Perceptual constancy, often defined as the perception of stable features under changing conditions, goes hand in hand with variation in how things look. A white wall in the orange afternoon sun still looks white, though its whiteness looks different compared with the same wall in the noon sun. Historically, this variation has often been explained in terms of our experience of “merely sensory” or subjective properties – an approach at odds with the fact that the variation does track objective (...) features of the perceptual situation, such as illumination. One approach, becoming more common, is to account for the variation in terms of further “dimensions” to perceptual experience. Especially in colour perception, this is a natural thought to have but the idea is often left vague. In this paper I argue that the “dimensional” strategy has problems of its own, but is useful in drawing out some interesting complications in the way perceptual experience is structured. Specifically, the structure of “constancy spaces” brings out the different ways in which there is stability and instability in the experience of constancy, without the need for novel or merely subjective features. Instability arises in a contingent structural feature of perceptual experience. (shrink)

Can young children such as 3-year-olds represent the world objectively? Some prominent developmental psychologists—such as Perner and Tomasello—assume so. I argue that this view is susceptible to a prima facie powerful objection: To represent objectively, one must be able to represent not only features of the entities represented but also features of objectification itself, which 3-year-olds cannot do yet. Drawing on Burge's work on perceptual constancy, I provide a response to this objection and motivate a distinction between three different (...) kinds of objectivity. This distinction helps advance current research on both objectivity and teleological action explanations in young children. (shrink)

Perceptual constancy has played a significant role in philosophy of perception. It figures in debates about direct realism, color ontology, and the minimal conditions for perceptual representation. Despite this, there is no general consensus about what constancyis. I argue that an adequate account of constancy must distinguish it from three distinct phenomena:meresensory stability through proximal change, perceptualcategorizationof a distal dimension, and stability throughirrelevantproximal change. Standard characterizations of constancy fall short in one or more of these respects. I develop (...) an account of constancy that overcomes these problems. The account has two parts: an analysis of constancy mechanisms, and an analysis of the conditions under which a constancy capacity is exercised. I then employ this account to evaluate whether constancy is a necessary condition for perceptual representation, as some have conjectured. I argue that explanatory practice in perceptual psychology fails to support this view. Rather, it fits better with the weaker principle that representation requires specific tracking of a distal dimension. (shrink)

Perceptual constancies have been studied by psychologists for decades, but in recent years, they have also become a major topic in the philosophy of mind. One reason for this surge of interest is Tyler Burge’s (2010) influential claim that constancy mechanisms mark the difference between perception and mere sensitivity, and thereby also the difference between organisms with genuine representational capacities and ‘mindless’ beings. Burge’s claim has been the subject of intense debate. It is becoming increasingly clear, however, that (...) we cannot hope to settle this debate (as well as related debates in the philosophy of mind) without a clear and substantive theoretical account of what perceptual constancies are. In the first part of this paper, I argue that the standard definitions in the literature fall short of providing such an account. Still, as I aim to show in the second part of the paper, by taking a closer look at some of the paradigm examples, it is possible to construct a plausible general account of perceptual constancies that is both clear and substantive, and that can serve as a firm foundation for settling debates like the dispute about Burge’s ‘constancy mechanism criterion’ for perception. (shrink)

Students of perception have long known that perceptual constancy is an important aspect of our perceptual interaction with the world. Here is a simple example of the phenomenon concerning color perception: there is some ordinary sense in which an unpainted ceramic coffee cup made from a uniform material looks a uniform color when it is viewed under uneven illumination, even though the light reflected by the shaded regions to our eyes is quite different from the light reflected by (...) the unshaded regions to our eyes (see figure 1). Or consider this example concerning size perception: there is some ordinary sense in which two telephone poles look the same size when the first is viewed from 100 meters and when the second is viewed from 1 meter, even though the visual angle subtended by the two poles on our retinae is very different (see figure 2). Or consider this example concerning shape perception: there is some ordinary sense in which a penny looks round both when viewed head on and when viewed from an acute angle, even though the area projected by the penny onto our retinae under these two conditions is very different (see figure 3). Or, finally, consider this example concerning auditory volume perception (which I cannot depict graphically): there is some ordinary sense in which a speaker’s voice sounds the same volume when heard from across the room and when heard from a distance of 1 meter, even though the energy striking our ears under these two conditions is very different. (shrink)

This chapter reconsiders the notion of perceptual constancy from the ground up. It distinguishes the phenomenology of perceptual constancy and stability from a functional characterization of perception as aiming at full constancy. Drawing on this distinction, we can attend to the phenomenology of constancy itself, and ask to what extent human perceivers attain constancy, as usually defined. Within this phenomenology, I distinguish phenomenal presentations of spatial features and color properties from categorizations, conceptualizations, and judgments that underlie verbal or (...) other responses to those presentations. Although phenomenal presentation and categorization commonly co-occur, they are distinct aspects of experience. After reviewing several standard descriptions of constancy, I present laboratory findings and my own phenomenological descriptions by way of confirming that, although perception "tends toward" constancy, human perceivers do not usually attain full constancy for either spatial or chromatic properties (as many investigators acknowledge). For spatial perception, I find that the phenomenology has been systematically misdescribed, and I offer a more adequate description of the phenomenology of everyday spatial perception. However, my greatest quarrel with previous theory concerns the functional aim of the constancies. I argue not only that perception does not achieve full constancy but that we should not characterize it as aiming for full constancy. Rather, perception seeks a stability of representation suitable for guiding our actions and which can also, as needed, enable us to classify and re-identify objects by phenomenally presented properties such as shape, size, or color. Further, I argue that theorists should not confuse these classifications with the qualitative character of phenomenal experience. My arguments underscore the need to distinguish phenomenal representation (better, "presentation") from conceptual categorization, and to distinguish perceptual presentations from subsequent processes that are involved in responding to them. (shrink)

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. (shrink)

Abstract: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. (shrink)

Abstract: In philosophy, perceptual constancy refers to the puzzling phenomenon of the perception of properties of objects despite our changing experience of those properties. Husserl developed a sophisticated description of perceptual constancy. In this paper I sketch Husserl's approach, which focuses on the suggestion that perception is partly constituted by the continuous interplay of intention and fulfilment. Unlike many contemporary theories, this framework gives us a way to understand the relationship between different appearances of the same object. I (...) will show how Husserl's work connects with contemporary theories which emphasize perceptual constancy from particular perspectives. These theories include appeals to perspectival properties and Cohen's counterfactual theory. Also, I show how Husserl's account shares important themes with Kelly's recent interpretation of Merleau-Ponty on perceptual constancy. (shrink)

A central topic in discussions about qualia concerns their purported transparency. According to transparency theorists, an experience is transparent in the sense that the subject having the experience is aware of nothing but the intended object of the experience. In this paper this notion is criticized for failing to account for the dynamical aspects of perception. A key assumption in the paper is that perceptual content has a certain temporal depth, in the sense that each act of perception can (...) present an object as extended in time and that objects can be perceived as persisting through time. An object that is seen as persisting through time is often seen as constant and unchanging, even though the presentation of it is changing. In this paper it is argued that in order to account for these cases of perceptual constancy, we must distinguish between the awareness of having perceived that an object has a property at a certain point in time, and perceptually intending that it has that property at that point in time. Consequently, we must in at least some instances be aware of something more than the object of the experience. But precisely this distinction is rejected by the transparency theory. (shrink)

Plant predictive processing suggests that plants anticipatorily perceive their environment. This hypothesis runs up against a challenge which takes the form of two constraints on per- ception advanced by Tyler Burge: the veridicality constraint and the constancy constraint. This paper argues that the veridicality constraint can be satisfied by assuming a general account of predictive processing. To show how the constancy constraint may be fulfilled, an ecologically informed account of invariant pick-up is developed and given a place within plant predictive (...) processing. It is concluded that, against our anthro- pocentric folk-psychological notions of perception, there is reason to believe that plants engage in minimal perception. (shrink)

We perceive the objective world through a subjective perceptual veil. Various perceived properties, particularly “secondary qualities” like colours and tastes, are mind-dependent. Although mind-dependent, our knowledge of many facts about the perceptual veil is immediate and secure. These are well-known facets of sense-datum theory. My aim is to carve out a conception of sense-datum theory that does not require the immediate and secure knowledge of a wealth of facts about experienced sense-data (§1). Such a theory is of value (...) on its own, given well-known challenges to epistemic foundationalism. Beyond this such a theory helps demonstrate how sense-datum theory can accommodate challenging perceptual phenomena like shape and size constancies (§3). These ideas are bridged by the roots of perceptual ambiguity (§2). In brief, tapering acquaintance knowledge creates space for perceptual representation to resolve the ambiguities in presented objects seemingly inherent in scenarios involving perceptual constancies. Thus, I offer a two-factor (acquaintance-representation) sense-datum theory to meet the challenge posed by constancies. Following Smith (2002), from whom this challenge is drawn, my focus is on shape and size constancies. Other constancies, notably colour constancy, are treated elsewhere (Brown 2014). (shrink)

Long tradition in philosophy and in empirical psychology has it that the perceptual recovery of enduring objective size and shape proceeds through initial spatial appearance experiences—like the sensed changing visual field size of a receding car, or the shifting shape appearance of a coin as it rotates in depth. The present paper carefully frames and then critically examines such proposals. It turns out that these are contingent, empirical matters, requiring close examination of relevant research in perception science in order (...) to decide. The paper concludes with extended discussions of the empirical study of the perception of slant, size, and shape. (shrink)

The phenomenon of size constancy is defined as the apparent perceptual invariance of the linear dimensions of a seen object as this approaches the eye or recedes from it. It has been interpreted as resulting from the application by the brain of a size correction, made possible by the subject's apprehension of distance cues present in the image. We present several observations which, by dissociating accommodation from distance of the seen object and by suppressing the optic effects of accommodation (...) on the visual image itself, show that this interpretation is incorrect, and that in fact the size correction of the visual image is a function of the central effort of accommodation, not of the distance of the seen object. (shrink)

Perception is the apprehension of the relatedness of things with reference to a particular space and time framework. The relatedness of things is revealed through action. As a result of the effectiveness of actions the individual builds a pattern of unconscious assumptions. This assumptive world at any particular time determines the individual's perceptions. Constancy behavior is defined as the attempt to maintain a world which deviates as little as possible from the world one has experienced in the past, which is (...) the only world one knows, and which offers one the best chance of acting effectively. (shrink)

In recent discussions of two important issues in the philosophy of perception, viz. the problems of perceptual presence and perceptual constancy, Merleau-Ponty’s ideas have been garnering attention thanks to the work of Sean Kelly and Alva Noë. Although both Kelly’s normative approach and Noë’s enactive approach highlight important aspects of Merleau-Ponty’s view, I argue that neither does full justice to it because they overlook the central role that style plays in his solution to these problems. I show that (...) a closer look at the Phenomenology and several other texts from this period reveals that, on Merleau-Ponty’s account, we are able to perceive the absent features of objects as present, constant properties, and constant objects because we recognize that the objects we perceive have a unique style that persists through and unifies all their appearances. (shrink)

In this essay, we draw on John Haugeland’s work in order to argue that Burge is wrong to think that exercises of perceptual constancy mechanisms suffice for perceptual representation. Although Haugeland did not live to read or respond to Burge’s Origins of Objectivity, we think that his work contains resources that can be developed into a critique of the very foundation of Burge’s approach. Specifically, we identify two related problems for Burge. First, if (what Burge calls) mere sensory (...) responses are not representational, then neither are exercises of constancy mechanisms, since the differences between them do not suffice to imply that one is representational and the other is not. Second, taken by themselves, exercises of constancy mechanisms are only derivatively representational, so merely understanding how they work is not sufficient for understanding what is required for something, in itself, to be representational (and thereby provide a full solution to the problem of perceptual representation). (shrink)

I argue for the following claims: (1) A core Husserlian account of perceptual constancy needs to be given in terms of indicative future-oriented conditionals but can be complemented by a counterfactual account; (2) thus conceived, constancy is a necessary aspect of content. I speak about a “core Husserlian” account so as to capture certain ideas that Michael Madary has presented as the core of Edmund Husserl's approach to perceptual constancy, viz., that “perception is partly constituted by the continuous (...) interplay of intention and fulfilment” and that this “gives us a way to understand the relationship between different appearances of the same object” (See Madary, M. (2012) “Husserl on Perceptual Constancy.” European Journal of Philosophy 20(1): 145–165.). I take myself to be developing, and perhaps correcting, Madary's view as I discuss the role of the core Husserlian ideas, and counterfactuals, in accounting for shape and color constancy, respectively. I bridge constancy and fulfilment-conditional content by appealing to the Husserlian notion of constitution, which captures the process in which objectivity and, correlatively, intentional experience, are built up in the experiential flow. (shrink)

Do the physical facts of the viewed environment account for the ordinary experiences we have of that environment? According to standard philosophical views, distal facts do account for our experiences, a phenomenon explained by appeal to perceptual constancy, the phenomenal stability of objects and environmental properties notwithstanding physical changes in proximal stimulation. This essay reviews a significant but neglected research tradition in experimental psychology according to which percepts systematically do not correspond to mind-independent distal facts. Instead, stability of percept (...) values comes in degrees, and physical facts about the viewed environment alone do not account for our ordinary experiences of the world. I conclude that more attention to descriptive research in psychophysics is warranted if what is sought is a philosophical theory of the nature of our perceptual relation with the world. (shrink)

At first pass, colour constancy occurs when one sees a thing in one’s environment to have a stable colour despite differences in the way it is illuminated. The phenomenon is intuitively grounded for example in everyday experiences in which something is partly shadowed but, in some sense, looks to be uniformly coloured. After a brief introduction to the colour constancy concept (§0) and the science of colour constancy (§1), my focus is on the significance of colour constancy for two intertwined (...) philosophical issues. The first is colour ontology, where constancy has been used to argue for the objectivity of colour, and in particular for a reductive form of it (see §2). The second is colour constancy’s complicated connection to colour experience and colour epistemology. Colour constancy is a subtle phenomenon: it is situated at the intersection of perceptual experience and judgement; it is influenced by myriad forces within our visual-cognitive systems; and is likely a composite of interestingly disparate phenomena. I approach this suite of issues from the perspective of the given in colour perception (§3). As will become plain, the ontological and epistemic issues are related in important ways. This does not, however, detract from the value of focusing on each individually. (shrink)

Sensory perceptions represent things in the outside world. This mundane fact raises a major problem for naturalistic theories of content: the ‘distality problem’. In a previous paper for this journal, I presented a solution to this problem which makes central appeal to constancy mechanisms. Justin Garson, also in this journal, recently criticized my solution and suggested a Dretskean alternative to it. Here, I defend my proposal by arguing, first, that Garson's criticisms ultimately miss the mark, and secondly, that his Dretskean (...) alternative is not viable, because it faces two fundamental problems: the empirical problem and the problem of changing response functions. (shrink)

Representationalism, the view that phenomenal character supervenes on intentional content, has attracted a wide following in recent years. Most representationalists have also endorsed what I call 'standard Russellianism'. According to standard Russellianism, phenomenal content is Russellian in nature, and the properties represented by perceptual experiences are mind-independent physical properties. I argue that standard Russellianism conflicts with the everyday experience of colour constancy. Due to colour constancy, standard Russellianism is unable to simultaneously give a proper account of the phenomenal content (...) of colour experience and do justice to its phenomenology. (shrink)

All representationalists maintain that there is a necessary connection between an experience’s phenomenal character and intentional content; but there is a disagreement amongst representationalists regarding the nature of those intentional contents that are necessarily connected to phenomenal character. Russellian representationalists maintain that the relevant contents are composed of objects and/or properties, while Fregean representationalists maintain that the relevant contents are composed of modes of presentation of objects and properties. According to Fregean representationalists such as David Chalmers and Brad Thompson, the (...) Fregean variety of the view is preferable to the Russellian variety because the former can accommodate purported counterexamples involving spectrum inversion without illusion and colour constancy while the latter cannot. I maintain that colour constancy poses a special problem for the Fregean theory in that the features of the theory that enable it handle spectrum inversion without illusion cannot be extended to handle colour constancy. I consider the two most plausible proposals regarding how the Fregean view might be developed in order to handle colour constancy—one of which has recently been defended by Thompson —and argue that neither is adequate. I conclude that Fregean representationalism is no more able to accommodate colour constancy than is Russellian representationalism and, as such, ought to be rejected. (shrink)

Philosophers have long sought to explain perceptual constancy—the fact that objects appear to remain the same color, size and shape despite changes in the illumination condition, perspective and the relative distance—in terms of a mechanism that actively categorizes variable stimuli under the same pre-formed conceptual categories. Contemporary representationalists, on the other hand, explain perceptual constancy in terms of a modular mechanism that automatically discounts variation in the visual field to represent the stable properties of objects. In this paper (...) I argue that while the former view is unmotivated by empirical evidence, the later fails to account for inter- and intra-personal variability, the influence of expectations on constancy, and the systematic and normal failures of color constancy. A Bayesian approach that builds on the representational tradition in psychology solves both problems. (shrink)

A central preoccupation of philosophy in the twentieth century was to determine constitutive conditions under which accurate (objective) empirical representation of the macrophysical environment is possible. A view that dominated attitudes on this project maintained that an individual cannot empirically represent a physical subject matter as having specific physical characteristics unless the individual can represent some constitutive conditions under which such representation is possible. The version of this view that dominated the century's second half maintained that objective empirical representation of (...) the physical environment requires the individual to be able to supplement this representation with representation of general constitutive features of objectivity. This essay criticizes instances of this version in P. F. Strawson and Quine. It maintains that all versions of the position postulate conditions on objective empirical representation that are more intellectual than are warranted. Such views leave it doubtful that animals and human infants perceptually represent elements in the physical environment. By appeal to common sense and to empirical perceptual psychology, this essay argues that unaided perception yields objective representation of the macrophysical environment. It does so in prelinguistic animals, even in animals that almost surely lack propositional attitudes. The essay concludes with explications of nondeflationary conceptions of representation and perception. It distinguishes nonperceptual sensing from perceptual representation and explicates perceptual representation as a type of objective sensory representation. Objectivity is marked by perceptual constancies. Representation is marked by a nontrivial role for veridicality conditions in explanations of the relevant states. (shrink)

Loosely put, colour constancy for example occurs when you experience a partly shadowed wall to be uniformly coloured, or experience your favourite shirt to be the same colour both with and without sunglasses on. Controversy ensues when one seeks to interpret ‘experience’ in these contexts, for evidence of a constant colour may be indicative a constant colour in the objective world, a judgement that a constant colour would be present were things thus and so, et cetera. My primary aim is (...) to articulate a viable conception of Present Constancy, of what occurs when a constant colour is present in experience, despite the additional presence of some experienced colour variation (e.g., correlating to a change in illumination). My proposed conception involves experienced colour layering – experiencing one opaque colour through another transparent one – and in particular requires one of those experienced layers to remain constant while the other changes. The aim is not to propose this layering conception of colour constancy as the correct interpretation of all constancy cases, but rather to develop the conception enough to demonstrate how it could and plausibly should be applied to various cases, and the virtues it has over rivals. Its virtues include a seamless application to constancy cases involving variations in filters (e.g., sunglasses) and illuminants; its ability to accommodate experiences of partial colours and error-free interpretations of difficult cases; and its broad theoretical-neutrality, allowing it to be incorporated into numerous perceptual epistemologies and ontologies. If layered constancy is prevalent, as I suspect it is, then our experiential access to colours is critically nuanced: we have been plunged into a world of colour without being told that we will rarely, if ever, look to a location and experience just one of them. (shrink)

This paper aims to provide an empirically informed sketch of how our perceptual capacities can interact with cognitive processes to give rise to new perceptual attributives. In section 1, I present ongoing debates about the reach of perception and direct focus toward arguments offered in recent work by Tyler Burge and Ned Block. In section 2, I draw on empirical evidence relating to language processing to argue against the claim that we have no acquired, culture-specific, high-level perceptual (...) attributives. In section 3, I turn to the cognitive dimension; I outline how cognitive procedures can be involved in the acquisition of what ought to, nonetheless, be recognized as genuinely perceptual capacities. Finally, in section 4, I argue for the importance of distinguishing these conclusions from more familiar and radical claims about rampant “cognitive penetration” into the perceptual domain. (shrink)

This paper resolves a paradox concerning colour constancy. On the one hand, our intuitive, pre-theoretical concept holds that colour constancy involves invariance in the perceived colours of surfaces under changes in illumination. On the other, there is a robust scientific consensus that colour constancy can persist in cerebral achromatopsia, a profound impairment in the ability to perceive colours. The first stage of the solution advocates pluralism about our colour constancy capacities. The second details the close relationship between colour constancy and (...) contrast. The third argues that achromatopsics retain a basic type of colour constancy associated with invariants in contrast processing. The fourth suggests that one person-level, conscious upshot of such processing is the visual awareness of chromatic contrasts ‘at’ the edges of surfaces, implicating the ‘colour for form’ perceptual function. This primitive type of constancy sheds new light on our most basic perceptual capacities, which mark the lower borders of representational mind. (shrink)

Expressions of emotion pose a serious challenge to the view that we perceive other people’s emotions directly. If we must perceive expressions in order to perceive emotions, then it is only ever the expressions that we are directly aware of, not emotions themselves. This paper develops a new response to this challenge by drawing an analogy between expressions of emotion and perceptual media. It is through illumination and sound, the paradigmatic examples of perceptual media, that we can see (...) and hear objects around us. Instead of screening these objects from view, however, they enable our perception while being transparent to us. With reference to perceptual constancy and transparency, I show how expressions show up in our experience of emotions in a surprisingly similar way. Given this, we can understand expressions as the media _through_ which we perceive emotions and overcome the above challenge to an otherwise attractive view. (shrink)

Disjunctivist views in the theory of perception hold that genuine perceptions differ in some relevant kind from misperceptions, such as illusions and hallucinations. In recent papers, Tyler Burge has argued that such views conflict with the basic tenets of perceptual psychology. According to him, perceptual psychology is committed to the view that genuine perceptions and misperceptions produced by the same proximal stimuli must be or involve perceptual states of the same kind. This, he argues, conflicts with disjunctivism. (...) In this paper, I defend epistemological disjunctivism from Burge’s inconsistency charge. To this end, I survey the perceptual psychological literature, and reveal that the perceptual kinds they tend to employ differ from and imply nothing about the kinds at issue for the epistemological disjunctivist. I then argue that Burge’s concerns with epistemological disjunctivism are best interpreted as motivated not by his commitment to empirical science, but instead by his views in epistemology and about human rationality. (shrink)

The sensory colors that figure in visual perceptual experience are either properties of the object of consciousness (naïve realism, sense-data theory), or properties of the subject of consciousness (adverbialism) (Section 1). I consider an argument suggested by the work of A. D. Smith that the existence of certain kinds of perceptual constancies shows that adverbialism is correct, for only adverbialism can account for such constancies (Section 3). I respond on behalf of the naïve realist that naïve (...) realism is compatible with the existence of such constancies, so long as naïve realism adopts the view that sensory colors are relational properties of physical objects, not intrinsic properties (Section 4). In other words, the naïve realist should adopt the theory of appearing (Section 5). (shrink)

The ability to perceive the shapes of things as enduring through changes in how they stimulate our sense organs is vital to our sense of stability in the world. But what sort of capacity is shape constancy, and how is it reflected in perceptual experience? This paper defends a pluralist account of shape constancy: There are multiple kinds of shape constancy centered on geometrical properties at various levels of abstraction, and properties at these various levels feature in the content (...) of perceptual experience, governing patterns of apparent shape similarity. I propose that the varieties of shape constancy are subserved by the syntactic complexity of perceptual shape representations. By assigning discrete constituents to various abstract shape parameters, these representations attune us to the preservation of certain abstract shape properties through changes in more determinate shape properties. Finally, I draw broader lessons concerning the nature and function of perceptual constancy. (shrink)

The universality, invariance, and elegance of principles governing the universe may be reflected in principles of the minds that have evolved in that universe – provided that the mental principles are formulated with respect to the abstract spaces appropriate for the representation of biologically significant objects and their properties. (1) Positions and motions of objects conserve their shapes in the geometrically fullest and simplest way when represented as points and connecting geodesic paths in the six-dimensional manifold jointly determined by the (...) Euclidean group of three-dimensional space and the symmetry group of each object. (2) Colors of objects attain constancy when represented as points in a three-dimensional vector space in which each variation in natural illumination is canceled by application of its inverse from the three-dimensional linear group of terrestrial transformations of the invariant solar source. (3) Kinds of objects support optimal generalization and categorization when represented, in an evolutionarily-shaped space of possible objects, as connected regions with associated weights determined by Bayesian revision of maximum-entropy priors. Key Words: apparent motion; Bayesian inference; cognition; color constancy; generalization; mental rotation; perception; psychological laws; psychological space; universal laws. (shrink)

There is variation in how people perceive colors and other secondary qualities. The challenge of perceptual variation is to say whose perceptions are accurate. According to Sextus, Protagoras’ response is that all of our perceptions might be accurate. As this response is traditionally developed, it is difficult to explain color illusion and color constancy. This difficulty is due to a widespread assumption called perceptual atomism. This chapter argues that, if we want to develop Protagoras’ response, we need to (...) give up perceptual atomism. It ends with a brief sketch of an alternative called perceptual structuralism. (shrink)

This paper presents an argument against A D Smith’s Direct Realist theory of perception, which attempts to defend Direct Realism against the argument from illusion by appealing to conscious perceptual states that are structured by the perceptual constancies. Smith’s contention is that the immediate objects of perceptual awareness are characterised by these constancies, which removes any difficulty there may be in identifying them with the external, or normal, objects of awareness. It is here argued that (...) Smith’s theory does not provide an adequate defence of Direct Realism because it does not adequately deal with the difficulties posed by the possibility of perceptual illusion. It is argued that there remain possible illusory experiences where the immediate objects of awareness, which in Smith’s account are those characterised by perceptual constancies, cannot be identified with the external objects of awareness, contrary to Direct Realism. A further argument is offered to extend this conclusion to all non-illusory cases, by adapting an argument of Smith’s own for the generalising step of the Argument from Illusion. The result is that Smith’s theory does not provide an adequate Direct Realist account of the possibility of perceptual illusion. (shrink)

Some experiments in perceptual psychology measure perceivers’ phenomenal experiences of objects versus their cognitive assessments of object properties. Analyzing such experiments, this article responds to Pizlo’s claim that much work on shape constancy before 1985 confused problems of shape ambiguity with problems of shape constancy. Pizlo fails to grasp the logic of experimental designs directed toward phenomenal aspects of shape constancy. In the domain of size perception, Granrud’s studies of size constancy in children and adults distinguish phenomenal from cognitive (...) factors. (shrink)

전도 문제는 하나의 지각에 대응하는 복수의 외부 자극 중에서 지각자는 무엇이 실재인지 구분할 수 없다는 문제이다. 이를 심각하게 여긴 퍼브스(Purves, D.)는 지각 내용이 외부대상이 아니라 누적된 내적 지각의 빈도에 의해 결정된다는 경험적 접근을 제안했다. 워타치(Wojtach, W.)는 이를 목적론적 표상 이론에 접목하여 경험 외재론으로 발전시켰다. 그에 따르면, 오표상이란 없으며 유기체는 성공적인 행위를 위해 높은 빈도로 나타났던 외부 자극에 대응하는 내적 표상을 만들어 낸다. 그러나 표상 이론가들은 오표상 없는 표상이론을 용인하지 않을 것이다. 본 연구는 퍼브스의 경험적 접근을 적절히 반영하는 대안으로서 간접 외재론을 (...) 제안한다. 경험 외재론은 특정 지각 내용과 높은 빈도의 외부 자극을 인과적으로 연결하는 표상 개념을 가정한다. 반면에 간접 외재론은 특정 지각 내용이 직접적으로는 누적된 내부 지각의 영향으로 결정되며, 자주 나타났던 외부 환경은 특정 지각이 아니라 내부 지각의 역사성에 기여함으로써 지각 내용에 간접적인 영향을 미친다고 주장한다. (shrink)

The notion of veridicality has and continues to play a significant role in both the psychology and philosophy of perception. This paper raises questions about the very idea of perceptual veridicality. In particular, it examines the role the veridical/nonveridical distinction plays in our conception of visual illusions and visual constancies.

This article seeks the origin, in the theories of Ibn al-Haytham (Alhazen), Descartes, and Berkeley, of two-stage theories of spatial perception, which hold that visual perception involves both an immediate representation of the proximal stimulus in a two-dimensional ‘‘sensory core’’ and also a subsequent perception of the three dimensional world. The works of Ibn al-Haytham, Descartes, and Berkeley already frame the major theoretical options that guided visual theory into the twentieth century. The field of visual perception was the first area (...) of what we now call psychology to apply mathematics, through geometrical models as used by Euclid, Ptolemy, Ibn al-Haytham, and Descartes (among others). The article shows that Kepler’s discovery of the retinal image, which revolutionized visual anatomy and entailed fundamental changes in visual physiology, did not alter the basic structure of theories of spatial vision. These changes in visual physiology are advanced especially in Descartes' Dioptrics and his L'Homme. Berkeley develops a radically empirist theory vision, according to which visual perception of depth is learned through associative processes that rely on the sense of touch. But Descartes and Berkeley share the assertion that there is a two-dimensional sensory core that is in principle available to consciousness. They also share the observation that we don't usually perceived this core, but find depth and distance to be phenomenally immediate, a point they struggle to accommodate theoretically. If our interpretation is correct, it was not a change in the theory of the psychology of vision that engendered the idea of a sensory core, but rather the introduction of the theory into a new metaphysical context. (shrink)

A central question, if not the central question, of philosophy of perception is whether sensory states have a nature similar to thoughts about the world, whether they are essentially representational. According to the content view, at least some of our sensory states are, at their core, representations with contents that are either accurate or inaccurate. Tyler Burge’s Origins of Objectivity is the most sustained and sophisticated defense of the content view to date. His defense of the view is problematic in (...) several ways. The most significant problem is that his approach does not sit well with mainstream perceptual psychology. (shrink)