Some recently popular accounts of perception account for the phenomenal character of perceptual experience in terms of the qualities of objects. My concern in this paper is with naturalistic versions of such a phenomenal externalist view. Focusing on visual spatial perception, I argue that naturalistic phenomenal externalism conflicts with a number of scientific facts about the geometrical characteristics of visual spatial experience.

Evolution and geometry generate complexity in similar ways. Evolution drives natural selection while geometry may capture the logic of this selection and express it visually, in terms of specific generic properties representing some kind of advantage. Geometry is ideally suited for expressing the logic of evolutionary selection for symmetry, which is found in the shape curves of vein systems and other natural objects such as leaves, cell membranes, or tunnel systems built by ants. The topology and (...) class='Hi'>geometry of symmetry is controlled by numerical parameters, which act in analogy with a biological organism’s DNA. The introductory part of this paper reviews findings from experiments illustrating the critical role of two-dimensional (2D) design parameters, affine geometry and shape symmetry for visual or tactile shape sensation and perception-based decision making in populations of experts and non-experts. It will be shown that 2D fractal symmetry, referred to herein as the “symmetry of things in a thing”, results from principles very similar to those of affine projection. Results from experiments on aesthetic and visual preference judgments in response to 2D fractal trees with varying degrees of asymmetry are presented. In a first experiment (psychophysical scaling procedure), non-expert observers had to rate (on a scale from 0 to 10) the perceived beauty of a random series of 2D fractal trees with varying degrees of fractal symmetry. In a second experiment (two-alternative forced choice procedure), they had to express their preference for one of two shapes from the series. The shape pairs were presented successively in random order. Results show that the smallest possible fractal deviation from “symmetry of things in a thing” significantly reduces the perceived attractiveness of such shapes. The potential of future studies where different levels of complexity of fractal patterns are weighed against different degrees of symmetry is pointed out in the conclusion. (shrink)

In the philosophy of perception, direct realism has come into vogue. Philosophical authors assert and assume that what their readers want, and what anyone should want, is some form of direct realism. There are disagreements over precisely what form this direct realism should take. The majority of positions in favor now offer a direct realism in which objects and their material or physical properties constitute the contents of perception, either because we have an immediate or intuitive acquaintance with those objects (...) and properties, or because our perceptual states have informational content that represents the properties of those objects (and which is not itself an object of perception and has no specifically subjective aspect). This paper considers various forms of perceptual realism, including, for purposes of comparison, the largely abandoned indirect or representative realism. After surveying the variety of perceptual realisms and considering their various commitments, I introduce some considerations concerning the phenomenology of visual space that cause trouble for most forms of direct realism. These considerations pertain to the perception of objects in the distance and, secondarily, to the perception of shapes at a slant. I argue that one of the lesser known varieties of perceptual realism, critical direct realism, can meet the challenges offered by the facts of spatial perception. (shrink)

The usual visual experiences possess a perspectival phenomenology as they seem to present objects from a certain perspective. Nevertheless, it is not obvious how to characterise experiential content determining such phenomenology. In particular, while there are many works investigating perspectival properties of experienced objects, a question regarding how subject is represented in visual perspectival experiences attracted less attention. In order to address this problem, I consider four popular phenomenal intuitions regarding perspectival experiences and argue that the major theories (...) of perspectival experiences do not account for all of them. Relying on these observations, I show how a theory which accommodates all these intuitions can be developed by (a) recognising that visual perspectival experiences are, in fact, multimodal visuo-bodily experiences and (b) distinguishing between egocentric and structural contents. (shrink)

Both introspection and empirical studies suggest that visual attention can affect the phenomenology of our visual experience. However, the exact character of such effects is far from clear. My aim in this chapter is to spell out the main difficulties involved in attempting to achieve a clearer view of these effects, and to make some suggestions as to how we can make progress with this issue while avoiding tempting mistakes. I do this by discussing the question of (...) whether there is a sense in which attention to a seen object can be said to contribute to the object’s visual phenomenal salience. It is often suggested that focusing visual attention on a seen object renders the object phenomenally salient. I look at potential evidence for this suggestion, and consider what form, if any, of visual phenomenal salience it may support. (shrink)

Both visual experience and conscious thought represent external objects, but in visual experience these objects seem present before the mind and available for direct access in a way that they don’t in conscious thought. In this paper, I introduce a couple of challenges that this “Scene-Immediacy” of visual experience raises for traditional versions of Representationalism. I then identify a resource to which Representationalists can appeal in addressing these challenges: the low-detail fringe of visual (...) experience. I argue that low-detail contents within visual experience provide the mind with a rich access to additional high-detail information, an access that is not found in conscious thought. This access, in turn, speaks to the challenges raised by the Scene-Immediacy of visual experience. Robert Schroer is an Assistant Professor at the University of Minnesota at Duluth. (shrink)

Abstract: How is it that we can visually experience complete three-dimensional objects despite being limited, in any given perceptual moment, to perceiving the sides facing us from a specific spatial perspective? To make sense of this, such visual experiences must refer to occluded or presently unseen back-sides which are not sense-perceptually given, and which cannot be sense- perceptually given while the subject is occupying the spatial perspective on the object that they currently are – I call this the (...) horizonality of visual experience. Existing accounts of these horizonal references are unsatisfactory. In providing a satisfactory account, this paper argues that the content and structure of the visual experience of complete three-dimensional objects is as follows: the object is presented as being perceptible from yet-to-be-determined alternative points of view. As part of the content of visual experience, this motivates non-propositional attitudes of anticipation. Explicating this proposal is the central positive aim of this paper. (shrink)

Science is a crowning glory of the human spirit and its applications remain our best hope for social progress. However, there are limitations to existing science and perhaps to any science. The general mind-body problem is known to be currently intractable and mysterious (8). This is one of many deep problems that are generally agreed to be beyond the present purview of Science, including many quantum phenomena, etc. However, all of these famous unsolved problems are either remote from everyday (...) class='Hi'>experience (entanglement, dark matter) or are hard to even define sharply (phenomenology, consciousness, etc.). In this note, we will consider some computational problems in vision that arise every time that we open our eyes and yet are demonstrably inconsistent with current theories of neural computation. The focus will be on two famous related phenomena, known as the neural binding problem and the experience of a detailed stable visual world. I, among many others, have struggled with these issues for more than fifty years (1, 2, 3). Somewhat paradoxically, the continuing progress in scientific methods and knowledge reveals that these are both unsolvable within existing neuroscience. By considering some basic facts about how the brain processes image input, we will show that, under the standard theory, there are not nearly enough brain neurons to compute what we experience as vision. Inconsistencies like the ones shown here have had a profound effect on paradigm change in the sciences. More directly, the discussions below suggest possible new theories and experiments. (shrink)

This paper argues that various phenomenological considerations support a non-representational causal account of visual experience. This position claims that visual experiences serve as a non-representational causally efficacious medium for the production of beliefs concerning the external world. The arguments are centered on defending a non-representational causal account’s understanding of the cognitive significance of visual experience. Among other things, such an account can easily explain the inextricable role that background beliefs and conceptual capacities play in perceptually-based (...) external world belief-formation processes, the fact that visual mental states constrain beliefs because of their presentational phenomenology, and the phenomenon known as the transparency of visual experience. (shrink)

Blindsight is a kind of residual vision found in people with lesions to V1. Subjects with blindsight typically report no visual awareness, but they are nonetheless able to make above-chance guesses about the shape, location, color and movement of visual stimuli presented to them in their blind field. A different kind of blindsight, sometimes called type 2 blindsight, is a kind of residual vision found in patients with V1 lesions in the presence of some residual awareness. Type 2 (...) blindsight differs from ordinary visual experience in lacking the particularity, transparency and fine-grainedness often taken to be essential to visual experience, at least in veridical cases. I argue that the case of type 2 blindsight provides a counterexample to the view that these characteristics are essential to veridical visual experience and that this gives us reason to resist the view that visual experience is essentially a perceptual relation to external objects. In the second part of the paper I argue that the case of type 2 blindsight yields important insights into the effects of attentional modulation on perceptual content and that cases of attentional modulation of appearance are not at odds with the view that the phenomenology of visual experience flows from its content. (shrink)

A visual experience, as understood here, is a sensory event that is conscious, or like something to undergo. This chapter focuses on three issues concerning such experiences. The first issue is the so-called ‘transparency’ of experiences. The chapter distinguishes a number of different interpretations of the suggestion that visual experiences are ‘transparent’. It then discusses in what sense, if any, visual experiences are ‘transparent’, and what further conclusions one can draw from that. The second issue is (...) which properties we are presented with in visual experiences. It is widely accepted that we sometimes experience red for example. But exactly which properties do we sometimes visually experience, and which properties do we never visually experience? The third issue is which particulars, if any, we are presented with in visual experiences. Do we for example sometimes visually experience mind-independent particulars like trees? Do we sometimes visually experience mind-dependent, particular ‘sense-data’? (shrink)

This paper proposes a classificatory framework for disjunctivism about the phenomenology of visual perceptual experience. Disjunctivism of this sort is typically divided into positive and negative disjunctivism. This distinction successfully reflects the disagreement amongst disjunctivists regarding the explanatory status of the introspective indiscriminability of veridical perception and hallucination. However, it is unsatisfactory in two respects. First, it cannot accommodate eliminativism about the phenomenology of hallucination. Second, the class of positive disjunctivism is too coarse-grained to provide an informative overview (...) of the current dialectical landscape. Given this, I propose a classificatory framework which preserves the positive-negative distinction, but which also includes the distinction between eliminativism and non-eliminativism, as well as a distinction between two subclasses of positive disjunctivism. In describing each class in detail, I specify who takes up each position in the existing literature, and demonstrate that this classificatory framework can disambiguate some existing disjunctivist views. (shrink)

I argue that, holding that the specification of Intentional content of the visual experience should be in the form of a proposition, John Searle gives up the first-person Intentionality and therefore bypasses the first-person important distinction between simple seeing and judgmental seeing. The specification of the content only in the form of the proposition does not allow making such a distinction on the level of description. Then I argue that the feature of the causal self-referentiality of the (...) class='Hi'>visual experience belongs to its psychological mode but not, as Searle holds, to the Intentional content of the visual experience. (shrink)

Through extensive training, experts acquire specialized knowledge and abilities. In this paper, I argue that experts also acquire specialized visual experiences. Specifically, I articulate and defend the account that experts enjoy visual experiences that represent gestalt properties through perceptual learning. I survey an array of empirical studies on face perception and perceptual expertise that support this account. I also look at studies on perceptual adaptation that some might argue present a problem for my account. I show how the (...) data are subject to an interpretation that is friendly to it. Last, I address two theoretical objections to the claim that visual experiences represent gestalt properties. (shrink)

Judgments of visual resemblance (‘A looks like B’), unlike other judgments of resemblance, are often induced directly by visual experience. What is the nature of this experience? We argue that the visual experience that prompts a subject looking at A to judge that A looks like B is a visual experience of B. After elucidating this thesis, we defend it, using the ‘phenomenal contrast’ method. Comparing our account to competing accounts, we show (...) that the phenomenal contrast between a visual experience that induces the judgment that A looks like B, and a visual experience that does not induce this judgment, is best explained by the fact that the former visually represents B, whereas the latter does not. (shrink)

I raise a problem for common-factor theories of experience concerning the demonstrative thoughts we form on the basis of experience. Building on an insight of Paul Snowdon 1992, I argue that in order to demonstratively refer to an item via conscious awareness of a distinct intermediary the subject must have some understanding that she is aware of a distinct intermediary. This becomes an issue for common-factor theories insofar as it is also widely accepted that the general, pre-philosophical or (...) ‘naïve’ view of experience does not accept that in normal perceptual cases one is consciously aware of non-environmental (inner, mental) features. I argue then that the standard common-factor view of experience should be committed to attributing quite widespread referential errors or failures amongst the general, nonphilosophical populace – which seems an unattractively radical commitment. After clarifying the various assumptions I am making about experience and demonstrative thoughts, I consider a number of possible responses on behalf of the common-factor theorist. I finish by arguing that my argument should apply to any common-factor theory, not just avowedly ‘indirect' theories. (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)

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)

This paper investigates the role of visual experience in Wittgenstein's work. The specific thesis is that visual experience provides not only diverse illustrative examples of what could be an explanation of meaning, but that it also provides a recurrent metaphor for the whole process of meaning and understanding. Wittgenstein uses a great number of visual examples in his texts. Their diversity may be accounted for by the great diversity of ways in which he attempts to (...) describe the relationship between a word and its meaning. The resultant variety of visual examples may be summarised by what I call the Visual Discontinuity Thesis. However, beneath this diversity there lies a thread of continuity. This is provided by the persistent use of visual experience in the description of the word-meaning relation. This use underlies the projection relationship of the Tractatus and the "seeing-as" relationship of the Investigations. This recurrent visual metaphor may be summarised by what I call the Visual Continuity Thesis. This paper presents the latter thesis in the context of a description of the former. (shrink)

Philosophers and psychologists alike have argued recently that relatively abstract beliefs or cognitive categories like those regarding race can influence the perceptual experience of relatively low-level visual features like color or lightness. Some of the proposed best empirical evidence for this claim comes from a series of experiments in which White faces were consistently judged as lighter than equiluminant Black faces, even for racially ambiguous faces that were labeled ‘White’ as opposed to ‘Black’ (Levin and Banaji 2006). The (...) latter result is considered especially indicative of cognitive penetration, based on the reasoning that the relevant distortions were a function of lexical labeling, and hence the effect must have been mediated by categorization at the cognitive level. I argue that this reasoning is flawed, and that the assumptions on which it relies are questionable on both empirical and theoretical grounds. I propose an alternative, low-level explanation of the phenomena, which I argue is empirically more plausible and abductively preferable to the cognitive-penetration account. The upshot is that cognitively impenetrable perceptual systems may be psychologically more plastic and hence philosophically more significant than is nowadays commonly assumed. (shrink)

In the past decade, three philosophers in particular have recently explored the relation between desert and intrinsic value. Fred Feldman argues that consequentialism need not give much weight – or indeed any weight at all – to the happiness of persons who undeservedly experience pleasure. He defends the claim that the intrinsic value of a state of affairs is determined by the “fit” between the amount of well-being that a person receives and the amount of well-being that the person (...) deserves. Shelly Kagan uses a similar claim to motivate the view that equality is not intrinsically valuable. Thomas Hurka argues that desert is a third-order value, which is a function of the relation between the second-order value of having a virtuous or vicious character and the first-order value of experiencing pleasure or pain. In this paper, we sketch a theory of desert as fittingness and defend a general account of the relation between desert, well-being, and intrinsic value. We then discuss various applications of our “geometry of desert,” including a solution to the problem of the Repugnant Conclusion. (shrink)

The role of conventions in the formulation of Thomas Reid’s theory of the geometry of vision, which he calls the “geometry of visibles”, is the subject of this investigation. In particular, we will examine the work of N. Daniels and R. Angell who have alleged that, respectively, Reid’s “geometry of visibles” and the geometry of the visual field are non-Euclidean. As will be demonstrated, however, the construction of any geometry of vision is subject to (...) a choice of conventions regarding the construction and assignment of its various properties, especially metric properties, and this fact undermines the claim for a unique non-Euclidean status for the geometry of vision. Finally, a suggestion is offered for trying to reconcile Reid’s direct realist theory of perception with his geometry of visibles. (shrink)

It is suggested that the relationship between visual attention and conscious visual experience can be simplified by distinguishing different aspects of both visual attention and visual experience. A set of principles is first proposed for any possible taxonomy of the processes involved in visual attention. A particular taxonomy is then put forward that describes five such processes, each with a distinct function and characteristic mode of operation. Based on these, three separate kinds—or possibly (...) grades—of conscious visual experience can be distinguished, each associated with a particular combination of attentional processes. (shrink)

Geometry defines entities that can be physically realized in space, and our knowledge of abstract geometry may therefore stem from our representations of the physical world. Here, we focus on Euclidean geometry, the geometry historically regarded as “natural”. We examine whether humans possess representations describing visual forms in the same way as Euclidean geometry – i.e., in terms of their shape and size. One hundred and twelve participants from the U.S. (age 3–34 years), and (...) 25 participants from the Amazon (age 5–67 years) were asked to locate geometric deviants in panels of 6 forms of variable orientation. Participants of all ages and from both cultures detected deviant forms defined in terms of shape or size, while only U.S. adults drew distinctions between mirror images (i.e. forms differing in “sense”). Moreover, irrelevant variations of sense did not disrupt the detection of a shape or size deviant, while irrelevant variations of shape or size did. At all ages and in both cultures, participants thus retained the same properties as Euclidean geometry in their analysis of visual forms, even in the absence of formal instruction in geometry. These findings show that representations of planar visual forms provide core intuitions on which humans’ knowledge in Euclidean geometry could possibly be grounded. (shrink)

I outline three conceptions of seeing that a creature might possess: ‘the headlamp conception,’ which involves an understanding of the causal connections between gazing at an object, certain mental states, and behavior; ‘the stage lights conception,’ which involves an understanding of the selective nature of visual attention; and seeing-as. I argue that infants and various nonhumans possess the headlamp conception. There is also evidence that chimpanzees and 3-year-old children have some grasp of seeing-as. However, due to a dearth of (...) studies, there is no evidence that infants or nonhumans possess the stage lights conception of seeing. I outline the kinds of experiments that are needed, and what we stand to learn about the evolution and development of perspective taking. (shrink)

Visual imagery is a form of sensory imagination, involving subjective experiences typically described as similar to perception, but which occur in the absence of corresponding external stimuli. We used the Activation Likelihood Estimation algorithm (ALE) to identify regions consistently activated by visual imagery across 40 neuroimaging studies, the first such meta-analysis. We also employed a recently developed multi-modal parcellation of the human brain to attribute stereotactic co-ordinates to one of 180 anatomical regions, the first time this approach has (...) been combined with the ALE algorithm. We identified a total 634 foci, based on measurements from 464 participants. Our overall comparison identified activation in the superior parietal lobule, particularly in the left hemisphere, consistent with the proposed ‘top-down’ role for this brain region in imagery. Inferior premotor areas and the inferior frontal sulcus were reliably activated, a finding consistent with the prominent semantic demands made by many visual imagery tasks. We observed bilateral activation in several areas associated with the integration of eye movements and visual information, including the supplementary and cingulate eye fields (SCEFs) and the frontal eye fields (FEFs), suggesting that enactive processes are important in visual imagery. V1 was typically activated during visual imagery, even when participants have their eyes closed, consistent with influential depictive theories of visual imagery. Temporal lobe activation was restricted to area PH and regions of the fusiform gyrus, adjacent to the fusiform face complex (FFC). These results provide a secure foundation for future work to characterise in greater detail the functional contributions of specific areas to visual imagery. (shrink)

Ordinary human perceivers know that visual objects are perceivable from standpoints other than their own. The aim of this paper is to provide an explanation of how perceptual experience equips perceivers with this knowledge. I approach the task by discussing a variety of action-based theories of perception. Some of these theories maintain that standpoint transcendence is required for shape perception. I argue that this standpoint transcendence must take place in the phenomenal present and that it can be explained (...) in terms of the experience of perceivers who jointly attend to an object. Joint perceivers experience objects as being perceived from standpoints other than their own. They operate in what I call “social space”, in which they single out objects by triangulating targets’ locations relative to their co-perceivers’ standpoints on these targets. It is then possible to explain the public character of the objects of individual experience by appeal to what I call “public space”. This is a spatial framework whose locations are presented as standpoints whence joint attention to the target would ensue, were they occupied by co-perceivers. If shape perception requires standpoint transcendence, then shape perceivers operate in public space and are thus capable of singling out targets by triangulating their locations from standpoints other than their own. If it doesn’t, then the introduction of a public spatial framework is an additional step whose introduction explains how perceivers come to experience objects as perceivable from standpoints other than their own. (shrink)

Common sense suggests that visual consciousness is essential to skilled motor action, but Andy Clark—inspired by Milner and Goodale's dual visual systems theory—has appealed to a wide range of experimental dissociations to argue that such an assumption is false. Critics of Clark's argument contend that the content driving motor action is actually within subjects' experience, just not easily discovered. In this article, I argue that even if such content exists, it cannot be guiding motor action, since a (...) review of current visual neuroscience indicates that the visual brain areas producing conscious representations are distinct from those driving motor action. (shrink)

Several studies (e.g., Becklen & Cervone, 1983; Mack & Rock, 1998; Neisser & Becklen, 1975) have found that observers attending to a particular object or event often fail to report the presence of unexpected items. This has been interpreted as inattentional blindness (IB), a failure to see unattended items (Mack & Rock, 1998). Meanwhile, other studies (e.g., Pashler, 1988; Phillips, 1974; Rensink et al., 1997; Simons, 1996) have found that observers often fail to report the presence of large changes in (...) a display when these changes occur simultaneously with a transient such as an eye movement or flash of the display. This has been interpreted as change blindness (CB), a failure to see unattended changes (Rensink et al., 1997). In both cases there is a striking failure to report an object or event that would be quite visible under other circumstances. And in both cases there is a widespread (although not universal) belief that the underlying cause has to do with the absence of attention. The question then arises as to how these effects might be related. Is CB the same thing as IB? If not, what is the relation between them? And given that these phenomena deal with failures of subjective perception, what can they teach us about the nature of our visual experience? In particular, what can they teach us about the role played by visual attention? (shrink)

The aim of this paper is to show that introspective beliefs about one’s own current visual experiences are not immediate in the sense that what justifies them does not include other beliefs that the subject in question might possess. The argument will take the following course. First, the author explains the notions of immediacy and truth-sufficiency as they are used here. Second, the author suggests a test to determine whether a given belief lacks immediacy. Third, the author applies this (...) test to a standard case of formation of an introspective belief about one’s own current visual experiences and concludes that the belief in question is neither immediate nor truth-sufficient. Fourth, the author rebuts several objections that might be raised against the argument. (shrink)

After sketching the historical development of “emergence” and noting several recent problems relating to “emergent properties”, this essay proposes that properties may be either “emergent” or “mergent” and either “intrinsic” or “extrinsic”. These two distinctions define four basic types of change: stagnation, permanence, flux, and evolution. To illustrate how emergence can operate in a purely logical system, the Geometry of Logic is introduced. This new method of analyzing conceptual systems involves the mapping of logical relations onto geometrical figures, following (...) either an analytic or a synthetic pattern (or both together). Evolution is portrayed as a form of discontinuous change characterized by emergent properties that take on an intrinsic quality with respect to the object(s) or proposition(s) involved. Causal leaps, not continuous development, characterize the evolution of human life in a developing foetus, of a thought out of certain brain states, of a new idea (or insight) out of ordinary thoughts, and of a great person out of a set of historical experiences. The tendency to assume that understanding evolutionary change requires a step-by-step explanation of the historical development that led to the appearance of a certain emergent property is thereby discredited. (shrink)

While there is a growing philosophical interest in analysing olfactory experiences, the mereological structure of odours considered in respect of how they are perceptually experienced has not yet been extensively investigated. The paper argues that odours are perceptually experienced as having a mereological structure, but this structure is significantly different from the spatial mereological structure of visually experienced objects. Most importantly, in the case of the olfactory part-structure, the classical weak supplementation principle is not satisfied. This thesis is justified by (...) referring to empirical results in olfactory science concerning the human ability to identify components in complex olfactory stimuli. Further, it is shown how differences between olfactory and visual mereologies may arise from the way in which these modalities represent space. (shrink)

Luminance and color are strong and self-sufficient cues to pictorial depth in visual scenes and images. The present study investigates the conditions Under which luminance or color either strengthens or overrides geometric depth cues. We investigated how luminance contrasts associated with color contrast interact with relative height in the visual field, partial occlusion, and interposition in determining the probability that a given figure is perceived as ‘‘nearer’’ than another. Latencies of ‘‘near’’ responses were analyzed to test for effects (...) of attentional selection. Figures in a pair were supported by luminance contrast or isoluminant color contrast and combined with one of the three geometric cues. The results of Experiment 1 show that luminance contrasts associated with hue, when it does not interact with other hues, produces the same effects as achromatic luminance contrasts: The probability of‘‘near’’ increases with luminance contrast while the latencies for ‘‘near’’ responses decrease. Partial occlusion is found to be a strong enough pictorial cue to support a weaker red luminance contrast. Interposition cues lose out against cues of spatial position and partial occlusion. The results of Experiment 2, with isoluminant displays of varying color contrast, reveal that red color contrast on a light background supported by any of the three geometric cues wins over green or white supported by any of the three geometric cues. On a dark background, red color contrast supported by the interposition cue loses out against green or white color contrast supported by partial occlusion. These findings reveal that color is not an independent depth cue, but is strongly influenced by luminance contrast and stimulus geometry. Systematically shorter response latencies for stronger ‘‘near’’ percepts demonstrate that selective visual attention reliably detects the most likely depth cue combination in a given configuration. (shrink)

Phenomenal objectivism explains perceptual phenomenal character by reducing it to an awareness of mind-independent objects, properties, and relations. A challenge for this view is that there is a sense in which a distant tree looks smaller than a closer tree even when they are the same objective size (perceptual size variation). The dual content view is a popular objectivist account in which such experiences are explained by my objective spatial relation to the tree, in particular visual angle (perspectival size). (...) I describe a series of first-person experiments for investigating size experience. I use a ruler as a first-person method for operationalising perspectival size (Experiment 1). I use the corridor illusion (Experiment 2), outlining one’s head in the mirror (Experiment 3), and outlining the size of objects on glass (Experiment 4) to show a phenomenal difference in size for items in different depth contexts, despite being identical in visual angle. These finding demonstrate that visual angle cannot account for these spatial experiences. Psychological evidence provides further support for the thesis that subjects do not experience visual angle when depth information is present. Together this evidence supports the hypothesis that perceptual size variation cannot be accounted for by visual angle, hence undermining a plausible version of the dual content theory. This outcome, combined with problems raised by alternative objectivist accounts of size variation, provides support for a subjectivist account of size experience. (shrink)

We present a theory of human artistic experience and the neural mechanisms that mediate it. Any theory of art has to ideally have three components. The logic of art: whether there are universal rules or principles; The evolutionary rationale: why did these rules evolve and why do they have the form that they do; What is the brain circuitry involved? Our paper begins with a quest for artistic universals and proposes a list of ‘Eight laws of artistic experience’ (...) -- a set of heuristics that artists either consciously or unconsciously deploy to optimally titillate the visual areas of the brain. One of these principles is a psychological phenomenon called the peak shift effect: If a rat is rewarded for discriminating a rectangle from a square, it will respond even more vigorously to a rectangle that is longer and skinnier that the prototype. We suggest that this principle explains not only caricatures, but many other aspects of art. Example: An evocative sketch of a female nude may be one which selectively accentuates those feminine form-attributes that allow one to discriminate it from a male figure; a Boucher, a Van Gogh, or a Monet may be a caricature in ‘colour space’ rather than form space. Even abstract art may employ ‘supernormal’ stimuli to excite form areas in the brain more strongly than natural stimuli. Second, we suggest that grouping is a very basic principle. The different extrastriate visual areas may have evolved specifically to extract correlations in different domains , and discovering and linking multiple features into unitary clusters -- objects -- is facilitated and reinforced by direct connections from these areas to limbic structures. In general, when object-like entities are partially discerned at any stage in the visual hierarchy, messages are sent back to earlier stages to alert them to certain locations or features in order to look for additional evidence for the object . Finally, given constraints on allocation of attentional resources, art is most appealing if it produces heightened activity in a single dimension rather than redundant activation of multiple modules. This idea may help explain the effectiveness of outline drawings and sketches, the savant syndrome in autists, and the sudden emergence of artistic talent in fronto-temporal dementia. In addition to these three basic principles we propose five others, constituting a total of ‘eight laws of aesthetic experience’. (shrink)

Malebranche holds that visual experience represents the size of objects relative to the perceiver's body and does not represent objects as having intrinsic or nonrelational spatial magnitudes. I argue that Malebranche's case for this body-relative thesis is more sophisticated than other commentators—most notably, Atherton and Simmons —have presented it. Malebranche's central argument relies on the possibility of perceptual variation with respect to size. He uses two thought experiments to show that perceivers of different sizes—namely, miniature people, giants, and (...) typical human beings—can experience the very same objects as having radically different sizes. Malebranche argues that there is no principled reason to privilege one of these ways of experiencing size over the others and, more specifically, that all three kinds of perceivers experience size veridically. From the possibility of this kind of veridical perceptual variation, Malebranche infers that visual experience represents only body-relative size. (shrink)

In the not-too-distant past, vision was often said to involve three levels of processing: a low level concerned with descriptions of the geometric and photometric properties of the image, a high level concerned with abstract knowledge of the physical and semantic properties of the world, and a middle level concerned with anything not handled by the other two. The negative definition of mid-level vision contained in this description reflected a rather large gap in our understanding of visual processing: How (...) could the here-and-now descriptions of the low levels combine with the enduring knowledge of the high levels to produce our perception of the surrounding world? A number of experimental and theoretical efforts have been made over the past few decades to solve this "mid-level crisis". One of the more recent of these is based on the phenomenon of change blindness—the difficulty in seeing a large change in a scene when the transients accompanying that change no longer convey information about its location (Rensink, O'Regan, & Clark, 1997; Rensink, 2000a). Phenomenologically, this effect is quite striking: the change typically is not seen for several seconds, after which it suddenly snaps into awareness. During the time the change remains "invisible", there is an apparent disconnection of the low-level descriptions (which respond to the change) from subjective visual experience (which does not). As such, this effect would seem to have the potential to help us understand how mid-level mechanisms might knit low- and high-level processes into a coherent representation of our surroundings. -/- It is argued here that this potential can indeed be realized, and that change blindness can teach us much about the nature of mid-level vision.3 A number of studies are first reviewed showing that the perception of a scene does not involve a steady buildup of detailed representation: rather, it is a dynamic process, with focused attention playing one of the main roles, viz., forming coherent object representations whenever needed. It is then argued that change blindness can also shed considerable light on the nature of focused attention itself, such as its speed, capacity, selectivity, and ability to bind together visual properties into coherent structures. (shrink)

The main contention of this paper is that, just as there is something it is like to smell a rose, taste chocolate, and hear a siren, there is something it is like to perform an action. In other words, I will argue that we ought to recognize, alongside these other familiar forms of phenomenology, a distinctive phenomenology of agency. My claim is not simply that there is some subjective experience that attaches to the performance of actions. No one disputes (...) that action is typically accompanied by a range of kinaesthetic and visual experiences, and often preceded by conscious thoughts about what to do. The position I wish to defend, rather, is that there is a proprietary phenomenology or subjective character associated with action that “goes beyond” (Horgan et al. 2003, p. 323) these familiar types of sensory and cognitive experience (for other treatments of this topic, see Horgan 2007; Bayne and Levy 2006; Bayne 2008; Pacherie 2008; Kriegel 2015; Shepherd 2017). (shrink)

Existentialist accounts maintain that visual phenomenal content takes the logical form of an existentially quantified sentence. These accounts do not make phenomenal content specific enough. Singularist accounts posit a singular content in which the seen object is a constituent. These accounts make phenomenal content too specific. My account gets the specificity of visual phenomenal content just right. My account begins with John Searle's suggestion that visual experience represents an object as seen, moves this relation outside the (...) scope of the existential quantifier and then replaces it with the relation of objects being ‘present as accessible’, as described by Alva Noë. (shrink)

At a time when professional art criticism is on the wane, the ancient quarrel between art and philosophy demands fresh answers. Professional art criticism provided a basis upon which to distinguish apt experiences of art from the idiosyncratic. However, currently the kind of narratives from which critics once drew are underplayed or discarded in contemporary exhibition design where the visual arts are concerned. This leaves open the possibility that art operates either as mere stimulant to private reverie or, in (...) the more contentful cases, as propaganda. The ancient quarrel between art and philosophy is that art influences surreptitiously while philosophy presents reasons that invite rational scrutiny. As such, in contrast to philosophy, art would undermine our agency. In July 2017, a group of philosophers gathered at the Art Gallery of NSW (AGNSW), in Sydney, Australia, in the presence of two AGNSW curators to explore the basis of their own experiences of selected artworks. Here, those commentaries are reproduced. Each reveal that objective grounds for an experience of art can be based in the community from which one draws one’s terms of reference. In our commentaries we see the expertise of the respective philosophical communities but other communities of culture or expertise might serve the same purpose and hence resolve the ancient quarrel. Before hearing these commentaries, I explain what is at stake when the ancient quarrel between art and philosophy is understood in contemporary terms. This Issue of the Curator also includes an article on the community-based art criticism that emerges from these commentaries followed by an exhibition review which reveals the incorrigible impulse (also demonstrated in the commentaries) to find the basis for the most apt experience of an artwork. A response by the AGNSW curators completes this issue. (shrink)

A common view in the philosophy of perception holds that states of seeing objects face to face have particular contents. When you see, say, a dog face to face, your visual state represents the particular dog that is in front of you. In this paper, I argue for a related claim about states of seeing objects in conventional photographs. When you see a dog in a photograph, for example, your visual state represents the particular dog that was in (...) front of the camera when the photograph was taken, that is, the photograph's depictum. The argument in this paper proceeds in two steps. In the first step, I discuss states of seeing objects face to face. I argue that such a state represents the particular object whose surface is responsible for the optical information that the visual system uses to construct the state's attributive representational content. In the second step, I apply the result of this discussion to states of seeing objects in photographs. I argue that a state of seeing an object in a photograph has a particular content that represents the object that was in front of the camera when the photograph was taken. (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)

In this paper I offer a theory of what makes certain influences on visual experiences by prior mental states (including desires, beliefs, moods, and fears) reduce the justificatory force of those experiences. The main idea is that experiences, like beliefs, can have rationally assessable etiologies, and when those etiologies are irrational, the experiences are epistemically downgraded.

Sensory substitution devices (SSDs) aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality. “The vOICe” is a visual-to-auditory SSD which encodes images taken by a camera worn by the user into “soundscapes” such that experienced users can extract information about their surroundings. Here we investigated how much detail was resolvable during the early induction stages by testing the acuity of blindfolded sighted, naïve vOICe (...) users. Initial performance was well above chance. Participants who took the test twice as a form of minimal training showed a marked improvement on the second test. Acuity was slightly but not significantly impaired when participants wore a camera and judged letter orientations “live”. A positive correlation was found between participants' musical training and their acuity. The relationship between auditory expertise via musical training and the lack of a relationship with visual imagery, suggests that early use of a SSD draws primarily on the mechanisms of the sensory modality being used rather than the one being substituted. If vision is lost, audition represents the sensory channel of highest bandwidth of those remaining. The level of acuity found here, and the fact it was achieved with very little experience in sensory substitution by naïve users is promising. (shrink)

In the visual representation of ontologies, in particular of part-whole relationships, it is customary to use graph theory as the representational background. We claim here that the standard graph-based approach has a number of limitations, and we propose instead a new representation of part-whole structures for ontologies, and describe the results of experiments designed to show the effectiveness of this new proposal especially as concerns reduction of visual complexity. The proposal is developed to serve visualization of ontologies conformant (...) to the Basic Formal Ontology. But it can be used also for more general applications, particularly in the biomedical domain. (shrink)

Seeing-in is the experience of seeing something in a picture. This experience is single and unified. It is not like the disjoint experience of perceiving one thing while simultaneously visualizing another. This is so despite the fact that, like the latter experience, seeing-in is twofold. It involves being visually aware of two distinct objects at the same time – an array of ink-marks, on the one hand, and the depicted scene, on the other. Plausibly, it also (...) involves being aware of them in two distinct ways: while we perceive the ink-marks before us, the manner of our visual awareness of the depicted object is not perceptual. In this paper, I offer a novel way of reconciling these two features of seeing-in. I argue that the modes of visual awareness operative in seeing-in have to be understood on the model of converse relations, like lighter and heavier, in the sense that the same state arises from the obtaining of each. (shrink)

Planar geometry was exploited for the computation of symmetric visual curves in the image plane, with consistent variations in local parameters such as sagitta, chordlength, and the curves’ height-to-width ratio, an indicator of the visual area covered by the curve, also called aspect ratio. Image representations of single curves (no local image context) were presented to human observers to measure their visual sensation of curvature magnitude elicited by a given curve. Nonlinear regression analysis was performed on (...) both the individual and the average data using two types of model: (1) a power function where. (shrink)