Online research in philosophy

In his ecological approach to perception, james gibson introduced the concept of affordance to refer to the perceived meaning of environmental objects and events. this paper examines the relational and causal character of affordances, as well as the grounds for extending affordances beyond environmental features with transcultural meaning to include those features with culturally-specific meaning. such an extension is seen as warranted once affordances are grounded in an intentional analysis of perception. toward this end, aspects of merleau-ponty's treatment (...) of perception are explored. finally, a resolution of the apparent tension between the relational and perceiver-independent nature of affordances is presented. (shrink)

Fodor & Pylyshyn (1981) criticize J. J. Gibson's ecological account of perception for failing to address what I call the 'correlation problem' in visual perception. That is, they charge that Gibson cannot explain how perceivers learn to correlate detectable properties of the light with perceptible properties of the environment. Furthermore, they identify the correlation problem as a crucial issue for any theory of visual perception, what I call a 'primary problem'—i.e. a problem which plays a (...) definitive role in establishing the concerns of a particular scientific research program. If they are correct, Gibson's failure to resolve this problem would cast considerable doubt upon his ecological approach to perception. In response, I argue that both Fodor & Pylyshyn's problem itself and their proposed inferential solution embody a significant mistake which needs to be eliminated from our thinking about visual perception. As part of my response, I also suggest a Gibsonian alternative to Fodor & Pylyshyn's primary problem formulation. (shrink)

A range of arguments are presented to demonstrate that (1) human visual orientations are conceptually constituted (concept?bound); (2) the concept?boundedness of visual orientations does not require a cognitivist account according to which a mental process of ?inference? or of ?interpretation? must be postulated to accompany a purely ?optical? registration of ?wavelengths of light?, ?photons?, or contentless ?information'; (3) concept?bound visual orientations are not all instances of ?seeing as?, contrary to some currently prominent cognitivist accounts; (4) the dispute (...) between cognitivist and realist accounts about the phenomenon of ?seeing as? is spurious, and is based upon a confusion about the fundamental analytical distinction made by Wittgenstein between ?seeing? and ?seeing as'; (5) ?perceiving?, ?seeing?, and ?seeing as? are but three of a large array of verbs of human visual orientation, and are not ?master categories? under which one can subsume these other modalities; (6) one cannot deduce a continuity of human visual orientation from a continuity of photon?photoreceptor interaction, a point we characterize as the ?staggered character? of human visual orientations; (7) detailed attention to the grammars of the diverse verbs of human visual orientation can open up a domain of study which we here refer to as a ?praxiology of perception'; (8) the nature of such an inquiry can be illustrated with exemplary reference to the analysis of the properties of ?noticing? as embedded in courses of practical action; and (9) such arguments, which claim that existing perceptual theories overly homogenize what is involved in visual orientations to the world, parallel those of Stroll, who proposes that standard accounts of ?what is perceived? overly homogenize the perceptible environment. (shrink)

In this paper I present a transcendental argument based on the findings of cognitive psychology and neurophysiology which invites two conclusions: First and foremost, that a pre-condition of visual perception itself is precisely what the Aristotelian and other commonsense realists maintain, namely, the independent existence of a featured, or pre-packaged world; second, this finding, combined with other reflections, suggests that, contra McDowell and other neo-Kantians, human beings have access to things as they are in the world via non-projective (...) perception. These two conclusions taken together form the basis of Aristotelian metaphysical realism and a refutation of the neo-Kantian two-factor approach to perception. (shrink)

This paper advances a novel argument that speech perception is a complex system best understood nonindividualistically and therefore that individualism fails as a general philosophical program for understanding cognition. The argument proceeds in four steps. First, I describe a "replaceability strategy", commonly deployed by individualists, in which one imagines replacing an object with an appropriate surrogate. This strategy conveys the appearance that relata can be substituted without changing the laws that hold within the domain. Second, I advance a "counterfactual (...) test" as an alternative to the replaceability strategy. Third, I show how the typical objects of cross-modal processes (in this case, auditory-visual speech perception), more clearly irreplaceable than the objects of the unimodal process examined by Burge [(1986) Individualism and psychology, The Philosophical Review, XCV, 3-45], supply a firm basis for a nonindividualist interpretation of such cases. Finally, I demonstrate that the routine violation of the individualist's Replaceability Condition occurs even in unimodal cases - so the violation of the replaceability constraint does not derive simply from the diversity of modal sources but rather from the causal complexity of psychological processes generally. The conclusion is that philosophical progress on this issue must await progress in psychology, or, at least, philosophical progress in accounting for psychological complexity--precisely the vicissitude predicted by a thoroughgoing naturalism. (shrink)

In recent years, a pair of intriguing phenomena has caused researchers working on vision and visual attention to reevaluate many of their assumptions. These phenomena, which have come to be called change blindness (CB) and inattentional blindness (IB), have led many to the conclusion that ordinary perceivers labor under a ``grand illusion'' concerning perception - an illusion that is..

A traditional view of perception and action makestwo assumptions: that the causal flow betweenperception and action is primarily linear or one-way,and that they are merely instrumentally related toeach other, so that each is a means to the other.Either or both of these assumptions can be rejected.Behaviorism rejects the instrumental but not theone-way aspect of the traditional view, thus leavingitself open to charges of verificationism. Ecologicalviews reject the one-way aspect but not theinstrumental aspect of the traditional view, so thatperception (...) and action are seen as instrumentallyinterdependent. It is argued here that a betteralternative is to reject both assumptions, resultingin a two-level interdependence view in whichperception and action co-depend on dynamicallycircular subpersonal relations and as a result may bemore than merely instrumentally interdependent. Thisis illustrated by reference to motor theories ofperception and control theories of action. (shrink)

The neural substrate of early visual processing in the macaque is used as a framework to discuss recent progress towards a precise anatomical localization and understanding of the functional implications of the syndromes of blindsight, achromatopsia and akinetopsia in humans. This review is mainly concerned with how these syndromes support the principles of organization of the visual system into parallel pathways and the functional hierarchy of visual mechanisms.

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

And in the end I came to believe that the whole theory of depth perception was false. I suggested a new theory in a book on what I called the visual world ...

Machine generated contents note: -- 1. Introduction -- Consciousness and Sensorimotor Dynamics: Methodological Issues -- 2. Computational consciousness, D. Ballard -- 3. Explaining what people say about sensory qualia, J. Kevin O'Regan -- 4. Perception, action, and experience: unraveling the golden braid, A. Clark -- The Two-Visual Systems Hypothesis -- 5. Cortical visual systems for perception and action, A.D. Milner and M.A. Goodale -- 6. Hermann Lotze's Theory of 'Local Sign': evidence from pointing responses (...) in an illusory figure, D.R. Melmoth -- Understanding Agency and Object Perception -- 7. Two visual systems and the feeling of presence, M. Matthen -- 8. Spatial coordinates and phenomenology in the two-visual systems model, P. Jacob and F. de Vignemont -- 9. Perceptual experience and the capacity to act, S. Schellenberg -- Perception and Action: Studies in Cognitive Neuroscience -- 10. Why does the perception-action functional dichotomy not match the ventral-dorsal streams in anatomical segregation: optic ataxia and the function of the dorsal stream, Y. Rossetti et al -- 11. Mapping the neglect syndrome onto neurofunctional streams, G. Vallar and F. Mancini -- 12. Motor representations and the perception of space: perceptual judgments of the boundary of action space, Y. Delevoye-Turrell -- The Role of Action and Sensorimotor Knowledge in Sensorimotor Theories of Perception -- 13. Vision without representation, A. Noe -- 14. Sensorimotor knowledge and the contents of experience, J. Kiverstein -- Boundaries of the Agent -- 15. Extended vision, R. A. Wilson. (shrink)

George Berkeley's apparently strange view – that nothing exists without a mind except for minds themselves – is notorious. Also well known, and equally perplexing at a superficial level, is his insistence that his doctrine is no more than what is consistent with common sense. It was every bit as crucial for Berkeley that it be demonstrated that the colors are really in the tulip, as that there is nothing that is neither a mind nor something perceived by a mind. (...) In what follows, I shall attempt to re-examine Berkeley's argument in terms of what it appears to have meant to him. I am especially interested in the connection between Berkeley's thought concerning the relation between perception and metaphysics and that of Maurice Merleau-Ponty, with whom, perhaps surprisingly, Berkeley shared a great many intuitions and concerns. Thus part of my objective is to compare and contrast the work of two thinkers who had many common interests, and whose thought frequently led them down similar paths. I shall be especially interested in apparent points of departure, both those that turn out to reflect real divergences and those which reflect confusions of one kind or another. My main objective, however, is not mere textual analysis. Like both Berkeley and Merleau-Ponty, my main hope is to make progress in clarifying how things are. As odd as some of Berkeley's pronouncements may sound to contemporary ears – concerning especially the metaphysical consequences of what he regarded as perceptual facts – I shall argue that, in substance, he was often not far wrong at all – at least as measured by important strands of more contemporary work on the subject. More particularly, I shall contend that for going a long way down an extraordinarily fruitful path which has been subsequently explored more fully by (especially) Martin Heidegger, Merleau-Ponty, Nelson Goodman and Hilary Putnam, Berkeley deserves considerably more credit than he is usually accorded as a progenitor of contemporary approaches to metaphysical issues. (shrink)

Pessoa et al. fail to make a clear distinction between visual perception and subjective visual awareness. Their most controversial claims, however, concern subjective visual awareness rather than visual perception: visual awareness is externalized to the “personal level,” thus denying the view that consciousness is a natural biological phenomenon somehow constructed inside the brain.

Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to general cognition. This paper sets out some of the arguments for both sides (arguments from computer vision, neuroscience, Psychophysics, perceptual learning and other areas of vision science) and defends the position that an important part of visual perception, which may be called early (...) vision or just vision, is prohibited from accessing relevant expectations, knowledge and utilities - in other words it is cognitively impenetrable. That part of vision is complex and articulated and provides a representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues, including the use of signal detection theory and event-related potentials to assess cognitive penetration of vision. A distinction is made among several stages in visual processing. These include, in addition to the inflexible early-vision stage, a pre-perceptual attention allocation stage and a post-perceptual evaluation, memory-accessing, and inference stage which provide several different highly constrained ways in which cognition can affect the outcome of visual perception. The paper discusses arguments that have been presented in both computer vision and psychology showing that vision is "intelligent" and involves elements of problem solving". It is suggested that these cases do not show cognitive penetration, but rather they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect. (shrink)

I set out two theses. The first is Lynn Robertson’s: (a) spatial awareness is a cause of object perception. A natural counterpoint is: (b) spatial awareness is a cause of your ability to make accurate verbal reports about a perceived object. Zenon Pylyshyn has criticized both. I argue that nonetheless, the burden of the evidence supports both (a) and (b). Finally, I argue conscious visual perception of an object has a different causal role to both: (i) non-conscious (...) perception of the object, and (ii) experience, e.g. hallucination, that may be subjectively indiscriminable from, but is not, perception of the object. (shrink)

The nature of perception has long been a central question in philosophy. It is of central importance not just for the philosophy of mind, but also for epistemology, metaphysics, aesthetics, and the philosophy of science. This volume represents the best of the latest research on perception, with contributions from some of the leading philosophers in the area, including Christopher Peacocke, Brian O'Shaughnessy and Michael Tye. As well as discussing traditional problems, the essays also approach the topic in (...) light of recent research on mental content and representation. (shrink)

Standard models of visual perception hold that vision is an inferential or interpretative process. Such models are said to be superior to competing, non-inferential views in explanatory power. In particular, they are said to be capable of explaining a number of otherwise mysterious, visual phenomena such as multi-stable perception. Multi-stable perception paradigmatically occurs in the presence of ambiguous figures, single images that can give rise to two or more distinct percepts. Different interpretations are said to (...) produce the different percepts. In this paper, I argue that a non-inferential account of visual perception is just as capable of explaining multi-stable perception. I propose an embedded understanding of vision, and show how the embedded account can, after properly qualifying them, use the explanatory resources of the inferential view to explain just what such a view explains. (shrink)

The aim of this paper is to develop a new theory of particularity. In so doing it redefines the concepts 'perception' and 'judgment'. The redefinition occurs once perception is understood as recognition. The move to recognition entails the centrality of repetition. Recognition, it is argued, is a form of repetition. Allowing for repetition necessitates changing the way the relationship between universals and particulars is understood. This is developed via an engagement with Hume and Plato. The article concludes with (...) the outline for a rethinking of the metaphysics of particularity. (shrink)

As many as two million people in the United Kingdom repeatedly see people, animals, and objects that have no objective reality. Hallucinations on the border of sleep, dementing illnesses, delirium, eye disease, and schizophrenia account for 90% of these. The remainder have rarer disorders. We review existing models of recurrent complex visual hallucinations (RCVH) in the awake person, including cortical irritation, cortical hyperexcitability and cortical release, top-down activation, misperception, dream intrusion, and interactive models. We provide evidence that these can (...) neither fully account for the phenomenology of RCVH, nor for variations in the frequency of RCVH in different disorders. We propose a novel Perception and Attention Deficit (PAD) model for RCVH. A combination of impaired attentional binding and poor sensory activation of a correct proto-object, in conjunction with a relatively intact scene representation, bias perception to allow the intrusion of a hallucinatory proto-object into a scene perception. Incorporation of this image into a context-specific hallucinatory scene representation accounts for repetitive hallucinations. We suggest that these impairments are underpinned by disturbances in a lateral frontal cortex–ventral visual stream system. We show how the frequency of RCVH in different diseases is related to the coexistence of attentional and visual perceptual impairments; how attentional and perceptual processes can account for their phenomenology; and that diseases and other states with high rates of RCVH have cholinergic dysfunction in both frontal cortex and the ventral visual stream. Several tests of the model are indicated, together with a number of treatment options that it generates. Key Words: Blindness; Charles Bonnet; cholinergic; cortical release; delirium; dementia; dream intrusion; hallucination; Perception and Attention Deficit (PAD) model; schizophrenia. (shrink)

Much recent discussion about the nature of perception has focused on the dispute between the Causal Theory of Perception and the rival Disjunctive View. There are different versions of the Causal Theory (the abbreviation I shall use), but the point upon which they agree is that perception involves a conscious experience which is logically distinct from the particular physical object perceived. 1 On the opposed Disjunctive View, the perceptual experience is held to be inseparable from the object (...) perceived; what is directly present to conscious experience is, literally, part of the physical environment. 2 One prima facie difficulty the Causal Theory appears to face is the problem of deviant causal chains, of providing sufficient conditions for perception; I shall not address this difficulty directly, though some of my concluding remarks will bear on it. My main aim in this paper is to show that, despite the deviant causal chains problem, the Causal Theory is to be preferred to the rival Disjunctive View. (shrink)

L. Albertazzi, G. J. van Tonder, and D. Vishwanath (eds): Perception Beyond Inference: The Information Content of Visual Processes Content Type Journal Article Pages 53-55 DOI 10.1007/s11023-011-9253-z Authors Lorenzo Magnani, Department of Philosophy and Computational Philosophy Laboratory, University of Pavia, Pavia, Italy Journal Minds and Machines Online ISSN 1572-8641 Print ISSN 0924-6495 Journal Volume Volume 22 Journal Issue Volume 22, Number 1.

This thesis falls into two parts, a characterizing part, and an explanatory part. In the first part, I outline some of the core aspects of our ordinary understanding of visual perception, and how we regard it as a means of knowing. What explains the fact that I know that the lemon before me is yellow is my visual perception: I know that the lemon is yellow because I can see it. Some explanations of how one knows (...) specify that in virtue of which one genuinely knows, as opposed to merely believes, some content. Such explanations are epistemically satisfactory explanations. We think that visual perceptual explanations of knowledge can be epistemically satisfactory. I argue that that is what it is to regard visual perception as being among our means of knowing. In the second part, I explore how we might explain the fact that visual perception is a means of knowing (assuming that it is a fact). I ask what makes it the case that visual perception is a means of knowing (in the way we ordinarily think that it is)? I suggest that part of the answer to this question is that visual perception, given the nature it has, has a reason giving role. And that is just to say that the nature of visual perception is such that visually perceiving can ensure the satisfaction of some important condition on knowledge (namely, that if one knows that something is the case one must have a good reason to believe that it is the case). In concluding I suggest that giving this sort of explanation doesn't require a specific theory of perception. (shrink)

Philosophical inquiries into the nature of consciousness have long been intrinsically tied to questions regarding the nature of the self. Although philosophers of mind seldom make reference to the role of cultural context in shaping consciousness, since antiquity culture has played a notable role in philosophical conceptions of the self. Western philosophers, from Plato to Locke, have emphasized an individualistic view of the self that is autonomous and consistent across situations, while Eastern philosophers, such as Lao Tzu and Confucius, have (...) argued for a collectivistic view of the self, one that is interconnected to others and embedded within specific social contexts and situations. Here we argue that a comprehensive theory of consciousness needs to account for the role of cultural context and its bidirectional interaction with neural and genetic mechanisms in shaping a variety of conscious phenomena, from visual perception to self- awareness. We review recent evidence of cultural variation in neurobiological mechanisms underlying these phenomena and discuss the implications of these cultural neuroscience findings for the study of consciousness. (shrink)

What is difficult to imagine is also surprising to perceive. This indicates that active visual imagery is an integral part of active visual perception. Erroneous mental transformations provide clues to prior assumptions in visual imagery, just as visual illusions provide clues to perceptual assumptions. Visual imagery and perception share generic assumptions about invariants in images of rigid objects.

Commentators agree that the Perception and Attention Deficit (PAD) model is a promising model for accounting for recurrent complex visual hallucinations (RCVH) across several disorders, though with varying detailed criticisms. Its central tenets are not modified, but further consideration of generative models of visual processing and the relationship of proto-objects and memory systems allows the PAD model to deal with variations in phenomenology. The commentaries suggest new ways to generate evidence that will test the model.

Visual conscious perception could be grounded in a nonconscious sensorimotor domain. Although invisible, information can be processed up to the level of response activation. Moreover, these nonconscious processes are modified by actual intentions. This notion bridges a gap in the theoretical framework of O'Regan & Noë.

Pylyshyn could have strengthened his case by avoiding side issues and by taking a sterner, firmer line on the unresolved (and perhaps unresolvable) problems plaguing the sensitivity (d') measure of top-down, cognitive effects, as well as the general (nearly utter!) lack of convincing evidence provided by proponents of the cognitive penetrability of visual perception.

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)

Shepard's notion of “internalisation” is better interpreted as a simile than a metaphor. A fractal encoding model of visual perception is sketched, in which image elements are transformed in such a way as to maximise symmetry with the current input. This view, in which the transforming system embodies what has been internalised, resolves some problems raised by the metaphoric interpretation. [Hecht; Shepard].

To see whether the mental and the neural have common attributes that could resolve some of the traditional dichotomies, we review neuroscientific data on the visual system. The results show that neuronal and perceptual function share a parallel and hierarchical architecture which is manifest not only in the anatomy and physiology of the visual system, but also in normal perception and in the deficits caused by lesions in different parts of the system. Based on the description of (...) parallel hierarchical levels of active information processing in the visual brain, we suggest a concept of dissociable levels of perception, advocating that the phenomenal perception and recognition is realized in the functional integrity of a network of reciprocal cortico-cortical connections. The properties shared by neuronal and perceptional functions provide a basis for a neuromental monism in which both functions are attributed a causal role. (shrink)

We present an investigation into the relation between design principles in Japanese gardens, and their associated perceptual effects. This leads to the realization that a set of design principles described in a Japanese gardening text by Shingen (1466), shows many parallels to the visual effects of perceptual grouping, studied by the Gestalt school of psychology. Guidelines for composition of rock clusters closely relate to perception of visual figure. Garden design elements are arranged into patterns that simplify figure-ground (...) segmentation, while seemingly balancing the visual salience of subparts and the global arrangement. Visual ‘ground’ is analyzed via medial axis transformation (MAT), often associated with shape perception in humans. MAT analysis reveals implicit structure in the visual ground of a quintessential rock garden design. The MAT structure enables formal comparison of structure of figure and ground. They share some aesthetic qualities, with interesting differences. Both contain naturalistic asymmetric, self-similar, branching structures. While the branching pattern of the ground converges towards the viewer, that of the figure converges in the opposite direction. (shrink)

Whether designing animals, insects, or plants, Nature draws upon symmetry and periodicity to play a fundamental role in defining the body plan. When implemented with the proper chemical mechanisms, these principles guide our bodies from single-celled embryos to bilaterally symmetric creatures with intricate periodic structures, such as the spine and rib cage. The properties of symmetry and periodicity also appear to be fundamental to visual perception. We will show that this is no coincidence, but is a consequence of (...) the fact that these properties are generated by the same underlying phenomenon, standing wave patterns formed from harmonic resonances. The symmetry in life forms arises from chemical harmonic resonances, whereas the symmetry in visual perception arises from harmonic resonances in the visual system. We will show that harmonic resonances have very interesting properties for the representation of geometrical form that make them eminently suitable for encoding geometric form for body plans as well as for visual perception. In particular, we will show that by being simultaneously invariant to perspective transformation and robust to deformation, such resonant representations have fundamental advantages over more traditional techniques. (shrink)

Three case studies offered here will support the conclusion that a successful scientific theory of visual cognition still makes room for some rather systematic and rather striking semantic indeterminacies-W.V. Quine's well-known pessimism about the wages of such indeterminacy not withstanding. The first case concerns the perception of shape, the second concerns color vision, and the third concerns the rules of inference involved in "unconscious inference" within the visual system.

Ecological science has at one time or another deemed nature a machine, an organism, a community, or a system. These metaphors do not refer to any metaphysical entity, but are useful fictions in terms of how they reflect the beliefs and values held by members of a scientific and cultural community. First I trace the history of ecological metaphors from the metaphysical and cultural perspectives. Then I document a gradual transition from a belief in structural natural order to a belief (...) in conceptual natural order. Finally, I conclude by arguing that the metaphysical allegiances of ecological theories have largely been shaped by aesthetic considerations. (shrink)

Vision has been the primary focus of naturalistic philosophical research concerning perception and perceptual experience. Guided by visual experience and vision science, many philosophers have focused upon theoretical issues dealing with the perception of objects. Recently, however, hearing researchers have discussed auditory objects. I present the case for object perception in vision, and argue that an analog of object perception occurs in auditory perception. I propose a notion of an auditory object that is stronger (...) than just that of an intentional object of audition, but that does not identify auditory objects with the ordinary material objects we see. (shrink)

Visual thinking -- visual imagination or perception of diagrams and symbol arrays, and mental operations on them -- is omnipresent in mathematics. Is this visual thinking merely a psychological aid, facilitating grasp of what is gathered by other means? Or does it also have epistemological functions, as a means of discovery, understanding, and even proof? By examining the many kinds of visual representation in mathematics and the diverse ways in which they are used, Marcus Giaquinto (...) argues that visual thinking in mathematics is rarely just a superfluous aid; it usually has epistemological value, often as a means of discovery. Drawing from philosophical work on the nature of concepts and from empirical studies of visual perception, mental imagery, and numerical cognition, Giaquinto explores a major source of our grasp of mathematics, using examples from basic geometry, arithmetic, algebra, and real analysis. He shows how we can discern abstract general truths by means of specific images, how synthetic a priori knowledge is possible, and how visual means can help us grasp abstract structures. Visual Thinking in Mathematics reopens the investigation of earlier thinkers from Plato to Kant into the nature and epistemology of an individual's basic mathematical beliefs and abilities, in the new light shed by the maturing cognitive sciences. Clear and concise throughout, it will appeal to scholars and students of philosophy, mathematics, and psychology, as well as anyone with an interest in mathematical thinking. (shrink)

Looking at a person’s expression is a good way of telling what she feels—what emotions she has. Why is that? Is it because we see her emotion, or is it because we infer her mental state from her expression? My claim is that there is a sense in which we do see the person’s emotion. I first argue that expressions are physical events that carry information about the emotions that produce them. I then examine evidence suggesting that specific brain areas (...) and structures are involved in the process that extracts such information and makes it available in the content of visual experience. I consider only what happens in early stages of visual processing and make no claim about the role of simulation and empathy. (shrink)

I consider the way in which spatial perception is necessary for object seeing. In section 1 I outline the operative conception of object seeing. I consider Cassam’s view that in order to see o, you must see it as spatially located (section 2). I argue that Cassam’s argument is unsound. Cassam’s argument relies on the claim that seeing o requires visual differentiation. But it is not the case that seeing o requires visual differentiation. This is because the (...) following principle is true: if S sees a visible proper part of o, then S sees o, and since there are cases in which S sees a visible proper part of o yet o is not visually differentiated for S , seeing o doesn’t require visual differentiation (section 3). In section 4 I suggest an alternative way of understanding the idea that spatial perception is necessary for object seeing. (shrink)

Ideally, psychological and phenomenological studies of visual experience should be mutually informative. In that spirit, this article outlines parts of Maurice Merleau-Ponty's phenomenological view of visual experience as a kind of independently active opaque bodily synthesis, and uses those views to (a) help ground and extend Alva Noë's rejection of the “snapshot” theory of visual experience in favor of a more enactive view of visual content, (b) critique a failing of Noë's account, and (c) show how (...) the assumptions underlying more internalist and Cartesian views of visual experience can illegitimately creep in even when they are being carefully criticized. (shrink)

Through computational modeling, here we examine whether visual and task characteristics of writing systems alone can account for lateralization differences in visual word recognition between different languages without assuming influence from left hemisphere (LH) lateralized language processes. We apply a hemispheric processing model of face recognition to visual word recognition; the model implements a theory of hemispheric asymmetry in perception that posits low spatial frequency biases in the right hemisphere and high spatial frequency (HSF) biases in (...) the LH. We show two factors that can influence lateralization: (a) Visual similarity among words: The more similar the words in the lexicon look visually, the more HSF/LH processing is required to distinguish them, and (b) Requirement to decompose words into graphemes for grapheme-phoneme mapping: Alphabetic reading (involving grapheme-phoneme conversion) requires more HSF/LH processing than logographic reading (no grapheme-phoneme mapping). These factors may explain the difference in lateralization between English and Chinese orthographic processing. (shrink)

This article contributes to understanding the relation within Gibson's perception theory between two questions that Gibson raised in the introductory paragraph of his final book, The Ecological Approach to Visual Perception: (a) how we see how to do things and (b) why things look to us as they do (Koffka's question). Although Gibson considered Koffka's question to be a crucial test for any psychological theory of visual perceiving, Gibson did not explicitly defend his ecological approach with (...) reference to Koffka's question. Gibson's entire final book is not, as some Gibsonians would suggest, Gibson's answer to Koffka's question. However, certain subsidiary parts of the book implicitly and almost explicitly suggest a place in Gibsonian perception theory for the phenomenal looks of things that we visually perceive. The present article considers some Gibsonian answers and reactions to Koffka's question, and argues that the phenomenal looks of things play a crucial role in Gibson's account of the visual control of locomotion. (shrink)

Seeking whether our perception produces knowledge which is not only relative or subjective perspective on things, is to be engaged in the realist/anti-realist debate regarding perception. In this article I pursue the naturalistic approach according to which the question whether perception delivers objective knowledge about the external world is inseparable from empirical investigation into mechanisms of perception. More precisely, I have focused on the dual aspect theory of perception, one of the most influential recent theories (...) of perception which unifies two traditionally opposite approaches to perception: ecological and constructivist. I have tried to show that the dualistic model of human vision does not support the majority of realist theses aimed at non-relativism, but supports only pragmatic realism about observational reports (dorsal system) and the moderate realism about observational reports (ventral system). (shrink)

Many philosophers have held that it is not possible to experience a spatial object, property, or relation except against the background of an intact awareness of a space that is somehow ‘absolute’. This paper challenges that claim, by analyzing in detail the case of a brain-damaged subject whose visual experiences seem to have violated this condition: spatial objects and properties were present in his visual experience, but space itself was not. I go on to suggest that phenomenological argumentation (...) can give us a kind of evidence about the nature of the mind even if this evidence is not absolutely incorrigible. (shrink)

An attempt is made to pinpoint the way in which perception is related to belief. Although, for familiar reasons, it is not true to say that we necessarily believe in the existence of the objects we perceive, nor that they actually have their ostensible characteristics, it is argued that the relation between perception and belief is more than merely contingent There are two main issues to address. The first is that `collateral' beliefs may impede perceptual belief. It is (...) argued that this still assigns an essential role to belief in perception, though the belief may be of an attenuated form. The second is Fred Dretske's claim that even attenuated belief may be entirely absent from perception. It is argued that (a) `non-epistemic' perception can be understood only by employing the concept of `epistemic' perception; (b) that the former can occur only partially-i.e., within perceptions that are otherwise epistemic; and (c) that by switching attention from the perception of objects to the Phenomenological tradition's concern with the perception of world, we can see that perception must be entirely permeated with `doxastic' force. (shrink)

How should we think about the role of visual spatial awareness in perception and perceptual knowledge? A common view, which finds a characteristic expression in Kant but has an intellectual heritage reaching back farther than that, is that an account of spatial awareness is fundamental to a theory of experience because spatiality is the defining characteristic of “outer sense”, of our perceptual awareness of how things are in the parts of the world that surround us. A natural counterpart (...) to this idea is to treat self-consciousness as residing in a kind of sense that is fundamentally “inner”, such as introspection or whatever else gives one privileged access to his own mental states as well as the proprioceptive and kinesthetic awareness of bodily position. This division is compatible, of course, with the idea that inner sense provides an awareness of a distinctive kind of “body space”, but it treats that as importantly different from the awareness of the worldly space around one. -/- In contrast to such a picture, this dissertation proposes an account of visual spatial awareness according to which it is no less a source of self-consciousness than of the awareness of the objects around us, and an account of self-awareness in which visual experience is essentially implicated. I begin by arguing that we should think of visual spatial awareness not as necessary for the individuation of visual sensations but rather as an essential element in the awareness of an experientially objective world. In the subsequent chapters, I argue that in being visually aware of the egocentric positions of the worldly objects around us we are often aware also of our own spatial locations with respect to them, and that the visual experience of the world around one and one’s own situation in it is often an essential component in the knowledge that a human agent will have of his own intentional actions. (shrink)

I argue against a Disjunctive approach to visual experience. I then critique three 'common-factor' views: Qualia Theory, Intentionalism and Sense-Date Theory. The latter two are combined to form Intentional Trope Theory; and that view is defended.

The notion of perceptual content is commonly introduced in the analysis of perception. It stems from an analogy between perception and propositional attitudes. Both kinds of mental states, it is thought, have conditions of satisfaction. I try to show that on the most plausible account of perceptual content, it does not determine the conditions under which perceptual experience is veridical. Moreover, perceptual content must be bipolar (capable of being correct and capable of being incorrect), whereas perception as (...) a mental state is not (if it is veridical, it is essentially so). This has profound consequences for the epistemological view that perception is a source of knowledge. I sktech a two-level epistemology which is consistent with this view. I conclude that the analogy between perception and propositional attitudes, from which the notion of perceptual content is born, may be more misleading than it is usually thought. (shrink)

The “Perky effect” is the interference of visual imagery with vision. Studies of this effect show that visual imagery has more than symbolic properties, but these properties differ both spatially (including “pictorially”) and temporally from those of vision. We therefore reject both the literal picture-in-the-head view and the entirely symbolic view.

This book is a major contribution to the interdisciplinary project of investigating the true nature of color vision. In recent times, research into color vision has been one of the main success stories of cognitive science. Each discipline in the field--neuroscience, psychology, linguistics, computer science and philosophy--has contributed significantly to our understanding of color. Evan Thompson provides an accessible review of current scientific and philosophical discussions of color vision. He steers a course between the subjective and objective positions on color, (...) arguing for a relational account. Thompson develops a novel "ecological" approach to color vision in cognitive science and the philosophy of perception. The book is vital reading for all cognitive scientists and philosophers whose interests touch upon this central area. (shrink)

Sydney Shoemaker argues that introspection, unlike perception, provides no identification information about the self, and that knowledge of one''s mental states should be conceived as arising in a direct and unmediated fashion from one''s being in those states. I argue that while one does not identify aself as the subject of one''s states, one does frequently identify and misidentify thestates, in ways analogous to the identification of objects in perception, and that in discourse about one''s mental states the (...) self plays the role of external reality in discourse about physical objects. Discourse about any sort of entity or property can be viewed as involving a domain or frame of reference which constrains what can be said about the entities; this view is related to Johnson-Laird''s theory of mental models. On my approach evidence, including sensory evidence, may be involved in decisions about one''s mental states. I conclude that while Shoemaker may well be right about different roles for sense impressions in introspection and perception, the exact differences and their significance remain to be established. (shrink)

Perceptual experience can be explained by contextualized brain dynamics. An inner loop of ongoing activity within the brain produces dynamic patterns of synchronization and de- synchronization that are necessary, but not sufficient, for visual experience. This inner loop is controlled by evolution, development, socialization, learning, task and perception- action contingencies, which constitute an outer loop. This outer loop is sufficient, but not necessary, for visual experience. Jointly, the inner and outer loop may offer sufficient and necessary conditions (...) for the emergence of visual experience. This hypothesis has methodological, empirical, theoretical, and philosophical implications. (shrink)

Consider the much-discussed case of the distracted driver, who is alleged to successfully navigate his car for miles despite being completely oblivious to his visual states. Perhaps he is deeply engrossed in the music playing over the radio or in philosophical reflection, and as a result he goes about unaware of the scene unfolding before him on the road. That the distracted driver has visual experiences of which he is not aware is a possibility that first-order representationalists (FOR) (...) happily accept, but higher-order representationalists (HOR) steadfastly deny. HOR claims that perceptual states become conscious only as the object of higher-order states; perceptual states are not intrinsically conscious. According to HOR, since the driver is supposed to be completely distracted by other cognitive tasks, he cannot form higher-order representations of his visual states, with the result that those states are disqualified as experiences.1 HOR theories have come in two flavors, those that claim that the relevant higher-order representations are thought-like (HOT) and those that that rely on an inner perception-like mechanism that is directed toward one. (shrink)

In his book Mind and World, John McDowell grapples with the problem that the world must and yet seemingly cannot constrain our empirical thought. I first argue that McDowell’s proposed solution to the problem throws him onto the horns of his own, intractable dilemma, and thus fails to solve the problem of rational constraint by the world. Next, I will argue that Wilfrid Sellars, in a series of articles written in the 1950s and 60s, provides the tools to solve the (...) dilemma McDowell sets before us. We will see how, borrowing from Sellars and certain neo-Sellarsians, we can solve the problem of rational constraint by perception without resorting to a McDowellian quasi-enchantment of the world. (shrink)

Neuroscience studies show many examples of very early modulation of visual cortex responses. It is argued that such early routing is essential for a rapid processing of information by the visual system.

O'Regan & Noë mistakenly identify visual processing with visual experience. I outline some reasons why this is a mistake, taking my data and arguments mainly from the literature on subliminal processing.

One of the more compelling beliefs about vision is that it is based on representations that are coherent and complete, with everything in the visual field described in great detail. However, changes made during a visual disturbance are found to be difficult to see, arguing against the idea that our brains contain a detailed, picture-like representation of the scene. Instead, it is argued here that a more dynamic, "just-in-time" representation is involved, one with deep similarities to the way (...) that users interact with external displays. It is further argued that these similarities can provide a basis for the design of intelligent display systems that can interact with humans in highly effective and novel ways. (shrink)

We question the usefulness of Pylyshyn's dichotomy between cognitively penetrable and cognitively impenetrable mechanisms as the basis for his distinction between cognition and early vision. This dichotomy is comparable to others that have been proposed in psychology prompting disputes that by their very nature could not be resolved. This fate is inevitable for Pylyshyn's thesis because of its reliance on internal representations and their interpretation. What is more fruitful in relation to this issue is not a difficult dichotomy, but a (...) different look at perception such as proposed by Gibson (1979). (shrink)