Vision

The dictionary tells you that a shadow is a dark area or volume caused by an opaque object blocking some light. The definition is correct, but we need to clarify a couple of its elements: darkness and blocking. The clarification leads to the view that to see a shadow is a degree of failing to see a surface. I will also argue that seeing a silhouette (i.e. a backlit object) is a particular way of failing to see an object. Thus (...) visual discriminability is not sufficient for seeing. Finally, I argue that comparative empirical research on shadows' contribution to amodal completion in apes and humans supports the view that humans, unlike apes, perceive shadows as shadows rather than as black objects, thus lending indirect support for my view that to see a shadow is a way and degree of failing to see a surface. (shrink)

Department of Philosophy Brown University Providence, RI 02915.

According to proponents of the sensorimotor contingency theory of perception (Hurley & Noë 2003, Noë 2004, O’Regan 2011), active control of camera movement is necessary for the emergence of distal attribution in tactile-visual sensory substitution (TVSS) because it enables the subject to acquire knowledge of the way stimulation in the substituting modality varies as a function of self-initiated, bodily action. This chapter, by contrast, approaches distal attribution as a solution to a causal inference problem faced by the subject’s perceptual systems. (...) Given all of the available endogenous and exogenous evidence available to those systems, what is the most probable source of stimulation in the substituting modality? From this perspective, active control over the camera’s movements matters for rather different reasons. Most importantly, it generates proprioceptive and efference-copy based information about the camera’s body-relative position necessary to make use of the spatial cues present in the stimulation that the subject receives for purposes of egocentric object localization. (shrink)

Molyneux asked whether a newly sighted person could distinguish a sphere from a cube by sight alone, given that she was antecedently able to do so by touch. This, we contend, is a question about general ideas. To answer it, we must ask (a) whether spatial locations identified by touch can be identified also by sight, and (b) whether the integration of spatial locations into an idea of shape persists through changes of modality. Posed this way, Molyneux’s Question goes substantially (...) beyond question (a), about spatial locations, alone; for a positive answer to (a) leaves open whether a perceiver might cross-identify locations, but not be able to identify the shapes that collections of locations comprise. We further emphasize that MQ targets general ideas so as to distinguish it from corresponding questions about experiences of shape and about the property of tangible (vs. visual) shape. After proposing a generalized formulation of MQ, we extend earlier work (“Many Molyneux Questions,” Australasian Journal of Philosophy 2020) by showing that MQ does not admit a single answer across the board. Some integrative data-processes transfer across modalities; others do not. Seeing where and how such transfer succeeds and fails in individual cases has much to offer to our understanding of perception and its modalities. (shrink)

In this paper I present an empirical solution to the puzzle of Macbeth's dagger. The puzzle of Macbeth's dagger is the question of whether, in having his fatal vision of a dagger, Macbeth sees a dagger. I answer this question by addressing a more general one: the question of whether perceptual verbs are intensional transitive verbs (ITVs). I present seven experiments, each of which tests a collection of perceptual verbs for one of the three features characteristic of ITVs. One of (...) these features is Nonexistence: the failure of sentences involving transitive verbs to entail the existence of their direct objects. The experiments reveal that with respect to all three of these features, "see" behaves much more like a paradigmatically extensional verb than an intensional one. But surprisingly, unlike "see", "perceive" behaves much more like a paradigmatically intensional verb. This shows that the category of perceptual verbs is not uniform with respect to the features of intensionality; while Macbeth does not see a dagger, he may still perceive one. (shrink)

Ensemble perception—the encoding of objects by their group properties—is known to be resistant to outlier noise. However, this resistance is somewhat paradoxical: how can the visual system determine which stimuli are outliers without already having derived statistical properties of the ensemble? A simple solution would be that ensemble perception is not a simple, one-step process; instead, outliers are detected through iterative computations that identify items with high deviance from the mean and reduce their weight in the representation over time. Here (...) we tested this hypothesis. In Experiment 1, we found evidence that outliers are discounted from mean orientation judgments, extending previous results from ensemble face perception. In Experiment 2, we tested the timing of outlier rejection by having participants perform speeded judgments of sets with or without outliers. We observed significant increases in reaction time (RT) when outliers were present, but a decrease compared to no-outlier sets of matched range suggesting that range alone did not drive RTs. In Experiment 3 we tested the timing by which outlier noise reduces over time. We presented sets for variable exposure durations and found that noise decreases linearly over time. Altogether these results suggest that ensemble representations are optimized through iterative computations aimed at reducing noise. The finding that ensemble perception is an iterative process provides a useful framework for understanding contextual effects on ensemble perception. (shrink)

In the September 2020 edition of Perception, Alan Gilchrist published an editorial entitled “The Integrity of Vision” (Gilchrist, 2020). In it, Gilchrist critiques motivated perception research. His main points are as follows: (1) Motivated perception is compromised by experimental demand: Results do not actually show motivated perception but instead reflect subjects’ desires to comply with inferred predictions. (2) Motivated perception studies use designs that make predictions obvious to subjects. These transparent designs conspire with experimental demand to yield confirmatory but compromised (...) results. (3) Motivated perception research lacks guiding theory and cannot explain what appear to be contradictory results. (4) Motivated perception presents an unsupportable assault upon the impermeability of perception. The present commentary responds to these four assertions. (shrink)

In his remarkable book, Visual Phenomenology, Michael Madary argues for the claim that “visual perception is an ongoing process of anticipation and fulfillment” (Madary 2017, p. 3), by drawing upon lines of evidence from Husserlian phenomenology, philosophy of perception, and the cognitive sciences. While he considers Edmund Husserl as a major influence upon his ideas, he does not aim to adhere to Husserl’s views in every regard, but instead to develop Husserl-inspired views of his own, muster support for them, and (...) bring them to bear on various issues (Ibid., pp. 4, 181). His book is therefore likely to be of interest not only to scholars of Husserlian phenomenology, but also to non-Husserlian philosophers of perception, as well as to cognitive scientists. (shrink)

Higher animals need to identify and track material objects because they depend on interactions with them for nutrition, reproduction, and social interaction. This paper investigates the perception of material objects. It argues, first, that material objects are tagged, in all five external senses, as bearers of the features detected by them. This happens through a perceptual process, here entitled Generalized Completion, which creates the appearance of objects that have properties that transcend the activation of sensory receptors. The paper shows, secondly, (...) that material objects are privileged subjects for perceived motion and interaction. That is, they are perceived as subjects for these properties while their parts seem to be subjects only derivatively. Material objects are the only perceptual subjects that are both multisensory and privileged. (shrink)

Jerry Fodor wrote the following assessment of Danto’s importance in 1993: “Danto has done something I’ve been very much wanting to do: namely, reconsider some hard problems in aesthetics in the light of the past 20 years or so of philosophical work on intentionality and representation” (Fodor 1993, p. 41). Fodor is absolutely right: some of Danto’s work could be thought of as the application of some influential ideas about perception that Fodor also shared. The problem is that these ideas (...) have turned out to be false. Both Danto and Fodor are modularist: they both think that perception is an encapsulated process that is in no way influenced by any kind of non-perceptual processing (see, e.g., Fodor 1983, Pylyshyn 1984). Many of Danto’s famous and influential arguments rely very directly on this modularist assumption. There is now, however, a wealth of evidence against modularism of the strong kind held to by Danto and Fodor. We now know that perceptual experience is not determined entirely by the retinal input: our visual processing is influenced at various point in a top-down manner. What we know and what kinds of visual stimuli we have encountered previously deeply influence how the retinal input is processed. The empirical literature on this is vast and conclusive (for an overview, see Teufel and Nanay 2017 but see also the references in the last section of this paper). What does this mean for Danto’s views on art and perception? While one of Danto’s premises may turn out to be false, the history and examples he gave are valuable and bear repeating. Even more importantly, Danto’s aesthetics can in part be separated out from his modularism, leading us to draw slightly different but arguably even more interesting conclusions from famous thought experiments such as the Gallery of Indiscernibles. (shrink)

We describe in our own words a visual phenomenon first described by Gallagher and Tsuchiya in 2020. The key to the phenomenon (as we describe it) is to direct one’s left eye at the image of one's left eye, while simultaneously directing one's right eye at the image of one's right eye. We suggest that one would naturally arrive at this phenomenon if one took a sufficiently literal reading of certain words of Socrates preserved in Plato's Alcibiades. We speculate that (...) perhaps Socrates was aware of the visual phenomenon in question. (shrink)

According to the decomposition thesis, perceptual experiences resolve without remainder into their different modality-specific components. Contrary to this view, I argue that certain cases of multisensory integration give rise to experiences representing features of a novel type. Through the coordinated use of bodily awareness—understood here as encompassing both proprioception and kinaesthesis—and the exteroceptive sensory modalities, one becomes perceptually responsive to spatial features whose instances couldn’t be represented by any of the contributing modalities functioning in isolation. I develop an argument for (...) this conclusion focusing on two cases: 3D shape perception in haptic touch and experiencing an object’s egocentric location in crossmodally accessible, environmental space. (shrink)

What is it like to perceive a feared object? According to a popular neo-Gibsonian theory in psychology, fear biases our perceptions of objects so as to encourage particular kinds of actions: when we are afraid, spiders may be perceived as physically closer than they are in order to promote fleeing. Firestone mounted severe criticisms against this view, arguing that these cases are better explained by non-perceptual biases that operate on accurate perceptions of the external environment. In this paper I will (...) argue that fear might indeed distort our perceptions of the world, but not in the way neo-Gibsonians suppose. In the view I favor, perceptual distortions occur as by-products of fearful attention, a special mode of attention that is part of an orchestrated defensive response that prepares the organism to deal effectively with a threat. To argue for this view I will rely on empirical evidence that fearful attention narrows down the focus of attention and favors processing of local rather than global features of stimuli, which may jointly explain why perceptual distortions might occur in fearful object seeing. This view has consequences not only for empirical investigations in fearful perceptual distortions, but also for an explanation of the intentionality of fear and the phenomenal integration of bodily and intentional elements in fear episodes. (shrink)

According to the Self-Location Thesis, certain types of visual experiences have self-locating and so first-person, spatial contents. Such self-locating contents are typically specified in relational egocentric terms. So understood, visual experiences provide support for the claim that there is a kind of self-consciousness found in experiential states. This paper critically examines the Self-Location Thesis with respect to dynamic-reflexive visual experiences, which involve the movement of an object toward the location of the perceiving subject. The main aim of this paper is (...) to offer an alternative interpretation of these cases which resists attributing them self-locating content, arguing for a replacement of the de se component with a non-conceptual equivalent of the indexical ‘here’. In its final section, the paper also considers an extension of the h-replacement account to cases of visual kinesthesis. (shrink)

Objectification involves treating someone as a thing. The role of images in perpetuating objectification has been discussed by feminist philosophers. However, the precise effect that images have on an individual's visual system is seldom explored. Kathleen Stock’s work is an exception—she describes certain images of women as causing viewers to develop an objectifying ‘gestalt’ which is then projected onto real-life women. However, she doesn’t specify the level of visual processing at which objectification occurs. In this paper, I propose that images (...) can affect a viewer's early visual system. I will argue that if a viewer is exposed to a lot of images that depict women as sexual objects, this will bias their early visual selection mechanisms in a way that can result in an objectifying way of seeing. This is an important contribution to work on objectification as it incorporates empirical studies on vision and findings from philosophy of mind. It also examines some of the epistemic and moral consequences of objectification occurring at this early visual stage. (shrink)

Kendall Walton argues that photographs are transparent; we literally see the things depicted in them, not just the depictions. This intriguing claim has endured numerous criticisms from those I call the ‘egocentrists’, according to whom seeing—literal seeing—requires the conveyance of egocentric information; to count as seeing something, a visual experience of that thing must impart some information, however spare, about its position relative to the viewer. Since photographs fail to convey such information, the egocentrists claim, Walton’s transparency thesis fails. This (...) paper considers several ways this egocentric condition on seeing has been developed and shows that none of them is persuasive. Seeing, I argue, does not require the conveyance of egocentric information. As such, and barring other problems, Walton’s transparency thesis stands. The paper closes with a speculative discussion of the kinds of empirical and action-guiding considerations that motivate egocentrism. (shrink)

Color-motion asynchrony (CMA) refers to an apparent lag of direction of motion when a dynamic stimulus changes both color and direction at the same time. The subjective order of simultaneous events, however, is not only perceptual but also subject to illusions during voluntary actions. Self-initiated actions, for example, seem to precede their sensory outcomes following an adaptation to a delay between the action and the sensory feedback. Here, we demonstrate that the extent of the apparent asynchrony can be substantially reduced (...) when direction change is induced by a voluntary key press following a delay adaptation regime. We also show that the reduced color-motion asynchrony effect size following a motor-sensory recalibration is not a result of a change in the onset of perceived direction change relative to that of the color. This is particularly important as it implies, for the first time in the literature, that voluntary action is not only important in forming action-sensory outcome associations but may also act as a binding factor between the two perceptual features of a sensory event. (shrink)

The reports of individuals who have had their vision restored after a long period of blindness suggest that, immediately after regaining their vision, such individuals are not able to recognize shapes by vision alone. It is often assumed that the empirical literature on sight restoration tells us something important about the relationship between visual and tactile representations of shape. However, I maintain that, immediately after having their sight restored, at least some newly sighted individuals undergo visual experiences that instantiate basic (...) shape phenomenology but which do not present (that is, neither represent nor involve acquaintance with) the corresponding shape properties. Consequently, the empirical literature on sight restoration tells us something important about the role that perceptual phenomenology plays in our perceptual awareness of an object’s properties—it tells us that the properties presented by perceptual experiences are not determined by or “built into” perceptual phenomenology. In addition, I maintain that the evidence concerning sight restoration suggests an alternative theory concerning the role that sensory phenomenology plays in our perceptual awareness of an object’s properties. Specifically, it suggests that, while not inherently representational, sensory phenomenal properties can serve as vehicles for the representation of an object’s properties. (shrink)

Van Eyck: An Optical RevolutionMuseum of Fine Arts, Ghent, Belgium, 1 February–30 April 2020.

According to a certain kind of naïve or folk understanding of physical matter, everyday ‘solid’ objects are composed of a homogeneous, gap-less substance, with sharply defined boundaries, which wholly fills the space they occupy. A further claim is that our perceptual experience of the environment represents or indicates that the objects around us conform to this sort of conception of physical matter. Were this further claim correct, it would mean that the way that the world appears to us in experience (...) conflicts with the deliverances of our best current scientific theories in the following respect: perceptual experience would be intrinsically misleading concerning the structure of physical matter. I argue against this further claim. Experience in itself is not committed to, nor does it provide evidence for, any such conception of the nature of physical matter. The naïve/folk conception of matter in question cannot simply be ‘read-off’ from perceptual appearances. (shrink)

The way in which vision represents objects as being the same despite movement and qualitative changes has been extensively investigated in contemporary psychology. However, the formal properties of the visual sameness relation are still unclear, for example, whether it is an identity-like, equivalence relation. The paper concerns one aspect of this problem: the transitivity of visual sameness. Results obtained by using different experimental paradigms are analysed, in particular studies using streaming/bouncing stimuli, multiple object tracking experiments and investigations concerning object-specific preview (...) benefit, and it is argued that the transitive interpretation of visual sameness is the most plausible given the current stage of knowledge. What is more, it is claimed that the way in which visual sameness is represented suggests that in some cases it should be characterized as a “primitive sameness”, similarly as in philosophical theories postulating “thisness”. (shrink)

Cognitive scientists have long known that the modalities interact during perceptual processing. Cross-modal illusions like the ventriloquism effect show that the course of processing in one modality can alter the course of processing in another. But how do the modalities interact in the specific domain of object perception? This paper distinguishes and analyzes two kinds of multisensory interaction in object perception. First, the modalities may bind features to a single object or event. Second, the modalities may cooperate when differentiating an (...) object or event from its surroundings. I critically evaluate evidence for various forms of multisensory binding. I then consider the case for multisensory differentiation. I argue that existing evidence for multisensory differentiation is inconclusive. I highlight ways that the issue might be empirically resolved. (shrink)

Two questions are addressed in this paper. First, what is it to see? I argue that it is veridical experience of things outside the perceiver brought about by looking. Second, what is it to see a material object? I argue that it is experience of an occupant of a spatial region that is a logical subject for other visual features, able to move to another spatial region, to change intrinsically, and to interact with other material objects. I show how this (...) theory is different from the idea that object-seeing is merely the visual segregation of a region of the visual field. Finally, I argue that we do not object-see objects reflected in mirrors, surfaces of back-lit objects, and depictions of objects. (shrink)

This chapter explores how our understanding of Molyneux’s question, and of the possibility of an experimental resolution to it, should be affected by recognizing the complexity that is involved in reidentifying shapes and other spatial properties across differing sensory manifestations of them. I will argue that while philosophers today usually treat the question as concerning ‘the relations between perceptions of shape in different sensory modalities’ (Campbell 1995, 301), in fact this is only part of the question’s real interest, and that (...) the answer to the question also turns on how shape is perceived within each of sight and touch individually. (shrink)

Sensorimotor expectations concern how visual experience covaries with bodily movement. Sensorimotor theorists argue from such expectations to the conclusion that the phenomenology of vision is constitutively embodied: objects within the visual field are experienced as 3-D because sensorimotor expectations partially constitute our experience of such objects. Critics argue that there are two ways to block the above inference: to explain how we visually experience objects as 3-D, one may appeal to such non-bodily factors as expectations about movements of objects, not (...) the perceiver, or to the role of mental imagery in visual experience. But instead of using sensorimotor expectations to explain how objects are experienced within the visual field, we can instead use them to explain our experience of the visual field itself and, in particular, our experience of its limits; that is, our ever-present visual sense of there being more to see, beyond what’s currently within the visual field. Crucially, this inference from sensorimotor expectations to the constitutive embodiment of visual phenomenology is not threatened by the above two challenges. I thus present here a sensorimotor theory of the phenomenology of the visual field, that is, our experience of our visual fields as such. (shrink)

Kant, Wittgenstein, and Husserl all held that visual awareness of objects requires visual awareness of the space in which the objects are located. There is a lively debate in the literature on spatial perception whether this view is undermined by the results of experiments on a Balint’s syndrome patient, known as RM. I argue that neither of two recent interpretations of these results is able to explain RM’s apparent ability to experience motion. I outline some ways in which each interpretation (...) may respond to this challenge, and suggest which way of meeting the challenge is preferable. I conclude that RM retains some awareness of the larger space surrounding the objects he sees. (shrink)

A short essay for a popular audience on why afterimages are difficult to fit into any ontology.

Ordinary cases of object seeing involve the visual perception of space and spatial location. But does seeing an object require such spatial perception? An empirical challenge to the idea that it does comes from reflection upon Bálint's syndrome, for some suppose that in Bálint's syndrome subjects can see objects without seeing space or spatial location. In this article, I question whether the empirical evidence available to us adequately supports this understanding of Bálint's syndrome, and explain how the aforementioned empirical challenge (...) can be resisted. (shrink)

Vision is organized around material objects; they are most of what we see. But we also see beams of light, depictions, shadows, reflections, etc. These things look like material objects in many ways, but it is still visually obvious that they are not material objects. This chapter articulates some principles that allow us to understand how we see these ‘ephemera’. H.P. Grice’s definition of seeing is standard in many discussions; here I clarify and augment it with a criterion drawn from (...) Fred Dretske. This enables me to re-analyse certain ephemera that have received counter-intuitive treatments in the work of Kendall Walton (photographs), Brian O’Shaughnessy (light), and Roy Sorenson (occlusions). (shrink)

Intentionalism about visual experiences is the view according to which the phenomenal character of a visual experience supervenes on the content of this experience. One of the most influential objections to this view is about blur: seeing a fuzzy contour clearly and seeing a sharp contour blurrily have different phenomenal character but the same content. I argue that this objection does not work if we understand perceptual content simply, and not particularly controversially, as partly constituted by the sum total of (...) perceptually attributed properties, some determinable, some determinate. (shrink)

This paper is a defense of an internalist view of the perception of shapes. A basic assumption of the paper is that perceptual experiences have certain parts which account both for the phenomenal character associated with perceiving shapes—phenomenal shapes—and for the intentional content presenting shapes—intentional shapes. Internalism about perceptions of shapes is defined as the claim that phenomenal shapes determine the intentional shapes. Externalism is defined as the claim that perceptual experiences represent whatever shape the phenomenal shape reliably tracks. The (...) argument against externalism proceeds in three steps. First, it is argued that phenomenal shapes are modality specific, such that a phenomenal shape that features in a visual perceptual experience cannot feature in a haptic perceptual experience, and vice versa. Second, it is argued that intentional shapes are amodal. Third, it is argued that externalism is incompatible with the fact that phenomenal shapes are modality specific and intentional shapes amodal. (shrink)

A good portion of the work in the ontology of color focuses on color properties, trying to figure out how they are related to more straightforwardly physical properties. Another focus is realism: are ordinary material objects such as pumpkins really colored? A third emphasis is the nature of what is referred to by the terms ‘what it’s like’ or ‘phenomenal character’, as applied to color. In contrast, this essay is exclusively about select color tokens. I will be arguing that whether (...) or not ordinary objects such as pumpkins are colored, regardless of what the true theory of color properties is, and independently of any talk of phenomenal character or what-it’s-likeness, some afterimage experiences are very hard to fit into any plausible ontology, physicalist or not. (shrink)

So-called "transparency theories" of self-knowledge, inspired by a remark of Gareth Evans, claim that we can obtain knowledge of our own beliefs by directing out attention towards the world, rather than introspecting the contents of our own minds. Most recent transparency theories concentrate on the case of self-knowledge concerning belief and desires. But can a transparency account be generalised to knowledge of one's own perceptions? In a recent paper, Alex Byrne (2012) argues that we can know what we see by (...) inferring from visual facts about our environment because such facts can exclusively be known by us through vision. I discuss his proposal and object that visual facts, as conceived of by Byrne, are odd: they cannot be remembered and we cannot, as yet, write them down. More needs to be said about them to make his account plausible. (shrink)

(Open Access article, freely available to download from publisher's site.) Our visual experiences of objects as located in external space, and as having definite three-dimensional shapes, are closely linked to our implicit expectations about what things will look like from alternative viewpoints. What sorts of contents do these expectations involve? One standard answer is that they relate to what things will look like to us upon changing our positions. And what sorts of mental representations do the expectations call upon? A (...) standard answer is that they involve our powers of visual imagery; this answer requires us to allow for the possibility of unconscious visual imagery, however. The current paper presents an alternative model of the contents of our implicit visual expectations, one that regards them as wholly nonreflexive. It also argues that, once we ascribe the relevant contents to the expectations, there is no longer any reason for holding that they involve our powers of visual imagery. (shrink)

This paper argues that a common form of representationalism has trouble accommodating empirical findings about visual space perception. Vision science tells us that the visual system systematically gives rise to different experiences of the same spatial property. This, combined with a naturalistic account of content, suggests that the same spatial property can have different veridical looks. I use this to argue that a common form of representationalism about spatial experience must be rejected. I conclude by considering alternatives to this view.

This paper first reviews our present understanding, and misunderstanding, of the 'binding' problem of how phenomenal colour, shape, and movement are integrated within the visual system. The traditional theory that this is done by interactions between the separate colour, shape, and motion computational centres in the visual cortex has been undermined by experiments carried out by Semir Zeki that suggest that such interactions do not take place. This is linked to the hypothesis that the visual system contains two channels: Ohyama's (...) hierarchical behavioural network and the visual phenomenal network. The review presents a further linkage between the computational mechanisms used in vision with those used in digital television. Then a number of theories designed to explain how the 'binding' may operate are examined. Two theories have their basis within the identity theory and a third theory is based on a recent version of the psychoneural interaction theory that distinguishes phenomenal space from physical space. The conclusion is made that the new formation presented in this review supports the latter theory. (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)

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)

A recent empirical study claims to show that the answer to Molyneux’s question is negative, but, as John Schwenkler points out, its findings are inconclusive: Subjects tested in this study probably lacked the visual acuity required for a fair assessment of the question. Schwenkler is undeterred. He argues that the study could be improved by lowering the visual demands placed on subjects, a suggestion later endorsed and developed by Kevin Connolly. I suggest that Connolly and Schwenkler both underestimate the difficulties (...) involved in rectifying the study they seek to fix. The problem is that the experimental paradigm under consideration fails to account for the role that rational inference plays in newly sighted subjects’ ability or inability to recognize spatial properties across modalities. Since answering Molyneux’s question requires establishing whether spatial properties can be recognized, across modalities, by newly sighted subjects without recourse to rational inference, this is a problem. Indeed, it is a problem that may be worsened by Schwenkler and Connolly’s suggestions regarding the lowering of visual demands on subjects in cross-modal matching tasks. (shrink)

I consider the geometrical structure of the apparent visual field. Although the optics of vision is well understood, the nature of visual awareness remains largely in the dark. A famous attempt at a formal description of the apparent visual field was by Helmholtz, in the late nineteenth century. It purportedly explains the phenomenon of the subjective curvatures often reported when viewing objectively straight lines of great extent. I consider the general problem, and suggest an alternative formal account. On phenomenological grounds (...) the very existence of a coherent geometry may be doubted. Yet, although seemingly an academic question, the issue has very real consequences. The two models I consider here may approximately apply to certain visual modes. The nature of such visual modes is discussed. (shrink)

Thomas Reid's Geometry of Visibles, according to which the geometrical properties of an object's perspectival appearance equal the geometrical properties of its projection on the inside of a sphere with the eye in its centre allows for two different interpretations. It may (1) be understood as a theory about phenomenal visual space – i.e. an account of how things appear to human observers from a certain point of view – or it may (2) be seen as a mathematical model of (...) viewpoint-relative but mind-independent relational properties of objects. This paper makes a systematic and a historical claim. I shall argue, first, that given certain features of the human visual system phenomenal visual space differs in several aspects from Reidean visual space. Secondly, I suggest that, since Reid was aware of some of these empirical facts, we should interpret Reid as endorsing the second interpretation of the Geometry of Visibles. (shrink)

According to an influential variety of the representational view of perceptual experience—the singular content view—the contents of perceptual experiences include singular propositions partly composed of the particular physical object a given experience is about or of. The singular content view faces well-known difficulties accommodating hallucinations; I maintain that there is also an analogue of Frege's puzzle that poses a significant problem for this view. In fact, I believe that this puzzle presents difficulties for the theory that are unique to perception (...) in that strategies that have been developed to respond to Frege's puzzle in the case of belief cannot be employed successfully in the case of perception. Ultimately, I maintain that this perceptual analogue of Frege's puzzle provides a compelling reason to reject the singular content view of perceptual experience. (shrink)

This book provides the first critical edition of Ibn al-Haytham’s On the Shape of the Eclipse with English translation and commentary, which records the first scientific analysis of the camera obscura. On the Shape of the Eclipse includes pioneering research on the conditions of formation of the image, in a time deemed to be committed to aniconism. It also provides an early attempt to merge the two branches of Ancient optics—the theory of light and theory of vision. What perhaps most (...) strongly characterizes this treatise is the close interaction of a geometric analysis of light and experimental reasoning. Ibn al-Haytham conducted his experiments in a systematic way by varying all that could be changed: the shape and size of the aperture, the focal length of the camera obscura, the distance and shape of the celestial bodies. This way, he achieved a thorough understanding. This work represents a decisive step in both the history of optics and the application of the experimental method that was just as efficient in medieval Islam as today. (shrink)

This book explores the interrelationships between optics, vision and perspective before the Classical Age, examining binocularity in particular. The author shows how binocular vision was one of the key juncture points between the three concepts and readers will see how important it is to understand the approach that scholars once took. In the Middle Ages and the Renaissance, the concept of Perspectiva – the Latin word for optics – encompassed many areas of enquiry that had been viewed since antiquity as (...) interconnected, but which a erwards were separated: optics was incorporated into the field of physics (i.e., physical and geometrical optics), vision came to be regarded as the sum of various psycho-physiological mechanisms involved in the way the eye operates (i.e., physiological optics and psychology of vision) and the word ‘perspective’ was reserved for the mathematical representation of the external world (i.e., linear perspective). The author shows how this division, which emerged as a result of the spread of the sciences in classical Europe, turns out to be an anachronism if we confront certain facts from the immediately preceding periods. It is essential to take into account the way medieval scholars posed the problem – which included all facets of the Latin word perspectiva – when exploring the events of this period. (shrink)