Perceptual constancy, often defined as the perception of stable features under changing conditions, goes hand in hand with variation in how things look. A white wall in the orange afternoon sun still looks white, though its whiteness looks different compared with the same wall in the noon sun. Historically, this variation has often been explained in terms of our experience of “merely sensory” or subjective properties – an approach at odds with the fact that the variation does track objective features (...) of the perceptual situation, such as illumination. One approach, becoming more common, is to account for the variation in terms of further “dimensions” to perceptual experience. Especially in colour perception, this is a natural thought to have but the idea is often left vague. In this paper I argue that the “dimensional” strategy has problems of its own, but is useful in drawing out some interesting complications in the way perceptual experience is structured. Specifically, the structure of “constancy spaces” brings out the different ways in which there is stability and instability in the experience of constancy, without the need for novel or merely subjective features. Instability arises in a contingent structural feature of perceptual experience. (shrink)

In this article, I argue that popular explanatory frameworks in perceptual psychology suggest the truth of color realism. I focus on perceptual judgments and their evidential basis: namely perceptual representation. I first draw a distinction between two sorts of normativities with respect to which we can evaluate representational capacities and systems: biological and psychological normativities. The former is defined in terms of evolutionary fitness, and the latter in terms of representational accuracy. Generally, representational systems achieve psychological and biological success hand (...) in hand, but in special circumstances, a representational system can be such that it serves the organism best while not generally furnishing the organism with accurate representations. I argue in this essay that an explanation how and why our ancestors developed color vision that cleaves its biological success conditions from its psychological success conditions cannot be given unless we are prepared to say the same about the visual perception of distance and other geometrical features of the world. Moreover, it is difficult to see how the anti-realist could begin to specify psychological success conditions for color representations. Hence, we ought to accept the biological utility of color vision as evidence that it is typically representationally successful, and regard our perceptual judgments about color as generally true. (shrink)

This paper resolves a paradox concerning colour constancy. On the one hand, our intuitive, pre-theoretical concept holds that colour constancy involves invariance in the perceived colours of surfaces under changes in illumination. On the other, there is a robust scientific consensus that colour constancy can persist in cerebral achromatopsia, a profound impairment in the ability to perceive colours. The first stage of the solution advocates pluralism about our colour constancy capacities. The second details the close relationship between colour constancy and (...) contrast. The third argues that achromatopsics retain a basic type of colour constancy associated with invariants in contrast processing. The fourth suggests that one person-level, conscious upshot of such processing is the visual awareness of chromatic contrasts ‘at’ the edges of surfaces, implicating the ‘colour for form’ perceptual function. This primitive type of constancy sheds new light on our most basic perceptual capacities, which mark the lower borders of representational mind. (shrink)

Colour constancy is a foundational and yet puzzling phenomenon. Standard appearance invariantism is threatened by the psychophysical matching argument, which is taken to favour variantism. This argument, however, is inconclusive. The data at best support a pluralist view: colour constancy is sometimes variantist, sometimes invariantist. I add another potential explanation of these data, complex invariantism, which adopts an atypical six-dimensional model of colour appearance. Finally I prospect for a unifying conception of constancy among two neglected notions: discriminatory colour constancy and (...) relational colour constancy. The former arguably marks a common core capacity that is present across widely differing viewing contexts. (shrink)

In this paper, I consider a view that explains colour experience by the independent representation of surface and illumination. This view implies that surface colour is a phenomenal perceptual content. I argue from facts of colour phenomenology to the conclusion that surface colour is not a phenomenal perceptual content. I then argue from results of surface-matching experiments to the conclusion that surface colour is neither a perceptual content of any kind nor any sort of computational output of the perceptual system. (...) These conclusions contradict widely accepted views in both the philosophy of perception and colour science. I finish by considering and rejecting a competing account of the surface-matching results, according to which surface colour is represented indeterminately in perception. (shrink)

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