Effects of surround/test field luminance ratio on induced colour

Abstract.— According to Kirschmann's third law the induced colour is at its maximum when the inducing and induced fields are of equal luminance. Later studies (Kinney, 1962) show the induced colour to be most pronounced at a luminance ratio (inducing/induced) of about 4/1. In the present study the amount of colour induced into an achromatic test field was determined for one inducing colour, red, by letting observers judge the colour strength of the induced field. The test (or induced) field luminance was varied to give luminance ratios between 0.5/1 and 2/1. The results show that both colour strength and blackness increase as the luminance ratio is increased. The fact that the test field was judged even to have maximum chromatic colour strength and maximum blackness at the same time is discussed in relation to the method used and in relation to earlier studies on the "mode of appearance" of colours and the bidimensionality of achromatic colours.     

Chromatic induction as a function of luminance relations

Chromatic induction by red, green, and blue surround was studied as a function of surround/test field luminance ratio using a compensation method. Luminance ratios from 0.01 to 28.7 were used. The number of subjects was 8–10 in the three experiments. The results show maximum induction to appear at a luminance ratio around 1.0 when varying the test field luminance (Experiment 1) and at higher ratios when varying the surrounding luminance (Experiments 2 and 3). This difference is discussed in relation to the Kirschmann-Kinney controversy (Kirschmann, 1890; Kinney, 1962) and in relation to an earlier study using a magnitude estimation method (Bergström & Derefeldt, 1975).     

Colour constancy in goldfish and man: influence of surround size and lightness

Colour constancy was investigated by using a series of 10 simultaneously presented surface colours ranging in small steps from green through gray to red-purple. Goldfish were trained to select one medium test field when the entire setup was illuminated with white light. In the tests, either red or green illumination was used. Colour constancy, as inferred from the choice behaviour, was perfect under green illumination when the test fields were presented on a gray or a white background, but imperfect on a black background. Under red illumination and a white background, however, colour constancy was overcompensated. Here, a colour contrast effect was observed. The influence of background lightness was also found when the surround was restricted to a narrow annulus of 4-11 mm width (test field diameter: 14 mm). By applying colour metrics it could be shown that the von Kries coefficient law can describe the overall effect of colour constancy. For an explanation of the effect of surround size and lightness, lateral inhibitory interactions have to be assumed in addition, which are also responsible for simultaneous colour contrast. Very similar results were obtained in experiments with the same colours in human subjects. They had to name the test field appearing 'neutral' under the different illumination and surround conditions, as tested in the goldfish experiment.     

Blue or red? The effects of colour on the emotions of Chinese people

Two experiments were performed to examine the effects of red and blue on the emotional pleasure of Chinese people. Experiment 1 explored the effects of the ‘physical’ colours red and blue on emotion, and the results showed that red induced positive and negative emotion, while blue only induced positive emotion. Experiment 2 further explored the effects of the ‘verbal’ colours red and blue on emotion, and the results showed that red induced only positive emotion, while blue induced neither positive nor negative emotion. The findings indicate that the influence of colour on emotion is rooted in both natural and social associations. For Chinese, the associations between blue and positive emotion, and red and negative emotion, were natural associations; however, the associations between red and positive emotion were social associations. Moreover, physical colour and verbal colour stimuli induced emotions by activating different mechanisms: physical colour induced emotions via both natural and social associations, whereas verbal colour induced emotions via social associations.     

Colour changes as a function of luminance contrast.

When spectral light increases in luminance, the hues change. Normally, long-wavelength light becomes increasingly yellow, and short-wavelength light turns blue or blue-green. This is known as the Bezold-Brücke hue shift. Less notice has been paid to the change in relative chromatic content (saturation or chromatic strength) that accompanies these shifts in hue. As luminance contrast increases from zero, chromatic strength increases to reach a maximum at a luminance that is wavelength dependent. Short-wavelength blueish light reaches this maximum at low relative luminances, whereas midspectral yellowish stimuli need several log units higher luminance. Red and green are somewhere in between. For luminances above this maximum, the chromatic content usually diminishes, and most light becomes more whitish in appearance. In this study it is demonstrated how the combined chromatic appearance of hue and chromatic strength change with intensity. Both phenomena find a common physiological interpretation in the nonlinear and nonmonotonic responses of colour-opponent P cells in the retina and lateral geniculate nucleus of the primate. A model that combines the outputs of six P-cell types accounts for observers' estimates of hue and chromatic strength.     

Scaling of saturation and hue

The study concerns the relation of saturation to the purity and luminance of aperture colors viewed in a dark surround. For the primary hues, red, yellow, green, and blue, and the intermediate hues, orange and yellowish green, the saturations increased as power functions of colorimetric purity. An IS-dB increase in luminance caused a threefold increase in the exponent for yellow, but luminance had little effect on the exponents of the other colors. The direct heterochromatic matching of saturation to saturation confirmed the validity of the scales determined by magnitude estimation and led to the construction of families of saturation scales based on a common unit called a crome. Equisection and jnd scales were also determined. Their nonlinearity suggests that saturation is a prothetic continuum. It was found that mixing red or green with yellow behaves much the same as mixing red or green with achromatic light. The changes in hue behave as prothetic continua, for the equisection and jnd scales are nonlinearly related to the power-function scales obtained by magnitude estimation and matching.     

Rod involvement in peripheral color processing

Abstract.— It has previously been suggested that rods act as blue receptors in peripheral color vision. Two experiments examining this issue were conducted. Experiment 1 investigated the perceived hue of a test light presented at a luminance level above chromatic threshold. At 8° in the periphery, the 500 nm test light was perceived as more blue under conditions of dark adaptation than after light adaptation. Similar differences were not found for foveal presentation. The increased blue in the periphery after dark adaptation was attributed to a rod contribution. In Experiment 2 an attempt was made to mix a rod contribution obtained with a 470 nm light below chromatic threshold, with a cone color obtained from a 670 nm light presented above chromatic threshold. No evidence was obtained to support the idea that a blue produced by rods stimulated below chromatic threshold could mix with a red produced by cones stimulated above chromatic threshold. The results are discussed in terms of a rod contribution to hue which is dependent on the luminance level of short wavelength stimulation.     

大学生颜色词分类的研究

运用自然分类和多维标度法．对279名大学生进行了11种基本颜色词的分类研究、结果表明,大学生将11种基本颜色词分成三类：(1)非彩色,包括黑、白、灰,也包括色彩暗淡的棕色;(2)暖色,包括红、橙、黄和粉红色;(3)冷色．包括绿、蓝和紫。基本颜色词的语义空间有两个纬度：(1)彩色／非彩色;(2)冷色／暖色。不同专业大学生对颜色词分类基本一致,但也具有专业特点。     

Flexibility over automaticity: Separable representations for colours and words

This study demonstrates that associations between colour words and the colours they denote are not mandatory. Experiments 1–3 used a go/no-go task in which participants responded to one print colour and one word and withheld response from another print colour and another word. In Experiment 1, the content of the words denoted noncolour entities. In Experiment 2 the two words denoted two colours that were different from the target print colours. In Experiment 3, the words denoted the same colours as the target print colours but each response set included incompatible print colour and word (e.g., one response to the print colour blue and the word “green” and another response to the print colour green and the word “blue”). Participants performed equally well in all the experiments. Experiment 4a used Arabic digits and words denoting numbers, two formats that are known to have shared representations. Here, participants had difficulties separating their responses to the digits and words. These results suggest that representations of words are distinct from the content that they represent, supporting the existence of distinct verbal and colour modules.     

Pink for Girls,Red for Boys,and Blue for Both Genders: Colour Preferences in Children and Adults

Colours carry social connotations like pink for girls and blue for boys. In a cross-sectional study, we investigated whether such early gender coding might be reflected in absolute colour preferences in children and adults of both genders. In two studies, participants selected their favourite (and least favourite, Study 2) colour from an unrestricted sample of colours. We tested 129 Swiss children (Study 1, 10–14 years-old, 68 boys) and 180 Swiss adults (Study 2, 17–48 years-old, 88 men). In children, we observed that girls chose pink/purple as their favourite hue more often than boys did, the most common favourite hue in girls and boys was blue, and boys chose red as their favourite more often than girls did. In adults, we observed that both genders almost never choose pink as their favourite, blue was a common favourite colour, and women were more likely to favour red than were men. In an additional study (n?=?183 Swiss participants, 47 men), we tested whether liking of pink, blue, and red was related to emotion associations with these colours. Pink was associated with positive emotions to the same extent as blue and red. Women further associated more positive emotions with pink than did men. We conclude that some commonalities (blue) and gender differences (pink and red) exist in absolute colour preferences. These differences, however, cannot be fully accounted by emotional associations. We speculate about these gendered colour preferences in relation to gender stereotypes and status differences between men and women.

     

Are there nontrivial constraints on colour categorization?

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.     

Newborns' discrimination of chromatic from achromatic stimuli

Two experiments assessed newborns' ability to discriminate chromatic from achromatic stimuli. In Experiment 1, newborns differentiated gray from green, from yellow, and from red: For each of these hues they preferred chromatic-and-gray checkerboards over gray squares matched in mean luminance, even though the luminance of the gray checks was varied systematically over a wide range so as to minimize nonchromatic cues. However, newborns showed no evidence of differentiating gray from blue: At some luminances they showed no preference for a blue-and-gray checkerboard over a gray square. In Experiment 2, newborns differentiated red from gray but appeared not to differentiate blue from gray: Following habituation to a series of gray squares of varying luminance, they looked longer at a red square than at a gray square of novel luminance but showed no such pattern of recovery to a blue square. The results imply that newborns have some, albeit limited, ability to discriminate chromatic from achromatic stimuli and hence, that they are at least dichromats.     

Color measurement and color theory: II. Opponent-colors theory

Quantitative opponent-colors theory is based on cancellation of redness by admixture of a standard green, of greenness by admixture of a standard red, of yellowness by blue, and of blueness by yellow. The fundamental data are therefore the equilibrium colors: the set A₁ of lights that are in red/green equilibrium and the set A₂ of lights that are in yellow/blue equilibrium. The result that a cancellation function is linearly related to the color-matching functions can be proved from more basic axioms, particularly, the closure of the set of equilibrium colors under linear operations. Measurement analysis treats this as a representation theorem, in which the closure properties are axioms and in which the colorimetric homomorphism has the cancellation functions as two of its coordinates.Consideration of equivalence relations based on opponent cancellation leads to a further step: analysis of equivalence relations based on direct matching of hue attributes. For additive whiteness matching, this yields a simple extension of the representation theorem, in which the third coordinate is luminance. For other attributes, precise representation theorems must await a better qualitative characterization of various nonlinear phenomena, especially the veiling of one hue attribute by another and the various hue shifts.     

Scaling of saturation and hue in the nonspectral region

The saturation of two nonspectral hues, magenta and violet, and the hue shift between red and blue through the nonspectral region were both scaled by two methods, equisection to produce a difference scale, ψ_D, and ratio judgments to produce a magnitude scale, ψ_M. The colored stimuli were viewed through apertures in a dark surround, with the luminance kept constant at one of three levels, 0.5, 2.5, and 12.6 cd/m². As previously found with saturation and hue shift between two adjacent primary hues in the spectral region, WD was linear with colorimetric purity for the saturation of magenta or violet and with the mixture ratio of red or blue for the hue shift, whereas ψ_M was a power function of colorimetric purity for the saturations and of the mixture ratio for the hue shift with exponents larger than unity in both cases. The present results were combined with previous results to give the change of parameters for saturation functions over the entire hue circle.     

Development of chromatic induction in infancy

The perception of colour in an embedded field is affected by the surround colour. This phenomenon is known as chromatic induction. In the present study we investigated whether the colour perception by infants aged 5–7 months could be affected by the surround colour. In Experiments 1 and 2 each stimulus was composed of an array of six squares in tandem. The colour appearance of the array in the familiarization stimulus was established by chromatic induction. In Experiment 1 we used familiarization stimuli that were perceived as two‐colour array with a two‐colour surround. In Experiment 2 we used a familiarization stimulus that was perceived as a uniform‐colour array with a two‐colour surround. In the test phase, the uniform‐colour array and the two‐colour array were presented on a white uniform‐colour surround in both experiments. The results showed that in Experiment 1 the 5‐ and 7‐month‐old infants had novelty preference for the uniform‐colour test array. This suggested that the infants' colour perception could be affected by surround colour. The results of Experiment 2 showed that the 7‐month‐olds showed a novelty preference for the two‐colour test array, but the 5‐month‐olds showed no novelty preference. This suggested that 7‐month‐olds' colour perception could be affected by surround colour, but that of 5‐month‐olds could not. We discuss the contradiction of the results between Experiments 1 and 2. Copyright © 2007 John Wiley & Sons, Ltd.     

A NOTE ON INTEROCULAR TRANSFER AND THE COLOUR OF VISUAL AFTER-IMAGES

Following monocular fixation of a red stimulus figure on a grey background, a projection field having the same colour as the stimulus figure was viewed either with ( a ) the stimulated eye, or ( b ) the non-stimulated eye. In case ( a ) the after-image appeared grey on a red background, but in case ( b ) green or blue, on a red background. In the latter case the brightness and to some extent the hue of the after-image varied when the amount of light coming to the originally stimulated eye varied. The data are in agreement with the assumption that after-images are primarily retinal.     

Morphological patterns and their colour

This study analyzed qualitative aspects in perception, particularly the relationship between morphological aspects of biological shapes and colour. The experiment reported by the study assessed the functional relation between shape and colour and, in particular, the relations among the patterns of shapes appearing in perceptual configurations, as well as certain characteristics of colour. Participants were shown 32 natural images and were asked to match them with a colour. The results indicated that some figures were more frequently associated (positively or negatively) with some colours instead of others. Type of shape, texture, and three-dimensionality were important elements in the participants' choices. Rounded figures and non-holed figures had positive matches with red; elongated figures were associated with colours between blue and green; and holed figures showed positive matches with colours between green and yellow. Type of shape and texture also exhibited a relationship with the warmth of the colour.     

Amount of surround and test-inducing separation in simultaneous brightness contrast

Simultaneous brightness contrast is investigated in the fovea as a function of (1) amount of surround of the inducing field (Experiment 1) and (2) separation between the test and inducing fields (Experiment 2). Circular test and match fields subtending 14 min (radius) are used throughout. The inducing field, held constant in area, is a circular annulus (615 sq min) varying from a quadrant on one side of the test circle to an annulus completely surrounding the test circle. Test-field apparent brightness is not significantly affected by amount of inducing-field surround when the separation between centers of the test and inducing fields is held constant (Experiment 1). Experiment 2, though, shows that apparent brightness increases significantly as the separation between the centers of the test and inducing fields is increased.     

Red-hot: How colour and semantic temperature processing interact in a Stroop-like paradigm

Temperature concepts and colour are commonly associated (i.e., red is “hot” and blue is “cold”), although their direction of influence (unidirectional, bidirectional) is unknown. Semantic Stroop effects, whereby words like fire influence colour categorization, suggest automatic semantic processing influences colour processing. The experiential framework of language comprehension indicates abstract concepts like temperature words simulate concrete experiences in their representation, where expressions like “red-hot” suggest colour processing influences conceptual processing. Participants categorized both colour (Experiment 1: red, blue; Experiment 2: red, green, blue) and word-meaning with matched lists of hot and cold meaning words in each colour. In Experiments 1 and 2, semantic categorization showed congruency effects across hot and cold words, while colour categorization showed facilitation only with hot words in Experiment 2. This asymmetry reflects a more consistent influence of colour categorization on semantic categorization than the reverse, suggesting experiential grounding effects may be more robust than the effects of semantic processing on colour processing.