Size Constancy Research Articles

Preferência de percepção tonal em crianças com ou sem educação musical formal

Among the mental functions recruited by music, timbre processing is possibly one of the most interesting, as it exemplifies the perceptual constancy that allows recognition of regularities in the environment. The objective of the present work was to investigate the musical perception of children with formal music education and the prevalence of fundamental and spectral lis-teners based on the differential perception of complex tones. Thirty children between 10 and 15 years old participated, who responded to 48 pairs of tones, in which the second tone should be judged as ascending or descending. The participants' responses allowed the calculation of an index of pitch perception preference (Δp). The results show that the Control Group pre-sented Δp closer to zero than the Musicians Group, both with normal distribution. Therefore, musicians and nonmusicians have subtle differences in the perception of complex tones, with a preference for fundamental listeners among the musicians investigated.

Contribution of auditory distance cues to size constancy in perception and grasping when visual cues are compromised

Contribution of auditory distance cues to size constancy in perception and grasping when visual cues are compromised

Projections, Perceptual Constancy, and Geometry

The notions "retinal images" and "retinal projection" are ubiquitous in both the scientific and philosophical literature on perception. However, this article argues that they belong to the former and should be kept out of the latter. In the context of the empirical investigation of perception, projections play a crucial role, and help articulate pressing research problems. But, as part of the phenomenological and conceptual analysis of perception, projections give rise to untenable models and to avoidable conundrums, such as the much discussed issue of perceptual constancy. Why are projections and retinal images so prevalent in the philosophical literature? The author conjectures that the reason has to do with conceptual fallouts of the effort to give a geometric representation to changes of perspective, a mission more daunting than it initially appears to be, and one that leads to the problematic insertion of projections into phenomenology. He suggests that correcting this shows perceptual constancy to be a starting point rather than a challenge for phenomenology.

Time course of encoding and maintenance of stereoscopically induced size–distance scaling

ABSTRACT The mechanism of size constancy assures that an object is perceived to be constant in size despite that its retinal size varies with viewing distance. Conversely, an object can be perceived as illusorily larger if the perceived distance becomes greater, due to the size–distance scaling mechanism. The present study aimed at exploring how size–distance scaling is modulated by the encoding duration and how its memory is affected by the retention duration. In Experiment 1, we presented two stimuli simultaneously at two stereoscopic depth planes and manipulated the presentation duration, and found that the magnitude of the size scaling increased with presentation duration. In Experiment 2, we examined the maintenance of size–distance scaling when component stimulus was kept in working memory with variable delays. The results showed that the size scaling was reliably retrieved from working memory if there was no disparity manipulation on the to-be-memorized item, but it decreased with retention if a disparity was applied to the to-be-memorized item. The findings suggest that although the post-scaling size can be stored in working memory, the scaling mechanism may still be in effect when there were conflicts in the oculomotor cues and disparity cues that produces depth perception.

The combination of target motion and dynamic changes in context greatly enhance visual size illusions.

Perceived size is a function of viewing distance, retinal images size, and various contextual cues such as linear perspective and the size and location of neighboring objects. Recently, we demonstrated that illusion magnitudes of classic visual size illusions may be greatly enhanced or reduced by adding dynamic elements. Specifically, a dynamic version of the Ebbinghaus illusion (classically considered a “size contrast” illusion) led to a greatly enhanced illusory effect, whereas a dynamic version of the Corridor illusion (a “size constancy” illusion) led to a greatly diminished illusory effect. Although these differences may arise from the different processes underlying these illusions (size contrast vs. size constancy), the dynamic variants we tested in our previous work also differed in the nature of the dynamic elements; specifically, whereas the Dynamic Ebbinghaus included a moving target and inducers that changed size and position, the Dynamic Corridor only included a moving target on a static background. Here, we explore further dynamic versions of the Ebbinghaus illusion and the Corridor and Ponzo illusions by separately manipulating three types of dynamic elements: target motion, context translation, and dynamic changes in context. Across five experiments examining 21 dynamic illusory configurations, adding target motion or a dynamically changing context separately resulted in little-to-no illusory effect. In contrast, the combination of target motion and a dynamically changing context led to a robust size illusion, consistent with an interactive effect. However, illusory effects that exceeded the matched classic, static illusory configuration were only observed for the dynamic versions of the Ebbinghaus illusion and the Revealed Ponzo illusions, in which the contextual elements changed size. We conclude that the combination of target motion and a dynamically changing context are necessary to produce dynamic size illusions, but that enhancement above and beyond static illusions may be largely specific to size contrast effects. Our results have important implications for the integration of motion signals, a ubiquitous environmental stimulus, in the perception of object size.

Preferência de percepção tonal em crianças com ou sem educação musical formal

Among the mental functions recruited by music, timbre processing is possibly one of the most interesting, as it exemplifies the perceptual constancy that allows recognition of regularities in the environment. The objective of the present work was to investigate the musical perception of children with formal music education and the prevalence of fundamental and spectral lis-teners based on the differential perception of complex tones. Thirty children between 10 and 15 years old participated, who responded to 48 pairs of tones, in which the second tone should be judged as ascending or descending. The participants' responses allowed the calculation of an index of pitch perception preference (Δp). The results show that the Control Group pre-sented Δp closer to zero than the Musicians Group, both with normal distribution. Therefore, musicians and non-musicians have subtle differences in the perception of complex tones, with a preference for fundamental listeners among the musicians investigated.

The Effects of Adding Pictorial Depth Cues to the Poggendorff Illusion.

We tested if the misapplication of perceptual constancy mechanisms might explain the perceived misalignment of the oblique lines in the Poggendorff illusion. Specifically, whether these mechanisms might treat the rectangle in the middle portion of the Poggendorff stimulus as an occluder in front of one long line appearing on either side, causing an apparent decrease in the rectangle’s width and an apparent increase in the misalignment of the oblique lines. The study aimed to examine these possibilities by examining the effects of adding pictorial depth cues. In experiments 1 and 2, we presented a central rectangle composed of either large or small bricks to determine if this manipulation would change the perceived alignment of the oblique lines and the perceived width of the central rectangle, respectively. The experiments demonstrated no changes that would support a misapplication of perceptual constancy in driving the illusion, despite some evidence of perceptual size rescaling of the central rectangle. In experiment 3, we presented Poggendorff stimuli in front and at the back of a corridor background rich in texture and linear perspective depth cues to determine if adding these cues would affect the Poggendorff illusion. The central rectangle was physically large and small when presented in front and at the back of the corridor, respectively. The strength of the Poggendorff illusion varied as a function of the physical size of the central rectangle, and, contrary to our predictions, the addition of pictorial depth cues in both the central rectangle and the background decreased rather than increased the strength of the illusion. The implications of these results with regards to different theories are discussed. It could be the case that the illusion depends on both low-level and cognitive mechanisms and that deleterious effects occur on the former when the latter ascribes more certainty to the oblique lines being the same line receding into the distance.

Size Constancy Mechanisms: Empirical Evidence from Touch.

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.

The Riemannian Geometry Theory of Visually-Guided Movement Accounts for Afterimage Illusions and Size Constancy.

This discussion paper supplements our two theoretical contributions previously published in this journal on the geometric nature of visual space. We first show here how our Riemannian formulation explains the recent experimental finding (published in this special issue on size constancy) that, contrary to conclusions from past work, vergence does not affect perceived size. We then turn to afterimage experiments connected to that work. Beginning with the Taylor illusion, we explore how our proposed Riemannian visual–somatosensory–hippocampal association memory network accounts in the following way for perceptions that occur when afterimages are viewed in conjunction with body movement. The Riemannian metric incorporated in the association memory network accurately emulates the warping of 3D visual space that is intrinsically introduced by the eye. The network thus accurately anticipates the change in size of retinal images of objects with a change in Euclidean distance between the egocentre and the object. An object will only be perceived to change in size when there is a difference between the actual size of its image on the retina and the anticipated size of that image provided by the network. This provides a central mechanism for size constancy. If the retinal image is the afterimage of a body part, typically a hand, and that hand moves relative to the egocentre, the afterimage remains constant but the proprioceptive signals change to give the new hand position. When the network gives the anticipated size of the hand at its new position this no longer matches the fixed afterimage, hence a size-change illusion occurs.

Can People Infer Distance in a 2D Scene Using the Visual Size and Position of an Object?

Depth information is limited in a 2D scene and for people to perceive the distance of an object, they need to rely on pictorial cues such as perspective, size constancy and elevation in the scene. In this study, we tested whether people could use an object’s size and its position in a 2D image to determine its distance. In a series of online experiments, participants viewed a target representing their smartphone rendered within a 2D scene. They either positioned it in the scene at the distance they thought was correct based on its size or adjusted the target to the correct size based on its position in the scene. In all experiments, the adjusted target size and positions were not consistent with their initially presented positions and sizes and were made larger and moved further away on average. Familiar objects influenced adjusted position from size but not adjusted size from position. These results suggest that in a 2D scene, (1) people cannot use an object’s visual size and position relative to the horizon to infer distance reliably and (2) familiar objects in the scene affect perceived size and distance differently. The differences found demonstrate that size and distance perception processes may be independent.

Binocular Viewing Facilitates Size Constancy for Grasping and Manual Estimation.

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.

Percepcja wzrokowa uczniów z lekką niepełnosprawnością intelektualną

Introduction: Visual perception is an important cognitive ability, which influences other skills, including the mastery of school techniques by students with mild intellectual disabilities. An important goal of supporting of childhood education is to develop visual perception in all its aspects. Developing aspects such as hand-eye coordination, perception of figures and background, perception stability, spatial position and perception of spatial relationships has a positive effect on the math skills and writing and reading of early schoolchildren. Research Aim : The aim of the research was to learn about the functioning of students with mild intellectual disability in terms of 5 aspects of visual perception: visual and motor coordination, perception of the figure and background, perception of the constancy of shape, figure position and spatial relations, and to develop practical implications for developing this function. Method: The research used the method of diagnostic survey. The observation technique and the tool of M. Frostig and D. Horne “Visual Perception Test” were used to collect the data. Results: The level of functioning of the examined students with mild intellectual disability in terms of visual perception is below the norm. In all the subjects, a decrease in the level of visual perception was found in 3 of the examined areas; perception of the figure and background, shape and position of the figure. In terms of eye-hand coordination and the perception of spatial relations, the dominant students are those with the tested feature below their age norm. Conclusions : On the basis of the obtained results, guidelines for working with students were formulated in order to improve their functioning in the field of visual perception in all examined aspects.

Are mirror-symmetric objects of special importance for 3D shape perception? A reply to Sawada and Pizlo (2022).

Yu, Todd, and Petrov (2021) and Yu, Petrov, and Todd (2021) investigated failures of shape constancy that occur when objects are viewed stereoscopically at different distances. Although this result has been reported previously with simple objects such as pyramids or cylinders, we examined more complex objects with bilateral symmetry to test the claim by Li, Sawada, Shi, Kwon, and Pizlo (2011) that the perception of those objects is veridical. Sawada and Pizlo (2022) offer several criticisms of our experiments, but they seem to suggest that the concept of shape is defined by what is computable by their model. If stimuli are used that cannot be discriminated by their model, they are dismissed as degenerate, and tasks that cannot be performed by their model are assumed to be based on something other than shape. This allows them to disregard empirical evidence that is inconsistent with their model. We argue, in contrast, that all reliable aspects of shape perception are deserving of explanation. We also argue that there are many different attributes of shape and many different sources of information about shape that may be relevant in different contexts. It is unlikely that all of them can be explained by a single model.

Reconsidering perceptual constancy

ABSTRACT The world shows some degree of invariance, and we perceive this invariance despite a lot of variation generated locally by our movements, changes in illumination, and the way in which our sense organs react to stimulation. Generally, philosophy and psychology each explain our perception of invariance through the notion of ‘perceptual constancy’. According to the traditional definition, perceptual constancies are capacities to perceive the objective (i.e., perceiver- and context-independent) local properties of external objects despite variation in the stimulation of sensory organs. In this paper, we argue that the traditional understanding of perceptual constancy should be expanded to include a broader range of phenomena connected to the perception of invariance. Our argument starts from an odd activity: pole balancing. Balancing a pole-shaped object (e.g., a broomstick) on the palm of your hand in order to maintain it in an upright position requires (multimodal) perception and continuous tracking (within a certain range) of a particular kind of global invariant feature in the world. By examining this activity and its connection to the notion of perceptual constancy as it is traditionally understood, we propose an alternative account with the goal of clarifying the relationship between the alleged mechanisms underlying constancy and the philosophical implications of the phenomenon.

The First-Person Perspective Is Not a Defining Feature of Consciousness

AbstractPhilosophers and scientists generally assume that consciousness is characterized by a ‘first-person perspective.’ On one interpretation of this claim, experiences are defined, at least in part, by representations that encode a subject-centred ‘point of view.’ But claims about the defining features of consciousness must be sensitive to the possibility of dissociation: if a neurobiological structure or psychological function is neither necessary nor sufficient for consciousness, it cannot be a defining feature in any robust sense. I appeal to research on unconscious emotion, visually guided action, perceptual constancy, and psychiatric disorder to argue that first-personal representations dissociate from conscious experience.

The Mechanisms of the Visual System Behind Visual Illusions: From Eye to Brain

Visual illusion is a psychological phenomenon characterized by perception that appears to differ from physical reality. Illusory perception persists even though the sufferers are aware of the physical properties of what they are observing. Thus, studying visual illusions has led to an improved understanding of the neural mechanism underlying visual information processing. Visual illusions are important tools in neuroscience. Some brightness illusions, such as the Hermann grid illusion or Chevreul illusion, can be explained by the function of the center-surround antagonistic receptive field of retinal ganglion cells. Additionally, color aftereffects were found to be produced in the retina. In addition, neurons in the primary visual cortex are responsible for the orientation-contingent color aftereffect, known as the McCollough effect. ISI reversal, a visual motion illusion, is known to be caused by a biphasic temporal mechanism located in the retinal or lower visual areas. Higher visual areas are responsible for the production of visual illusions such as the Ponzo illusion, size constancy illusion, or tabletop illusion. These illusions are perceived through the process of achieving size constancy from a two-dimensional retinal image. Thus, both low-level and high-level vision are involved in the perception of visual illusions.

Developmental Trajectories of Size Constancy as Implicitly Examined by Simple Reaction Times

It is still unclear whether size constancy is an innate ability or whether it develops with age. As many developmental studies are limited to the child’s comprehension of the task instructions, here, an implicit measure of perceived size, namely, simple manual reaction time (RT), was opted for based on the assumption that perceptually bigger objects generate faster detection times. We examined size constancy in children (from 5 to 14 years of age) and adults using a simple RT approach. Participants were presented with pictures of tennis balls on a screen that was physically moved to two viewing distances. Visual stimuli were adjusted in physical size in order to subtend the same visual angle across distances, determining two conditions: a small-near tennis ball vs. a big-far tennis ball. Thanks to size constancy, the two tennis balls were perceived as different even though they were of equal size on the retina. Stimuli were also matched in terms of luminance. Participants were asked to react as fast as possible to the onset of the stimuli. The results show that the RTs reflected the perceived rather than the retinal size of the stimuli across the different age groups, such that participants responded faster to stimuli that were perceived as bigger than those perceived as smaller. Hence, these findings are consistent with the idea that size constancy is already present in early childhood, at least from the age of five, and does not require extensive visual learning.

Determination of the Error in Transferring of Length Unit’s Size when Measuring the Nanoparticles’ Diameter Using an Analyzer of Particles’ Differential Electrical Mobility

The quality of nanomaterials and nanotechnologies is largely determined by the stability of the applied technologies, which, to a large extent, depend on the constancy of particle sizes. In this regard, metrological problems arise that are associated both with measuring the dimensions of the microstructure of aerosols, suspensions and powders, and with ensuring the uniformity of measurements when transferring a unit of a physical quantity from a standard to working measuring instruments. The purpose of this work was to determine and calculate the error in transferring the size of a unit of length when measuring the diameter of nanoparticles.An analyzer of differential electric mobility of particles was determined as a reference measuring instrument for which the calculation was made. It allows the separation of aerosol particles based on the dependence of their electrical mobility on the particle size. In combination with a condensation particle counter, it allows you to scan an aerosol and build a particle size distribution function. This measurement method is the most accurate in the field of measuring the diameters of particles in aerosols, therefore, the error in the transmission of particle size must be set as for a standard.The paper describes the physical principles of measurement by this method and presents an equation for determining the diameter of nanoparticles. Based on this equation, the sources of non-excluded systematic error were identified. Also, an experimental method was used to determine the random component of the measurement error of nanoparticles and to calculate the error in transferring the size of a unit of length when measuring the diameter of nanoparticles.The obtained results will be used for metrological support of standard samples of particle size, ensuring traceability of measurements of aerosol particle counters and for aerosol research.

A review on various explanations of Ponzo-like illusions.

This article reviews theoretical and empirical arguments for and against various theories that explain the classic Ponzo illusion and its variants from two different viewpoints concerning the role of perceived depth in size distortions. The first viewpoint argues that all Ponzo-like illusions are driven by perceived depth. The second viewpoint argues that the classic Ponzo illusion is unrelated to depth perception. This review will give special focus to the first viewpoint and consists of three sections. In the first section, the role of the number of pictorial depth cues and previous experience in the strength of all Ponzo-like illusions are discussed. In the second section, we contrast the first viewpoint against the theories that explain the classic Ponzo illusion with mechanisms that are unrelated to depth perception. In the last section, we propose a Bayesian-motivated reconceptualization of Richard Gregory's misapplied size constancy theory that explains Ponzo-variant illusions in terms of prior information and prediction errors. The new account explains why some studies have provided inconsistent evidence for misapplied size constancy theory.

The time course of normalizing speech variability in vowels

To achieve perceptual constancy, listeners utilize contextual cues to normalize speech variabilities in speakers. The present study tested the time course of this cognitive process with an event-related potential (ERP) experiment. The first neurophysiological evidence of speech normalization is observed in P2 (130–250 ms), which is functionally related to phonetic and phonological processes. Furthermore, the normalization process was found to ease lexical retrieval, as indexed by smaller N400 (350–470 ms) after larger P2. A cross-language vowel perception task was carried out to further specify whether normalization was processed in the phonetic and/or phonological stage(s). It was found that both phonetic and phonological cues in the speech context contributed to vowel normalization. The results suggest that vowel normalization in the speech context can be observed in the P2 time window and largely overlaps with phonetic and phonological processes.