constancy algorithms will ever deliver better indexing than color normalization. The main result of this paper is to demonstrate equivalence between color constancy and color invariant computation. The equivalence is empirically derived based on color object recognition experiments. colorful objects are imaged under several different colors of light. To remove dependency due to illumination these images are preprocessed using either a perfect color constancy algorithm or the comprehensive color image normalization. In the perfect color constancy algorithm the illuminant is measured rather than estimated. The import of this is that the perfect color constancy algorithm can determine the actual illuminant without error and so bounds the performance of all existing and future algorithms. Post-color constancy or color normalization processing, the color content is used as cue for object recognition. Counter-intuitively perfect color constancy does not support perfect recognition. In comparison the color invariant normalization does deliver near-perfect recognition. That the color constancy approach fails implies that the scene effective illuminant is different from the measured illuminant. This explanation has merit since it is well known that color constancy is more difficult in the presence of physical processes such as fluorescence and mutual illumination. Thus, in a second experiment, image colors are corrected based on a scene dependent "effective illuminant". Here, color constancy preprocessing facilitates near-perfect recognition. Of course, if the effective light is scene dependent then optimal color constancy processing is also scene dependent and so, is equally a color invariant normalization.

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TURNBULL, OLIVER H., DAVID P. CAREY, and ROSALEEN A. McCARTHY. "The neuropsychology of object constancy." Journal of the International Neuropsychological Society 3, no. 3 (May 1997): 288–98. http://dx.doi.org/10.1017/s1355617797002889.

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There have been several proposals for the mechanism by which we are able to recognize an object across a number of viewpoints. Viewpoint-dependent accounts suggest that recognition may be based on an incremental transformation (e.g., mental rotation) strategy, while a variety of viewpoint-independent mechanisms for object recognition have also been proposed. Recent research in neurobiology, based on the two cortical visual systems account, suggest that the processes of viewpoint-dependent and viewpoint-independent object recognition may rely on separate anatomical regions, and that brain lesions may leave patients with selective access to particular types of representation. Evidence from a variety of neuropsychological disorders are reviewed to support the position that viewpoint-independent object recognition depends upon the integrity of occipitotemporal structures. In addition, it is suggested that viewpoint-dependent processes (perhaps depending on occipitoparietal structures) may supplement this primary system under nonoptimal circumstances. (JINS, 1997, 3, 288–298.)

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Turner, Jessica, and Myron L. Braunstein. "Size Constancy in Structure from Motion." Perception 24, no. 10 (October 1995): 1155–64. http://dx.doi.org/10.1068/p241155.

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The relative motions of points in a structure-from-motion display involving parallel projection provide depth information in an object-centered framework: differences in velocity do not reflect differences in distance from an eyepoint. In contrast, size constancy is generally regarded to be a perspective effect, based on the relationship between projected size and distance from an eyepoint. Five subjects judged the relative sizes of objects in structure-from-motion scenes. Although the scenes were displayed without perspective, judged size was related to the simulated separation in depth of the objects. These results suggest that relative depths recovered from object-centered information are incorporated into a viewer-centered framework.

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Ripamonti, C., M. Bloj, R. E. Hauck, K. Mitha, and D. H. Brainard. "Object lightness constancy: effects of object pose and shape." Journal of Vision 3, no. 9 (March 16, 2010): 295. http://dx.doi.org/10.1167/3.9.295.

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Zdravkovic, Suncica. "Lightness constancy: Object identity and temporal integration." Psihologija 41, no. 1 (2008): 5–20. http://dx.doi.org/10.2298/psi0801005z.

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Studies of lightness constancy typically involve the comparison of two objects of the same shade that have been placed under different illuminations. In this study, we introduce factors such as object identity and immediate prior experience to measure the effect of these manipulations on constancy. In the first experiment, conditions sufficient to reproduce classical constancy failure (illumination difference, target values, articulation level) were determined. In the second experiment a lightness judgment was made for a gray target that was then seen to move into another illumination level for the second match. Motion was used in an attempt to stress the target?s identity. The shade was still judged significantly lighter when placed under the higher than under the lower illumination. Failure of constancy thus occurred even when object identity was not in question. In the third experiment a priming paradigm was used, to assess the strength of constancy: one shade would appear in one illumination level and another shade in the other illumination level. Motion was used to trick observers into thinking that only a single object was presented. The estimated shade varied as a function of the shade of the prime. In the last experiment, observers were asked to make another match when the object was removed from view: the match of its true color independent of illumination. The value of this match-from-memory was based on the value obtained in the higher illumination level. Taken together, the experiments show that through object identity, immediate prior experience can influence lightness in systematic fashion.

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Hahn, William K. "Developing Object Constancy in Group Psychotherapy." International Journal of Group Psychotherapy 43, no. 2 (April 1993): 223–35. http://dx.doi.org/10.1080/00207284.1994.11491218.

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Qian, J., and Y. Petrov. "StarTrek Illusion--General object constancy phenomenon?" Journal of Vision 12, no. 2 (February 16, 2012): 15. http://dx.doi.org/10.1167/12.2.15.

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SOLNIT, ALBERT J., and PETER B. NEUBAUER. "Object Constancy and Early Triadic Relationships." Journal of the American Academy of Child Psychiatry 25, no. 1 (January 1986): 23–29. http://dx.doi.org/10.1016/s0002-7138(09)60595-1.

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Thornton, William A. "Improving color constancy of object colors." Color Research & Application 11, no. 4 (1986): 278–86. http://dx.doi.org/10.1002/col.5080110409.

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Luo, Xun, Robert V. Kenyon, Derek G. Kamper, Daniel J/ Sandin, and Thomas A. DeFanti. "On the Determinants of Size-Constancy in a Virtual Environment." International Journal of Virtual Reality 8, no. 1 (January 1, 2009): 43–51. http://dx.doi.org/10.20870/ijvr.2009.8.1.2712.

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An important aspect of a subject�s perception of virtual objects in a virtual environment is whether the size of the object is perceived as it would be in the physical world, which is named size-constancy. The ability of subjects to appreciate size-constancy in an immersive virtual environment was studied while scene complexity, stereovision and motion parallax visual factors were manipulated resulting in twelve different viewing conditions. Under each visual condition, 18 subjects made size judgments of a virtual object displayed at five different distances from them. Responses from the majority of our population demonstrated that scene complexity and stereovision have a significant impact on subjects' ability to appreciate size-constancy. In contrast, motion parallax produced by moving the virtual environment or by the movements of the observer alone proved not to be a significant factor in determining size-constancy performance. Consequently, size-constancy is best obtained when scene complexity and stereovision are components of the viewing conditions.

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Hu, De Kun, Li Zhang, Wei Dong Zhao, and Tao Yan. "Object Classification via PCANet and Color Constancy Model." Applied Mechanics and Materials 635-637 (September 2014): 997–1000. http://dx.doi.org/10.4028/www.scientific.net/amm.635-637.997.

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In order to classify the objects in nature images, a model with color constancy and principle component analysis network (PCANet) is proposed. The new color constancy model imitates the functional properties of the HVS from the retina to the double-opponent cells in V1. PCANet can be designed and learned extremely, which comprises only the very basic data processing components: cascaded principal component analysis (PCA), binary hashing, and block-wise histograms. At last, a SVM is trained to classify the object in the image. The results of experiments demonstrate the potential of the model for object classification in wild color images.

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Johnston, Alan. "Object Constancy in Face Processing: Intermediate Representations and Object Forms." Irish Journal of Psychology 13, no. 4 (January 1992): 426–39. http://dx.doi.org/10.1080/03033910.1992.10557903.

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Tamè, Luigi, Suzuki Limbu, Rebecca Harlow, Mita Parikh, and Matthew R. Longo. "Size Constancy Mechanisms: Empirical Evidence from Touch." Vision 6, no. 3 (July 1, 2022): 40. http://dx.doi.org/10.3390/vision6030040.

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Several studies have shown the presence of large anisotropies for tactile distance perception across several parts of the body. The tactile distance between two touches on the dorsum of the hand is perceived as larger when they are oriented mediolaterally (across the hand) than proximodistally (along the hand). This effect can be partially explained by the characteristics of primary somatosensory cortex representations. However, this phenomenon is significantly attenuated relative to differences in acuity and cortical magnification, suggesting a process of tactile size constancy. It is unknown whether the same kind of compensation also takes place when estimating the size of a continuous object. Here, we investigate whether the tactile anisotropy that typically emerges when participants have to estimate the distance between two touches is also present when a continuous object touches the skin and participants have to estimate its size. In separate blocks, participants judged which of two tactile distances or objects on the dorsum of their hand felt larger. One stimulation (first or second) was aligned with the proximodistal axis (along the hand) and the other with the mediolateral axis (across the hand). Results showed a clear anisotropy for distances between two distinct points, with across distances consistently perceived as larger than along distances, as in previous studies. Critically, however, this bias was significantly reduced or absent for judgments of the length of continuous objects. These results suggest that a tactile size constancy process is more effective when the tactile size of an object has to be approximated compared to when the distance between two touches has to be determined. The possible mechanism subserving these results is described and discussed. We suggest that a lateral inhibition mechanism, when an object touches the skin, provides information through the distribution of the inhibitory subfields of the RF about the shape of the tactile RF itself. Such a process allows an effective tactile size compensatory mechanism where a good match between the physical and perceptual dimensions of the object is achieved.

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Sherwood, Vance R. "Object constancy: The illusion of being seen." Psychoanalytic Psychology 6, no. 1 (1989): 15–30. http://dx.doi.org/10.1037/0736-9735.6.1.15.

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Humphreys, Glyn W., and M. Jane Riddoch. "Authors’ Correction to “Routes to Object Constancy”." Quarterly Journal of Experimental Psychology Section A 37, no. 3 (August 1985): 493–95. http://dx.doi.org/10.1080/14640748508400946.

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Brill, Michael H. "Color constancy: A case for multiple levels and paradigms." Behavioral and Brain Sciences 24, no. 4 (August 2001): 658. http://dx.doi.org/10.1017/s0140525x01250080.

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Shepard claims that color constancy needs linear basis-function spectra, and infers the illuminant before removing its dependency. However, of the models of color constancy that have exact (and reasonable) spectral regimes, some do not need linear basis-function expansions of reflectance and illuminant spectra, some do not solve for the illuminant, and some estimate only partial object-reflectance information for single or multiple objects. [Shepard]

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Abrams, Alicia B., James M. Hillis, and David H. Brainard. "The Relation Between Color Discrimination and Color Constancy: When Is Optimal Adaptation Task Dependent?" Neural Computation 19, no. 10 (October 2007): 2610–37. http://dx.doi.org/10.1162/neco.2007.19.10.2610.

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Color vision supports two distinct visual functions: discrimination and constancy. Discrimination requires that the visual response to distinct objects within a scene be different. Constancy requires that the visual response to any object be the same across scenes. Across changes in scene, adaptation can improve discrimination by optimizing the use of the available response range. Similarly, adaptation can improve constancy by stabilizing the visual response to any fixed object across changes in illumination. Can common mechanisms of adaptation achieve these two goals simultaneously? We develop a theoretical framework for answering this question and present several example calculations. In the examples studied, the answer is largely yes when the change of scene consists of a change in illumination and considerably less so when the change of scene consists of a change in the statistical ensemble of surface reflectances in the environment.

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Wiebelt, Alexandra. "Do symmetrical letter pairs affect readability?" Written Language and Literacy 7, no. 2 (March 22, 2005): 275–303. http://dx.doi.org/10.1075/wll.7.2.07wie.

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Our everyday experience shows that we have problems in recognizing objects which only differ in their symmetry properties (street signs with two arrows in different directions or mathematical signs such as 〈 and 〉). Perception is closely correlated with an inner comparison: the perceived object with its surrounding, the perceived object with former experience and so on. The brain has evolved different constancy abilities (e.g. colour constancy) and one of them is object constancy. This object constancy makes it possible to perceive an object regardless of its orientation in space. Symmetric letter pairs with different sound representations (such as 〈b〉 and 〈d〉) are, due to object constancy, typically identified as one object. This deficiency of distinctiveness should affect their readability. The above hypothesis was examined in many scripts. The result was that mature scripts (which usually developed for a long time) avoid these symmetric letter pairs (called extrinsic symmetry) by adding distinctive features such as serifs or different stroke thickness. On the other hand, if a writer is allowed to invent letter shapes freely, he makes use of extrinsic symmetrical letter pairs. This is supposed to have aesthetic reasons — letters are often perceived as a standing object or even as a “body” on a plane. It is therefore possible to statistically separate mature scripts which show up no extrinsic symmetry from invented scripts full of extrinsic symmetry. The runes are a writing system which does not quite fit in this widely proved distinction. They have developed from the Latin writing system (or a close relative of it) and have therefore inherited the avoidance of extrinsic symmetry. The reduction of the character set from 24 signs in the Old Futhark to 16 characters in the Younger Futhark is accompanied by a simplification of runic signs. During this period the runes develop a high degree of extrinsic symmetry. Moreover, the letter shapes are often related to different sound representations. These irregularities in usage may be caused by interference from the Latin writing system. The resulting lesser readability could have been one reason for the decline of the runes. This paper shows in many figures and graphs how symmetry emerges and under what circumstances it is used to create new letter shapes.

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Witzel, Christoph, and Karl R. Gegenfurtner. "Color Perception: Objects, Constancy, and Categories." Annual Review of Vision Science 4, no. 1 (September 15, 2018): 475–99. http://dx.doi.org/10.1146/annurev-vision-091517-034231.

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Color has been scientifically investigated by linking color appearance to colorimetric measurements of the light that enters the eye. However, the main purpose of color perception is not to determine the properties of incident light, but to aid the visual perception of objects and materials in our environment. We review the state of the art on object colors, color constancy, and color categories to gain insight into the functional aspects of color perception. The common ground between these areas of research is that color appearance is tightly linked to the identification of objects and materials and the communication across observers. In conclusion, we argue that research should focus on how color processing is adapted to the surface properties of objects in the natural environment in order to bridge the gap between the known early stages of color perception and the subjective appearance of color.

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de ALMEIDA, VASCO M. N., PAULO T. FIADEIRO, and SÉRGIO M. C. NASCIMENTO. "Color constancy by asymmetric color matching with real objects in three-dimensional scenes." Visual Neuroscience 21, no. 3 (May 2004): 341–45. http://dx.doi.org/10.1017/s0952523804213074.

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Color matching experiments use, in general, stimuli that are poor representations of the natural world. The aim of this work was to compare the degree of color constancy for a range of illuminant pairs using a new matching technique that uses both real objects and three-dimensional (3-D) real scenes. In the experiment, observers viewed a 3-D real scene through a large beamsplitter that projects on the right-hand side of the scene (match scene), the virtual image of a 3-D object (match object) such it appeared part of the scene. On the left-hand side of the scene (test scene), observers viewed a symmetrical scene containing a test object identical to the match object. Test and match objects were both surrounded by the same reflectances with identical spatial arrangement. The illuminant on the test scene had always a correlated color temperature of 25,000 K. The illuminant on the match scene could be any of seven different illuminants with correlated color temperatures in the range 25,000 K–4000 K. In each trial, the observers, who were instructed to perform surface color matches, adjusted the illuminant on the match object. Constancy indices were very high (0.81–0.93), varied with the color of the match object, and increased with the extent of the illuminant change. Observer's mismatches, however, were independent of the extent of the illuminant change.

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Sebastian, Linda. "Promoting Object Constancy: Writing as a Nursing Intervention." Journal of Psychosocial Nursing and Mental Health Services 29, no. 1 (January 1991): 21–23. http://dx.doi.org/10.3928/0279-3695-19910101-09.

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Zdravkovic, S. "The influence of object identity on lightness constancy." Journal of Vision 8, no. 6 (March 27, 2010): 566. http://dx.doi.org/10.1167/8.6.566.

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Wells, Marolyn, and Cheryl Glickauf-Hughes. "Techniques to develop object constancy with borderline clients." Psychotherapy: Theory, Research, Practice, Training 23, no. 3 (1986): 460–68. http://dx.doi.org/10.1037/h0085639.

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Sperandio, Irene, Irene Sperandio, and Philippe A. Chouinard. "The Mechanisms of Size Constancy." Multisensory Research 28, no. 3-4 (2015): 253–83. http://dx.doi.org/10.1163/22134808-00002483.

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Size constancy is the result of cognitive scaling operations that enable us to perceive an object as having the same size when presented at different viewing distances. In this article, we review the literature on size and distance perception to form an overarching synthesis of how the brain might combine retinal images and distance cues of retinal and extra-retinal origin to produce a perceptual visual experience of a world where objects have a constant size. A convergence of evidence from visual psychophysics, neurophysiology, neuropsychology, electrophysiology and neuroimaging highlight the primary visual cortex (V1) as an important node in mediating size–distance scaling. It is now evident that this brain area is involved in the integration of multiple signals for the purposes of size perception and does much more than fulfil the role of an entry position in a series of hierarchical cortical events. We also discuss how information from other sensory modalities can also contribute to size–distance scaling and shape our perceptual visual experience.

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Lee, Robert J., and Hannah E. Smithson. "Motion of glossy objects does not promote separation of lighting and surface colour." Royal Society Open Science 4, no. 11 (November 2017): 171290. http://dx.doi.org/10.1098/rsos.171290.

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The surface properties of an object, such as texture, glossiness or colour, provide important cues to its identity. However, the actual visual stimulus received by the eye is determined by both the properties of the object and the illumination. We tested whether operational colour constancy for glossy objects (the ability to distinguish changes in spectral reflectance of the object, from changes in the spectrum of the illumination) was affected by rotational motion of either the object or the light source. The different chromatic and geometric properties of the specular and diffuse reflections provide the basis for this discrimination, and we systematically varied specularity to control the available information. Observers viewed animations of isolated objects undergoing either lighting or surface-based spectral transformations accompanied by motion. By varying the axis of rotation, and surface patterning or geometry, we manipulated: (i) motion-related information about the scene, (ii) relative motion between the surface patterning and the specular reflection of the lighting, and (iii) image disruption caused by this motion. Despite large individual differences in performance with static stimuli, motion manipulations neither improved nor degraded performance. As motion significantly disrupts frame-by-frame low-level image statistics, we infer that operational constancy depends on a high-level scene interpretation, which is maintained in all conditions.

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Gillan, Douglas J. "Constancy of Height and Speed in Three-Dimensional Information Displays." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 61, no. 1 (September 2017): 1562–66. http://dx.doi.org/10.1177/1541931213601754.

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Pictorial cues to depth create a three-dimensional appearance in two-dimensional displays. With sufficient pictorial depth cues, a given physical size appears to be larger at a greater perceived distance (or the perceived size is constant at different perceived depths, despite changes in the retinal image – size constancy). Two experiments investigated the effects of perceived depth on the relation between the actual height of an object and the perceived height (Experiment 1) and the relation between the actual speed of the object the perceived speed (Experiment 2). Consistent with Emmert’s Law (Perceived Size = Retinal Image Size x Perceived Depth), perceived depth influenced both perceived height and perceived speed. These findings suggest that displays that use pictorial cues to depth could easily result in misperception of the height or speed of objects in the display.

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Perdreau, Florian, James R. H. Cooke, Mathieu Koppen, and W. Pieter Medendorp. "Causal inference for spatial constancy across whole body motion." Journal of Neurophysiology 121, no. 1 (January 1, 2019): 269–84. http://dx.doi.org/10.1152/jn.00473.2018.

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The brain uses self-motion information to internally update egocentric representations of locations of remembered world-fixed visual objects. If a discrepancy is observed between this internal update and reafferent visual feedback, this could be either due to an inaccurate update or because the object has moved during the motion. To optimally infer the object’s location it is therefore critical for the brain to estimate the probabilities of these two causal structures and accordingly integrate and/or segregate the internal and sensory estimates. To test this hypothesis, we designed a spatial updating task involving passive whole body translation. Participants, seated on a vestibular sled, had to remember the world-fixed position of a visual target. Immediately after the translation, the reafferent visual feedback was provided by flashing a second target around the estimated “updated” target location, and participants had to report the initial target location. We found that the participants’ responses were systematically biased toward the position of the second target position for relatively small but not for large differences between the “updated” and the second target location. This pattern was better captured by a Bayesian causal inference model than by alternative models that would always either integrate or segregate the internally updated target location and the visual feedback. Our results suggest that the brain implicitly represents the posterior probability that the internally updated estimate and the visual feedback come from a common cause and uses this probability to weigh the two sources of information in mediating spatial constancy across whole body motion. NEW & NOTEWORTHY When we move, egocentric representations of object locations require internal updating to keep them in register with their true world-fixed locations. How does this mechanism interact with reafferent visual input, given that objects typically do not disappear from view? Here we show that the brain implicitly represents the probability that both types of information derive from the same object and uses this probability to weigh their contribution for achieving spatial constancy across whole body motion.

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Nascimento, Sérgio M. C., Vasco M. N. de Almeida, Paulo T. Fiadeiro, and David H. Foster. "Effect of Scene Complexity on Colour Constancy with Real Three-Dimensional Scenes and Objects." Perception 34, no. 8 (August 2005): 947–50. http://dx.doi.org/10.1068/p5182.

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The effect of scene complexity on colour constancy was tested with a novel technique in which a virtual image of a real 3-D test object was projected into a real 3-D scene. Observers made discriminations between illuminant and material changes in simple and complex scenes. The extent of colour constancy achieved varied little with either scene structure or test-object colour, suggesting a dominant role of local cues in determining surface-colour judgments.

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Leek, E. C., and S. J. Johnston. "The role of polar features in visual object constancy." Journal of Vision 5, no. 8 (September 1, 2005): 745. http://dx.doi.org/10.1167/5.8.745.

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Beridze, Jevgenija, Shin'ya Nishida, and Alan Johnston. "Object constancy from view-based models of the face." Journal of Vision 15, no. 12 (September 1, 2015): 418. http://dx.doi.org/10.1167/15.12.418.

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Qian, J., and Y. Petrov. "Depth perception in the framework of General Object Constancy." Journal of Vision 13, no. 11 (September 10, 2013): 7. http://dx.doi.org/10.1167/13.11.7.

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Auchincloss, Elizabeth L., and Richard W. Weiss. "Paranoid Character and the Intolerance of Indifference." Journal of the American Psychoanalytic Association 40, no. 4 (December 1992): 1013–37. http://dx.doi.org/10.1177/000306519204000403.

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This paper suggests that aspects of paranoid character are structured around fantasies of magical and concrete connectedness to objects; these fantasies serve to avoid the terrors of object inconstancy. The authors describe how these fantasies are expressed in the psychoanalytic situation and explore their relation to common paranoid phenomena. The paranoid person must maintain these fantasies of connectedness at all cost or risk experiencing unbearable indifference between self and object. Paradoxically, the sacrifice of self and object boundaries inherent in these fantasies makes object constancy even more difficult to achieve because of the secondary defensive use of anger mobilized to protect the boundaries of the self.

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Reyes, Napoleon H., and Elmer P. Dadios. "Dynamic Color Object Recognition Using Fuzzy Logic." Journal of Advanced Computational Intelligence and Intelligent Informatics 8, no. 1 (January 20, 2004): 29–38. http://dx.doi.org/10.20965/jaciii.2004.p0029.

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This paper presents a novel Logit-Logistic Fuzzy Color Constancy (LLFCC) algorithm and its variants for dynamic color object recognition. Contrary to existing color constancy algorithms, the proposed scheme focuses on manipulating a color locus depicting the colors of an object, and not stabilizing the whole image appearance per se. In this paper, a new set of adaptive contrast manipulation operators is introduced and utilized in conjunction with a fuzzy inference system. Moreover, a new perspective in extracting color descriptors of an object from the rg-chromaticity space is presented. Such color descriptors allow for the reduction of the effects of brightness/darkness and at the same time adhere to human perception of colors. The proposed scheme tremendously cuts processing time by simultaneously compensating for the effects of a multitude of factors that plague the scene of traversal, eliminating the need for image pre-processing steps. Experiment results attest to its robustness in scenes with multiple white light sources, spatially varying illumination intensities, varying object position, and presence of highlights.

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Koenderink, Jan J., Andrea J. van Doorn, Chris Christou, and Joseph S. Lappin. "Shape Constancy in Pictorial Relief." Perception 25, no. 2 (February 1996): 155–64. http://dx.doi.org/10.1068/p250155.

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Pictorial relief was measured for a series of pictures of a smooth solid object. The scene was geometrically identical (ie the perspective of the three-dimensional scene remained the same) for all pictures, the rendering different. Some of the pictures were monochrome full-scale photographs taken under different illumination of the scene. Also included were a silhouette (uniform black on uniform white) and a ‘cartoon’-style rendering (visual contour and key linear features rendered in thin black line on a uniform white ground). Two subjects were naive and started with the silhouette, saw the cartoon next, and finally the full-scale photographs. Another subject had seen the object and did the experiment in the opposite sequence. The silhouette rendering is impoverished, but has considerable relief with much of the basic shape. The cartoon rendering yields well-developed pictorial relief, even for the naive subjects. Shading adds only small local details, but different illumination produces significant alterations of relief. It is concluded that shape constancy under changes in illumination is dominant throughout, but that the (small) deviations from true constancy reveal the effect of cues such as shading in a natural setting. Such a ‘perturbation analysis’ appears more promising than either stimulus-reduction or cue-conflict paradigms.

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Craddock, Matt, and Rebecca Lawson. "Do Left and Right Matter for Haptic Recognition of Familiar Objects?" Perception 38, no. 9 (January 1, 2009): 1355–76. http://dx.doi.org/10.1068/p6312.

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Two experiments were carried out to examine the effects of dominant right versus non-dominant left exploration hand and left versus right object orientation on haptic recognition of familiar objects. In experiment 1, participants named 48 familiar objects in two blocks. There was no dominant-hand advantage to naming objects haptically and there was no interaction between exploration hand and object orientation. Furthermore, priming of naming was not reduced by changes of either object orientation or exploration hand. To test whether these results were attributable to a failure to encode object orientation and exploration hand, experiment 2 replicated experiment 1 except that the unexpected task in the second block was to decide whether either exploration hand or object orientation had changed relative to the initial naming block. Performance on both tasks was above chance, demonstrating that this information had been encoded into long-term haptic representations following the initial block of naming. Thus when identifying familiar objects, the haptic processing system can achieve object constancy efficiently across hand changes and object-orientation changes, although this information is often stored even when it is task-irrelevant.

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Rinner, Oliver, and Karl R. Gegenfurtner. "Cone Contributions to Colour Constancy." Perception 31, no. 6 (June 2002): 733–46. http://dx.doi.org/10.1068/p3352.

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Colour constancy refers to the stable perception of object colour under changing illumination conditions. This problem has been reformulated as relational colour constancy, or the ability of the observer to discriminate between material changes and changes in illumination. It has been suggested that local cone excitation ratios play a prominent role in achieving such constancy. Here we show that perceptual colour constancy measured by achromatic adjustments is to a large part complete after 25 ms. This speaks against a prominent role for receptor adaptation, which takes significantly longer. We also found no difference in colour constancy between colour changes that were compatible with a change of illuminant, and between colour changes where local cone ratios were uncorrelated between the two illuminants. Our results show that constant cone ratios are not necessary for colour constancy.

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Nityananda, Vivek, Geoffrey Bissianna, Ghaith Tarawneh, and Jenny Read. "Small or far away? Size and distance perception in the praying mantis." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1697 (June 19, 2016): 20150262. http://dx.doi.org/10.1098/rstb.2015.0262.

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Stereo or ‘3D’ vision is an important but costly process seen in several evolutionarily distinct lineages including primates, birds and insects. Many selective advantages could have led to the evolution of stereo vision, including range finding, camouflage breaking and estimation of object size. In this paper, we investigate the possibility that stereo vision enables praying mantises to estimate the size of prey by using a combination of disparity cues and angular size cues. We used a recently developed insect 3D cinema paradigm to present mantises with virtual prey having differing disparity and angular size cues. We predicted that if they were able to use these cues to gauge the absolute size of objects, we should see evidence for size constancy where they would strike preferentially at prey of a particular physical size, across a range of simulated distances. We found that mantises struck most often when disparity cues implied a prey distance of 2.5 cm; increasing the implied distance caused a significant reduction in the number of strikes. We, however, found no evidence for size constancy. There was a significant interaction effect of the simulated distance and angular size on the number of strikes made by the mantis but this was not in the direction predicted by size constancy. This indicates that mantises do not use their stereo vision to estimate object size. We conclude that other selective advantages, not size constancy, have driven the evolution of stereo vision in the praying mantis. This article is part of the themed issue ‘Vision in our three-dimensional world’.

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Niechwiej-Szwedo, Ewa, Michael Cao, and Michael Barnett-Cowan. "Binocular Viewing Facilitates Size Constancy for Grasping and Manual Estimation." Vision 6, no. 2 (April 20, 2022): 23. http://dx.doi.org/10.3390/vision6020023.

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A prerequisite for efficient prehension is the ability to estimate an object’s distance and size. While most studies demonstrate that binocular viewing is associated with a more efficient grasp programming and execution compared to monocular viewing, the factors contributing to this advantage are not fully understood. Here, we examined how binocular vision facilitates grasp scaling using two tasks: prehension and manual size estimation. Participants (n = 30) were asked to either reach and grasp an object or to provide an estimate of an object’s size using their thumb and index finger. The objects were cylinders with a diameter of 0.5, 1.0, or 1.5 cm placed at three distances along the midline (40, 42, or 44 cm). Results from a linear regression analysis relating grip aperture to object size revealed that grip scaling during monocular viewing was reduced similarly for both grasping and estimation tasks. Additional analysis revealed that participants adopted a larger safety margin for grasping during monocular compared to binocular viewing, suggesting that monocular depth cues do not provide sufficient information about an object’s properties, which consequently leads to a less efficient grasp execution.

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Kasaei, S. Hamidreza, Maryam Ghorbani, Jits Schilperoort, and Wessel van der Rest. "Investigating the importance of shape features, color constancy, color spaces, and similarity measures in open-ended 3D object recognition." Intelligent Service Robotics 14, no. 3 (February 12, 2021): 329–44. http://dx.doi.org/10.1007/s11370-021-00349-8.

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AbstractDespite the recent success of state-of-the-art 3D object recognition approaches, service robots still frequently fail to recognize many objects in real human-centric environments. For these robots, object recognition is a challenging task due to the high demand for accurate and real-time response under changing and unpredictable environmental conditions. Most of the recent approaches use either the shape information only and ignore the role of color information or vice versa. Furthermore, they mainly utilize the $$L_n$$ L n Minkowski family functions to measure the similarity of two object views, while there are various distance measures that are applicable to compare two object views. In this paper, we explore the importance of shape information, color constancy, color spaces, and various similarity measures in open-ended 3D object recognition. Toward this goal, we extensively evaluate the performance of object recognition approaches in three different configurations, including color-only, shape-only, and combinations of color and shape, in both offline and online settings. Experimental results concerning scalability, memory usage, and object recognition performance show that all of the combinations of color and shape yield significant improvements over the shape-only and color-only approaches. The underlying reason is that color information is an important feature to distinguish objects that have very similar geometric properties with different colors and vice versa. Moreover, by combining color and shape information, we demonstrate that the robot can learn new object categories from very few training examples in a real-world setting.

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Zaidi, Q., B. Spehar, and J. S. DeBonnet. "Adaptation to Variegated Scenes and Colour Constancy." Perception 25, no. 1_suppl (August 1996): 184. http://dx.doi.org/10.1068/v96l0613.

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For a visual system to possess colour constancy across varying illumination, chromatic signals from a scene must remain constant at some neural stage. We found that photoreceptor and opponent-colour signals from a large sample of natural and man-made objects under one kind of natural daylight were almost perfectly correlated with the signals from those objects under every other spectrally different phase of daylight. Therefore, in scenes consisting of many objects, the effect of illumination changes on specific colour mechanisms can be simulated by shifting all chromaticities by an additive or multiplicative constant along a theoretical axis. When the effect of the illuminant change was restricted to specific colour axes, thresholds for detecting a change in the perceived colours in a scene were significantly elevated in the presence of spatial variations along the same axis. Probe-flash threshold curves revealed that adaptation to variegated scenes is qualitatively different from independent adaptation to the constituents or to the space-average, but is similar to adaptation to prolonged temporal modulation (Shapiro and Zaidi, 1992 Vision Research32 2065 – 2076), which would be caused by small eye-movements across object boundaries. The data are consistent with a ‘response equalisation’ model, which modifies the response function of each mechanism to match the cumulative frequency distribution of its inputs (Zaidi and Shapiro, 1993 Biological Cybernetics69 415 – 428). In a variegated scene, correlations between spatially local chromatic signals across illuminants, and adaptation caused by eye movements across spatial variations, help the visual system to attenuate the perceptual effects due to changes in illumination.

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Colarusso, Calvin A. "The Development of time Sense: From Object Constancy to Adolescence." Journal of the American Psychoanalytic Association 35, no. 1 (February 1987): 119–44. http://dx.doi.org/10.1177/000306518703500106.

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Lawson, Rebecca. "Achieving visual object constancy across plane rotation and depth rotation." Acta Psychologica 102, no. 2-3 (September 1999): 221–45. http://dx.doi.org/10.1016/s0001-6918(98)00052-3.

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Lamotte, R. H., R. M. Friedman, C. Lu, P. S. Khalsa, and M. A. Srinivasan. "Raised Object on a Planar Surface Stroked Across the Fingerpad: Responses of Cutaneous Mechanoreceptors to Shape and Orientation." Journal of Neurophysiology 80, no. 5 (November 1, 1998): 2446–66. http://dx.doi.org/10.1152/jn.1998.80.5.2446.

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LaMotte, R. H., R. M. Friedman, C. Lu, P. S. Khalsa, and M. A. Srinivasan. Raised object on a planar surface stroked across the fingerpad: responses of cutaneous mechanoreceptors to shape and orientation. J. Neurophysiol. 80: 2446–2466, 1998. The representations of orientation and shape were studied in the responses of cutaneous mechanoreceptors to an isolated, raised object on a planar surface stroked across the fingerpad. The objects were the top portions of a sphere with a 5-mm radius, and two toroids each with a radius of 5 mm along one axis and differing radii of 1 or 3 mm along the orthogonal axis. The velocity and direction of stroking were fixed while the orientation of the object in the horizontal plane was varied. Each object was stroked along a series of laterally shifted, parallel, linear trajectories over the receptive fields of slowly adapting, type I (SA), and rapidly adapting, type I (RA) mechanoreceptive afferents innervating the fingerpad of the monkey. “Spatial event plots” (SEPs) of the occurrence of action potentials, as a function of the location of each object on the receptive field, were interpreted as the responses of a spatially distributed population of fibers. That portion of the plot evoked by the curved object (the SEPc) provided a representation of the shape and orientation of the two-dimensional outline of the object in the horizontal plane in contact with the skin. For both SAs and RAs, the major vector of the SEPc, obtained by a principal components analysis, was linearly related to the physical orientation of the major axis of each toroid. The spatial distribution of discharge rates [spatial rate surface profiles (SRSs), after plotting mean instantaneous frequency versus spatial locus within the SEPc] represented object shape in a third dimension, normal to the skin surface. The shape of the SA SRSs, well fitted by Gaussian equations, better represented object shape than that of the RA SRSs. A cross-sectional profile along the minor axis [spatial rate profile (SRP)] was approximately triangular for SAs. After normalization for differences in peak height, the falling slopes of the SA SRPs increased, and the base widths decreased with curvature of the object's minor axis. These curvature-related differences in slopes and widths were invariant with changes in object orientation. It is hypothesized that circularity in object shape is coded by the constancy of slopes of SA SRPs between peak and base and that the constancy of differences in the widths and falling slopes evoked by different raised objects encodes, respectively, the differences in their sizes and shapes regardless of differences in their orientation on the skin.

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Yu, Huanglin, Ke Chen, Kaiqi Wang, Yanlin Qian, Zhaoxiang Zhang, and Kui Jia. "Cascading Convolutional Color Constancy." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 07 (April 3, 2020): 12725–32. http://dx.doi.org/10.1609/aaai.v34i07.6966.

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Regressing the illumination of a scene from the representations of object appearances is popularly adopted in computational color constancy. However, it's still challenging due to intrinsic appearance and label ambiguities caused by unknown illuminants, diverse reflection properties of materials and extrinsic imaging factors (such as different camera sensors). In this paper, we introduce a novel algorithm – Cascading Convolutional Color Constancy (in short, C4) to improve robustness of regression learning and achieve stable generalization capability across datasets (different cameras and scenes) in a unique framework. The proposed C4 method ensembles a series of dependent illumination hypotheses from each cascade stage via introducing a weighted multiply-accumulate loss function, which can inherently capture different modes of illuminations and explicitly enforce coarse-to-fine network optimization. Experimental results on the public Color Checker and NUS 8-Camera benchmarks demonstrate superior performance of the proposed algorithm in comparison with the state-of-the-art methods, especially for more difficult scenes.

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Lee, Haemy, and Christian Wallraven. "Exploiting object constancy: effects of active exploration and shape morphing on similarity judgments of novel objects." Experimental Brain Research 225, no. 2 (December 24, 2012): 277–89. http://dx.doi.org/10.1007/s00221-012-3368-1.

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Journal articles on the topic 'Object constancy'

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