This paper proposes to define metaphor as a visual-material structure, the sphere of which is ontological rather than cognitive or conceptual. It argues that the essence of metaphor, as either an aesthetic or a communicative unit or both, resides in the qualitative dimension and appearance, or even materiality, of the metaphorical medium and its form. The paper thus offers a new theory of metaphor, focusing on the medium of metaphor, which composes and transfigures or reconstructs its target anew: a (...) composition that is prior to understanding or conceptualizing the target. In doing so, the paper presents a formalist ontology of metaphors, established via an externalist account of metaphors, as opposed to the prevailing cognitivist-conceptualist account which I characterize as internalist. The various kinds of metaphor – linguistic, poetic, visual or material – are based on their external structure, rather than an internal-conceptual mechanism of understanding, as assumed by a significant segment of the literature. Visual metaphor, therefore, is the paradigmatic kind of metaphor, the analysis of which can be generalized to other kinds of metaphor. Furthermore, the paper tries to overcome the current discrepancy between the formalist character of the metaphorical medium and the dominance of cognitivist and conceptualist theories of metaphor. Challenging these, I claim that if the identity of metaphor is indeed based on its composition, then it is actually based on its aesthetic qualities. That is to say, not only are there autonomous visual or material metaphors, that are not based on linguistic or conceptual ones, but linguistic and conceptual metaphors are based on visuality: they are enabled by the structural possibilities offered by visual media. (shrink)

Four experiments investigated the extent to which abstract quantitative information can be conveyed by basic visual features. This was done by asking observers to estimate and discriminate Pearson correlation in graphical representations where the first data dimension of each element was encoded by its horizontal position, and the second by the value of one of its visual features; perceiving correlation then requires combining the information in the two encodings via a common abstract representation. Four visual features were (...) examined: luminance, color, orientation, and size. All were able to support the perception of correlation. Indeed, despite the strikingly different appearances of the associated stimuli, all gave rise to performance that was much the same: just noticeable difference was a linear function of distance from complete correlation, and estimated correlation a logarithmic function of this distance. Performance differed only in regards to the level of noise in the feature, with these values compatible with estimates of channel capacity encountered in classic experiments on absolute perceptual magnitudes. These results suggest that quantitative information can be conveyed by visual features that are abstracted at relatively low levels of visual processing, with little representation of the original sensory property. It is proposed that this is achieved via an abstract parameter space in which the values in each perceptual dimension are normalized to have the same means and variances, with perceived correlation based on the shape of the joint probability density function of the resultant elements. (shrink)

East Asians and Westerners differ in various aspects of perception and cognition. For example, visual memory for East Asians is believed to be more influenced by the contextual aspects of a scene than is the case for Westerners (Masuda & Nisbett, 2001). There are also differences in visual search: for Westerners, search for a long line among short is faster than for short among long, whereas this difference does not appear to hold for East Asians (Ueda et al., (...) submitted). However, it is unclear how these group-level differences originate. To investigate the extent to which they depend upon environment, we tested visual search and visual memory in East Asian immigrants who had lived in Canada for different amounts of time. Recent immigrants were found to exhibit no search asymmetry, unlike Westerners who had spent their lives in Canada. However, immigrants who had lived in Canada for more than two years showed performance comparable to that of Westerners. These differences could not be explained by the general analytic/holistic processing distinction believed to differentiate Westerners and East Asians, since all observers showed a strong holistic tendency for visual recognition. Results instead support the suggestion that exposure to a new environment can significantly affect the particular processes used to perceive a given stimulus. (shrink)

Assertions about appearances license inferences about the speaker's perceptual experience. For instance, if I assert, 'Tom looks like he's cooking', you will infer both that I am visually acquainted with Tom (what I call the "individual acquaintance inference"), and that I am visually acquainted with evidence that Tom is cooking (what I call the "evidential acquaintance inference"). By contrast, if I assert, 'It looks like Tom is cooking', only the latter inference is licensed. I develop an account of the (...) acquaintance inferences of appearance assertions building on two main previous lines of research: first, the copy raising literature, which has aimed to account for individual acquaintance inferences through the "perceptual source" semantic role; second, the subjectivity literature, which has focused on the status of acquaintance inferences with predicates of personal taste, but hasn't given much attention to the added complexities introduced by appearance language. I begin by developing what I take to be the most empirically-sound version of a perceptual source analysis. I then show how its insights can be maintained, while however taking anything about perception out of the truth conditions of appearance sentences. This, together with the assumption that appearance assertions express experiential attitudes, allows us to capture the acquaintance inferences of bare appearance assertions without making incorrect predictions about the behavior of appearance verbs in embedded environments. (shrink)

Among the extant masterworks of Roman art, there is probably none that has generated more scholarly debate than the Portland Vase over the interpretation of its elegant frieze. No fewer than forty-four different theories attempting to interpret the scenes on the vase have appeared in the last 400 years. In the main, the theories fall into two categories, those relating the frieze to Greek myth, and those linking the figures to Roman personages. Moreover, there is no consensus whether the frieze (...) is two separate scenes or one continuous story. The obstacle to interpreting the frieze is that all but one of the figures lack identifying attributes. This paper will demonstrate (1) that in lieu of standard iconography, a synthesis of visual and literary tropes in the form of hidden letters, that is, cryptograms, tells the viewer how to read the frieze; (2) that scene A of the frieze illustrates specifically lines 26-30 of Catullus 64 by visually rendering the epithets and tropes used in those lines; (3) that visual reproductions of other tropes in Catullus 64 further substantiate the relationship between frieze and poem; (4) that scene B of the frieze is an intentional aberration from the poem; (5) that there is a complex and unfinished interaction between scenes A and B which the viewer must complete; and (6) that in the final analysis, the frieze duplicates both the theme and central structure of Catullus 64.10 . (shrink)

In this paper I will present a puzzle about visual appearance. There are certain necessary constraints on how things can visually appear. The puzzle is about how to explain them. I have no satisfying solution. My main thesis is simply that the puzzle is a puzzle. I will develop the puzzle as it arises for representationalism about experience because it is currently the most popular theory of experience and I think it is along the right lines. However, everyone faces (...) a form of the puzzle, including the naïve realist. In §1 I explain representationalism about experience. In §§2-3 I develop the puzzle and criticize a response due to Ned Block and Jeff Speaks and another response based on a novel form of representationalism (“sensa representationalism”). In §4 I argue that defenders of “perceptual confidence” (Morrison, Munton, my earlier self) face an instance of the puzzle. In §5 I suggest that everyone faces a form of the puzzle. (shrink)

Metacognition is associated with planning, monitoring, evaluating and repairing performance Designers of elearning systems can improve the quality of their environments by explicitly structuring the visual and interactive display of learning contexts to facilitate metacognition. Typically page layout, navigational appearance, visual and interactivity design are not viewed as major factors in metacognition. This is because metacognition tends to be interpreted as a process in the head, rather than an interactive one. It is argued here, that cognition and metacognition (...) are part of a continuum and that both are highly interactive. The tenets of this view are explained by reviewing some of the core assumptions of the situated and distribute approach to cognition and then further elaborated by exploring the notions of active vision, visual complexity, affordance landscape and cue structure. The way visual cues are structured and the way interaction is designed can make an important difference in the ease and effectiveness of cognition and metacognition. Documents that make effective use of markers such as headings, callouts, italics can improve students’ ability to comprehend documents and ‘plan’ the way they review and process content. Interaction can be designed to improve ‘the proximal zone of planning’ – the look ahead and apprehension of what is nearby in activity space that facilitates decisions. This final concept is elaborated in a discussion of how e-newspapers combine effective visual and interactive design to enhance user control over their reading experience. (shrink)

The argument from appearance for the content view or intentionalism attracts a lot of attention recently. In my paper, I follow Charles Travis to argue against the key premise that representational content can be ‘read off’ from a certain way that a thing looks to a subject. My arguments are built upon Travis’s original objection and a reinterpretation of Rodrick Chisholm’s comparative and noncomparative uses of appearance words. Byrne, Schellenberg and others interpret Travis’ ‘visual looks’ as Chisholm’s comparative use, (...) and appeal to the noncomparative use as an alternative to avoid Travis’s objection. I demonstrate that they misunderstand both Chisholm and Travis. Both the comparative use and the noncomparative use are semantic notions, while ‘visual looks’ is a metaphysical one. Although Chisholm’s appearance objectivism –– that appearance expressions attribute appearances to ordinary objects –– is close to ‘visual looks’, appearance objectivism is not exceptional to the noncomparative use as Byrne interprets. In the end, I also show that Byrnean’s conception of distinctive visual gestalt cannot exclude contrary representational contents, because a distinctive visual gestalt can be shared by different kinds of things. Besides, Byrne and others do not explain why a distinctive visual gestalt should be presented as ‘being instantiated’. Therefore, I conclude that representational content cannot be read off from a certain way that a thing looks to a subject; the argument from appearance thus fails. (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)

I introduce a perceptual phenomenon so far overlooked in the philosophical literature: ‘visual evanescence’. ‘Evanescent’ objects are those that due to their structured visible appearances have a tendency to vanish or evanesce from sight at certain places and for certain ‘biologically apt’ perceivers. Paradigmatically evanescent objects are those associated with certain forms of animal camouflage. I show that reflection on visual evanescence helps create conceptual room for a treatment of looks statements not explicit in the contemporary literature, (...) one which takes its cue from the relatively neglected philosophy of perception of G.E.M. Anscombe. In sensory contexts in which evanescence is known to have occurred, the use of ‘looks invisible’ seems to be intelligible, a fact that sensationalist and objectivist treatments of the nature of looks, as I call them, cannot obviously accommodate - at least, as I explain, when coupled with what Cora Diamond (1981) describes as a ‘natural’ understanding of nonsense. Focusing on a number of imaginative scenarios in which the statement ‘looks invisible’ is permissible, I oppose these ontological treatments with the grammatical approach I draw from Anscombe and in doing so I uncover a degree of unity across the cases I consider: something can intelligibly be said to ‘look invisible’ if one can see or appears to see the entirety of the region that the ‘invisible’ thing occupies. The region ‘looks empty’ but is full. (shrink)

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

At the intersection of aesthetics and the philosophy of perception lies a problem about representational images. When you look at Vermeer's View of Delft, do you in fact get to see Delft? It would be nice if we could answer in the affirmative, as it would so neatly explain many of our practices in engaging with images. Be it in churches, advertising, or psychology labs, we typically use images as substitutes for the immediate perception of things. Here is what I (...) claim: Images make it possible to see the objects they represent, and they do so because they can function in vision as perceptual mediators. A perceptual mediator is an object of perception by means of which we can perceive something wholly distinct from it. I show that, while such perceptual mediators may be exceptional in vision, in other sensory modalities they occur universally. Our sensory lives would be impoverished without the possibility of perceiving things mediately. In Chapter 1 I identify a fundamental dispute about images. The dispute is about whether images represent by making absent scenes appear to a viewer, or by merely copying the way an object or event looks. Many philosophers favour the idea that images merely copy how things look. In Chapter 2 I explain my dissatisfaction with the copy view. I lay out my main positive proposal in Chapter 3. How does the idea that images make absent objects visible fit with our current concept of perception? I formulate my answer through a study of the other sensory modalities. In audition, it is no mystery that sounds can make other things heard. My arguments forge a connection between images and sounds that has not been explored in recent work on representation or perception. I show how it offers an attractive solution to our problem. In Chapter 4, I argue that moreover, we may regard mediate perception as a purely sensory mode of perception. There is no need to rely on non-sensory or quasi-sensory effects of thought or cognition. Instead, coming to see a painted surface as an image consists in no more than discovering a previously unseen aspect of our visible surroundings. In Chapter 5 I consider at a more general level how visual images contribute to visual perception. Overall, I establish how visual representation has a structural place in our visual world. (shrink)

The human eyes and brain, which have finite boundaries, create a ‘‘virtual’’ space within our central nervous system that interprets and perceives a space that appears boundless and infinite. Using insights from studies on the visual system, we propose a novel fast processing mechanism involving the eyes, visual pathways, and cortex where external vision is imperceptibly processed in our brain in real time creating an internal representation of external space that appears as an external view. We introduce the (...) existence of a three-dimension default space consisting of intrapersonal body space that serves as the framework where visual and non-visual sensory information is sensed and experienced. We propose that the thalamus integrates processed information from corticothalamic feedback loops and fills-in the neural component of 3D default space with an internal visual representation of external space, leading to the experience of visual consciousness. This visual space inherently evades perception so we have introduced three easy clinical tests that can assist in experiencing this visual space. We also review visual neuroanatomical pathways, binocular vision, neurological disorders, and visual phenomenon to elucidate how the representation of external visible space is recreated within the mind. (shrink)

According to an influential philosophical view I call “the relational properties view”, “perspectival” properties, such as the elliptical appearance of a tilted coin, are relational properties of external objects. Philosophers have assessed this view on the basis of phenomenological, epistemological or other purely philosophical considerations. My aim in this paper is to examine whether it is possible to evaluate RPV empirically. In the first, negative part of the paper I consider and reject a certain tempting way of doing so. In (...) the second, positive part of the paper I suggest a novel way of evaluating RPV empirically, relying on the influential object files framework. (shrink)

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

Small changes in daylight in the environment can produce large changes in reflected light, even over short intervals of time. Do these changes limit the visual recognition of surfaces by their colour? To address this question, information-theoretic methods were used to estimate computationally the maximum number of surfaces in a sample that can be identified as the same after an interval. Scene data were taken from successive hyperspectral radiance images. With no illumination change, the average number of surfaces distinguishable (...) by colour was of the order of 10,000. But with an illumination change, the average number still identifiable declined rapidly with change duration. In one condition, the number after two minutes was around 600, after 10 min around 200, and after an hour around 70. These limits on identification are much lower than with spectral changes in daylight. No recoding of the colour signal is likely to recover surface identity lost in this uncertain environment. (shrink)

When viewing a circular coin rotated in depth, it fills an elliptical region of the distal scene. For some, this appears to generate a two-fold experience, in which one sees the coin as simultaneously circular (in light of its 3D shape) and elliptical (in light of its 2D ‘perspectival shape’ or ‘p-shape’). An energetic philosophical debate asks whether the latter p-shapes are genuinely presented in perceptual experience (as ‘perspectivalists’ argue) or if, instead, this appearance is somehow derived or inferred from (...) experience (as ‘anti-perspectivalists’ argue). This debate, however, has largely turned on introspection. In a recent study, Morales, Bax, and Firestone (2020) aim to provide the first empirical test of this question. They asked subjects to find an elliptical coin seen face-on from a search array that also included a circular coin seen either face-on or at an angle. They found that subjects reacted more slowly when the distracting circle was seen at an angle, such that it’s p-shape matched that of the target ellipse. From this, they concluded that the similar p-shape between the ellipse and circle constituted a phenomenal similarity between the two, and thus that perspectivalism is true. We show that these results can also be explained by pre-attentive guidance by unconscious representations (in what follows, just “unconscious pre-attentive guidance”) and that this explanation is at least as plausible as one from phenomenal similarity. Thus, we conclude that the experiment does not support perspectivalism over anti-perspectivalism. (shrink)

Neuroscience hasn’t shown how quite similar sensory circuits encode quite different colors and other qualia, nor how the unified pictorial form of images is encoded, nor how these codes yield conscious images. Neuroscience’s fixation here on cortical codes may be the culprit. Treating conscious images partly as retinal substances may avoid these problems. The evidence for conscious retinal images is that (a) the cortical codes for images are quite problematic, (b) injecting retinas with certain genes turns dichromats into trichromats without (...) cortical help, (c) retinas can discern colors by themselves without cortex, (d) retinal distortions appear in images but cortical distortions don’t, (e) retinal detectors support finely detailed colors, but V4 detectors don’t, due to their big receptive fields, (f) retinal activity has pictorial form, but viable cortical codes for pictorial form don’t exist. So, the colors and unified pictorial form of images arguably arise mainly across arrays of retinal detectors—not from abstract cortical codes. Images may be hidden in retinal activity beyond what EEGs show of it (cf. Strawson’s monism). Also, cortex refines these retinal images but cortical impairment (anesthesia, lesions, etc.) blocks awareness of them, for they’re no longer accessible to the mind’s subject-centered consciousness, resident in cortex. This proposal is largely testable and based in recent evidence. It avoids neuroscience’s elusive, problematic coded images and enigmatic explanations of how they become conscious. (shrink)

Imagine I hold up a Granny Smith apple for all to see. You would thereby gain justified beliefs that it was green, that it was apple, and that it is a Granny Smith apple. Under classical foundationalism, such simple visual beliefs are mediately justified on the basis of reasons concerning your experience. Under dogmatism, some or all of these beliefs are justified immediately by your experience and not by reasons you possess. This paper argues for what I call the (...) looks view of the justification of simple visual beliefs. According to the looks view, such beliefs are mediately justified on the basis of reasons concerning how the relevant things look. Unlike under classical foundationalism, under the looks view as I develop it, these reasons are public. They are public with respect to both their content and possession: with respect to content, they are not about ourselves and our experiences, and with respect to their possession, many people can have the very same looks-related reasons. (shrink)

This chapter critically assesses recent arguments that acquiring the ability to categorize an object as belonging to a certain high-level kind can cause the relevant kind property to be represented in visual phenomenal content. The first two arguments, developed respectively by Susanna Siegel (2010) and Tim Bayne (2009), employ an essentially phenomenological methodology. The third argument, developed by William Fish (2013), by contrast, is supported by an array of psychophysical and neuroscientific findings. I argue that while none of these (...) arguments ultimately proves successful, there is a substantial body of empirical evidence that information originating outside the visual system can nonetheless modulate the way an object’s low-level attributes visually appear. Visual phenomenal content, I show, is not only significantly influenced by crossmodal interactions between vision and other exteroceptive senses such as touch and audition, but also by interactions between vision and non-perceptual systems involved in motor planning and construction of the proprioceptive body-image. (shrink)

Visual perception is widely taken to present properties such as redness, roundness, and so on. This in turn might be thought to give rise to accuracy conditions for experience, and so content, regardless of which metaphysical view of perception one endorses. An influential version of this argument—Susanna Siegel’s ’Argument from Appearing’—aims to establish the existence of content as common ground between representational and relational views of perception. This goes against proponents of ‘austere’ relationalism who deny that content plays a (...) substantive role in philosophical explanations of conscious perceptual experience. Though Siegel’s argument purports to be neutral with respect to the metaphysics of perception, it relies upon an equivocation between the presentation of property-types and property-instances. Consequently, the argument begs the question against the austere relational view, and so fails to establish the desired conclusion. So while relationalists can and should allow that experiences have accuracy conditions, it does not follow from this that they have contents of any philosophically interesting or significant kind. (shrink)

Consider the distinctive qualitative property grass visually appears to have when it visually appears to be green. This property is an example of what I call sensuous color. Whereas early modern mechanists typically argue that bodies are not sensuously colored, Margaret Cavendish (1623–73) disagrees. In cases of veridical perception, she holds that grass is green in precisely the way it visually appears to be. In defense of her realist approach to sensuous colors, Cavendish argues that (i) it is impossible to (...) conceive of colorless bodies, (ii) the very possibility of color experience requires that bodies are sensuously colored, and (iii) the attribution of sensuous colors to bodies provides the best explanation of color constancy. Although some passages might suggest that Cavendish endorses a reductive account of sensuous color, according to which sensuous color reduces to a body's microscopic surface texture (or some other mechanistically respectable property), I argue that she accepts a nonreductive account, on which sensuous color is not thus reducible. (shrink)

This paper develops Richard Wollheim’s claim that the proper appreciation of a picture involves not only enjoying a seeing-in experience but also abiding by a standard of correctness. While scholars have so far focused on what fixes the standard, thereby discussing the alternative between intentions and causal mechanisms, the paper focuses on what the standard does, that is, establishing which kinds, individuals, features and standpoints are relevant to the understanding of pictures. It is argued that, while standards concerning kinds, individuals (...) and features can be relevant also to ordinary perception, standards concerning standpoints are specific to pictorial experience. Drawing on all this, the paper proposes an ontology of depiction according to which a picture is constituted by both its visual appearance and its standard of correctness. (shrink)

An account of depiction should explain its key features. I identify six: that depiction is from a point of view; that it represents its objects as having a visual appearance; that it depictive content is always reasonably detailed; that misrepresentation is possible, but only within limits; and that the ability to interpret depictions co-varies, given general competence with pictures, with knowledge of what the depicted objects look like. All this suggests that picturing works by capturing appearances, but how (...) more precisely does it operate? I show how to use the notion of experienced resemblance in outline shape to analyse depiction in such a way as to answer this question, and to explain the six key features above. (shrink)

In the museum context, curators and conservators often play a role in shaping the nature of contemporary artworks. Before, during and after the acquisition of an art object, curators and conservators engage in dialogue with the artist about how the object should be exhibited and conserved. As a part of this dialogue, the artist may express specifications for the display and conservation of the object, thereby fixing characteristics of the artwork that were previously left open. This process can make a (...) significant difference to the visual appearance of the work, the nature of the audience's experience, and how the work should be interpreted. I present several case studies in which the nature of the artwork has been shaped by such dialogues, and discuss principles for resolving cases in which there is a conflict between instructions specified by the artist and those adopted by the museum. (shrink)

There are some objects of perception that are either too far from us to touch or that cannot be touched at all. Typical examples are the sky and the various phenomena that appear in the sky such as rainbows and sunsets. This paper is concerned with the ontological status of the rainbow. Does it exist when it is not actually perceived? Does it exist even when it is not possibly perceived? My conclusion is that a rainbow is a physical event, (...) and that, although it is recognized as a rainbow by its characteristic visual appearance, it should not be identified with that appearance. I suggest that the case of the rainbow might give us useful hints for the analysis of secondary qualities like colors and sounds. (shrink)

The visual system adapts to a wide range of visual features, from lower-level features like color and motion to higher-level features like causality and, perhaps, number. According to some, adaptation is a strictly perceptual phenomenon, such that the presence of adaptation licenses the claim that a feature is truly perceptual in nature. Given the theoretical importance of claims about adaptation, then, it is important to understand exactly when the visual system does and does not exhibit adaptation. Here, (...) we take as a case study one specific kind of adaptation: visual adaptation to size. Supported by evidence from four experiments, we argue that, despite robust effects of size adaptation in the lab, (1) size adaptation effects are phenomenologically underwhelming (in some cases, hardly appreciable at all), (2) some effects of size adaptation appear contradictory, and difficult to explain given current theories of size adaptation, and (3) prior studies on size adaptation may have failed to isolate size as the adapted dimension. Ultimately, we argue that while there is evidence to license the claim that size adaptation is genuine, size adaptation is a puzzling and poorly understood phenomenon. (shrink)

Perceptual filling-in for vision is the insertion of visual properties (e.g., color, contour, luminance, or motion) into one’s visual field, when those properties have no corresponding retinal input. This paper introduces and provides preliminary empirical support for filled/non-filled pairs, pairs of images that appear identical, yet differ by amount of filling-in. It is argued that such image pairs are important to the experimental testing of theories of consciousness. We review recent experimental research and conclude that filling-in involves brain (...) activity with relatively high integrated information (Phi) compared to veridical visual perceptions. We then present filled/non-filled pairs as an empirical challenge to the integrated information theory of consciousness, which predicts that phenomenologically identical experiences depend on brain processes with identical Phi. (shrink)

As observers, we generally have a strong impression of seeing everything in front of us at any moment. But compelling as it is, this impression is false – there are severe limits to what we can consciously experience in everyday life. Much of the evidence for this claim has come from two phenomena: change blindness (CB) and inattentional blindness (IB). -/- CB refers to the failure of an observer to visually experience changes that are easily seen once noticed. This can (...) happen even if the changes are large, constantly repeat, and the observer has been informed that they will occur. A related phenomenon is IB – the failure to visually experience an object or event when attention is directed elsewhere. For example, observers may fail to notice an unexpected object that enters their visual field, even if this object is large, appears for several seconds, and has important consequences for the selection of action. -/- Both phenomena involve a striking failure to report an object or event that is easily seen once noticed. As such, both are highly counterintuitive, not only in the subjective sense that observers have difficulty believing they could fail so badly at seeing but also in the objective sense that these findings challenge many existing ideas about how we see. But as counterintuitive as these phenomena are, progress has been made in understanding them. Indeed, doing so has allowed us to better understand the limitations of human perception in everyday life and to gain new insights into how our visual systems create the picture of the world that we experience each moment our eyes are open. (shrink)

Hill's views on visual experience are critically examined.

We present a rigorous way to evaluate the visual perception of correlation in scatterplots, based on classical psychophysical methods originally developed for simple properties such as brightness. Although scatterplots are graphically complex, the quantity they convey is relatively simple. As such, it may be possible to assess the perception of correlation in a similar way. Scatterplots were each of 5.0 extent, containing 100 points with a bivariate normal distribution. Means were 0.5 of the range of the points, and standard (...) deviations 0.2 of this range. Precision was determined via an adaptive algorithm to find the just noticeable differences (jnds) in correlation, i.e., the difference between two side-by-side scatterplots that could be discriminated 75% of the time. Accuracy was measured by direct estimation, using reference scatterplots with fixed upper and lower values, with a test scatterplot adjusted so that its correlation appeared to be halfway between these. This process was recursively applied to yield several further estimates. Results of the discrimination tests show jnd(r) = k (1/b – r), where r is the Pearson correlation, and parameters 0 < k, b < 1. Integration yields a subjective estimate of correlation g(r) = ln(1 – br) / ln(1– b). The values of b found via discrimination closely match those found via direct estimation. As such, it appears that the perception of correlation in a scatterplot is completely described by two related performance curves, specified by two easily-measured parameters. (shrink)

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

One of the most widely recognised intuitions about knowledge is that knowing precludes believing truly as a matter of luck. On Pritchard’s highly influential modal account of epistemic luck, luckily true beliefs are, roughly, those for which there are many close possible worlds in which the same belief formed in the same way is false. My aim is to introduce a new challenge to this account. Starting from the observation—as documented by a number of recent EEG studies—that our capacity to (...) detect visual stimuli fluctuates with the phase of our neural oscillations, I argue that there can be very close possible worlds in which an actual-world detectable stimulus is undetectable. However, this doesn’t diminish our willingness to attribute knowledge in the case that the stimulus is detectable, even when undetectability would result in the same belief formed in the same way being false. As I will argue at length, the modal account appears unable to accommodate this result. (shrink)

When interpreting the meanings of visual features in information visualizations, observers have expectations about how visual features map onto concepts (inferred mappings.) In this study, we examined whether aspects of inferred mappings that have been previously identified for colormap data visualizations generalize to a different type of visualization, Venn diagrams. Venn diagrams offer an interesting test case because empirical evidence about the nature of inferred mappings for colormaps suggests that established conventions for Venn diagrams are counterintuitive. Venn diagrams (...) represent classes using overlapping circles and express logical relationships between those classes by shading out regions to encode the concept of non-existence, or none. We propose that people do not simply expect shading to signify non-existence, but rather they expect regions that appear as holes to signify non-existence (the hole hypothesis.) The appearance of a hole depends on perceptual properties in the diagram in relation to its background. Across three experiments, results supported the hole hypothesis, underscoring the importance of configural processing for interpreting the meanings of visual features in information visualizations. (shrink)

This is a chapter from my introductory book *Perception* covering the representational view of experience. I use the Ramsey-Lewis method to define the theoretical term "experiential representation". I clarify and discuss various questions for representationalists, for instance, "how rich is the content of experience?" and "is the content of visual experience singular or general?" Finally, I address some objections to representationalism - in particular, that it cannot explain perceptual presence (John Campbell), and that it cannot explain the "laws of (...) appearance" (constraints on how things can appear). (shrink)

Victor Vasarely's (1906–1997) important legacy to the study of human perception is brought to the forefront and discussed. A large part of his impressive work conveys the appearance of striking three-dimensional shapes and structures in a large-scale pictorial plane. Current perception science explains such effects by invoking brain mechanisms for the processing of monocular (2D) depth cues. Here in this study, we illustrate and explain local effects of 2D color and contrast cues on the perceptual organization in terms of figure-ground (...) assignments, i.e. which local surfaces are likely to be seen as “nearer” or “bigger” in the image plane. Paired configurations are embedded in a larger, structurally ambivalent pictorial context inspired by some of Vasarely's creations. The figure-ground effects these configurations produce reveal a significant correlation between perceptual solutions for “nearer” and “bigger” when other geometric depth cues are missing. In consistency with previous findings on similar, albeit simpler visual displays, a specific color may compete with luminance contrast to resolve the planar ambiguity of a complex pattern context at a critical point in the hierarchical resolution of figure-ground uncertainty. The potential role of color temperature in this process is brought forward here. Vasarely intuitively understood and successfully exploited the subtle context effects accounted for in this paper, well before empirical investigation had set out to study and explain them in terms of information processing by the visual brain. (shrink)

This article analyzes the value of geometric models to understand matter with the examples of the Platonic model for the primary four elements (fire, air, water, and earth) and the models of carbon atomic structures in the new science of crystallography. How the geometry of these models is built in order to discover the properties of matter is explained: movement and stability for the primary elements, and hardness, softness and elasticity for the carbon atoms. These geometric models appear to have (...) a double quality: firstly, they exhibit visually the scientific properties of matter, and secondly they give us the possibility to visualize its whole nature. Geometrical models appear to be the expression of the mind in the understanding of physical matter. (shrink)

I will use three simple arguments to refute the thesis that I appear to directly perceive a mind-independent material object. The theses I will use are similar to the time-gap argument and the argument from the relativity of perception. The visual object of imagination and the object of experience are in the same place. They also share common qualities such as the content, subjectivity, change in virtue of conditions of observers, and the like. This leads to the conclusion that (...) both a tree-image and a tree-experience are distinct from a material tree. Perception of an object is caused by human nature, the senses and consciousness, and mind may prevent the direct perception of the external world. The strongest objection against that consequence is that there is no extra entity called sense-datum or appearance between a subject-in-itself and a real external thing-in-itself. That is, we see books, not book-images. The possible reply would be that a person sees no mental pictures except that which they see via pictures. (shrink)

I will use three simple arguments to refute the thesis that I appear to directly perceive a mind-independent material object. The theses I will use are similar to the time-gap argument and the argument from the relativity of perception. The visual object of imagination and the object of experience are in the same place. They also share common qualities such as the content, subjectivity, change in virtue of conditions of observers, and the like. This leads to the conclusion that (...) both a tree-image and a tree-experience are distinct from a material tree. Perception of an object is caused by human nature, the senses and consciousness, and mind may prevent the direct perception of the external world. The strongest objection against that consequence is that there is no extra entity called sense-datum or appearance between a subject-in-itself and a real external thing-in-itself. That is, we see books, not book-images. The possible reply would be that a person sees no mental pictures except that which they see via pictures. (shrink)

For a stable visual world, the colours of objects should appear the same under different lights. This property of colour constancy has been assumed to be fundamental to vision, and many experimental attempts have been made to quantify it. I contend here, however, that the usual methods of measurement are either too coarse or concentrate not on colour constancy itself, but on other, complementary aspects of scene perception. Whether colour constancy exists other than in nominal terms remains unclear.

Pain asymbolia is a rare condition caused by brain damage, usually in adulthood. Asymbolics feel pain but appear indifferent to it, and indifferent also to visual and verbal threats. How should we make sense of this? Nikola Grahek thinks asymbolics’ pains are abnormal, lacking a component that make normal pains unpleasant and motivating. Colin Klein thinks that what is abnormal is not asymbolics’ pains, but asymbolics: they have a psychological deficit making them unresponsive to unpleasant pain. I argue that (...) an illuminating account requires elements of both views. Asymbolic pains are indeed abnormal, but they are abnormal because asymbolics are. I agree with Klein that asymbolics are incapable of caring about their bodily integrity; but I argue against him that, if this is to explain not only their indifference to visual and verbal threat, but also their indifference to pain, we must do the following: (i) take asymbolics’ lack of bodily care not as an alternative to, but as an explanation of their pains’ missing a component, and (ii) claim that the missing component consists in evaluative content. Asymbolia, I conclude, reveals not only that unpleasant pain is composite, but that its ‘hedomotive component’ is evaluative. (shrink)

I open my eyes and see that the lemon before me is yellow. States like this—states of seeing that $p$ —appear to be visual perceptual states, in some sense. They also appear to be propositional attitudes (and so states with propositional representational contents). It might seem, then, like a view of perceptual experience on which experiences have propositional representational contents—a Propositional View—has to be the correct sort of view for states of seeing that $p$ . And thus we can’t (...) sustain fully general non-Propositional but Representational, or Relational Views of experience. But despite what we might initially be inclined to think when reflecting upon the apparent features of states of seeing that $p$ , a non-propositional view of seeing that $p$ is, I argue, perfectly intelligible. (shrink)

This paper explores some surprising effects of psychological trauma on memory and develops the puzzle of observer memory for trauma. Memory for trauma tends to have a third-person perspective, or observer perspective. But it appears observer memory, by having a novel visual point of view, tends to misrepresent the past. And many find it plausible that if a memory type tends to misrepresent, it cannot yield knowledge of, or justification for believing, details of past events. But it is also (...) plausible that, with respect to details of past trauma, observer memory can yield knowledge or justification. I argue for a novel set of views that offers a way out of the puzzle: observer memory does tend to misrepresent, but it still has epistemic power regarding details of the past, although with special limits; but observer memory for trauma has other epistemic powers too, in that it allows for a kind of self-awareness. (shrink)

Many epistemologists hold that an agent can come to justifiably believe that p is true by seeing that it appears that p is true, without having any antecedent reason to believe that visual impressions are generally reliable. Certain reliabilists think this, at least if the agent’s vision is generally reliable. And it is a central tenet of dogmatism (as described by Pryor (2000) and Pryor (2004)) that this is possible. Against these positions it has been argued (e.g. by Cohen (...) (2005) and White (2006)) that this violates some principles from probabilistic learning theory. To see the problem, let’s note what the dogmatist thinks we can learn by paying attention to how things appear. (The reliabilist says the same things, but we’ll focus on the dogmatist.) Suppose an agent receives an appearance that p, and comes to believe that p. Letting Ap be the proposition that it appears to the agent that p, and → be the material implication, we can say that the agent learns that p, and hence is in a position to infer Ap → p, once they receive the evidence Ap.1 This is surprising, because we can prove the following. (shrink)

The complexity definition has appeared during analysis of visual structures perception. The binary model of visual impacts finding was essential here for a possibility of the general (abstract) research. The Abstract Complexity Definition is one of the research results. The definition meets intuitive complexity criterion and could be a common surface for all existing definitins of complexity.

This paper proposes a novel experimental approach that would help to determine whether perspectival shapes, such as the elliptical profile of a tilted plate or coin, are part of perceptual experience. If they are part of perceptual experience, then it should be possible to identify these shapes simply by attending appropriately to them. Otherwise, in order to identify perspectival shapes they must first be constructed in the visual imagination. We propose that these accounts of perspectival identification can be tested (...) by measuring the interference between visual and verbal working memory load, respectively, and the identification of perspectival shapes in the appearance of a 3D object. (shrink)

This paper is a contribution to the philosophical debate on visual blur from a relationalist perspective. At the same time, it offers a methodological reflection on the adequacy of explanations of phenomenal similarities and differences among perceptual experiences. The debate on seeing blurrily has been shaped by two implicit assumptions concerning our explanations of differences and similarities between experiences of seeing blurrily and other experiences. I call those assumptions into question, and argue that we do not need to provide (...) a unified explanation of the character of blurry experiences for our account to be adequate. The diversity of blurry experiences supports a different, pluralist approach to explanations of how things appear to subjects. (shrink)

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

We show that true colors as defined by Chevreul (1839) produce unsuspected simultaneous brightness induction effects on their immediate grey backgrounds when these are placed on a darker (black) general background surrounding two spatially separated configurations. Assimilation and apparent contrast may occur in one and the same stimulus display. We examined the possible link between these effects and the perceived depth of the color patterns which induce them as a function of their luminance contrast. Patterns of square-shaped inducers of a (...) single color (red, green, blue, yellow, or grey) were placed on background fields of a lighter and a darker grey, presented on a darker screen. Inducers were always darker on one side of the display and brighter on the other in a given trial. The intensity of the grey backgrounds varied between trials only. This permitted generating four inducer luminance contrasts, presented in random order, for each color. Background fields were either spatially separated or consisted of a single grey field on the black screen. Experiments were run under three environmental conditions: dark-adaptation, daylight, and rod-saturation after exposure to bright light. In a first task, we measured probabilities of contrast, assimilation, and no effect in a three-alternative forced-choice procedure (background appears brighter on the ‘left’, on the ‘right’ or the ‘same’). Visual adaptation and inducer contrast had no significant influence on the induction effects produced by colored inducers. Achromatic inducers produced significantly stronger contrast effects after dark-adaptation, and significantly stronger assimilation in daylight conditions. Grouping two backgrounds into a single one was found to significantly decrease probabilities of apparent contrast. Under the same conditions, we measured probabilities of the inducers to be perceived as nearer to the observer inducers. These, as predicted by Chevreul’s law of contrast, were determined by the luminance contrast of the inducers only, with significantly higher probabilities of brighter inducers to be seen as nearer, and a marked asymmetry between effects produced by inducers of opposite sign. Implications of these findings for theories which attempt to link simultaneous induction effects to the relative depth of object surfaces in the visual field are discussed. (shrink)