The two contrasting theoretical approaches to visual perception, the constructivist and the ecological, are briefly presented and illustrated through their analyses of space and size perception. Earlier calls for their reconciliation and unification are reviewed. Neurophysiological, neuropsychological, and psychophysical evidence for the existence of two quite distinct visual systems, the ventral and the dorsal, is presented. These two perceptual systems differ in their functions; the ventral system's central function is that of identification, while the dorsal system is mainly engaged in (...) the visual control of motor behavior. The strong parallels between the ecological approach and the functioning of the dorsal system, and between the constructivist approach and the functioning of the ventral system are noted. It is also shown that the experimental paradigms used by the proponents of these two approaches match the functions of the respective visual systems. A dual-process approach to visual perception emerges from this analysis, with the ecological-dorsal process transpiring mainly without conscious awareness, while the constructivist-ventral process is normally conscious. Some implications of this dual-process approach to visual-perceptual phenomena are presented, with emphasis on space perception. Key Words: constructivist; dual-process approach; ecological; size perception; space perception; two visual systems; visual perception theories. (shrink)

There is nothing in this World constant but Inconstancy. [Swift 1711: 258] In this paper I argue that two standard characterizations of colour constancy are inadequate to the phenomenon. This inadequacy matters, since, I contend, philosophical appeals to colour constancy as a way of motivating illumination-independent conceptions of colour turn crucially on the shortcomings of these characterizations. After critically reviewing the standard characterizations, I provide a novel counterfactualist understanding of colour constancy, argue that it avoids difficulties of its traditional rivals, (...) and defend it from objections. Finally, I show why, on this improved understanding, colour constancy does not have the philosophical consequences that have been claimed for it in the literature. (shrink)

In Origins of Objectivity Burge advances a theory of perception according to which perceptions are, themselves, objective representations. The possession of veridicality conditions by perceptual states—roughly, non-propositional analogues of truth-conditions—is central to Burge’s account of how perceptual states differ, empirically and metaphysically, from sensory states. Despite an impressive examination of the relevant empirical literatures, I argue here that Burge has not succeeded in securing a distinction between perception and “mere” sensation.

What are the earliest beings that have minds in evolutionary order? Two marks of mind are consciousness and representation. I focus on representation. I distinguish a psychologically distinctive notion of representation from a family of notions, often called ‘representation’, that invoke information, causation, and/or function. The psychologically distinctive notion implies that a representational state has veridicality conditions as an aspect of its nature. Perception is the most primitive type of representational state. It is a natural psychological kind, recognized in a (...) mature science: perceptual psychology. This kind involves a type of objectification, and is marked by perceptual constancies. The simplest animals known to exhibit perceptual constancies, perception, and representation in a distinctively psychological sense, are certain arthropods. Representational mind, or representational psychology, begins in the arthropods. We lack scientific knowledge about the beginnings of consciousness. Consciousness is neither necessary nor sufficient for perception. I conclude by reflecting on the kinds mind and psychology. (shrink)

Abstract“Sign stimuli” elicit specific patterns of behavior when an organism's motivation is appropriate. In the toad, visually released prey-catching involves orienting toward the prey, approaching, fixating, and snapping. For these action patterns to be selected and released, the prey must be recognized and localized in space. Toads discriminate prey from nonprey by certain spatiotemporal stimulus features. The stimulus-response relations are mediated by innate releasing mechanisms (RMs) with recognition properties partly modifiable by experience. Striato-pretecto-tectal connectivity determines the RM's recognition and localization (...) properties, whereas medialpallio-thalamo-tectal circuitry makes the system sensitive to changes in internal state and to prior history of exposure to stimuli. RMs encode the diverse stimulus conditions referring to the same prey object through different combinations of “specialized” tectal neurons, involving cells selectively tuned to prey features. The prey-selective neurons express the outcome of information processing in functional units consisting of interconnected cells. Excitatory and inhibitory interactions among feature-sensitive tectal and pretectal neurons specify the perceptual operations involved in distinguishing the prey from its background, selecting its features, and discriminating it from predators. Other connections indicate stimulus location. The results of these analyses are transmitted by specialized neurons projecting from the tectum to bulbar/spinal motor systems, providing a sensorimotor interface. Specific combinations of such projective neurons – mediating feature- and space-related messages – form “command releasing systems” that activate corresponding motor pattern generators for appropriate prey-catching action patterns. (shrink)

Blindsight and vision for action seem to be exemplars of unconscious visual processes. However, researchers have recently argued that blindsight is not really a kind of uncon- scious vision but is rather severely degraded conscious vision. Morten Overgaard and col- leagues have recently developed new methods for measuring the visibility of visual stimuli. Studies using these methods show that reported clarity of visual stimuli correlates with accuracy in both normal individuals and blindsight patients. Vision for action has also come under (...) scrutiny. Recent findings seem to show that information processed by the dor- sal stream for online action contributes to visual awareness. Some interpret these results as showing that some dorsal stream processes are conscious visual processes (e.g., Gallese, 2007; Jacob & Jeannerod, 2003). The aim of this paper is to provide new support for the more traditional view that blindsight and vision for action are genuinely unconscious per- ceptual processes. I argue that individuals with blindsight do not have access to the kind of purely qualitative color and size information which normal individuals do. So, even though people with blindsight have a kind of cognitive consciousness, visual information process- ing in blindsight patients is not associated with a distinctly visual phenomenology. I argue further that while dorsal stream processing seems to contribute to visual awareness, only information processed by the early dorsal stream (V1, V2, and V3) is broadcast to working memory. Information processed by later parts of the dorsal stream (the parietal lobe) never reaches working memory and hence does not correlate with phenomenal awareness. I con- clude that both blindsight and vision for action are genuinely unconscious visual processes. (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)

Tyler Burge presents an original study of the most primitive ways in which individuals represent the physical world. By reflecting on the science of perception and related psychological and biological sciences, he gives an account of constitutive conditions for perceiving the physical world, and thus aims to locate origins of representational mind.

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)

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)

The perceptual system estimates distal conditions based upon proximal sensory input. It typically exploits information from multiple cues across and within modalities: it estimates shape based upon visual and haptic cues; it estimates depth based upon convergence, binocular disparity, motion parallax, and other visual cues; and so on. Bayesian models illuminate the computations through which the perceptual system combines sensory cues. I review key aspects of these models. Based on my review, I argue that we should posit co-referring perceptual representations (...) corresponding to distinct sensory cues. For example, the perceptual system represents a distal size using a representation canonically linked with vision and a distinct representation canonically linked with touch. Distinct co-referring perceptual representations represent the same denotation, but they do so under different modes of presentation. Bayesian cue combination models demonstrate that psychological explanation of perception should attend to mode of presentation and not simply to denotation. (shrink)

Objects are central to perception and our interactions with the world. We perceive the world as parsed into discrete entities that instantiate particular properties, and these items capture our attention and shape how we interact with the environment. Recently there has been some debate about whether the sense of smell allows us to perceive odours as discrete objects, with some suggesting that olfaction is aspatial and doesn’t allow for object-individuation. This paper offers two empirically tractable criteria for assessing whether particular (...) objects are exhibited in perceptual experience— susceptibility to figure-ground segregation and perceptual constancies—and argues that these criteria are fulfilled by olfactory perception, and thus there are olfactory objects. I argue that there are, in fact, two different ways that olfaction allows for figure-ground segregation. First, I look at various Gestalt grouping principles, which are thought to govern when features are perceived as grouped into structured wholes, segregated from everything around them. I argue that these principles apply to olfactory experience, providing evidence of non-spatial figure-ground segregation. Second, I defend the contentious idea that a spatial variety of figure-ground segregation can also occur in olfaction. To see this, however, we need to look to empirical evidence showing that tactile stimulation and bodily movements play a crucial role in olfactory phenomenology. Finally, I draw on empirical evidence and olfactory phenomenology to argue that there are perceptual constancies in olfactory experience, allowing us to perceive odours as coherent objects that survive shifts in our perspectives on the world. (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)

Perceptual representations have distal content: they represent external objects and their properties, not light waves or retinal images. This basic fact presents a fundamental problem for ‘input-oriented’ theories of perceptual content. As I show in the first part of this paper, this even holds for what is arguably the most sophisticated input-oriented theory to date, namely Karen Neander's informational teleosemantics. In the second part of the paper, I develop a new version of informational teleosemantics, drawing partly on empirical psychology, and (...) partly on philosophical considerations. I shall argue that this version has all the virtues of Neander's original theory, but also the further crucial advantage of being able to account for the distality of perceptual content. (shrink)

Teleosemantic theories of representation are often criticized as being “too liberal”, i.e. as categorizing states as representations which are not representational at all. Recently, a powerful version of this objection has been put forth by Tyler Burge. Focusing on perception, Burge defends the claim that all teleosemantic theories apply too broadly, thereby missing what is distinctive about representation. Contra Burge, I will argue in this paper that there is a teleosemantic account of perceptual states that does not fall prey to (...) this problem, and that we can arrive at this account by combining some of Burge’s insights with a producer-oriented version of teleosemantics. The resulting theory turns out to be attractive and perfectly coherent. By contrast, the coherence of Burge’s own anti-teleosemantic approach becomes quite doubtful under closer examination—or so I will argue. (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)

Perceptions "present" objects as red, as round, etc.-- in general as possessing some property. This is the "perceptual content" of the title, And the article attempts to answer the following question: what is a materialistically adequate basis for assigning content to what are, after all, neurophysiological states of biological organisms? The thesis is that a state is a perception that presents its object as "F" if the "biological function" of the state is to detect the presence of objects that are (...) "F". The theory contrasts with causal/informational theories, and with internalist theories, for example those which assign content on the basis of introspected feel. Its advantages are that it permits perceptual error while at the same time allowing content to be expressed in terms of external properties. The argument of the paper is illustrated throughout by examples from biology and computational psychology. (shrink)

According to the homeostatic property cluster family of accounts, one of the main conditions for groups of properties to count as natural is that these properties be frequently co-instantiated. I argue that this condition is, in fact, not necessary for natural-kindness. Furthermore, even when it is present, the focus on co-occurrence distorts the role natural kinds play in science. Co-occurrence corresponds to what information theorists call redundancy: observing the presence of some of the properties in a frequently co-occurrent cluster makes (...) observations of other members of the cluster comparatively uninformative. Yet, scientific practice often, and increasingly often, singles out as natural groups of properties that are not redundant, but synergic: instantiations of properties in synergic clusters are not necessarily informative about instantiations of other properties in the cluster; rather, it is their joint instantiation that plays the explanatory role for which the natural kind is recruited. (shrink)

We can start with a definition. “[C]olour constancy is the constancy of the perceived colours of surfaces under changes in the intensity and spectral composition of the illumination.” (Foster et al. 1997) Given the definition we can now ask a question: Does human color vision exhibit color constancy?1 The answer to the question depends in part on how we interpret it. If the question is understood as asking whether human color vision displays constancy for every possible scene across every possible (...) illumination then the answer is no.2 If the question is understood as asking whether human color vision displays some degree of constancy for some scenes across some range of illuminants then the answer is yes. The more interesting questions involve characterizing the degree of constancy human vision displays, the types of scenes and ranges of illuminants for which approximate constancy can be achieved and the.. (shrink)