The problem of nonreflectors perceived as colored is the central problem for Byrne & Hilbert's (B&H's) physicalism. Vision scientists and other interested parties need to consider the motivation for their account of “productance physicalism.” Is B&H's theory motivated by scientific concerns or by philosophical interests intended to preserve a physicalist account of color as a posteriori necessary?

Since the publication of Brent Berlin and Paul Kay's Basic color terms in 1969 there has been continuing debate as to whether or not there are linguistic universals in the restricted domain of color naming. In this paper I am primarily concerned with the attempt to explain the existence of basic color terms in languages. That project utilizes psychological and ultimately physiological generalizations in the explanation of linguistic regularities. The main problem with this strategy is that it cannot account for (...) a particular subset of basic color words: words that the Berlin-Kay tradition calls “composite”. The existence of such words does not compromise the claim that there are basic color words. It does suggest that such words—and basic terms in general—require a more complex type of explanatory strategy than much contemporary work on color naming supposes. It is my main contention that the central problems with the Berlin-Kay tradition arise from the difficulty of linking conceptually and empirically disparate domains: linguistic, psychological, physiological. What is needed is not an attempt to reduce color naming to biology or to culture but, rather, an adequate conceptual account of how people may come to have and use basic color terms—an account which stands between the biological and the cultural. (shrink)

Reflectance physicalism only provides a partial picture of the ontology of color. Byrne & Hilbert’ account is unsatisfactory because the replacement of reflectance functions by productance functions is ad hoc, unclear, and only leads to new problems. Furthermore, the effects of color contrast and differences in illumination are not really taken seriously: Too many “real” colors are tacitly dismissed as illusory, and this for arbitrary reasons. We claim that there cannot be an all-embracing ontology for color.

According to a familiar modern view, color and other so-called secondary qualities reside only in consciousness, not in the external physical world. Many have argued that this “Galilean” view is the source of the mind-body problem in its current form. This paper critically examines a radical alternative to the Galilean view, which has recently been defended or sympathetically discussed by several philosophers, a view I call “anti-modernism.” Anti-modernism holds, roughly, that the modern Galilean scientific image is incomplete – in particular, (...) it leaves out certain irreducible qualitative properties, such as colors – and that we can solve (or dissolve) the hard problem of consciousness by accepting these properties as objective features of the external physical world. I argue, first, that anti-modernism cannot fulfill its promise. Even if the outer world is resplendent with primitive colors, color experience remains a mystery. Second, I argue that the theoretical costs of accepting irreducible colors in the world are enormous. Even if irreducible colors in the world could dispel the mysteries surrounding consciousness, the theoretical benefit would not be worth the cost. If the problems of consciousness and color require that we posit irreducible properties somewhere, it would be far more plausible to accept irreducible phenomenal properties on the side of the subject, and to reject irreducible colors on the side of the object. (shrink)

En el presente texto se evalúan las posibilidades conceptuales de una interpretación fisicalista de la conciencia. Con dicho fin se toman en cuenta posiciones representativas en el ámbito de la filosofía, así como investigaciones neurocientíficas recientes. Ambas líneas de investigación suponen el cuestionamiento de los acercamientos de sentido común al tema de la conciencia. No obstante, no suponen una completa eliminación de lo que dicho acercamiento puede representar. En este sentido, se propone una interpretación epistemológica de la perspectiva intuitiva de (...) primera persona en relación con la perspectiva científica de tercera persona. (shrink)

The colors we perceive are the outcome of an attempt to meaningfully order the spectral information from the environment. These colors are not the result of a straightforward mapping of a physical property to a sensation, but arise from an interaction between our environment and our visual system. Thus, although one may infer from a surface’ reflectance characteristics that it will be perceived as “colored,” true colors only arise by virtue of the interaction of the reflected light with the eye (...) (and brain) of an observer. (shrink)

Perceptual Confidence is the thesis that perceptual experiences can be probabilistic. This thesis has been defended and criticised based on a variety of phenomenological, epistemological, and explanatory arguments. One gap in these arguments is that they neglect the question of whether perceptual experiences satisfy the formal conditions that define the notion of probability to which Perceptual Confidence is committed. Here, we focus on this underexplored question and argue that perceptual experiences do not satisfy such conditions. But if they do not, (...) then ascriptions of perceptual confidence are undefined; and so, Perceptual Confidence cannot be true. (shrink)

In many cases of variation in color vision, there is no non-arbitrary way of choosing between variants. Byrne and Hilbert insist that there is an unknown standard for choosing, while eliminativists claim that all the variants are erroneous. A better response relativizes colors to perceivers, thereby providing a color realism that avoids the need to choose between variants.

Primary quality theories of color claim that colors are intrinsic, objective, mind-independent properties of external objects — that colors, like size and shape, are examples of the sort of properties moderns such as Boyle and Locke called primary qualities of body.¹ Primary quality theories have long been seen as one of the main philosophical options for understanding the nature of color.

Can psychology explain the qualitative content of experience? A persistent philosophical objection to that discipline is that it cannot. Qualitative states or 'qualia' are argued to have characteristics which cannot be explained in terms of their relationships to other psychological states, stimuli, and behavior. Since psychology is confined to descriptions of such relationships, it seems that psychology cannot explain qualia. A paradigm case of qualia is provided by simultaneous color contrast effects, in which a neutral grey patch is made to (...) look reddish by being enclosed in a green surround. If the qualia based objections are sound, psychology ought not to be able to explain simultaneous color contrast; but psychology at least seems to be able quite successfully to explain those effects. This paper analyzes the logic of psychological explanations of simultaneous color contrast effects, and the import of various qualia based objections to those explanations. I argue that the qualia objections do not demonstrate any explanatory inadequacy in existing psychological explanations of 'looks'. Psychology succeeds in explaining at least some qualia. In a more positive vein, I argue that once the structure of such explanations is sufficiently understood, a place can be found for qualia within the emerging scientific account of color perception. The resulting account can deal with many of the traditional perplexities over qualia. (shrink)

We argue that any theory of color physicalism must include consideration of ecological interactions. Ecological and sensorimotor contingencies resulting from relative surface motion and observer motion give rise to measurable effects on the spectrum of light reflecting from surfaces. These contingencies define invariant manifolds in a sensory-spatial space, which is the physical underpinning of all subjective color experiences.

Drawing on the findings of neuroscience, this text proposes and defends the hypothesis that the various modalities of sensation share a generic form that the author, Austen Clark, calls feature-placing.

The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in (...) the mind." The article has two other purposes: first, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. (shrink)

Our reply is in three parts. The first part concerns some foundational issues in the debate about color realism. The second part addresses the many objections to the version of physicalism about color ("productance physicalism") defended in the target article. The third part discusses the leading alternative approaches and theories endorsed by the commentators.

Where are we to look for the unique hues? Out in the world? In the eye? In more central processing? 1. There are difficulties looking for the structure of the unique hues in simple combinations of cone-response functions like ( L − M ) and ( S − ( L + M )): such functions may fit pretty well the early physiological processing, but they don’t correspond to the structure of unique hues. It may seem more promising to look to, (...) e.g., Hurvich & Jameson’s ‘chromatic response functions’; but these report on psychophysical behaviour, not on underlying physiology. So ‘opponent processing’ isn’t any particular help on the unique hues—and even physiology in general seems not to have come up with any good correlate or explanation. 2. Wright ( Review of Philosophy and Psychology 2: 1–17, 2011 ) looks in a different place: to (a) magnitude of total visual response that a stimulus light provokes, the maxima and minima of which, he thinks, give us the boundaries of the main hue categories (Wright connects these with Thornton’s ‘prime’ and ‘antiprime’ colours in an illuminant: Journal of the Optical Society of America 61 ( 1971 ): 1155–1163); and (b) the ratio of chromatic to achromatic response, the maxima and minima of which, he suggests, give us the focal points of the unique hues. The suggestions are extremely interesting; but the desired correspondences have some counterexamples; and where they hold, one could wonder how much they depend upon the particular choice of functions to measure (a) and (b); and one could hope for more of an explanatory linkage between the sets of items in question. 3. Could the unique hues come from, so to speak, the external world? White and black can easily be defined as particular kinds of reflectance. What of the standard four unique hues? Variation in kinds of sunlight and skylight coincides well with variation along a line from unique yellow to unique blue (cf. Shepard 1992 , Mollon 2006 ). If we wanted something to calibrate our standards for unique yellow and blue as the lens of the eye changes with age, and despite interpersonal cone differences, this would be a good basis—and there are several ways this can be extended to surface colours. But is there any essential connection between these things: is there any rationale why the light of the sun and the sky should be counted as unique hued ? An answer may be: because in our environment, these illuminants are as close to white (or the natural illuminant colour) as you can get—to see things tinged with sunlight or skylight should be to see them minimally tinged with any alien colour. Whereas other hues in an illuminant would be treated as tinging with a more alien colour the thing seen. (shrink)

Byrne & Hilbert (B&H) assert that reflectances embody the reality of color, but metamerism smears the authors' “real” color categories into uselessness. B&H ignore this problem, possibly because they implicitly adopt a sort of subjectivism, whereby an object is defined by the percepts (or more generally by the measurements) it engenders. Subjectivism is unwieldy, and hence prone to such troubles.

We consider several puzzles of bounded rationality. These include the Allais- and Ellsberg paradox, the disjunction effect, and related puzzles. We argue that the present account of quantum cognition—taking quantum probabilities rather than classical probabilities—can give a more systematic description of these puzzles than the alternate treatments in the traditional frameworks of bounded rationality. Unfortunately, the quantum probabilistic treatment does not always provide a deeper understanding and a true explanation of these puzzles. One reason is that quantum approaches introduce additional (...) parameters which possibly can be fitted to empirical data but which do not necessarily explain them. Hence, the phenomenological research has to be augmented by responding to deeper foundational issues. In this article, we make the general distinction between foundational and phenomenological research programs, explaining the foundational issue of quantum cognition from the perspective of operational realism. This framework is motivated by assuming partial Boolean algebras. They are combined into a uniform system via a mechanism preventing the simultaneous realization of perspectives. Gleason’s theorem then automatically leads to a distinction between probabilities that are defined by pure states and probabilities arising from the statistical mixture of pure states. This formal distinction relates to the conceptual distinction between risk and ignorance. Another outcome identifies quantum aspects in dynamic macro-systems using the framework of symbolic dynamics. Finally, we discuss several ideas that are useful for justifying complementarity in cognitive systems. (shrink)

The considerable agreement across languages in the way they categorize the color domain, despite independent historical development, demands an explanation. One option is to postulate a universal innate representation of the color categories, 'hardwired' into each observer's brain. An alternative is that observers internalize their color categories through a process of cultural transmission, constrained by some kind of 'optimality hypothesis' to account for the cross-language agreement. A number of optimality hypotheses are reviewed. It is tempting to believe that the vivid (...) experiential quality of the categories can only be explained if they are determined by innate representations rather than by linguistic imprinting. However, linguistic transmission of color categories – perturbed from their optimal boundaries by special circumstances – fits best with the experience of dichromats. Even for the 'primary hue' categories, where the case for innate representations should be strongest, the evidence is far from convincing. (shrink)

Byrne & Hilbert defend color realism, which assumes that: (a) colors are properties of objects; (b) these objects are physical; hence, (c) colors are physical properties. I accept (a), agree that in a certain sense (b) can be defended, but reject (c). Colors are properties of perceptual objects – which also have underlying physical properties – but they are not physical properties.

To identify the set of reflectances that constitute redness, the authors must first determine which surfaces are red. They do this by relying on widespread agreement among us. However, arguments based on the possible ways in which humans would perceive colors show that mere widespread agreement among us is not a satisfactory way to determine which surfaces are red.

There exist two widely used notions concerning the structure of phenomenal color space. The first is the notion of unique/binary hue structure, which maintains that there are four unique hues from which all other hues are composed. The second notion is the similarity structure of hues, which describes the interrelations between the hues and hence does not divide hues into two types as the first notion does. Philosophers have considered the existence of the unique/binary hue structure to be empirically and (...) phenomenally well-grounded, and the structure has been considered to be primary because this can account for the similarity structure. Consequently, the unique/binary hue structure has played a central role in color philosophy. This calls for the assessment of the justification for its existence carried out in this paper. It is concluded that, despite the prevalent view among philosophers, none of their reasons for endorsing the existence of the unique/binary hue structure are justified. Since the notion of the unique/binary hue structure appears intuitively plausible for many, however, a sketch explaining this intuition is outlined at the end. (shrink)

We ran a pilot experiment to explore, using a new psychophysical method, the hypothesis proposed by Zietz and Werner in the ’30s, that a sound presented simultaneously with an afterimage can change its phenomenal appearance in non-synaesthetes. The method we adopted is able to directly collect and visualise the apparent changes in intensity of the afterimages, by recording observers’ interactions with a physical feedback mechanism, without referring to verbal descriptions. These first findings support some of the most meaningful observations reported (...) by Werner and Zietz, according to which the colours of the afterimages ‘disintegrate’ at the hearing of a low sound and ‘concentrate’ for a high sound. This relationship is particularly evident with the Yellow stimulus, where the perceived colour intensity of its afterimage seems to have a faster negative change with a low-pitched tone sound, and an increase in intensity and duration when perceived simultaneously with a soprano sound. These data are also coherent with the crossmodal correspondences between both pitch and loudness in audition and lightness and brightness in vision reported in the literature. (shrink)

This chapter explores the evidence for the existence of such new colour experiences and what their philosophical ramifications would be. I first define the notion of ‘novel colours’ and discuss why I think that this is the best name for such colours, rather than the numerous other names that they have sometimes been given in the literature. I then introduce the evidence and arguments for thinking that experiences as of novel colours exist, along with objections that people have had to (...) that evidence and to those arguments. To do so, I outline some facts about ordinary, non-novel colours before considering whether experiences as of novel colours, exist. Then I discuss the potentially significant ramifications the existence of novel colour experiences would have for theories of the metaphysics of colour, theories of the nature of colour experience, and for theories of the nature of perception more generally. (shrink)

Evidence has accumulated that rod activation under mesopic and scotopic light levels alters visual perception and performance. Here we review the most recent developments in the measurement of rod and cone contributions to mesopic color perception and temporal processing, with a focus on data measured using the four-primary photostimulator method that independently controls rod and cone excitations. We discuss the findings in the context of rod inputs to the three primary retinogeniculate pathways to understand rod contributions to mesopic vision. Additionally, (...) we present evidence that hue perception is possible under scotopic, pure rod-mediated conditions that involves cortical mechanisms. (shrink)

Hardin’s empirically-grounded argument for color eliminativism has defined the color realism debate for the last 30 years. By Hardin’s own estimation, phenomenal structure—the unique/binary hue distinction in particular—poses the greatest problem for color realism. Examination of relevant empirical findings shows that claims about the unique hues which play a central role in the argument from phenomenal structure should be rejected. Chiefly, contrary to widespread belief amongst philosophers and scientists, the unique hues do not play a fundamental role in determining all (...) color appearances. Among the consequences of this result is that greater attention should be paid to certain proposals for putting the structure of phenomenal color into principled correspondence with surface reflectance properties. While color realism is not fully vindicated, it has much greater empirical plausibility than previously thought. (shrink)

The authors favor a “color realism” theory that considers colors to be physical properties residing in objects that reflect, emit, or transmit light. It is opposed to the theory that colors are sensations or visual experiences. This commentary suggests that both theories are correct, and that context usually indicates which of these dual aspects is being considered.

The reflectance types that Byrne & Hilbert identify with colors count as types only in a way that is more dependent on, and more relative to color perceivers, than their account suggests. Their account of perceptual content may be overly focused on input conditions and distal causes.

As demonstrated by several example displays, color illusions challenge color realism, because they involve a one-to-many reflectance-to-color mapping. Solving this problem by differentiating between veridical and illusory colors corresponding to the same reflectance is hampered because of the lack of an appropriate criterion. However, the difference between veridical and illusory color perception can still be maintained.

Different explanations of color vision favor different philosophical positions: Computational vision is more compatible with objectivism (the color is in the object), psychophysics and neurophysiology with subjectivism (the color is in the head). Comparative research suggests that an explanation of color must be both experientialist (unlike objectivism) and ecological (unlike subjectivism). Computational vision's emphasis on optimally prespecified features of the environment (i.e., distal properties, independent of the sensory-motor capacities of the animal) is unsatisfactory. Conceiving of visual perception instead as the (...) visual guidance of activity in an environment that is determined largely by that very activity suggests new directions for research. (shrink)

Vision scientists are interested in three diverse entities: physical stimuli, neural states, and consciously perceived colors, and in the mapping rules among the three. In this worldview, the three kinds of entities have coequal status, and views that attribute color exclusively to one or another of them, such as color realism, have no appeal.