Basic Color Categories Research Articles

Poster Session II: Constrained color-sorting and the evolution of color terms.

Constrained color-sorting-the partition of a color palette into sequential numbers, n, of categories or "piles," n = {2, 3, …, N}-has been used to examine universal vs. culture-dependent processes that underlie color-term evolution. Here we use sorting to test two hypotheses related to these ideas. 1) If the constrained color sorts (CCSs) depend solely on universal processes that guide color-term evolution, then CCSs should be relatively insensitive to the exact composition of the color palette. 2) Otherwise, CCSs should at least be "optimal" (as measured by well-formedness: Regier et al., 2007). We report three studies, each using a different palette, where English speakers sorted the color samples into 2 … 6 piles; one study also included Somali speakers. All palettes included good examples of the Basic Color Categories (BCCs), but they differed in how hue, saturation, and lightness covaried. Results showed that pile-sorts reflected psychologically salient features of colors, which were mostly linked to BCCs. However, 1) the unfolding of sort-categories with increasing n differed greatly across palettes, and the order in which the sort-categories appeared always deviated from predictions based on classical theories of color term evolution; 2) pile-sorts were not optimal. Taken together, our results reveal strong dependence of CCSs on pre-existing lexical categories but only weak dependence on universal pre-linguistic representations of color related to color-term evolution.

Robust categorical color constancy along daylight locus in red-green color deficiency.

Categorical color constancy in normal trichromats has been found to be very robust in real scenes. In this study, we investigated categorical color constancy in red-green dichromats and anomalous trichromats. Eight dichromats (two protanopes and six deuteranopes), eight anomalous trichromats (four protanomalous and four deuteranomalous trichromats), and eight normal trichromats sorted 208 Munsell matte surfaces into Berlin and Kay's basic color categories under D65 illuminant, F illuminant with correlated color temperature 4200 K, and TL84 illuminant with correlated color temperature 2700 K. Color constancy was quantified by a color constancy index. The results showed that the constancy index of dichromats (0.79) was considerable and significantly lower than that of normal trichromats (0.87) while that of anomalous trichromats (0.84) was not. The impairment of color constancy performance in dichromats was expected to be caused by their large intra-subject variabilities in color naming. The results indicate robust categorical color constancy along daylight locus in red-green dichromats and anomalous trichromats, which might be contributed by cone adaptation mechanism and be independent of color discrimination mechanism. It suggests that the color categorization by color vision deficient subjects can be reasonable without any assistants of artificial equipment in daily life under sunlight and common illuminations.

"Red-Green" or "Brown-Green" Dichromats? The Accuracy of Dichromat Basic Color Terms Metacognition Supports Denomination Change.

Two experiments compared “Red-Green” (R-G) dichromats’ empirical and metacognized capacities to discriminate basic color categories (BCCs) and to use the corresponding basic color terms (BCTs). A first experiment used a 102-related-colors set for a pointing task to identify all the stimuli that could be named with each BCT by each R-G dichromat type (8 protanopes and 9 deuteranopes). In a second experiment, a group of R-G dichromats (15 protanopes and 16 deuteranopes) estimated their difficulty discriminating BCCs-BCTs in a verbal task. The strong coincidences between the results derived from the pointing and the verbal tasks indicated that R-G dichromats have very accurate metacognition about their capacities (they only had considerable difficulty discriminating 13 out of the total of 55 possible BCT pairs) and limitations (Brown-Green and Blue-Purple pairs were rated especially difficult to differentiate) in the use of BCTs. Multidimensional scaling (MDS) solutions derived from both tasks were very similar: BCTs in R-G dichromats were properly represented in 2D MDS solutions that clearly show one chromatic dimension and one achromatic dimension. Important concordances were found between protanopes and deuteranopes. None of these dichromats showed substantial difficulty discriminating the Red-Green pair. So, to name them “R-G” dichromats is misleading considering their empirical capacities and their metacognition. Further reasons to propose the use of the alternative denomination “Brown-Green” dichromats are also discussed. We found some relevant differences between the “Brown-Green” dichromats’ empirical and self-reported difficulties using BCTs. Their metacognition can be considered a “caricature” of their practical difficulties. This caricature omits some difficulties including their problems differentiating “white” and “black” from other BCTs, while they overestimate their limitations in differentiating the most difficult pairs (Brown-Green and Blue-Purple). Individual differences scaling (INDSCAL) analyses indicated that the metacognition regarding the use of BCTs in “Brown-Green” dichromats, especially deuteranopes, is driven slightly more by the chromatic dimension and driven slightly less by the achromatic dimension, than their practical use of BCTs. We discuss the relevance of our results in the framework of the debate between the linguistic relativity hypothesis (LRH) and the universal evolution (UE) theories.

Basic color categories in Mandarin Chinese revealed by cluster analysis.

Previous claims of the number of color categories and corresponding basic color terms in modern Mandarin Chinese remain irreconcilable, mainly due to the shortage in objectively evaluating the basicness of color terms with statistical significance. Therefore the present study applied k-means cluster analysis to investigate native Mandarin Chinese speakers’ color naming data of 330 color chips similar to those used in World Color Survey. Results confirmed that there are 11 basic color categories among modern Mandarin speakers in Taiwan, one corresponding to each basic color term. Results also showed that observers overwhelmingly agreed in their use of Mandarin color terms, including those that had yielded ambiguous results in previous studies (gray, brown, pink, and orange). There is significant cross-language similarity when comparing the distribution of color categories in the World Color Survey chart with American English and Japanese data. The motif analysis and group mutual information analysis suggest that Mandarin color terms used in Taiwan describe very similar categories and are, hence, similarly precise in communicating color information as those in Japanese and American English. These results show that three languages of fundamentally different cultures and histories have very similar basic color terms.

Are light and dark blue used as separate basic color categories in English?: A corpus linguistics approach to studying visual perception

Are light and dark blue used as separate basic color categories in English?: A corpus linguistics approach to studying visual perception

Coherence of achromatic, primary and basic classes of colour categories

A range of explanations have been advanced for the systems of colour names found in different languages. Some explanations give special, fundamental status to a subset of colour categories. We argue that a subset of colour categories, if fundamental, will be coherent - meaning that a non-trivial criterion distinguishes them from the other colour categories. We test the coherence of subsets of achromatic (white, black and grey), primary (white, black, red, green, yellow, blue) and basic (primaries plus brown, orange, purple, pink and grey) colour categories in English. Criteria for defining colour categories were expressed in terms of behavioural, linguistic and geometric features derived from colour naming and linguistic usage data; and were discovered using machine learning methods. We find that achromatic and basic colour categories are coherent subsets but not primaries. These results support claims that the basic colour categories have special status, and undermine claims about the fundamental role of primaries in colour naming systems.

Russian blues reveal the limits of language influencing colour discrimination

Chromatic stimuli across a boundary of basic colour categories (BCCs; e.g. blue and green) are discriminated faster than colorimetrically equidistant colours within a given category. Russian has two BCCs for blue, sinij ‘dark blue’ and goluboj ‘light blue’. These language-specific BCCs were reported to enable native Russian speakers to discriminate cross-boundary dark and light blues faster than English speakers (Winawer et al., 2007, PNAS, 4, 7780–7785). We re-evaluated this finding in two experiments that employed identical tasks as in the cited study. In Experiment 1, Russian and English speakers categorised colours as sinij/goluboj or dark blue/light blue respectively; this was followed by a colour discrimination task. In Experiment 2, Russian speakers initially performed the discrimination task on sinij/goluboj and goluboj/zelënyj ‘green’ sets. They then categorised these colours in three frequency contexts with each stimulus presented: (i) an equal number of times (unbiased); more frequent (ii) either sinij or goluboj; (iii) either goluboj or zelënyj. We observed a boundary response speed advantage for goluboj/zelënyj but not for sinij/goluboj. The frequency bias affected only the sinij/goluboj boundary such that in a lighter context, the boundary shifted towards lighter shades, and vice versa. Contrary to previous research, our results show that in Russian, stimulus discrimination at the lightness-defined blue BCC boundary is not reflected in processing speed. The sinij/goluboj boundary did have a sharper categorical transition than the dark blue/light blue boundary, but it was also affected by frequency and order biases, demonstrating that “Russian blues” are less well-structured than previously thought.

Basic color categories and Mandarin Chinese color terms

Basic color terms used in Mandarin Chinese have been controversial since first discussed by Berlin and Kay in 1969. Previous studies showed much inconsistency on what should be considered as basic color terms in Mandarin Chinese. In the present study, we investigated categories of color rather than merely the color terms used by Taiwanese native Mandarin speakers. Using samples conforming to the Berlin and Kay survey, various colors were chosen from a collection of Natural Color System (NCS) colored papers and mounted on a piece of neutral gray card. The card was then mounted on a touch-screen, under D65 illumination. Thirty-two single-character color related Mandarin terms were selected from a Chinese character database according to frequency of use. Participants were required to select the color sample that matched the term by pressing a virtual button on the touch screen. The results show that certain terms can be directly correlated to basic color terms in English, comparable with the results of Berlin and Kay’s original study and those that followed. However, some terms, such as Mo (墨 ink), Tie (鐵 iron), and Cai (菜vegetable), show a wide spread of term maps and inconsistent use among subjects. Principle component analysis (PCA) procedures were used to analysis the commodity of data among subjects. The findings suggest that the basic color categories among Mandarin Chinese speakers are similar to those found in the World Color Survey (WCS), but are represented by wide-spread and inconsistent color terms among speakers.

Delving Deeper Into Color Space.

So far, color-naming studies have relied on a rather limited set of color stimuli. Most importantly, stimuli have been largely limited to highly saturated colors. Because of this, little is known about how people categorize less saturated colors and, more generally, about the structure of color categories as they extend across all dimensions of color space. This article presents the results from a large Internet-based color-naming study that involved color stimuli ranging across all available chroma levels in Munsell space. These results help answer such questions as how English speakers name a more complex color set, whether English speakers use so-called basic color terms (BCTs) more frequently for more saturated colors, how they use non-BCTs in comparison with BCTs, whether non-BCTs are highly consensual in less saturated parts of the solid, how deep inside color space basic color categories extend, or how they behave on the chroma dimension.

Basic Color Terms (BCTs) and Categories (BCCs) in Three Dialects of the Spanish Language: Interaction Between Cultural and Universal Factors.

Two experiments were performed to identify and compare the Basic Color Terms (BCTs) and the Basic Color Categories (BCCs) included in three dialects (Castilian, Mexican, and Uruguayan) of the Spanish language. Monolexemic Elicited lists were used in the first experiment to identify the BCTs of each dialect. Eleven BCTs appeared for the Spanish and the Mexican, and twelve did so for the Uruguayan. The six primary BCTs (rojo “red,” verde “green,” amarillo “yellow,” azul “blue,” negro “black,” and blanco “white”) appeared in the three dialects. This occurred for only three derived BCTs (gris “gray,” naranja “orange,” and rosa “pink”) but not for the other five derived BCTs (celeste “sky blue,” marrón “brown,” café “brown,” morado “purple,” and violeta “purple”). Color transitions were used in the second experiment for two different tasks. Extremes naming task was used to determine the relation between two different dialects' BCTs: equality, equivalence or difference. The results provided the first evidence for marrón “brown” and café “brown” being equivalent terms for the same BCC (brown in English) as is the case of morado “purple” and violeta “purple.” Uruguayan celeste “sky blue” had no equivalent BCT in the other two dialects. Boundary delimitation task required the selection of the color in the boundary between two categories. The task was used to reasonably estimate the volume occupied by each BCC in the color space considering its chromatic area and lightness range. Excluding sky blue (celeste “sky blue”) and blue (azul “blue”), the other BCCs color volumes were similar across the three dialects. Uruguayan sky blue and blue volumes conjointly occupied the portion of the color space corresponding to the Castilian and Mexican blue BCC. The fact that the BCT celeste “sky blue” only appeared in Uruguayan very probably derived from specific cultural factors (the use of the color in the flags and the arrival of an important number of Italian immigrants). Nevertheless, these cultural factors seem to nurture from a perceptive structuring of the color space, which nature is universal, as the boundaries of this category can be delimited from the responses of Spanish and Mexican participants.

Recognition memory for hue: Prototypical bias and the role of labeling.

How does the concurrent use of language affect perception and memory for exemplars? Labels cue more general category information than a specific exemplar. Applying labels can affect the resulting memory for an exemplar. Here 3 alternative hypotheses are proposed for the role of labeling an exemplar at encoding: (a) labels distort memory toward the label prototype, (b) labels guide the level of specificity needed in the current context, and (c) labels direct attention to the label's referent among all possible features within a visual scene. University students were shown hues on object silhouettes that they either labeled with basic color categories, made preference judgments about, or indicated the animacy of its category. Experiments 1 and 2 established that there are response shifts toward the category prototype regardless of labeling, showing a pervasive influence of category knowledge on response bias. They also established an effect of labeling whereby labeling decreases the magnitude of shifts. Experiments 3 and 4 investigated the uniqueness and necessity of language in causing the decreased shift-neither of which proved to be the case. Overall, category-relative bias was pervasive and labeling appears to direct attention to the feature resulting in less biased memory. The results highlight that the context at encoding affects how memory is formed. (PsycINFO Database Record

“Categorical Perception” and Linguistic Categorization of Color

This paper offers a conceptual clarification of the phenomenon commonly referred to as categorical perception of color, both in adults and in infants. First, I argue against the common notion of categorical perception as involving a distortion of the perceptual color space. The effects observed in the categorical perception research concern categorical discrimination performance and the underlying processing; they need not directly reflect the relations of color similarity and difference. Moreover, the methodology of the research actually presupposes that the relations of similarity and difference do not vary with languages. The observed categorical perception effects should be conceived independently of the perceptual color space. Second, I challenge the usual opinion that the existing evidence on infant “categorical perception” allows us to conclude that infants perceptually categorize color, and in particular, that they have perceptual categories that resemble the basic color categories of English. Such conclusions rest on an unjustified interpretation of the infant “categorical perception” findings in terms of adult linguistic categorical boundaries. Based on the suggested new understanding, I propose that the phenomenon, as present in infants, should be conceived and examined as a possible explanatory factor with respect to the existing patterns of color naming in languages of the world.

Color naming in Italian language

AbstractThe present study investigated Italian basic color terms (BCTs). It is an extension of our previous work that explored Italian basic color categories (BCCs) using a constrained color‐naming method, with 11 Italian BCTs allowed, including blu for naming the BLUE area. Since a latter outcome indicated a categorization bias, here monolexemic color‐naming method was employed, enabling also use of azzurro, deeply entrenched Italian term that designates light blue. In Experiment 1, colors (N = 367), sampling the Munsell Mercator projection, were presented on a CRT; color names and reaction times of vocalization onset were recorded. Naming consistency and consensus were estimated. Consistency was obtained for 12 CTs, including the two blue terms; consensus was found for 11 CTs, excluding rosso “red.” For each consensus category, color with the shortest response time was considered focal. In Experiment 2, consensus stimuli (N = 72) were presented; on each trial, observers indicated the focal color (“best example”) in an array of colors comprising a consensus category. For each of the 12 Italian CCs, centroid was calculated and focal color (two measures) estimated. Compared to English color terms, two outcomes are specific to Italian color naming: (i) naming of the RED‐PURPLE area is highly refined, with consistent use of emergent non‐BCTs; (ii) azzurro and blu both perform as BCTs dividing the BLUE area along the lightness dimension. The findings are considered in the framework of the weak relativity hypothesis. Historico‐linguistic, environmental, and pragmatic communication factors are discussed that conceivably have driven the extension of the BCT inventory in Italian. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 402–415, 2016

Emotion and colour: Physiology, lexicalisation and conceptualisation

In English and in many other European languages, Croatian included, it is quite common to use colour terms as an indicator of different emotions. When we talk about colour and humans, we areactually referring to the colour of their skin, more precisely their face. The main goal of this study is to investigate the correlation between the primary colour terms in collocational units and their corresponding emotions in English and Croatian. Since most of the current research on emotion concepts has focused on English, we would like to provide further evidence from Croatian expressions of emotions. A cross-linguistic corpus-based analysis of the two language corpora (the British National Corpus and the Croatian National Corpus) in the first part of the paper should offer a better insight into the salience of basic emotion categories in reference to basic colour categories. The second part of the paper investigates the motivation behind some of the linguistic expressions within the framework of cognitive linguistics. Despite the obvious cross-linguistic differences as to the system of preference by which each language links colours and emotions, some systematic patterns, due to their motivational force, are likely to appear in both languages under study. Key words: emotion, colour, collocational units, conceptual metaphor, metonymy

Hadza color naming and the origins of basic color categories

Hadza color naming and the origins of basic color categories

Colour constancy in natural images through colour naming and sensor sharpening

Colour is derived from three physical properties: incident light, object reflectance and sensor sensitivities. Incident light varies under natural conditions; hence, recovering scene illuminant is an important issue in computational colour. One way to deal with this problem under calibrated conditions is by following three steps, 1) building a narrow-band sensor basis to accomplish the diagonal model, 2) building a feasible set of illuminants, and 3) defining criteria to select the best illuminant. In this work we focus on colour constancy for natural images by introducing perceptual criteria in the first and third stages.To deal with the illuminant selection step, we hypothesize that basic colour categories can be used as anchor categories to recover the best illuminant. These colour names are related to how the human visual system has evolved to encode relevant natural colour statistics. Therefore the recovered image provides the best representation of the scene labelled with the basic colour terms. We demonstrate with several experiments how this selection criterion achieves current state-of-art results in computational colour constancy. In addition to this result, we psychophysically prove that usual angular error used in colour constancy does not correlate with human preferences, and we propose a new perceptual colour constancy evaluation.The implementation of this selection criterion strongly relies on the use of a diagonal model for illuminant change. Then, the second contribution focuses on building an appropriate narrow-band sensor basis to represent natural images. We propose to use the spectral sharpening technique to compute a unique narrow-band basis optimized to represent a large set of natural reflectances under natural illuminants and given in the basis of human cones. The proposed sensors allow predicting unique hues and the World colour Survey data independently of the illuminant by using a compact singularity function. Additionally, we studied different families of sharp sensors to minimize different perceptual measures. This study brought us to extend the spherical sampling procedure from 3D to 6D.Several research lines remain still open, such as, measuring the effects of using the computed sharp sensors on the category hypothesis; or inserting spatial contextual information to improve category hypothesis. Finally, to explore how individual sensors can be adjusted to the colours in a scene.

P1-15: Categorical Color Perception of LED Illuminant Color for Deuteranomals

Color information has great value in our everyday lives, but it is not mindful of people with color vision deficiency (CVD). We can choose several color names to categorize a lot of colors around us. Eleven color names (white, black, red, green, yellow, blue, brown, orange, pink, and gray) are known as basic color categories, but people with CVD cannot necessarily describe colors as people who are color vision normal (CVN) do. Previous studies showed that it was hard for people with CVD to discriminate illuminant color from object color, and their color perception changed largely depending on experimental conditions. In this study we investigated categorical color perception of illuminant color for deuteranomals, using a mixture of light which consists of a red, a green, and a blue LED as a test stimulus. We tested those stimuli with three luminance levels (180 cd/m2, 18 cd/m2, 1.8 cd/m2) and two visual angles (10 deg, 0.5 deg). Subjects were three deuteranomals and three people who are CVN. Our result sh...

Categorical color constancy for real surfaces

In everyday experience, perceived colors of objects remain approximately constant under changes in illumination. This constancy is helpful for identifying objects across viewing conditions. Studies on color constancy often employ monitor simulations of illumination and reflectance changes. Real scenes, however, have features that might be important for color constancy but that are in general not captured by monitor displays. Here, we investigate categorical color constancy employing real surfaces and real illuminants in a rich viewing context. Observers sorted 450 Munsell samples into the 11 basic color categories under a daylight and four filtered daylight illuminants. We additionally manipulated illuminant cues from the local surround. Color constancy as quantified both with a classification consistency index and a standard color constancy index was high in both cue conditions. Observers generally classified colors with the same precision across different illuminants as across repetitions for the daylight illuminant. Moreover, the pattern of classification consistency in terms of stimulus hue, value, and chroma was similar when comparing different observers for the daylight illuminant and when comparing individual observers across different illuminants. We conclude that color categorization is robust under illuminant changes as well as across observers, thus potentially serving both object identification and communication.

Basic Color Terms in Estonian Sign Language

The article is written in the tradition of Brent Berlin and Paul Kay’s theory of basic color terms. According to this theory there is a universal inventory of eleven basic color categories from which the basic color terms of any given language are always drawn. The number of basic color terms varies from 2 to 11 and in a language having a fully developed color system there are eleven basic color terms: white, black, red, green, yellow, blue, brown, purple, pink, orange and gray . The studies about basic color terms in sign languages show that lexicalization of basic color terms in sign languages follows the same pattern found in spoken languages. The current study is the first close study on the color terminology in Estonian Sign Language. The survey was carried out in summer 2005 and consisted of three tasks, following Davies and Corbett’s field method: the list task, the City University color vision test and the color-naming task. Fifty ESL users from different parts of Estonia were interviewed for the study. The collected data shows that the BCT hierarchy is clearly displayed in Estonian Sign Language and it may be concluded that Estonian Sign Language is a Stage VII language and has nine basic color terms: black , white , red , yellow , green , blue , gray , brown and pink / purple .

The color of night: Surface color categorization by color defective observers under dim illuminations

People with normal trichromatic color vision experience variegated hue percepts under dim illuminations where only rod photoreceptors mediate vision. Here, hue perceptions were determined for persons with congenital color vision deficiencies over a wide range of light levels, including very low light levels where rods alone mediate vision. Deuteranomalous trichromats, deuteranopes and protanopes served as observers. The appearances of 24 paper color samples from the OSA Uniform Color Scales were gauged under successively dimmer illuminations from 10 to 0.0003 Lux (1.0 to -3.5 log Lux). Triads of samples were chosen representing each of eight basic color categories; "red," "pink," "orange," "yellow," "green," "blue," "purple," and "gray." Samples within each triad varied in lightness. Observers sorted samples into groups that they could categorize with specific color names. Above -0.5 log Lux, the dichromatic and anomalous trichromatic observers sorted the samples into the original representative color groups, with some exceptions. At light levels where rods alone mediate vision, the color names assigned by the deuteranomalous trichromats were similar to the color names used by color normals; higher scotopic reflectance samples were classified as blue-green-grey and lower reflectance samples as red-orange. Color names reported by the dichromats at the dimmest light levels had extensive overlap in their sample scotopic lightness distributions. Dichromats did not assign scotopic color names based on the sample scotopic lightness, as did deuteranomalous trichromats and colour-normals. We reasoned that the reduction in color gamut that a dichromat experiences at photopic light levels leads to a limited association of rod color perception with objects differing in scotopic reflectance.