Byrne & Hilbert (B&H) give some excellent replies to the objections to realism about color. However, the particular form of realism they propose, based on opponent processing, prompts several challenges. Why characterize a color by its tendency to produce an intermediate brain signal, rather than in terms of the final effect – either a perception or a neural substrate for it? At the level of the retina, and even of the cortex, there are processes that partly parallel (...) the structure of color experience; but the correspondence is not exact. Must we assume that there is any place in the brain where an exact structural correspondence is found? At the level of psychophysical functioning, there is indeed opponency; but it is not clear that this gives us the kind of type-reduction that B&H want. (shrink)

This book presents the most complete translation to date of Erwin Schrödinger's work on colorimetry. In his work Schrödinger proposed a projective geometry of color space, rather than a Euclidean line-element. He also proposed new (at the time) colorimetric methods - in detail and at length - which represented a dramatic conceptual shift in colorimetry. Schrödinger shows how the trichromatic (or Young-Helmholtz) theory of color and the opponent-process (or Hering) theory of color are (...) formally the same theory, or at least only trivially different. These translations of Schrödinger's bold concepts for color space have a fresh resonance and importance for contemporary color theory. (shrink)

Hering’s opponent-colors theory suggests that our color sensations are produced by three mechanisms: a red–green mechanism, a yellow–blue mechanism, and a white–black mechanism. The first two mechanisms give rise to our sensations of hued colors; the third mechanism gives rise to our sensations of hueless colors. Noticeably, whereas the pair of colors produced by each of the hued mechanisms do not mix to yield a phenomenal intermediate (i.e., there are no greenish reds, reddish greens, yellowish blues, or (...) bluish yellows), the colors produced by the hueless mechanism, white and black, do have a phenomenal intermediate—gray. This different behavior of the white–black mechanism poses a problem for Hering’s theory. Several attempts to fix this problem have been suggested. This paper focuses on the suggestion made by Paul Heggelund a century after Hering proposed his theory. In Heggelund’s amendment of Hering’s theory, the hueless colors are not confined to the one-dimensional gamut between black and white, but rather require two components for their full description: a light–dark (or luminous–black) component, where light and dark are mutually exclusive sensations, and a white component, which doesn’t have an opponent counterpart. Here I show that although Heggelund’s theory indeed provides a solution to the problem that the hueless colors pose to Hering’s theory, it is not self-consistent. I go on to revise Heggelund’s theory to obtain a consistent opponent-colors theory. (shrink)

There have been a number of criticisms, based on visual processes, of the Australian view that colour is an objective property of the world. These criticisms have led to subjective theories about colour. These visual processes (metamers, retinex theory, opponent processes, simultaneous contrast, colour constancy, subjective colours) have been examined and it is suggested that they do not carry their supposed critical weight against an objective theory. In particular, it is argued that metamers don’t occur in nature (...) and primate colour vision evolved without metamers. Thus normal colour vision occurs without the problem of metamers. This argument, in conjunction with evidence against the critical roles of opponent processes and retinex theory in colour vision, is taken to suggest that colour can be given a photon energy/wavelengthrealism explanation. This proposal allows an account of the many microstructural bases of colour generation put forward by Nassau (1983). It is argued that neither disjunctive realism or reflectance realism are adequate objective explanations of colour. (shrink)

A neighbor who strikes it rich evokes both admiration and envy, and a similar mix of emotions must be aroused in many neighborhoods of cognitive science when the residents look at the results of research on color perception. It provides what is probably the most widely acknowledged success story of any domain of scientific psychology: the success, against all expectation, of the opponent process theory of color perception. Initially proposed by a Ewald Hering, a nineteenth‐century (...) physiologist, it drew its inspiration from the existence of opposing muscle groups. Hering thought that analogous opposing processes could explain some aspects of color perception, but the resulting theory was more complicated and less intuitive than that proposed by the great Hermann von Helmholtz. Helmholtz carried his day, but in the long run Hering turned out to be right. (shrink)

I show that the mathematical description of opponent-colors theory is identical to the mathematical description of two-state quantum systems in a mixed state. Based on the dual-aspect theory of phenomenal consciousness, which suggests that one or more physical entities in our universe have phenomenal aspects that are dual to their physical aspects and therefore predicts an exact correspondence between a system’s phenomenal states and the objective states of its underlying physical substrate, I hypothesize that color sensations (...) are phenomenal dual aspects of two-state quantum systems in a mixed state. Since nothing in this hypothesis suggests that what brings about the phenomenal experience that is dual to two-state quantum systems is the two-dimensionality of these systems, it is natural to generalize this hypothesis and suggest that other types of phenomenal experience (e.g., taste, odor, sound) are phenomenal dual aspects of quantum systems of higher dimensionalities. Finally, I propose that the two-state quantum systems that give rise to color in the brain are two-state ion-channels. (shrink)

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 neighbor who strikes it rich evokes both admiration and envy, and a similar mix of emotions must be aroused in many neighborhoods of cognitive science when the residents look at the results of research in color perception. It provides what is probably the most widely acknowledged success story of any domain of scientific psychology: the success, against all expectation, of the opponent process theory of color perception. Initially proposed by a Ewald Hering, a nineteenth (...) century physiologist, it drew its inspiration from the existence of opposing muscle groups. Hering thought that analogous opposing processes could explain some aspects of color perception, but the resulting theory was more complicated and less intuitive than that proposed by the great Hermann von Helmholtz. Helmholtz carried his day, but in the long run Hering turned out to be right. (shrink)

Our reply is in four parts. The first part, R1, addresses objections to our claim that there might be “unknowable” color facts. The second part, R2, discusses the use we make of opponent process theory. The third part, R3, examines the question of whether colors are causes. The fourth part, R4, takes up some issues concerning the content of visual experience.

This study examines the cross‐cultural generality of Hering's (1878/1964) color‐opponent theory of color appearance. English‐speaking and Somali‐speaking observers performed variants of two paradigms classically used to study color‐opponency. First, both groups identified similar red, green, blue, and yellow unique hues. Second, 25 English‐speaking and 34 Somali‐speaking observers decomposed the colors present in 135 Munsell color samples into their component Hering elemental sensations—red,green,blue, yellow, white, and black—or else responded “no term.” Both groups responded no term (...) for many samples, notably purples. Somali terms for yellow were often used to name colors all around the color circle, including colors that are bluish according to Hering's theory. Four Somali Grue speakers named both green and blue elicitation samples by their term for green. However, that term did not name the union of all samples called blue or green by English speakers. A similar pattern was found among three Somali Achromatic speakers, who called the blue elicitation sample black or white. Thus, color decomposition by these Somali‐speaking observers suggests a lexically influenced re‐dimensionalization of color appearance space, rather than a simple reduction of the one proposed by Hering. Even some Somali Green‐Blue speakers, whose data were otherwise similar to English, showed similar trends in yellow and blue usage. World Color Survey data mirror these results. These within‐ and cross‐cultural violations of Hering's theory do not challenge the long‐standing view that universal sensory processes mediate color appearance. However, they do demonstrate an important contribution of language in the human understanding of color. (shrink)

I show that the mathematical description of opponent-colors theory is identical to the mathematical description of two-state quantum systems in a mixed state. Following the principles of dual-aspect theory of phenomenal consciousness, which predicts an exact correspondence between a system’s phenomenal states and the objective states of its underlying physical substrate, I suggest that color sensations are phenomenal dual aspects of two-state quantum systems in a mixed state. Since nothing in this hypothesis suggests that what brings (...) about the phenomenal experience that is dual to two-state quantum systems is the two-dimensionality of these systems, it is natural to generalize this hypothesis and suggest that other types of phenomenal experience (e.g., taste, odor, sound) are phenomenal dual aspects of quantum systems of higher dimensionalities. Finally, I propose that the two-state quantum systems that give rise to color in the brain are two-state ion-channels. (shrink)

If all the participants in the color ontology debate are naturalists with good sciences on their side, how could color subjectivism win? The apparent reason is that subjectivism is supported by the opponent process theory that is a successful neurophysiological reduction of colors. We will argue that the real reason is the unique reductive methodology of the opponent paradigm. We will undermine subjectivism by arguing against the methodology.

If all the participants in the color ontology debate are naturalists with good sciences on their side, how could color subjectivism win? The apparent reason is that subjectivism is supported by the opponent process theory that is a successful neurophysiological reduction of colors. We will argue that the real reason is the unique reductive methodology of the opponent paradigm. We will undermine subjectivism by arguing against the methodology.

Probably colour is the best worked-out example of allegedly neurophysiologically innate response categories determining percepts and percepts determining concepts, and hence biology fixing the basic categories implicit in the use of language. In this paper I argue against this view and I take C. L. Hardin's Color for Philosophers [1988] as my main target. I start by undermining the view that four unique hues stand apart from all other colour shades (Section 2) and the confidence that the solar spectrum (...) is naturally divided into four categories (Section 3). For such categories to be truly universal, they have to be true for all peoples and in Section 4 I show that Berlin and Kay's [1969] widely quoted theory of basic colour categories is not sufficiently supported to lend it any credibility.Having disposed of the view that inspection of language or ‘pure’ perception unveils the universal colour categories. I turn to neurophysiological and psychophysical theories of colour vision to see whether they provide a more solid basis for deciding what the innate response categories are. In Section 5 I show that Hardin's account of the opponent-process theory neither supports his view that ‘colour-coding’takes place early in the visual neural pathway, nor his view that knowledge of colour vision science will help us solve many philosophical mysteries about colour.In Section 6 I give a more detailed review of what is known today about the neurophysiology of colour vision and I show that there's nothing in the brain which could be called a colour module, let alone a module with homunculi for particular basic colour categories. In Section 7 I show that psychophysical models do not support such rigid constraints on category formation either. Hence (Section 8), at least in the case of colour, current science supports a plasticity in the formation of categories that goes far beyond the requirements of those naturalistic philosophers who would like to ground primitive concepts in biology. (shrink)

This chapter focuses on the incompatibility of afterimage colors. Several quasilogical, semantic, and metaphysical questions having to do with incompatibility come up in color theory, and the problem is so complicated and fragile that it is argued here that, despite some marvelous work on the topic, the problem remains to be sorted out. Every naive subject who encounters afterimages without prejudice has agreed that they have color; this is mentioned here because it is the initial and also (...) the commonsense view. However, accepting that a physical account of color incompatibility is right for physical colors makes an account for the incompatibility of afterimage colors improbable. One can provide a physiological account based on opponent processes, but this will deliver only a contingent truth or a necessity relative only to a particular retinal structure and postretinal neural coding. (shrink)

Our reply is in four parts. The first part addresses objections to our claim that there might be "unknowable" color facts. The second part discusses the use we make of opponent process theory. The third part examines the question of whether colors are causes. The fourth part takes up some issues concerning the content of visual experience. Our target article had three aims: (a) to explain clearly the structure of the debate about color realism; (b) (...) to introduce an interdisciplinary audience to the way philosophers have thought about the issue; (c) to argue that colors are certain sorts of physical properties ("productances"). We are very grateful to the commentators in this continuing commentary for their criticism and constructive suggestions. (shrink)

There is a strong philosophical intuition that direct study of the brain can and will constrain the development of psychological theory. When this intuition is tested against case studies on the neurophysiology and psychology of perception and memory, it turns out that psychology has led the way toward knowledge of neurophysiology. An abstract argument is developed to show that psychology can and must lead the way in neuroscientific study of mental function. The opposing intuition is based on mainly weak (...) arguments about the fundamentality or objectivity of physics or physiology in relation to psychology. -/- Philosophy of Science, Vol. 67, Supplement. Proceedings of the 1998 Biennial Meetings of the Philosophy of Science Association. Part II: Symposia Papers (Sep., 2000). (shrink)

Habituation is defined as a decline in responding to a repeated stimulus. After more than eighty years of research, there is an enduring consensus among researchers on the existence of 9-10 behavioral regularities or parameters of habituation. There is no similar agreement, however, on the best approach to explain these facts. In this paper, we demonstrate that the Sometimes Opponent Processes (SOP) model of stimulus processing accurately describes all of these regularities. This model was proposed by Allan Wagner as (...) a quantitative elaboration of Priming Theory, which states that the processing of a stimulus, and therefore its capacity to provoke its response, depends inversely on the degree to which the stimulus is pre-represented in short-term memory. Using computer simulations, we show that all the facts involving within-session effects or short-term habituation might be the result of priming from recent presentations of the stimulus (self-generated priming). The characteristics involving between-sessions effects or long-term habituation would result from the retrieval of the representation of the stimulus from memory by the associated context (associatively-generated priming). (shrink)

Farhad Dalal argues that people differentiate between races in order to make a distinction between the "haves" and "must-not-haves", and that this process is cognitive, emotional and political rather than biological. Examining the subject over the past thousand years, Race, Colour and the Process of Racialisation covers theories of racism and a general theory of difference based on the works of Fanon, Elias, Matte-Blanco and Foulkes, as well as application of this theory to race and racism. (...) Farhad Dalal concludes that the structures of society are reflected in the structures of the psyche, and both of these are colour coded. This book will be invaluable to students, academics and practitioners in the areas of psychoanalysis, group analysis, psychotherapy and counseling. (shrink)

Evidence from molecular genetics bolsters the claim that color is not a perceptuolinguistic and behavioral universal. Neurobiology continues to fill in many details about the flow of color information from photon reception to central processing in the brain. Humans have the most acute color vision in the biosphere because of natural selection and adaptation, not coincidence.

The logic of the basic taste concept is discussed in relation to the physiology and psychophysics of color vision. An alternative version of the basic taste model, analogous to opponent-process theory is introduced. The logic of quality naming experiments is clarified.

Colour is, according to prevailing orthodoxy in perceptual psychology, a kind of autonomous and unitary attribute. It is regarded as unitary or homogeneous by assuming that its core properties do not depend on the type of ‘perceptual object’ to which it pertains and that‘colour per se’ constitutes a natural attribute in the functional architecture of the perceptual system. It is regarded as autonomous by assuming that it can be studied in isolation of other perceptual attributes. These assumptions also provide the (...) pillars for the technical field of colorimetry, and have proved very fruitful for neurophysiological investigations into peripheral colour coding. They also have become, in a technology-driven cultural process of abstraction, part of our common-sense conception of colour. With respect to perception theory, however, both assumptions are grossly inadequate, on both empirical and theoretical grounds. All the same, the idea of an internal homogeneous and autonomous attribute of ‘colour per se’, mostly taken not as an empirical hypothesis but as a kind of truism, became a guiding idea in perceptual psychology. Here, it has impeded the identification of relevant theoretical issues and consequently has become detrimental for the development of explanatory frameworks for the role of ‘colour’ within the structure of our perceptual system. The chapter argues that enquiries into colour perception cannot be divorced from general enquiries into the structure of the conceptual forms underlying perception. (shrink)

Traditional theory of mind (ToM) accounts for social cognition have been at the basis of most studies in the social cognitive neurosciences. However, in recent years, the need to go beyond traditional ToM accounts for understanding real life social interactions has become all the more pressing. At the same time it remains unclear whether alternative accounts, such as interactionism, can yield a sufficient description and explanation of social interactions. We argue that instead of considering ToM and interactionism as mutually (...) exclusive opponents, they should be integrated into a more comprehensive account of social cognition. We draw on dual process models of social cognition that contrast two different types of social cognitive processing. The first type (labeled Type 1) refers to process es that are fast, efficient, stimulus-driven, and relatively inflexible. The second type (labeled Type 2) refers to processes that are relatively slow, cognitively laborious, flexible, and may involve conscious control. We argue that while interactionism captures aspects of social cognition mostly related to Type 1 processes, ToM is more focused on those based on Type 2 processes. We suggest that real life social interactions are rarely based on either Type 1 or Type 2 processes alone. On the contrary, we propose that in most cases both types of processes are simultaneously involved and that social behavior may be sustained by the interplay between these two types of processes. Finally, we discuss how the new integrative framework can guide experimental research on social interaction. (shrink)

Most philosophical or scientific theories suppose that colour composition judgments refer to the way colours appear to us. The dominant view is therefore phenomenalist in the sense that colour composition is phenomenally given to perceivers. This paper argues that there is no evidence for a phenomenalist view of colour composition and that a conventionalist approach should be favoured.

In this target article the following hypotheses are discussed: (1) Colour is autonomous: a perceptuolinguistic and behavioural universal. (2) It is completely described by three independent attributes: hue, brightness, and saturation: (3) Phenomenologically and psychophysically there are four unique hues: red, green, blue, and yellow; (4) The unique hues are underpinned by two opponent psychophysical and/or neuronal channels: red/green, blue/yellow. The relevant literature is reviewed. We conclude: (i) Psychophysics and neurophysiology fail to set nontrivial constraints on colour categorization. (ii) (...) Linguistic evidence provides no grounds for the universality of basic colour categories. (iii) Neither the opponent hues red/green, blue/yellow nor hue, brightness, and saturation are intrinsic to a universal concept of colour. (iv) Colour is not autonomous. (shrink)

In this paper, I present the enactive theory of color that implies a form of color relationism. I argue that this view constitutes a better alternative to color subjectivism and color objectivism. I liken the enactive view to Husserl’s phenomenology of perception, arguing that both deconstruct the clear duality of subject and object, which is at the basis of the other theories of color, in order to claim the co-constitution of subject and object in (...) the process of experience. I also extend the enactive and phenomenological account of color to the more general topic of the epistemological and ontological status of sensory qualities (qualia), outlining the fields of enactive phenomenology and enactive ontology. (shrink)

Color experience is structured. Some ?unique? colors (red, green, yellow, and blue) appear as ?pure,? or containing no trace of any other color. Others can be considered as a mixture of these colors, or as ?binary colors.? According to a widespread assumption, this unique/binary structure of color experience is to be explained in terms of neurophysiological structuring (e.g., by opponent processes) and has no genuine explanatory basis in the physical stimulus. The argument from structure builds on (...) these assumptions to argue that colors are not properties of surfaces and that color experiences are neural processes without environmental counterparts. We reconsider the argument both in terms of its logic and in the light of recent models in vision science which point at environment-involving patterns that may be at the basis of the unique/binary structure of color experience. We conclude that, in the light of internal and external problems which arise for it, the argument from structure fails. (shrink)

According to color subjectivism, colors are mental properties, processes, or events of visual experiences of color. I first lay out an argument for subjectivism founded on claims from visual science and show that it also relies on a philosophical assumption. I then argue that subjectivism is untenable because this view cannot provide a plausible account of color perception. I describe three versions of subjectivism, each of which combines subjectivism with a theory of perception, namely sense datum (...) theory, adverbialism, and the virtual color proposal, and argue that each version faces serious objections. Considering these three theories of perception to be exhaustive of those available to the subjectivist, I conclude that subjectivism is untenable and that the scientifically motivated argument for this view is unsound. I then offer the diagnosis that the philosophical assumption on which this argument relies is mistaken. (shrink)

Scholars of color have been instrumental in advancing nursing knowledge development but find limited spaces where one can authentically share their philosophical perspective. Although there is a call for antiracism in nursing and making way for more diverse and inclusive theories and philosophies, our voices remain at the margins of nursing theory and philosophy. In nursing philosophy, there continues to be a lack of racial diversity in those who are given the platform to share their scholarship. Five nurse (...) scholars of color attended the International Nursing Philosophy Conference in August 2022. We established a collective system of support by sharing our experiences as researchers, scholars, and educators with each other. The theory of emancipatory nursing praxis informed this process. In this dialogue, we reflected on what it is like to present at and attend predominantly white nursing conferences. We shared our experiences of how we exist as nurse scholars, our philosophical views, and our thoughts on how we create spaces where scholars of color can feel welcomed and acknowledged for their contributions to advancing nursing knowledge. (shrink)

What is colour vision for? In the popular imagination colour vision is for “seeing the colours” — adding hue to the achromatic world of shape, depth and motion. On this view colour vision plays little more than an ornamental role, lending glamour to an otherwise monochrome world. This idea has guided much theorising about colour within vision science and philosophy. However, we argue that a broader approach is needed. Recent research in the psychology of colour demonstrates that colour vision is (...) integral to a variety of visual processes, helping us to perform many types of visual tasks. We discuss some of this research and consider its implications for philosophical theories of colour. (shrink)

This paper examines the role of a proper opponent (phyi rgol yang dag) in debate from the standpoint of the Tibetan Buddhist theory of argumentation. A proper opponent is a person who is engaged in the process of truth-seeking. He is not a debater who undertakes to refute the tenets of a proponent. But rather, he is the model debater to whom a proponent can teach truth by using a probative argument in the most effective way. (...) A proper opponent is thus the model thinker conceived by Tibetan Buddhist scholars, especially by the dGe lugs pa exegetes, to explain the idea of “inference for others.” The term phyi rgol yang dag figures in many text books of the dGe lugs pa school. And the germ of the dGe lugs pa's idea of ``proper opponent'' is found in early Tibetan tshad ma literature, too. The present paper shows that the dGe lugs pa scholars are largely concerned with the process by which one obtains an inferential knowledge about the unknown object, and also that they, when talking about a proper opponent, emphasize the pedagogical role of dialectic conversation rather than the competitive feature of debates. (shrink)

Social justice is put forth as a core professional nursing value, although conceptualizations within foundational documents and among nurse educators remain inconsistent and contradictory. The purpose of this study was to explore how faculty teach social justice in theory courses in Baccalaureate programs. This qualitative study utilized constructivist grounded theory methods to examine processes informing participants' teaching. Participants utilize four overarching approaches: fostering engaging classroom climates, utilizing various naming strategies, framing diversity and culture as social justice, and role (...) modeling a critical stance. They deploy specific strategies, varying largely by race, educational background, and nursing specialty. A background in social sciences supports pedagogy that interrogates health inequities rather than merely raising awareness about disparities. Findings also reveal that faculty of color navigate institutional structures predicated upon colorblind racism and problematic views of culture, which many white faculty teaching non‐Community Health Nursing courses described doing. To enact social justice and be answerable to our communities, concerted anti‐oppression efforts are needed across education, research, practice, and policy. This includes sustained commitment to address colonialism and whiteness in every institution that defines, promotes, and claims to advance nursing so that we can fulfill our responsibility to address unjust systems and structures to serve our communities. (shrink)

This chapter discusses color blindness and how it can be considered a guide and test for theories of normal vision. There are a multitude of stories to be told about the physiology of the receptor pigments of the eye and the genes that code for them, about the various kinds of cells in the retina and elsewhere in the visual system, and about color processing in the brain. It is a topic on which psychologists, physicists, biologists, and neurophysiologists (...) have reason to be proud and glad of the convergence of interests and views. Color blindness might, at first, seem just a peripheral abnormality, but it has often been both a guide to the nature of normal color vision and a test application for theories of it. It has the potential to provide cases where the various components of a complex process that are either hard or impossible to separate artificially are found already separated in nature. (shrink)

This essay explores the intersection of racism, racial embodiment theory and the recent hostility aimed at immigrants and foreigners in the United States, especially the targeting of people of Latin American descent and Latino/as. Anti-immigrant and anti-foreigner sentiment is racist. It is the embodiment of racial privilege for those who wield it and the materiality of racial difference for those it is used against. This manifestation of racial privilege and difference rests upon a redrawing of the color line (...) that is meant towards preserving exclusive categories of political membership. The charge of racism, however, is elided by the fact that this hostility takes the form of a specious embracement of law and lawfulness. “Illegal” in this sense not only captures the actions of those who enter the United States through clandestine or informal means, but, in light of the history of immigration and citizen- ship law, the term operates as a racial trope that designates non-white status, thus marginalizing and alienating certain immigrants from ongoing nation-formation processes. I explain the source for anti-immigrant hostility in the United States, which I take to be connected to the longevity of white normativity as the basis for American identity. I then critically assess how the idea of national belonging is crucial to the perpetuation of white-ways-of-being, especially when citizenship has historically been a venue for the embodiment of racial and even colonial privilege. I conclude by posing several questions about the nature of racial identities and racism that suggest new avenues for further research on racial embodiment in a “postracial” era. pp. 65–90. (shrink)

In this paper, we show that Higher{Order Coloured Uni cation { a form of uni cation developed for automated theorem proving { provides a general theory for modeling the interface between the interpretation process and other sources of linguistic, non semantic information. In particular, it provides the general theory for the Primary Occurrence Restriction which (Dalrymple et al., 1991)'s analysis called for.

Colour constancy refers to the ability to extract information about surface colours independently of illumination conditions. A ripe strawberry, for example, appears the same red when viewed under a blue sky or a reddish sunset. Since Land's pioneering work, discussion has centred on the issue whether colour constancy is achieved primarily in the retina or visual cortex. Recently, the debate has shifted to a consideration of the constraints imposed by various psychophysical tasks and instructions. Humans can judge illuminant colour, reflected-light (...) colour, surface colour, and the relationship between surface colours within a scene. Such observations suggest that colour constancy may not be a unitary phenomenon, and that its different aspects may be mediated at different levels in the visual system. Several questions therefore arise: are the tasks of surface estimation and illuminant estimation complementary, insofar as good performance in one implies poor performance in the other? How does retinal adaptation alter performance? Is colour vision tuned to the statistical composition of natural surfaces and illuminants? What role does colour-opponent processing in retina and cortex play in colour constancy? These and related questions are explored here in order to better understand what we mean when we ask: "Why do strawberries look red?". (shrink)

Newton began his optical studies believing in the modification theory, which was still universally accepted at that time, and in the perception of colour as a physiological process—a process in which the eye responds differently to the different velocities of identical globules. His discovery that white light is heterogeneous led him to switch to considering colour in purely physical terms.A century later, Goethe started out by accepting Newton's physical theory. He soon abandoned it, however, finding modification (...) to be more in keeping with his own insights. One beneficial consequence of this was that he developed an awareness of the importance of the physiological aspect of colour perception, and was therefore able to demonstrate that Newton's theory of light and colours is too simplistic; that there is more to colour than variable refrangibility. (shrink)

Early psychophysical methods as codified by Fechner motivate the development of quantitative theories of subjective experience. The basic insight is that just noticeable differences between experiences can serve as units for measuring a sensory domain. However, the methods described by Fechner tacitly assume that the experiences being investigated can be linearly ordered. This assumption is not true for all sensory domains; for example, there is no trivial linear order over all possible color sensations. This paper discusses key developments in (...) the history of psychophysical methods for measuring color experience. In particular, a clear distinction between topological and metrical structure allowed Helmholtz to use opponent colors as a standard for measuring the gross structure of color space. Once this gross structure had been determined, lines through color space could be defined and Fechner-style methods employed for determining local structure. Extensions of these methods due to Wright, MacAdam, and others provide detailed evidence for the degree of agreement in the qualities of color experience across individuals. This allows a precise statement of the evidential support for the claim that your experience of color and mine are the same. (shrink)

The place of the subjective -- Everything that is of a whole constitutes an obstacle to it insofar as it is included in it -- Action, manor of the subject -- The real is the impasse of formalization : formalization is the locus of the passing-into-force of the real -- Hegel : "the activity of force is essentially activity reacting against itself" -- Subjective and objective -- The subject under the signifiers of the exception -- Of force as disappearance, whose (...) effect is the whole from which it has disappeared -- Deduction of the splitting -- A la nue accablante tu? -- Any subject is a forced exception, which comes in second place -- Jewelry for the sacred of any subtraction of existence -- Lack and destruction -- The new one forbids the new one and presupposes it -- On the side of the true -- There are no class relations -- Every subject crosses a lack of being and a destruction -- The subjects antecedence to itself -- Torsion -- Theory of the subject according to Sophocles, theory of the subject according to Eeschylus -- Of the strands of the knot, knowing only the color -- A materialist reversal of materialism -- The Black sheep of materialism -- The indissoluble salt of truth -- Answering to the sphinx demands from the subject not to have to answer or the sphinx -- Algebra and topology -- Neigborhoods -- Consistency, second name of the real after the cause -- So little ontology -- Subjectivization and subjective process -- The topological opposite of the knot is not the cut-dispersion but the destruction-recomposition -- Subjectivizing anticipation, retroaction of the subjective process -- Hurry! hurry! word of the living! -- The inexistent -- Logic of the excess -- Topics of ethics -- Where? -- The subjective twist : and -- Diagonals of the imaginary -- Schema -- Ethics as the dissipation of the paradoxes of partisanship -- Classical detour -- Love what you will never believe twice. (shrink)

In psychophysical experiments, the use of a psychophysical procedure of brightness/darkness cancellation shed light on interactions between spatial arrangement and figure–ground contrast in the perceptual filling in of achromatic and colored surfaces.Achromatic and chromatic Kanizsa squares with varying contrast, contrast polarity, and inducer spacingwere used to test how these factors interact in the perceptual filling in of surface brightness or darkness. The results suggest that the neuronal processing of surfaces with apparent contrast, leading to figure–ground segregation (i.e., perceptual organization), is (...) governed by mechanisms that integrate both luminance contrast and spatial information carried by the inducing stimuli, while discarding information on contrast polarity or color. The findings are discussed in relation to earlier observations on brightness assimilation and contrast. They support theories of nonantagonistic neural mechanisms suppressing local contrast or color signs in brightnessbased figure–ground percepts. Such mechanismsmight be necessary to cancel potentially conflicting polarities in geometricallycomplex visual stimuli so that perceptual filling in resulting in the most plausible representation of figure and ground can be achieved. (shrink)