This paper examines Milner and Goodale’s hypothesis about the two visual streams and raises the questions of whether properties in egocentric space (commonly associated with the vision-for-action, or "dorsal," stream) can be part of the phenomenal content of perceptual experience, or only properties in allocentric space (commonly associated with the vision-for-perception, or "ventral," stream) can play this role, and how (if at all) properties in egocentric space differ from properties in allocentric space. These questions are reminiscent of (...) issues raised by Christopher Peacocke's "equal-sized trees" case: if you are looking at equal-sized trees on the side of a road, the trees will phenomenally look to you to be equally tall. But it is also true that a tree will take up more of the space in your visual field the closer it is to you. So, the equal-sized trees will also phenomenally look to you to have different heights. Your (visual) perceptual experience is not illusory. That is, the trees veridically look to you to have the same height, and they also veridically look to you to have different heights. Call the sort of issue raised here the "problem of dual looks." I provide a solution to the problem of dual looks that helps shed light on whether properties in egocentric space can be part of the phenomenal content of perceptual experience, and how (if at all) properties in egocentric space differ from properties in allocentric space. (shrink)

David Milner and Melvyn Goodale’s dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action-related “unconscious” stream and a ventral, perception-related “conscious” stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, (...) conscious vision for perception, and unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action (Bruno & Franz, 2009; Dassonville & Bala, 2004; Franz & Gegenfurtner, 2008; McIntosh & Lashley, 2008). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process (Schenk & McIntosh, 2010). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action-guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi-conservative view that the dissociation hypothesis is best understood as a tripartite division. (shrink)

Common everyday materials such as textiles, foodstuffs, soil or skin can have complex, mutable and varied appearances. Under typical viewing conditions, most observers can visually recognize materials effortlessly, and determine many of their properties without touching them. Visual material perception raises many fascinating questions for vision researchers, neuroscientists and philosophers, yet has received little attention compared to the perception of color or shape. Here we discuss some of the challenges that material perception raises and argue that (...) further philosophical thought should be directed to how we see materials. (shrink)

Mental capacities for perceiving, remembering, thinking, and planning involve the processing of structured mental representations. A compositional semantics of such representations would explain how the content of any given representation is determined by the contents of its constituents and their mode of combination. While many have argued that semantic theories of mental representations would have broad value for understanding the mind, there have been few attempts to develop such theories in a systematic and empirically constrained way. This paper contributes to (...) that end by developing a semantics for a ‘fragment’ of our mental representational system: the visual system’s representations of the bounding contours of objects. At least three distinct kinds of composition are involved in such representations: ‘concatenation’, ‘feature composition’, and ‘contour composition’. I sketch the constraints on and semantics of each of these. This account has three principal payoffs. First, it models a working framework for compositionally ascribing structure and content to perceptual representations, while highlighting core kinds of evidence that bear on such ascriptions. Second, it shows how a compositional semantics of perception can be compatible with holistic, or Gestalt, phenomena, which are often taken to show that the whole percept is ‘other than the sum of its parts’. Finally, the account illuminates the format of a key type of perceptual representation, bringing out the ways in which contour representations exhibit domain-specific form of the sort that is typical of structured icons such as diagrams and maps, in contrast to typical discursive representations of logic and language. (shrink)

One necessary condition on any adequate account of perception is clarity regarding whether unconscious perception exists. The issue is complicated, and the debate is growing in both philosophy and science. In this paper we consider the case for unconscious perception, offering three primary achievements. First, we offer a discussion of the underspecified notion of central coordinating agency, a notion that is critical for arguments that purportedly perceptual states are not attributable to the individual, and thus not genuinely (...) perceptual. We develop an explication of what it is for a representational state to be available to central coordinating agency for guidance of behavior. Second, drawing on this explication, we place a more careful understanding of the attributability of a state to the individual in the context of a range of empirical work on vision-for-action, saccades, and skilled typing. The results place pressure on the skeptic about unconscious perception. Third, reflecting upon broader philosophical themes running through debates about unconscious perception, we highlight how our discussion places pressure on the view that perception is a manifest kind, rather than a natural kind. In doing so, we resist the tempting complaint that the debate about unconscious perception is merely verbal. (shrink)

Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic (...) operation of perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure-function details of the presented mechanism of perception. (shrink)

Traditionally, vision science and information/data visualization have interacted by using knowledge of human vision to help design effective displays. It is argued here, however, that this interaction can also go in the opposite direction: the investigation of successful visualizations can lead to the discovery of interesting new issues and phenomena in visual perception. Various studies are reviewed showing how this has been done for two areas of visualization, namely, graphical representations and interaction, which lend themselves to work (...) on visual processing and the control of visual operations, respectively. The results of these studies have provided new insights into aspects of vision such as grouping, attentional selection and the sequencing of visual operations. More generally yet, such results support the view that the perception of visualizations can be a useful domain for exploring the nature of visual cognition, inspiring new kinds of questions as well as casting new light on the limits to which information can be conveyed visually. (shrink)

The aim of this paper is to draw the attention of those conducting research on imagery to the different kinds of visual information deployed by expert drawers compared to non-expert drawers. To demonstrate this difference I draw upon the cognitive science literature on vision and imagery to distinguish between three different ways that visual phenomena can be represented in memory: structural descriptions, denotative descriptions, and configural descriptions. Research suggests that perception and imagery deploy the same mental processes and (...) that the drawing of one's imagery would require the simultaneous deployment of these very processes. I reason that drawing a picture of one's imagery is not possible. I hypothesize that when required to draw a picture from memory, both expert and non-expert drawers access their denotative description of the object rather than their imagery. I then suggest how my hypothesis could be tested and if accurate, how this finding would impact upon the design and interpretation of experiments on imagery when drawing is involved. I also suggest why the constraints that perception places upon the simultaneous deployment of imagery appear not to cause the same constraints in autistic savant drawers and visual agnosia patients. (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)

Philosophical discussion about the reality of sensory perceptions has been hijacked by two tendencies. First, talk about perception has been largely centered on vision. Second, the realism question is traditionally approached by attaching objects or material structures to matching contents of sensory perceptions. These tendencies have resulted in an argumentative impasse between realists and anti-realists, discussing the reliability of means by which the supposed causal information transfer from object to perceiver takes place. Concerning the nature of sensory experiences (...) and their capacity to provide access to reality, this article challenges the standard categories through which most arguments in this debate have been framed to date. Drawing on the underexplored case of olfaction, I first show how the details of the perception process determine the modalities of sensory experiences. I specifically examine the role of measurement and analyze its influence on the characterization of perceptions in olfaction. My aim is to argue for an understanding of perception through a process view, rather than one pertaining to objects and properties of objects. (shrink)

In this short paper, I outline four philosophical arguments concerning the objects we perceive. These arguments build up to the conclusion that the objects of perceptual experience are material objects. I then show that the first three of these arguments parallel important psychological positions in vision science. Thus, (1) the notion of object used in Logical Atomism resembles the concept as it is defined in the Feature Integration Theory of Treisman and Gelade (1980). But (2) Frank Jackson's (1975) Many-Property (...) Problem leads to a substrate-quality structure for visual experience that corresponds to the structure of attended experience in Feature Integration Theory. A third philosophical argument (3) concerns the perception of movement. This argument culminates in the proposition that perceptual features are seen as belonging to material objects. There is a close resemblance between these objects and those of Zenon Pylyshyn's (1980) FINSTs. Finally, (4) I argue that material objects are the only substrates of multimodal perceptual experience. Perceptual psychology has yet to investigate this structure. (shrink)

Vision constitutes an interesting domain, or range of domains, for debate over the extended mind thesis, the idea that minds physically extend beyond the boundaries of the body. In part this is because vision and visual experience more particularly are sometimes presented as a kind of line in the sand for what we might call externalist creep about the mind: once all reasonable concessions have been made to externalists about the mind, visual experience marks a line beyond which (...) lies a safe haven for individualists. Here I want to put a little more pressure on such a view of visual experience, as well as to offer a more constructive, positive argument in defense of the idea of extended vision. (shrink)

Drawing on Merleau-Ponty’s “Eye and Mind” and Bergson’s Matière et mémoire and “La perception du changement,” I ask what resources are available in vision for interrupting objectifying habits of seeing. While both Bergson and Merleau-Ponty locate the possibility of seeing differently in the figure of the painter, I develop by means of their texts, and in dialogue with Iris Marion Young’s work, a more general phenomenology of hesitation that grounds what I am calling “critical-ethical vision.” Hesitation, I (...) argue, stems from affect and leads to critical memory. In hesitation, the seeming coincidence between my habits of seeing and the visible is decentered, revealing these habits and their social reference as the constitutive horizon of my field of vision. Hesitation, then, provides the phenomenological moment within which vision may become at once critically watchful, destabilizing its objectifying habits, and ethically responsive, recollecting its affective grounds. The critical and the ethical are here inseparable. Critically, this vision is an awareness of the structures of invisibility, diacritical and habitual, social and historical, to which my vision owes—dimensions which institute particular ways of seeing and being as norm while eliding others. Ethically, this is the recognition of how seeing is already seeing with others—others whose affective influence is operative within vision, even as their existence is reductively represented or denied. (shrink)

According to a common opinion, human olfactory experiences are significantly different from human visual experiences. For instance, olfaction seems to have only rudimentary abilities to represent space; it is not clear whether olfactory experiences have any mereological structure; and while vision presents the world in terms of objects, it is a matter of debate whether there are olfactory object-representations. This paper argues that despite these differences visual and olfactory experiences share a hierarchical subject/property structure. Within this structure, olfactorily experienced (...) odours and visual objects have the same status: they are primary subjects which unify other represented elements into perceptual units. (shrink)

How do we see the world aright? This question is central to Iris Murdoch’s philosophy as well as to that of her great source of inspiration, Simone Weil. For both of them, not only our action, but the very quality of our being depends on the ability to see things as they are, where vision is both a metaphor for immediate understanding and a literal expression of the requirement to train our perception so as to get rid of (...) illusions. For both, too, the method to achieve this goal is attention. For both, finally, attention requires a dethronement of the self, considered as the source of illusion. In this paper I investigate what moral perception means for each of these philosophers and how it operates through attention and its relationship with the self. I will show that, despite many striking similarities, Murdoch’s project does not equal ‘Weil minus God’, but offers a different concept of the self, a different understanding of its removal, and therefore a different picture of attention and moral perception. In evaluating both views, I will gesture towards a third way represented by Zen Buddhism, which both philosophers variously consider but do not embrace. (shrink)

In this paper, I explore Augustine’s account of sense cognition in book 11 of De Trinitate. His discussion in this context focuses on two types of sensory state—what he calls “outer vision” and “inner vision,” respectively. His analysis of both types of state is designed to show that cognitive acts involving external and internal sense faculties are susceptible of a kind of trinitarian analysis. A common way to read De Trin. 11, is to interpret Augustine’s account of “outer” (...) vision as an analysis of sense perception and his account “inner” vision as an analysis of occurrent sensory memory and imagination. I argue against such a reading of De Trin. 11, however. Insofar as we take perception to be a phenomenally conscious mode of sensory awareness, outer vision cannot, I claim, be the equivalent of ordinary sense perception. For, on Augustine’s view, the deliverances of outer vision only reach the threshold of consciousness, when outer vision occurs in conjunction with inner vision. Hence, on my analysis, sense perception turns out to be a complex, hybrid state—one that involves both outer and inner vision. If I am right, acts of sense perception turn out not to be directly susceptible to trinitarian analysis. Even so, the account is interesting and nuanced for all that. (shrink)

Often when there is no attention to an object, there is no conscious perception of it either, leading some to conclude that conscious perception is an attentional phenomenon. There is a well-known perceptual phenomenon—visuo-spatial crowding, in which objects are too closely packed for attention to single out one of them. This article argues that there is a variant of crowding—what I call ‘‘identity-crowding’’—in which one can consciously see a thing despite failure of attention to it. This conclusion, together (...) with new evidence that attention to an object occurs in unconscious perception, suggests there may be a double dissociation between conscious perception of an object and attention to that object, constraining the extent to which consciousness can be constitutively attentional. The argument appeals to a comparison between the minimal resolution (or ‘‘grain’’) of object-attention and object-seeing. (shrink)

It seems intuitively obvious that metameric matching of color samples entails a loss of information, for spectrophotometrically diverse materials appear the same. This intuition implicitly relies on a conception of the function of color vision and on a related conception of how color samples should be individuated. It assumes that the function of color vision is to distinguish among spectral energy distributions, and that color samples should be individuated by their physical properties. I challenge these assumptions by articulating (...) a different conception of the function of color vision, according to which color vision serves to partition object surfaces into discrimination classes. (shrink)

Our visual experience of the world is one of diverse objects and events, each with particular colors, shapes, and motions. This experience is so coherent, so immediate, and so effortless that it seems to result from a single system that lets us experience everything in our field of view. But however appealing, this belief is mistaken: there are severe limits on what can be visually experienced. -/- For example, in a display for air-traffic control it is important to track all (...) moving items. For a single item, this can be done without problem. Three or four can also be tracked, although some degree of effort may be needed. As the number is increased further, accurate tracking becomes more and more difficult—and eventually, impossible. Performance is evidently affected by a factor within the observer which enables certain kinds of perception to occur, but is limited in some way. This factor is generally referred to as attention. -/- At various times, attention has been associated with clarity of perception, intensity of perception, consciousness, selection, or the allocation of a limited “resource” enabling various operations (see Hatfield, 1998). During the past several decades, considerable progress has been achieved by focusing on the idea of selection (Broadbent, 1982). In particular, attention can be productively viewed as contingently selective processing. This can be embodied in various ways by various processes—there need not be a single quantity identified with all forms of attention, or a single site where it operates (Allport, 1993; Tsotsos, 2011). Although “paying attention” is often considered to be a unitary operation, it may simply refer to the control of one or more selective processes, ideally in a co-ordinated way. While this view has some cost in terms of conceptual simplicity, it can help make sense of a large set of phenomena. -/- This article surveys several of the major issues in our understanding of attention and how it relates to perception. It focuses on vision, since many—if not all—considerations are similar for all sensory modalities, and the level of understanding achieved in this domain is currently the most advanced. (shrink)

One of the most influential ideas of twentieth-century art history and aesthetics is that vision has a history and it is the task of art history to trace how vision has changed. This claim has recently been attacked for both empirical and conceptual reasons. My aim is to argue for a new version of the history of vision claim: if visual attention has a history, then vision also has a history. And we have some reason to (...) think that at least in certain contexts, visual attention does have a history. (shrink)

It will be obvious to anyone with a slight knowledge of twentieth-century analytic philosophy that one of the central themes of this kind of philosophy is the nature of perception: the awareness of the world through the five senses of sight, touch, smell, taste, and hearing. Yet it can seem puzzling, from our twenty-first-century perspective, why there is a distinctively philosophical problem of perception at all. For when philosophers ask ‘what is the nature of perception?’, the question (...) can be confused with other, purely empirical, questions. For example: how do our sense-organs actually work? What are the mechanisms of smell and taste? How do vision and touch actually provide us with information about the world around us? There is much general agreement, in its broad outlines, about how to answer such questions empirically; but it is not clear what role, if any, philosophy has to play in answering these empirical questions. So if these were the only questions about the nature of perception, then it would not be clear exactly what the philosophy of perception is supposed to be about. (shrink)

In the contemporary discussions concerning unconscious perception it is not uncommon to postulate that content and phenomenal character are ‘orthogonal’, i.e., there is no type of content which is essentially conscious, but instead, every representational content can be either conscious or not. Furthermore, this is not merely treated as a thesis justified by theoretical investigations, but as supported by empirical considerations concerning the actual functioning of the human cognition. In this paper, I address unconscious color perception and argue (...) for a negative thesis—that the main experimental paradigms used in studying unconscious color perception do not provide support for the position that conscious and unconscious color representations have the same type of content. More specifically, I claim that there is no significant support for the claim that unconscious vision categorically represents surface colors. (shrink)

In the essays which make up The Sovereignty of Good, Iris Murdoch gives us a picture of moral life in which ‘the metaphor of vision [is] almost irresistibly suggested’. This chapter aims to clarify the role played by the metaphor of vision in Murdoch’s philosophical thinking. I’ll examine two different things which might be meant by the term ‘moral vision’: vision of moral things or vision which is itself moral. The suggestion will be that whilst (...) both capture something important about Murdoch’s work, each may mislead about what is distinctive in her views. For Murdoch, I shall suggest, there is no distinctively moral vision. There is only vision: a loving gaze directed upon the reality of others. (shrink)

Pictures are 2D surfaces designed to elicit 3D-scene-representing experiences from their viewers. In this essay, I argue that philosophers have tended to underestimate the relevance of research in vision science to understanding the nature of pictorial experience. Both the deeply entrenched methodology of virtual psychophysics as well as empirical studies of pictorial space perception provide compelling support for the view that pictorial experience and seeing face-to-face are experiences of the same psychological, explanatory kind. I also show that an (...) empirically informed account of pictorial experience provides resources to develop a novel, resemblance-based account of depiction. According to what I call the deep resemblance theory, pictures work by presenting virtual models of objects and scenes in phenomenally 3D, pictorial space. (shrink)

The experiments reported herein probe the visual cortical mechanisms that control near–far percepts in response to two-dimensional stimuli. Figural contrast is found to be a principal factor for the emergence of percepts of near versus far in pictorial stimuli, especially when stimulus duration is brief. Pictorial factors such as interposition (Experiment 1) and partial occlusion Experiments 2 and 3) may cooperate, as generally predicted by cue combination models, or compete with contrast factors in the manner predicted by the FACADE model. (...) In particular, if the geometrical conŽ guration of an image favors activation of cortical bipole grouping cells, as at the top of a T-junction, then this advantage can cooperate with the contrast of the conŽ guration to facilitate a near–far percept at a lower contrast than at an X-junction. Varying the exposure duration of the stimuli shows that the more balanced bipole competition in the X-junction case takes longer exposure times to resolve than the bipole competition in the T-junction case (Experiment 3). (shrink)

Raftopoulos’s most recent book argues, among other things, for the cognitive impenetrability of early vision. Before we can assess any such claims, we need to know what’s meant by “early vision” and by “cognitive penetration”. In this contribution to this book symposium, I explore several different things that one might mean – indeed, that Raftopoulos might mean – by these terms. I argue that whatever criterion we choose for delineating early vision, we need a single criterion, not (...) a mishmash of distinct criteria. And I argue against defining cognitive penetration in partly epistemological terms, although it is fine to offer epistemological considerations in defending some definitions as capturing something of independent interest. Finally, I raise some questions about how we are to understand the “directness” of certain putative cognitive influences on perception and about whether there’s a decent rationale for restricting directness in the way that Raftopoulos apparently does. (shrink)

In this paper I suggest ways in which vision theory and psychology of perception may illuminate our understanding of beauty. I identify beauty as a phenomenon which is (i) ineffable, (ii) subjectively universal (intersubjective), and (iii) manifested in objects as formal structure. I present a model of perception by which I can identify a representation whose underlying principles would explain these features of beauty. The fact that these principles underlie the representation rather than constitute the content of (...) representation, provides an explanation for the ineffability and subjective universality of the perception of beauty in the form of objects. In part one, I set out two models of perception conducive to this approach. In part two, I suggest how such theories can offer a way of explaining and understanding the experience of beauty. (shrink)

The question of whether blindsight is a form of unconscious perception continues to spark fierce debate in philosophy and psychology. One side of the debate holds that while the visual information categorized in blindsight is not access-conscious, it is nonetheless a form of perception, albeit a form of unconscious perception. The opposition, by contrast, holds that blindsight is just a form of degraded conscious perception that makes the categorized information harder to access because it is degraded. (...) In this chapter, we address the opposition’s arguments for thinking that blindsight is a form of degraded conscious vision and then argue that the residual awareness found in blindsight is a form of non-perceptual awareness. To back this claim, we examine the residual visual abilities to detect and discriminate colour found in some blindsight patients and show that residual consciousness in blindsight is indirect and lacks the phenomenal character characteristic of conscious vision. (shrink)

Recent developments in vision science have resulted in several major changes in our understanding of human visual perception. For example, attention no longer appears necessary for "visual intelligence"--a large amount of sophisticated processing can be done without it. Scene perception no longer appears to involve static, general-purpose descriptions, but instead may involve dynamic representations whose content depends on the individual and the task. And vision itself no longer appears to be limited to the production of a (...) conscious "picture"--it may also guide processes outside the conscious awareness of the observer. (shrink)

Many philosophical debates take for granted that there is such a thing as ‘the’ common-sense conception of the phenomenon of interest. Debates about the nature of perception tend to take for granted that there is a single, coherent common-sense conception of vision, consistent with Direct Realism. This conception is often accorded an epistemic default status. We draw on philosophical and psychological literature on naïve theories and belief fragmentation to motivate the hypothesis that untutored common sense encompasses conflicting Direct (...) Realist and Indirect Realist conceptions: there is no such thing as ‘the’ common-sense conception of vision that could enjoy epistemic default status. To examine this hypothesis, a survey administered an agreement rating task with verbal and pictorial stimuli to lay participants. We found many laypeople simultaneously hold conflicting Direct Realist and Indirect Realist beliefs about vision. Against common assumptions, Direct Realist beliefs are not clearly dominant, and consistent adherence to Direct Realism is not the norm, but the exception. These findings are consistent with recent accounts of belief fragmentation. They forcefully challenge common methodology in philosophical debates about the nature of perception and beyond. (shrink)

What if a blind person could 'see' with her ears? Thanks to Sensory Substitution Devices (SSDs), blind people now have access to out-of-reach objects, a privilege reserved so far for the sighted. In this paper, we show that the philosophical debates have fundamentally been mislead to think that SSDs should be fitted among the existing senses or that they constitute a new sense. Contrary to the existing assumption that they get integrated at the sensory level, we present a new thesis (...) according to which they are not sensory, and get vertically integrated on the top of existing sensory abilities, from which they should be theoretically distinguished. (shrink)

The question of whether cognition can influence perception has a long history in neuroscience and philosophy. Here, we outline a novel approach to this issue, arguing that it should be viewed within the framework of top-down information-processing. This approach leads to a reversal of the standard explanatory order of the cognitive penetration debate: we suggest studying top-down processing at various levels without preconceptions of perception or cognition. Once a clear picture has emerged about which processes have influences on (...) those at lower levels, we can re-address the extent to which they should be considered perceptual or cognitive. Using top-down processing within the visual system as a model for higher-level influences, we argue that the current evidence indicates clear constraints on top-down influences at all stages of information processing; it does, however, not support the notion of a boundary between specific types of information-processing as proposed by the cognitive impenetrability hypothesis. (shrink)

Pylyshyn restricts cognitively penetrable vision to late vision, whereas he does not make any distinction between different kinds of penetrating cognition. I argue that this approach disconnects early vision content from late vision content and blurs the distinction between the latter and the content of thought. To overcome this problem I suggest that we should not distinguish between different kinds of visual content but instead introduce a restriction on the kind of cognition that can directly penetrate (...) visual experience. In particular, I suggest that visual experience, unlike thought, is directly penetrated only by practical non-propositional knowledge. I specify this weak cognitive penetrability in anti-representational terms. In particular, I suggest that the dependence of visual content on practical non-propositional knowledge should be conceived as a rational non-inferential relation, for it is in this way that we can account for the distinctive content of visual experience. (shrink)

Pylyshyn restricts cognitively penetrable vision to late vision, whereas he does not make any distinction between different kinds of penetrating cognition. I argue that this approach disconnects early vision content from late vision content and blurs the distinction between the latter and the content of thought. To overcome this problem I suggest that we should not distinguish between different kinds of visual content but instead introduce a restriction on the kind of cognition that can directly penetrate (...) visual experience. In particular, I suggest that visual experience, unlike thought, is directly penetrated only by practical non-propositional knowledge. I specify this weak cognitive penetrability in anti-representational terms. In particular, I suggest that the dependence of visual content on practical non-propositional knowledge should be conceived as a rational non-inferential relation, for it is in this way that we can account for the distinctive content of visual experience. (shrink)

Within contemporary philosophy of perception, it is commonly claimed that flavour experiences are paradigmatic examples of multimodal perceptual experiences. In fact, virtually any sensory system, including vision and audition, is believed to influence how we experience flavours. However, there is a strong intuition, often expressed in these works, that not all of these sensory systems make an equal contribution to the phenomenology of flavour experiences. More specifically, it seems that the activities of some sensory systems are constitutive for (...) flavour perception while others merely influence how we experience flavours. This paper aims to answer the question regarding the constitutive factors of flavour perception in a twofold way. First, a theoretical framework is developed, relying on debates regarding constitutivity in analytic metaphysics and philosophy of science, which defines the stronger and weaker senses in which the activities of sensory systems may be constitutive for flavour perception. Second, relying on empirical results in flavour science, the constitutive status of activities related to distinct sensory systems in the context of flavour perception is investigated. (shrink)

Traditionally, philosophers have appealed to the phenomenological similarity between visual experience and visual imagery to support the hypothesis that there is significant overlap between the perceptual and imaginative domains. The current evidence, however, is inconclusive: while evidence from transcranial brain stimulation seems to support this conclusion, neurophysiological evidence from brain lesion studies (e.g., from patients with brain lesions resulting in a loss of mental imagery but not a corresponding loss of perception and vice versa) indicates that there are functional (...) and anatomical dissociations between mental imagery and perception. Assuming that the mental imagery and perception do not overlap, at least, to the extent traditionally assumed, then the question arises as to what exactly mental imagery is and whether it parallels perception by proceeding via several functionally distinct mechanisms. In this review, we argue that even though there may not be a shared mechanism underlying vision for perception and conscious imagery, there is an overlap between the mechanisms underlying vision for action and unconscious visual imagery. On the basis of these findings, we propose a modification of Kosslyn’s model of imagery that accommodates unconscious imagination and explore possible explanations of the quasi-pictorial phenomenology of conscious visual imagery in light of the fact that its underlying neural substrates and mechanisms typically are distinct from those of visual experience. (shrink)

Research in vision science, developmental psychology, and the foundations of cognitive science has led some theorists to posit referential mechanisms similar to indices. This hypothesis has been framed within a Fodorian conception of the early vision module. The article shows that this conception is mistaken, for it cannot handle the ‘interface problem’—roughly, how indexing mechanisms relate to higher cognition and conceptual thought. As a result, I reject the inaccessibility of early vision to higher cognition and make some (...) constructive remarks on the perception–cognition interface. -/- 1 The Case for Visual Indices 1.1 Preliminary assumptions 1.2 Transcendental arguments 1.3 Evidence from vision science 2 Visual Indices, Object Files, and Fodorian Modularity 3 The Interface Problem 3.1 Top-down attention and modularity 3.2 Selective attention and information 4 Revising the Indexing Hypothesis 4.1 Revising the perception–cognition interface 4.2 Revising the modularity of early vision 5 Concluding Remarks. (shrink)

For almost half a century dual-stream advocates have vigorously defended the view that there are two functionally specialized cortical streams of visual processing originating in the primary visual cortex: a ventral, perception-related ‘conscious’ stream and a dorsal, action-related ‘unconscious’ stream. They furthermore maintain that the perceptual and memory systems in the ventral stream are relatively shielded from the action system in the dorsal stream. In recent years, this view has come under scrutiny. Evidence points to two overlapping action pathways: (...) a dorso-dorsal pathway that calculates features of the object to be acted on, and a ventro-dorsal pathway that transmits stored information about skilled object use from the ventral stream to the dorso-dorsal pathway. This evidence suggests that stored information may exert significantly more influence on visually guided action than hitherto assumed. I argue that this, in turn, supports the notion of skilled automatic action that is nonetheless agential. My focus here will be on actions influenced by implicit biases (stereotypes/prejudices). Action that is biased in this way, I argue, is in an important sense intentional and agential. (shrink)

What representational state mediates between perception and action? Bence Nanay says pragmatic representations, which are outputs of perceptual systems. This commits him to the view that optic ataxics face difficulty in performing visually guided arm movements because the relevant perceptual systems output their pragmatic representations incorrectly. Here, I argue that it is not enough to say that pragmatic representations are output incorrectly; we also need to know why they are output that way. Given recent evidence that optic ataxia impairs (...) peripersonal space representation, I argue that pragmatic representations are output incorrectly because the organizing principle of the vision-for-action system is blocked by optic ataxia. I then show how this means that this principle, not pragmatic representations, is the representational state that mediates between perception and action, i.e. the principle, not pragmatic representations, is the immediate mental antecedent of action. (shrink)

Much recent philosophy of perception is preoccupied with finding a place for phenomenal character in a physical world. By contrast, Locke’s philosophy of sensory perception is an episode in his ‘Historical, plain method’ and seeks to map out the processes by which we experience ordinary objects. On Locke’s account, our ideas of primary and secondary qualities enter the mind ‘simple and unmixed’; having an idea of a colour, for example, is not necessary for the visual experience of a (...) shape. An analysis of the Molyneux problem reveals that, for Locke, judgment corrects the initial two-dimensional idea vision presents us with. Nevertheless, Locke’s position is problematic: he has no account of how we pair ideas of primary and secondary qualities, nor of how we could experience a colourless visual idea of shape. (shrink)

Is the sense of smell a source of aesthetic perception? Traditional philosophical aesthetics has centered on vision and audition but eliminated smell for its subjective and inherently affective character. This article dismantles the myth that olfaction is an unsophisticated sense. It makes a case for olfactory aesthetics by integrating recent insights in neuroscience with traditional expertise about flavor and fragrance assessment in perfumery and wine tasting. My analysis concerns the importance of observational refinement in aesthetic experience. I argue (...) that the active engagement with stimulus features in perceptual processing shapes the phenomenological content, so much so that the perceptual structure of trained smelling varies significantly from naive smelling. In a second step, I interpret the processes that determine such perceptual refinement in the context of neural decision-making processes, and I end with a positive outlook on how research in neuroscience can be used to benefit philosophical aesthetics. (shrink)

I propose a reading of Berkeley's Essay towards a New Theory of Vision in which Molyneux-type questions are interpreted as thought experiments instead of arguments. First, I present the general argumentative strategy in the NTV, and provide grounds for the traditional reading. Second, I consider some roles of thought experiments, and classify Molyneux-type questions in the NTV as constructive conjectural thought experiments. Third, I argue that (i) there is no distinction between Weak and Strong Heterogeneity theses in the NTV; (...) (ii) that Strong Heterogeneity is the basis of Berkeley's theory; and (iii) that Molyneux-type questions act as illustrations of Strong Heterogeneity. (shrink)

Representationalism is the position that the phenomenal character of a perceptual experience supervenes upon its representational content. The phenomenon of blurry vision is thought to raise a difficulty for this position. More specifically, it is alleged that representationalists cannot account for the phenomenal difference between clearly seeing an indistinct edge and blurrily seeing a distinct edge solely in terms of represented features of the surrounding environment. I defend representationalism from this objection by offering a novel account of the phenomenal (...) difference between these two kinds of cases. (shrink)

The role of the physiological processes involved in human vision escapes clarification in current literature. Many unanswered questions about vision include: 1) whether there is more to lateral inhibition than previously proposed, 2) the role of the discs in rods and cones, 3) how inverted images on the retina are converted to erect images for visual perception, 4) what portion of the image formed on the retina is actually processed in the brain, 5) the reason we have (...) an after-image with antagonistic colors, and 6) how we remember space. This theoretical article attempts to clarify some of the physiological processes involved with human vision. The global integration of visual information is conceptual; therefore, we include illustrations to present our theory. Universally, the eyeball is 2.4 cm and works together with membrane potential, correspondingly representing the retinal layers,photoreceptors, and cortex. Images formed within the photoreceptors must first be converted into chemical signals on the photoreceptors’ individual discs and the signals at each disc are transduced from light photons into electrical signals. We contend that the discs code the electrical signals into accurate distances and are shown in our figures. The pre-existing oscillations among the various cortices including the striate and parietal cortex,and the retina work in unison to create an infrastructure of visual space that functionally ‘‘places” the objects within this ‘‘neural” space. The horizontal layers integrate all discs accurately to create a retina that is pre-coded for distance. Our theory suggests image inversion never takes place on the retina,but rather images fall onto the retina as compressed and coiled, then amplified through lateral inhibition through intensification and amplification on the OFF-center cones. The intensified and amplified images are decompressed and expanded in the brain, which become the images we perceive as external vision. (shrink)

Quilty-Dunn et al.'s wide-ranging defense of the Language of Thought Hypothesis (LoTH) argues that vision traffics in abstract, structured representational formats. We agree: Vision, like language, is compositional – just as words compose into phrases, many visual representations contain discrete constituents that combine in systematic ways. Here, we amass evidence extending this proposal, and explore its implications for how vision interfaces with the rest of the mind.

In a recent article on Reid’s theory of single and double vision, James Van Cleve considers an argument against direct realism presented by Hume. Hume argues for the mind-dependent nature of the objects of our perception from the phenomenon of double vision. Reid does not address this particular argument, but Van Cleve considers possible answers Reid might have given to Hume. He finds fault with all these answers. Against Van Cleve, I argue that both appearances in double (...) vision could be considered visible figures of the object, and show how this solution might preserve Reid’s direct realism. However, this solution is not compatible with the single appearance of an object predicted by Reid’s theory of single and double vision. This consequence will appear evident once we consider the critique of Reid’s theory of single and double vision formulated by William Charles Wells (1757-1817). Wells argues that Reid’s theory is either incomplete or incompatible with other claims made by Reid. It is incomplete since it fails to specify the unique direction in which we the object in single vision; if it not incomplete and is compatible with the law of monocular direction given by Reid, then it is incompatible with Reid’s claim that we do not perceive immediately distance by sight. (shrink)

This paper explores the extent to which a scientific framework for visualization might be possible. It presents several potential parts of a framework, illustrated by application to the visualization of correlation in scatterplots. The first is an extended-vision thesis, which posits that a viewer and visualization system can be usefully considered as a single system that perceives structure in a dataset, much like "basic" vision perceives structure in the world. This characterization is then used to suggest approaches to (...) evaluation that take advantage of techniques used in vision science. Next, an optimal-reduction thesis is presented, which posits that an optimal visualization enables the given task to be reduced to the most suitable operations in the extended system. A systematic comparison of alternative designs is then proposed, guided by what is known about perceptual mechanisms. It is shown that these elements can be extended in various ways—some even overlapping with parts of vision science. As such, a science of some kind appears possible for at least some parts of visualization. It would remain distinct from design practice, but could nevertheless assist with the design of visualizations that better engage human perception and cognition. (shrink)

Our emotional states affect how we perceive the world. If I am stressed, annoyed, or irritated, I might experience the sound of children laughing and screaming as they play around the house in a negative manner — it is unpleasant, loud, piercing, and so on. Yet, if I’m in a relaxed, happy, loving mood, the very same sounds might be experienced as pleasant, playful, warm, and so on. The sounds being made by the children are the same in both cases, (...) but how they are experienced differs. The auditory experience is affected by the emotional state that I am in. I perceive the sounds differently depending on how I’m feeling. Although this might at first seem to be a trivial observation, it certainly is not. We take for granted that our perceptual experiences give rise to justified beliefs and knowledge. Thus, if my perceptual experience of an object can differ based on my emotional state, and I take my perceptual experience to justify my beliefs and even lead to knowledge, then we might have a problem. If emotions — which are not fixed and in large part uncontrolled — affect our ability to accurately perceive the world, then they may undermine the justified beliefs and knowledge gained on the basis of our perceptual experience of the world. My goal here is to explore this potential problem. -/- I consider how we might understand the effect that emotions have on the justification of our perceptual beliefs about the world, beliefs that we acquire from a variety of sensory modalities — audition, gustation olfaction, and so on. I take the problem to be associated with one of two forms of perceptual influence: penetration or multisensory integration. In any given perceptual moment there are multiple sensory modalities and mental states at play, each affecting the overall experience. Whether we understand the influence of emotion on perception as a form of non-perceptual penetration or a form of non-visual sensory perception of the inner body — interoception — the potential epistemological difficulties remain: how can we be said to acquire justified beliefs and knowledge on the basis of such influenced perceptual experience. As has been the norm, only the five exteroceptive senses of vision, audition, olfaction, taste and touch are typically discussed in the context of sensory perception. However, as I argue, there is strong reason to accept the claim that emotional experience is a form of interoception, and that interoception ought to be considered when discussing sensory perception. In this way, then, I propose that clarifying the role played by interoception in sense perception across modalities is necessary if we are to make progress on the epistemological problems at hand. (shrink)

Many philosophers believe that there is a causal condition on perception, and that this condition is a conceptual truth about perception. A highly influential argument for this claim is based on intuitive responses to Gricean-style thought experiments. Do the folk share the intuitions of philosophers? Roberts et al. (2016) presented participants with two kinds of cases: Blocker cases (similar to Grice’s case involving a mirror and a pillar) and Non-Blocker cases (similar to Grice’s case involving a clock and (...) brain stimulation). They found that a substantial minority agreed that seeing occurs in the Non-Blocker cases, and that in the Blocker cases significantly less agreed that seeing occurs. They thus hypothesized that folk intuitions better align with a no blocker condition than with a causal condition. This paper continues this line of enquiry with two new experiments. The paper investigates the generality and robustness of Roberts et al.’s findings by expanding the sense modalities tested from only vision to audition and olfaction as well. The paper also uses Gricean-style thought experiments as a case study for investigating the “reflection defense” against the negative project in experimental philosophy. Our results replicate and extend Roberts et al.’s study and support their hypothesis that folk intuitions better align with a no blocker condition. They also provide an empirical reason to doubt the reflection defense. (shrink)