A survey of color science and color vision.

Tracking theories of mental representation posit a privileged relation between color representations and the color properties of objects. Tracking theories of mental representation have been used to motivate color realism as they posit that the function of color vision is to represent the colors of objects. It has been argued that tracking theories have a major flaw, namely they cannot account for reliable misrepresentation. It has further been suggested that reliable color misrepresentation is a (...) live possibility. In this chapter, I argue that the current evidence indicates that our color representations reliably misrepresent. This conclusion undermines tracking theories and the color realist theories they purport to motivate. (shrink)

Over the last 25 years, there has been a concerted effort to settle questions about multiple realization by bringing detailed scientific evidence to bear. Ken Aizawa and Carl Gillett have pursued this scientific approach to multiple realization with a precise theory and applications. This paper reviews the application of the Dimensioned approach to human color vision, addressing objections that have appeared in the literature.

In the second volume of the "Handbuch der physiologischen Optik", published in 1860, Helmholtz sets out a three-receptor theory of color vision using coterminal response curves, and shows that this theory can unify most phenomena of color mixing known at the time. Maxwell had publicized the same theory five years earlier, but Helmholtz barely acknowledges this fact in the "Handbuch". Some historians have argued that this is because Helmholtz independently discovered the theory around the same time as (...) Maxwell. This paper argues that this hypothesis is implausible. By writing what he did in the "Handbuch", Helmholtz influenced the field's perception of its own history. As a result, Helmholtz has received more recognition for his contributions to the field of color mixing than was his due, and Maxwell less. (shrink)

This paper critically examines color relationalism and color relativism, two theories of color that are allegedly supported by variation in normal human color vision. We mostly discuss color relationalism, defended at length in Jonathan Cohen's The Red and the Real, and argue that the theory has insuperable problems.

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

Should a principle of charity be applied to the interpretation of the colour concepts exercised in visual experience? We think not. We shall argue, for one thing, that the grounds for applying a principle of charity are lacking in the case of colour concepts. More importantly, we shall argue that attempts at giving the experience of colour a charitable interpretation either fail to respect obvious features of that experience or fail to interpret it charitably, after all. Charity to visual experience (...) is therefore no motive for resisting the natural, Galilean response to a scientific understanding of light and vision. The best interpretation of colour experience ends up convicting it of widespread and systematic error. (shrink)

A stubborn problem for reflectance physicalism about color is to account for individual differences in normal trichromat color perception. The identification of determinate colors with physical properties of visible surfaces in a universal, perceiver-independent way is challenged by the observation that the same surfaces in identical viewing conditions often look different in color to different human subjects with normal color vision. Recently, leading representatives of reflectance physicalism have offered some arguments to defend their view against (...) the individual differences challenge. In this paper I challenge their defense. I argue thateven though individual differences are present in shape perception as well as in color perception, the mechanisms of shape perception and those of color perception differ in ways which make them completely different regarding their evidential status for certain identity claims. Thus comparing color perception to shape perception offers no support for identifying hues with reflectances. On the other hand, drawing a parallel between the temperature-mean kinetic energy of molecules (MKE) identification and the proposed hue-reflectance identities is no support for reflectance physicalism either, since there is an important disanalogybetween the two cases. While individual differences obtain in color perception, the effects of temperature (e.g., melting, thermal expansion) do not exhibit analogous variation, which makes the temperature-MKE identification unproblematic compared to the hue-reflectance identification. One motivation for this ongoing debate is that the success or failure of reflectance physicalism has far-reaching consequences regarding externalist theories of phenomenal consciousness. (shrink)

This paper articulates a case for supposing that all shades of colour are visually complex.

Back when researchers thought about the various forms that color vision could take, the focus was primarily on the retinal mechanisms. Since that time, research on human color vision has shifted from an interest in retinal mechanisms to cortical color processing. This has allowed color research to provide insight into questions that are not limited to early vision but extend to cognition. Direct cortical connections from higher-level areas to lower-level areas have been found (...) throughout the brain. One of the classic questions in cognitive science is whether perception is influenced, and if so to what extent, by cognition and whether a clear distinction can be drawn between perception and cognition. Since perception is seen as providing justification for our beliefs about properties in the external world, these questions also have metaphysical and epistemological significance. The aim of this paper is to highlight some of the areas where research on color perception can shed new light on questions in the cognitive sciences. A further aim of the paper is to raise some questions about color research that are in dire need of further reflection and investigation. (shrink)

A major part of the mind–body problem is to explain why a given set of physical processes should give rise to qualia of one sort rather than another. Colour hues are the usual example considered here, and there is a lively debate between, for example, Hardin, Levine, Jackson, Clark and Chalmers as to whether the results of colour vision science can provide convincing explanations of why colours actually look the way they do. This paper examines carefully the type of (...) explanation that is needed here, and it is concluded that it does not have to be reductive to be effective. What needs to be explained more than anything is why inverted hue scenarios are more intuitive than other sensory inversions: and the issue of physicalism versus dualism is only of marginal relevance here. (shrink)

The philosophical debate over the nature of color has been governed by what we have learnt from color vision science and what color phenomenology suggests to us. It is usually thought that color eliminativism, which maintains that physical objects do not have any properties that can be identified with colors, can account for the former but not the latter. After all, what could be more obvious than the external world to be colored? Here I outline (...) one color eliminativistic response to the objections based on phenomenology. (shrink)

Martine Nida-Rümelin (1996) argues that color science indicates behaviorally undetectable spectrum inversion is possible and raises this possibility as an objection to functionalist accounts of visual states of color. I show that her argument does not rest solely on color science, but also on a philosophically controversial assumption, namely, that visual states of color supervene on physiological states. However, this assumption, on the part of philosophers or vision scientists, has the effect of simply ruling out (...) certain versions of functionalism. While Nida-Rümelin is quite right to search for empirical tests for claims about the nature of visual states, philosophical issues remain pivotal in determining the correctness of these claims. (shrink)

How the visual systems of different species enable them to detect and discriminate colour patterns and how such visual abilities contribute to their survival is discussed. The influence of evolutionary and environmental pressures on both perceptual capacity and colour trait production is to be considered. Visual systems with different functional anatomy have evolved in response to such pressures.

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.

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

I argue against a class of philosophical views of color perception, especially insofar as such views posit the existence of color sensations. I argue against the need to posit such nonconceptual mental intermediaries between the stimulus and the eventual conceptualized perceptual judgment. Central to my arguments are considerations of certain color illusions. Such illusions are best explained by reference to high-level, conceptualized knowledge concerning, for example, object identity, likely lighting conditions, and material composition of the distal stimulus. (...) Such explanations obviate the need to appeal to nonconceputal mental links in the causal chains eventuating in conceptualized color discriminations. (shrink)

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

Color-vision defects constitute a spectrum of disorders with varying degrees and types of departure from normal human color vision. One form of color-vision defect is dichromacy; by mixing together only two lights, the dichromat can match any light, unlike normal trichromatic humans, who need to mix three. In a philosophical context, our titular question may be taken in two ways. First, it can be taken at face value as a question about visible properties of (...) external objects, and second, it may be interpreted as the more intangible question of “what it’s like” to be color-blind. (shrink)

Martine Nida-Rümelin (1996) argues that color science indicates behaviorally undetectable spectrum inversion is possible and raises this possibility as an objection to functionalist accounts of visual states of color. I show that her argument does not rest solely on color science, but also on a philosophically controversial assumption, namely, that visual states of color supervene on physiological states. However, this assumption, on the part of philosophers or vision scientists, has the effect of simply ruling out (...) certain versions of functionalism. While Nida-Rümelin is quite right to search for empirical tests for claims about the nature of visual states, philosophical issues remain pivotal in determining the correctness of these claims. (shrink)

A quarter of a century ago, the first systematic behavioral experiments were performed to clarify the nature of color constancy—the effect whereby the perceived color of a surface remains constant despite changes in the spectrum of the illumination. At about the same time, new models of color constancy appeared, along with physiological data on cortical mechanisms and photographic colorimetric measurements of natural scenes. Since then, as this review shows, there have been many advances. The theoretical requirements for (...) constancy have been better delineated and the range of experimental techniques has been greatly expanded; novel invariant properties of images and a variety of neural mechanisms have been identified; and increasing recognition has been given to the relevance of natural surfaces and scenes as laboratory stimuli. Even so, there remain many theoretical and experimental challenges, not least to develop an account of color constancy that goes beyond deterministic and relatively simple laboratory stimuli and instead deals with the intrinsically variable nature of surfaces and illuminations present in the natural world. (shrink)

Now with extra footnotes, by editorial demand! Final version accepted by Oxford Studies in Ancient Philosophy. -/- This essay consists in a trick and a potential insight. The trick consists in a minimalist interpretation of color mixture. The account of color mixture is minimalist in the sense that, given certain background assumptions, there is no more to Timaeus’ account of color mixture than the list of the chromatic pathēmata and the list of how these combine to elicit (...) perceptions of all the colors. The only potential controversial elements of the minimalist interpretation are the relevant background assumptions and the interpretation of the chromatic pathēmata. The potential insight concerns a motive that Plato, in the guise of Timaeus, may have for presenting an account of color mixture. Specifically, I shall argue that on the minimalist interpretation, Plato may be read as reconciling the Democritrean four color scheme with an older tradi- tion where white and black are the fundamental chromatic opposition. As we shall see, this bears on the interpretation of the chromatic pathēmata. (shrink)

Mazviita Chirimuuta proposes a new “adverbialist” ontology of color. I argue that ontological disputes in the philosophy of color are uniformly terminological. Chirimuuta's proposal too is a terminological variant on others, though it has some hortatory value in directing attention to aspects of color science that have hitherto been neglected. On a side note, I also take issue with Chirimuuta's laudatory take on early modern theories of color.

The thresholds of human observers detecting line targets improve significantly when the targets are presented in a spatial context of collinear inducing stimuli. This phenomenon is referred to as spatial facilitation, and may reflect the output of long-range interactions between cortical feature detectors. Spatial facilitation has thus far been observed with luminance-defined, achromatic stimuli on achromatic backgrounds. This study compares spatial facilitation with line targets and collinear, edge-like inducers defined by luminance contrast to spatial facilitation with targets and inducers defined (...) by color contrast. The results of a first experiment show that achromatic inducers facilitate the detection of achromatic targets on gray and colored backgrounds, but tend to suppress the detection of chromatic targets. Chromatic inducers facilitate the detection of chromatic targets on gray and colored backgrounds, but tend to suppress the detection of achromatic targets. Chromatic spatial facilitation appears to be strongest when inducers and background are isoluminant. The results of a second experiment show that spatial facilitation with chromatic targets and inducers requires a longer exposure duration of the inducers than spatial facilitation with achromatic targets and inducers, which is already fully effective at an inducer exposure of 30 ms only. The findings point towards two separate mechanisms for spatial facilitation with collinear form stimuli: one that operates in the domain of luminance, and one that operates in the domain of color contrast. These results are consistent with neural models of boundary and surface formation which suggest that achromatic and chromatic visual cues are represented on different cortical surface representations that are capable of selectively attracting attention. Multiple copies of these achromatic and chromatic surface representations exist corresponding to different ranges of perceived depth from an observer, and each can attract attention to itself. Color and contrast differences between inducing and test stimuli, and transient responses to inducing stimuli, can cause attention to shift across these surface representations in ways that sometimes enhance and sometimes interfere with target detection. (shrink)

Mark Eli Kalderon presents an original study of perception, taking as its starting point a puzzle in Empedocles' theory of vision: if perception is a mode of material assimilation, how can we perceive colors at a distance? Kalderon argues that the theory of perception offered by Aristotle in answer to the puzzle is both attractive and defensible.

Review of: R. Steven Turner, In the Eye's Mind: Vision and the Helmholtz-Hering Controversy. xiv + 338 pp., frontis., illus., figs., tables, bibl., index. Princeton, N.J.: Princeton University Press, 1994.

This is a commentary on Laurence Maloney’s chapter in Mausfeld R., and Heyer, D. (Eds.): Colour Perception: Mind and the Physical World. Oxford: Oxford University Press, 2003. I discuss two related proposals as to the nature of object color formulated by Maloney. On the first proposal colors are photoreceptor excitations; on the second, they are fundamental, universal reflectance characteristics of terrestrial surfaces. I argue that the second proposal is suitable for purposes of color objectivism, whereas the first one (...) is not. However, if we look at Maloney’s – and Brian Wandell’s – models of color vision and color constancy more thoroughly, not even the second version supports absolutist versions of color objectivism, according to which observer-independent reflectance properties determine, or are identical to, the phenomenal character of color experience. (shrink)

The overreliance on verbal models and theories in psychology has been criticized for hindering the development of reliable research programs (Harris, 1976; Yarkoni, 2020). We demonstrate how the conceptual space framework can be used to formalize verbal theories and improve their precision and testability. In the framework, scientific concepts are represented by means of geometric objects. As a case study, we present a formalization of an existing three-dimensional theory of emotion which was developed with a spatial metaphor in mind. Wundt (...) posits that the range of human emotion can be represented along three axes of basic emotions (pleasure/displeasure, excitement/inhibition, tension/relaxation), just as color vision can be represented using three basic colors. We use dimensions to represent basic emotions, points to represent emotional states, and regions to represent broader emotional concepts. We then compare our formalization to an existing structuralist formalization of Wundt’s theory. Further, we discuss the empirical predictions that our formalization generates, such as comparisons of similarity and intensity. We conclude by demonstrating how the tools developed in the conceptual space framework can be used to formulate a theory of emotion based on empirical observation. (shrink)

The overreliance on verbal models and theories in psychology has been criticized for hindering the development of reliable research programs (Harris, 1976; Yarkoni, 2020). We demonstrate how the conceptual space framework can be used to formalize verbal theories and improve their precision and testability. In the framework, scientific concepts are represented by means of geometric objects. As a case study, we present a formalization of an existing three-dimensional theory of emotion which was developed with a spatial metaphor in mind. Wundt (...) posits that the range of human emotion can be represented along three axes of basic emotions (pleasure/displeasure, excitement/inhibition, tension/relaxation), just as color vision can be represented using three basic colors. We use dimensions to represent basic emotions, points to represent emotional states, and regions to represent broader emotional concepts. We then compare our formalization to an existing structuralist formalization of Wundt’s theory. Further, we discuss the empirical predictions that our formalization generates, such as comparisons of similarity and intensity. We conclude by demonstrating how the tools developed in the conceptual space framework can be used to formulate a theory of emotion based on empirical observation. (shrink)

Everyone would agree that the American flag is red, white and blue. Everyone should also agree that it looks red, white and blue to people with normal color vision in appropriate circumstances. If a philosophical theory led to the conclusion that the red stripes cannot look red to both men and women, both blacks and whites, both young and old, we would be reluctant (to say the least) to accept that philosophical theory. But there is a widespread philosophical (...) view about the nature of conscious experience that, together with some empirical facts, suggests that color experience cannot be veridical for both men and women, both blacks and whites, both young and old. (shrink)

Reflection Theory holds that our sensations reflect physical properties, whereas Empiricism believes that sense (data), presentations, and phenomena are the ultimate existence. Lenin adhered to Reflection Theory and criticized Helmholtz’s sensory symbolism for affirming the similarity between a sensation and a physical property. By using information and color vision theories, analyzing the ostensive definition with inverted qualia, and extending the relativity principle, this paper affirms the external world’s existence independent of personal sensations. Still, it denies the similarity between (...) a sense and a physical property. Then, it improves symbolism to analog symbolism and Reflection Theory to Information Reflection Theory. (shrink)

Scientific realists argue that a good track record of multi-agent, and multiple method, validation of empirical claims is itself evidence that those claims, at least partially and approximately, reflect ways nature actually is independent of the ways we conceptualize it. Constructivists contend that successes in validating empirical claims only suffice to establish that our ways of modelling the world, our “constructions,” are useful and adequate for beings like us. This essay presents a thought experiment in which beings like us intersubjectively (...) validate claims about properties of particular things in nature under conditions in which those beings have profoundly different personal phenomenological experiences of those properties. I submit that the thought experiment scenario parallels our actual situation, and argue that this shows that successes in intersubjectively validating empirical claims are indeed enough to claim victory for the realist. More specifically, I champion a variation of realism that marries Ronald Giere’s brand of ‘perspectival realism’ with Philip Kitcher’s ‘real realism,’ and posits that causal relations between ourselves and properties instantiated in nature ground our references to the relevant properties even though our conceptions of them are perspective relative. (shrink)

In Berkeley’s writings the topic of light is discussed in two different ways, within a theory of perception and within a metaphysics of nature of a Platonic stamp. In his first work, the original Essay for a New Theory of Vision, light and colours are regarded as condition and object of vision; they are examined as contents of visual perception distinct from tangible perception. Light will be dealt with in a completely different manner in Berkeley’s last work, Siris, (...) in which a spiritualistic reading of the natural world is superimposed on modern science in general and on Newtonian physics in particular. In Siris, light is the instrument by which the causal activity of divine Intellect orders and permeates the natural world. A detailed analysis of the topic of light in the two aforementioned contexts shows inconsistencies and strained interpretations which derive from the apologetic use of the theory of vision in Berkeley’s early immaterialism and from the multi-layered and confused speculations of his late Siris. On the whole, Berkeley conceives light within the idealistic frame inherited from Platonic metaphysics of light; however, the specific themes examined in the Essay for a New Theory of Vision and in Siris derive from acquisitions of modern science, and are recast within a spiritualistic interpretation which intended both to neutralize scientific ideas through their phenomenistic reading and to exploit them for apologetic ends. (shrink)

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

Blindsight and vision for action seem to be exemplars of unconscious visual processes. However, researchers have recently argued that blindsight is not really a kind of uncon- scious vision but is rather severely degraded conscious vision. Morten Overgaard and col- leagues have recently developed new methods for measuring the visibility of visual stimuli. Studies using these methods show that reported clarity of visual stimuli correlates with accuracy in both normal individuals and blindsight patients. Vision for action (...) has also come under scrutiny. Recent findings seem to show that information processed by the dor- sal stream for online action contributes to visual awareness. Some interpret these results as showing that some dorsal stream processes are conscious visual processes (e.g., Gallese, 2007; Jacob & Jeannerod, 2003). The aim of this paper is to provide new support for the more traditional view that blindsight and vision for action are genuinely unconscious per- ceptual processes. I argue that individuals with blindsight do not have access to the kind of purely qualitative color and size information which normal individuals do. So, even though people with blindsight have a kind of cognitive consciousness, visual information process- ing in blindsight patients is not associated with a distinctly visual phenomenology. I argue further that while dorsal stream processing seems to contribute to visual awareness, only information processed by the early dorsal stream (V1, V2, and V3) is broadcast to working memory. Information processed by later parts of the dorsal stream (the parietal lobe) never reaches working memory and hence does not correlate with phenomenal awareness. I con- clude that both blindsight and vision for action are genuinely unconscious visual processes. (shrink)

The current state of philosophy of science is characterized by stasis in the struggle between realism and antirealism. In recent years, a number of authors have come out with a program of scientific perspectivism that claims to sublate this great collision and gain the status of a new epistemological paradigm: “perspectivism, or, better, perspectival realism, is one of the newest attempts to find a middle ground between scientific realism and antirealism” [1. P. 2]. Important milestones of the perspective movement were (...) the works of Ronald Giere, Francois Recanati, Bas van Fraassen, Michela Massimi, and others. The thesis of the article is that perspectivism has not yet realized its claims to autonomy, although it has become an important new arena for discussions between realists and antirealists who try to appropriate perspectivist concepts and arguments. The “middle ground,” when thought out consistently and thoroughly, turns out to lie not “between,” but either in the territory of realism or in the territory of antirealism, depending on the presumptions of the author of a particular perspectivist conception. This is demonstrated by the analysis of the conceptions of Giere, Massimi, and Recanati. Giere’s perspectivism is based on the metaphor of color vision, and for him only some (secondary) qualities of real objects turn out to be perspectival, i.e., subject-dependent. Massimi’s perspectivism attempts, on the basis of a visual arts metaphor, to combine the phenomenon of the plurality of scientific theories (“perspectival disagreement” about what an object is) with the general realist attitude of science (agreement about that there is an object). Recanati’s perspectivism syncretizes realism about ordinary objects and relativism about other things. The first two versions of perspectivism rely on a perceptual metaphor: perspective is conditioned by the perceptual constitution of the observer, that is, it arises at the mental or cognitive level. Recanati’s version attempts to derive perspective from contextuality, that is, it is semantic. However, it does not show exactly how perceptual categories are superimposed on theories or how scientific concepts reveal their perspectival character. The isomorphism of perception and theoretical thinking, sensibility and understanding, remains undemonstrated. On the one hand, perspectivist efforts are motivated by an important concern to account for antirealist critique (lack of access to the “view from nowhere,” factual and semantic underdetermination, difficulties with the idea of approaching the truth, the historicity of knowledge, the activeness of the constructing subject, etc.) while preserving the scientific commitment to universality, validity, and truthfulness. On the other hand, the ontological question remains fundamental and unavoidable, and perspectivism (yet?) fails to circumvent it. As we see, all three versions of perspectivism considered in this article turn out to be varieties of realism: Giere and Massimi recognize this explicitly, while Recanati de facto assumes a quite respectable and conservative position of selective realism with respect to ordinary objects. (shrink)

In this paper, I argue for a new solution to Mary’s puzzle in Jackson’s famous knowledge argument. We are told that imprisoned Mary knows all facts or truths about color and color vision. On her release, she learns something new according to B-type of materialism and according to property dualism. I argue that this cognitive improvement can only be accounted for in terms of what Schellenberg has recently called “capacitism,” namely the claim that that experience is constitutively (...) a matter of discriminating and singling out particulars by employing perceptual capacities. Of course, I am not claiming that knowing the phenomenal character is simply the possession of abilities, let alone that the phenomenal character is a sort of know-how. That is why my claim is not affiliated with Lewis and Nemirow's ability hypothesis position. I take for granted here a sort of property-representationalism, according to which the phenomenal character of experience supervenes on the cluster of properties that the respective experiences represent. On her release, Mary acquires those perceptual abilities on the basis of which she learns to discriminate all shades of color. And after applying her old physical concept RED to the shade of red, she comes to know what it is like to experience red (propositional knowledge). (shrink)

Frank Jackson’s knowledge argument (KA) aims to prove, by means of a thought experiment concerning the hypothetical scientist Mary, that conscious experiences have non-physical properties, called qualia. Mary has complete scientific knowledge of colours and colour vision without having had any colour experience. The central intuition in the KA is that, by seeing colours, Mary will learn what it is like to have colour experiences. Therefore, her scientific knowledge is incomplete, and conscious experiences have qualia. In this paper I (...) consider an objection to the KA raised by Daniel Dennett. He maintains that the KA is vitiated by Jackson’s account of Mary’s scientific knowledge. While endorsing this criticism, I will defend the plausibility and relevance of the type of strategy involved in the KA by offering an account of Mary’s scientific knowledge. This account involves formulating a reasonable and not immediately false version of the physicalist thesis with regard to colour experiences. Whether this version of the KA is successful against this type of physicalism is not investigated here. (shrink)

In this chapter, data concerning the development of principal aspects of vision is reviewed. First, the development of colour vision and luminance perception is discussed. Relevant data accumulated so far indicates that perception of colour and luminance is present by 6-9 months of age. The presence of typical color illusions at this age suggests that the phenomenal character of color experience is comparable to that of adults well before the first birthday. Thus it seems plausible that (...) color perception develops on the grounds of genetically preprogrammed maturation, in which perceptual learning and plasticity play a limited role. This claim also seems to be supported by case studies of newly sighted patients. On the other hand, perceptual integration of edges and forms in the visual environment as well as the development of binocular vision, and the perception of ambiguous figures seem to depend crucially on early perceptual learning. Both developmental and clinical data indicate a more significant involvement of perceptual learning in such mid-level and higher level perceptual phenomena. (shrink)

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

Aristotle held that perception consists in the reception of external sensory qualities (or sensible forms) in the sensorium. This idea is repeated in many forms in contemporary philosophy, including, with regard to vision, in the idea (still not firmly rejected) that the retinal image consists of points of colour. In fact, this is false. Colour is a quality that is constructed by the visual system, and though it is possible to be a realist about colour, it is completely misleading (...) to think of it as received by the retina. Moreover, such supposedly “charitable” interpretations of Aristotle’s doctrines, based on miscon- ceptions of perception-science, distort our understanding of his historical context. (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)

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)

It is often assumed that adaptation — a temporary change in sensitivity to a perceptual dimension following exposure to that dimension — is a litmus test for what is and is not a “primary visual attribute”. Thus, papers purporting to find evidence of number adaptation motivate a claim of great philosophical significance: That number is something that can be seen in much the way that canonical visual features, like color, contrast, size, and speed, can. Fifteen years after its reported (...) discovery, number adaptation’s existence seems to be nearly undisputed, with dozens of papers documenting support for the phenomenon. The aim of this paper is to offer a counterweight — to critically assess the evidence for and against number adaptation. After surveying the many reasons for thinking that number adaptation exists, we introduce several lesser-known reasons to be skeptical. We then advance an alternative account — the old news hypothesis — which can accommodate previously published findings while explaining various (otherwise unexplained) anomalies in the existing literature. Next, we describe the results of eight pre-registered experiments which pit our novel old news hypothesis against the received number adaptation hypothesis. Collectively, the results of these experiments undermine the number adaptation hypothesis on several fronts, whilst consistently supporting the old news hypothesis. More broadly our work raises questions about the status of adaptation itself as a means of discerning what is and is not a visual attribute. (shrink)

Global climate change has been characterised as the crisis of reason (Val Plumwood), imagination (Amitav Ghosh) and language (Elizabeth Rush), to mention some. The 'everything change', as Margaret Atwood calls it, arguably also impacts on how we aesthetically perceive, interpret and appreciate nature. This article looks at philosophical theories of nature appreciation against global environmental change. The article examines how human-induced global climate change affects the 'scientific' approaches to nature appreciation which base aesthetic judgment on scientific knowledge and the competing (...) 'non-scientific' approaches which emphasise the role of emotions, imagination and stories in the aesthetic understanding of environment. The author claims that both approaches are threatened by global climate change and cannot continue as usual. In particular, he explores aesthetic imagination in contemporary times when our visions about environment are thoroughly coloured by worry and uncertainty and there seems to be little room for awe and wonder, which have traditionally characterised the aesthetic experience of nature. Finally, he proposes that art could stimulate environmental imagining in this age of uncertainty. (shrink)

Philosophers of perception widely agree that sensory properties, like color, are represented in perceptual experience. Arguments are usually needed to establish that something other than sensory properties, for example three-dimensional objects or kind properties, are part of perceptual content. Call the idea that sensory properties are represented in perceptual experience the Sensation View (SV). Given its widespread acceptance, we may expect to find strong reasons for holding SV. In this paper, I argue that we lack such reasons: SV is (...) largely unjustified. We have surprisingly poor justification for thinking that sensory properties are represented in perception. By focusing on the case of vision, I show that an embedded understanding of visual perception, and empirical evidence in cognitive psychology, indicate that SV is far from warranted. (shrink)

Synesthesia is the “union of the senses” whereby two or more of the five senses that are normally experienced separately are involuntarily and automatically joined together in experience. For example, some synesthetes experience a color when they hear a sound or see a letter. In this paper, I examine two cases of synesthesia in light of the notions of “experiential parts” and “conscious unity.” I first provide some background on the unity of consciousness and the question of experiential parts. (...) I then describe two very different cases of synesthesia. Finally, I critically examine the cases in light of two central notions of “unity.” I argue that there is good reason to think that the neural “vehicles” of conscious states are distributed widely and can include multiple modalities. I also argue that some synesthetic experiences do not really enjoy the same “object unity” associated with normal vision. (shrink)

Spatial facilitation has been observed with luminance-defined, achromatic stimuli on achromatic backgrounds as well as with targets and inducers defined by colour contrast. This paper reviews psychophysical results from detection experiments with human observers showing the conditions under which spatially separated contour inducers facilitate the detection of simultaneously presented target stimuli. The findings point towards two types of spatial mechanisms: (i) Short-range mechanisms that are sensitive to narrowly spaced stimuli of small size and, at distinct target locations, selective to the (...) contrast polarity of targets and inducers. (ii) Long-range mechanisms that are triggered by longer stimuli, generate facilitation across wider spatial gaps between targets and inducers, and are insensitive to their contrast polarity. Spatial facilitation with chromatic stimuli requires a longer inducer exposure than spatial facilitation with achromatic stimuli, which is already fully effective at inducer exposures of 30 ms. This difference in temporal dynamics indicates some functional segregation between mechanisms for colour and luminance contrast in the perception of space. (shrink)

In this essay I explore the encounter between religion and music via ideas taken from Olivier Messiaen. I first present his categorization of music and the concepts of sound-colour and dazzlement as the 'directional meaning' of music. I then show how Messiaen relates this to the phenomena of natural resonance and afterimages, and based on this, I present-via Goethe and Rudolf Steiner-the notion of an etheric, evanescent or incorporeal matter. This understanding and experience of matter is then brought to bear (...) on music. In this context the notion of a 'religious experience' can be understood as both referring to content and sentiment related to a religious belief, and, in a more general sense of 'religare' (to bind), as a deeper bond with the material-temporal flow of nature. This gives way to a Johannine vision of Messiaen's musical thinking where the creative-sounding Logos or 'word' is both spirit and matter, and where music may represent a potential awakening to this reality. (shrink)