Constraints on children's color term acquisition

Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) address an age-old question: Why do children find it difficult to learn color terms? Here these articles are reflected on, providing a focused examination of the issues central to this question. First, the criteria by which children are said to find color naming difficult are considered. Although the age of color term acquisition is decreasing, and color naming might not be more difficult than other abstract attributes, several stages of difficulty are identified. Second, it is argued that there are potentially multiple constraints (e.g., conceptual, attentional, and linguistic) for these multiple stages of difficulty with color term acquisition. Third, it is argued that the validity and reliability of techniques for identifying constraints need to be considered and that converging evidence for the constraints should be provided. Finally, a series of new questions that need to be asked to provide a well-rounded explanation of the difficulties children face when learning color terms is outlined.     

Taking the task seriously: reflections on measures of color acquisition

The experiments described in the lead articles by Kowalski and Zimiles and by O'Hanlon and Roberson examine factors that lead to color term acquisition. These experiments touch on the debate regarding the relative contributions of language and concepts in word learning. In this reflection, we examine how conclusions concerning the debate depend deeply on the particular task presented to children, and we propose an alternative approach to studying color term acquisition.     

What can we learn from toddlers about categorical perception of color? Comments on Goldstein, Davidoff, and Roberson

We comment on Goldstein, Davidoff, and Roberson’s replication and extension (Journal of Experimental Child Psychology, 102, 219-238 [2009]) of our study of the effect of toddlers’ color term knowledge on their categorical perception (CP) of color (Journal of Experimental Child Psychology, 90, 114-141 [2005]). First, we discuss how best to assess color term knowledge when concerned with the effects of language on color CP. A reanalysis of our data indicates that even toddlers who do not know the terms for the relevant focal colors still show CP. Second, we comment on Goldstein and colleagues’ finding of blue-purple CP, as we did, but not of blue-green CP in Himba toddlers. We present contrasting data from Wright (unpublished PhD thesis, University of Surrey, 2006) that demonstrates blue-green CP in Himba toddlers. Finally, we discuss the limitations of the approach taken by all of these investigations and discuss theoretical accounts of the origin and nature of color CP.     

Testing the Cross-Cultural Generality of Hering's Theory of Color Appearance

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.     

Color term knowledge does not affect categorical perception of color in toddlers

Categorical perception of color is shown when colors from the same category are discriminated less easily than equivalently spaced colors that cross a category boundary. The current experiments tested various models of categorical perception. Experiment 1 tested for categorical responding in 2- to 4-year-olds, the age range for the onset establishment of color term knowledge. Experiment 2 tested for categorical responding in Himba toddlers, whose language segments the color space differently from the way in which the English language does so. Experiment 3 manipulated the conditions of the task to explore whether the categorical responding in Experiments 1 and 2 was equivalent to categorical perception. Categorical perception was shown irrespective of naming and was not stronger in those children with more developed color term knowledge. Cross-cultural differences in the extent of categorical perception were not found. These findings support universalistic models of color categorization and suggest that color term knowledge does not modify categorical perception, at least during the early stages of childhood.     

Proving universalism wrong does not prove relativism right: Considerations on the ongoing color categorization debate

For over a century, the question of the relation of language to thought has been extensively discussed in the case of color categorization, where two main views prevail. The relativist view claims that color categories are relative while the universalistic view argues that color categories are universal. Relativists also argue that color categories are linguistically determined, and universalists that they are perceptually determined. Recently, the argument for the perceptual determination of color categorization has been undermined, and the relativist view has regained some ground. This paper argues that although the universalistic account of color categorization has been called into question, this is not enough to establish relativism. Color categories can still be said to be universal or particular, independent of the accounts of their universality or relativity. Because of its polarization, the debate has disregarded some issues that are key in our understanding of color categorization: the question of what a color category is and how to identify it.     

The structure of color experience and the existence of surface colors

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.     

Color naming universals: the case of Berinmo

Proponents of a self-identified 'relativist' view of cross-language color naming have confounded two questions: (1) Is color naming largely subject to local linguistic convention? and (2) Are cross-language color naming differences reflected in comparable differences in color cognition by their speakers? The 'relativist' position holds that the correct answer to both questions is Yes, based on data from the Berinmo language of Papua New Guinea. It is shown here that the Berinmo facts instead support a more complex view -- that cross-language color naming follows non-trivial universal tendencies, while cross-language color-naming differences do indeed correlate with differences in color cognition. The rhetoric of 'relativity' versus 'universalism' impedes understanding of cross-language color naming and cognition.     

Seasonal Variations in Color Preference

We investigated how color preferences vary according to season and whether those changes could be explained by the ecological valence theory (EVT). To do so, we assessed the same participants’ preferences for the same colors during fall, winter, spring, and summer in the northeastern United States, where there are large seasonal changes in environmental colors. Seasonal differences were most pronounced between fall and the other three seasons. Participants liked fall‐associated dark‐warm colors—for example, dark‐red, dark‐orange (brown), dark‐yellow (olive), and dark‐chartreuse—more during fall than other seasons. The EVT could explain these changes with a modified version of Palmer and Schloss’ (2010) weighted affective valence estimate (WAVE) procedure that added an activation term to the WAVE equation. The results indicate that color preferences change according to season, as color‐associated objects become more/less activated in the observer. These seasonal changes in color preferences could not be characterized by overall shifts in weights along cone‐contrast axes.     

Reflections on how color term acquisition is constrained

Compared with object word learning, young children typically find learning color terms to be a difficult linguistic task. In this reflections article, I consider two questions that are fundamental to investigations into the developmental acquisition of color terms. First, I consider what constrains color term acquisition and how stable these constraints are over culture and age. I review recent studies that have identified conceptual, attentional, and linguistic constraints that seemingly operate on the acquisition of color terms compared with object words and the differential acquisition of color terms within a given language. Second, I consider whether these constraints are specific to the acquisition of color terms or whether they reflect more general constraints that operate on other classes of lexical terms such as different abstract property terms.     

Clustering colors

Regier, Kay, and Khetarpal report the results of computer simulations that cluster color stimuli on the basis of their coordinates in CIELAB space, one of two commonly used perceptual color spaces. Regier and coauthors find partitions of those stimuli that are strikingly similar to the way actual color lexicons partition color space. They do not argue for the custom-made clustering method used in their simulations, nor for the assumption of CIELAB space. The present paper aims to answer the question to what extent their computational results depend on these assumptions. It does this by applying a great variety of known clustering methods to Regier et al.’s stimuli, and by assuming not only CIELAB space but also CIELUV space, the other main color space.     

Stroop dilution depends on the nature of the color carrier but not on its location

Stroop dilution is the reduction of the Stroop effect in the presence of a neutral word. It has been attributed to competition for attention between the color word and neutral word, to competition between all stimuli in the visual field, and to perceptual interference. Five experiments tested these accounts. The critical manipulation was whether the color to be named was carried by the color word or the neutral word. Neutral words diluted the Stroop effect when they were the color carrier, but not when the color word was the color carrier. We argue that Stroop dilution is due to attentional competition between the color word and neutral word, with priority given to the color carrier.     

The role of perception, language, and preference in the developmental acquisition of basic color terms

When learning basic color vocabulary, young children show a selective delay in the acquisition of brown and gray relative to other basic color terms. In this study, we first establish the robustness of this finding and then investigate the extent to which perception, language, and color preference may influence color conceptualization. Experimental tasks were designed to measure different aspects of perceptual color processing (discrimination and saliency), color preference and objective counts of color term frequency in preschool-directed language (books and mothers' speech) were used to compare the acquisition of three groups of colors: primary colors, secondary colors (orange, pink, and purple) that appear at the same time as the primary colors, and secondary colors (brown and gray) that appear late. Although our results suggest that perception does not directly shape young children's color term acquisition, we found that children prefer brown and gray significantly less than basic colors and that these color terms appear significantly less often in child-directed speech, suggesting that color preference, linguistic input, and developing color cognition may be linked.     

The interaction between surface color and color knowledge: behavioral and electrophysiological evidence

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks - a surface and a knowledge verification task - using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the differences between typical and atypical color objects in each task. In the color knowledge task, we found two significant clusters that were consistent with the N350 and late positive complex (LPC) effects. Atypical color objects elicited more negative ERPs compared to typical color objects. The color effect found in the N350 time window suggests that surface color is an important cue that facilitates the selection of a stored object representation from long-term memory. Moreover, the observed LPC effect suggests that surface color activates associated semantic knowledge about the object, including color knowledge representations. We did not find any significant differences between typical and atypical color objects in the surface color verification task, which indicates that there is little contribution of color knowledge to resolve the surface color verification. Our main results suggest that surface color is an important visual cue that triggers color knowledge, thereby facilitating object identification.     

Knowing color terms enhances recognition: further evidence from English and Himba

Two experiments attempted to reconcile discrepant recent findings relating to children’s color naming and categorization. In a replication of Franklin and colleagues (Journal of Experimental Child Psychology, 90 (2005) 114-141), Experiment 1 tested English toddlers’ naming and memory for blue-green and blue-purple colors. It also found advantages for between-category presentations that could be interpreted as support for universal color categories. However, a different definition of knowing color terms led to quite different conclusions in line with the Whorfian view of Roberson and colleagues (Journal of Experimental Psychology: General, 133 (2004) 554-571). Categorical perception in recognition memory was now found only for children with a fuller understanding of the relevant terms. It was concluded that color naming can both underestimate and overestimate toddlers’ knowledge of color terms. Experiment 2 replicated the between-category recognition superiority found in Himba children by Franklin and colleagues for the blue-purple range. But Himba children, whose language does not have separate terms for green and blue, did not show a cross-category advantage for that set; rather, they behaved like English children who did not know their color terms.     

Color categories: evidence for the cultural relativity hypothesis

The question of whether language affects our categorization of perceptual continua is of particular interest for the domain of color where constraints on categorization have been proposed both within the visual system and in the visual environment. Recent research (Roberson, Davies, & Davidoff, 2000; Roberson et al., in press) found substantial evidence of cognitive color differences between different language communities, but concerns remained as to how representative might be a tiny, extremely remote community. The present study replicates and extends previous findings using additional paradigms among a larger community in a different visual environment. Adult semi-nomadic tribesmen in Southern Africa carried out similarity judgments, short-term memory and long-term learning tasks. They showed different cognitive organization of color to both English and another language with the five color terms. Moreover, Categorical Perception effects were found to differ even between languages with broadly similar color categories. The results provide further evidence of the tight relationship between language and cognition.     

Color charts, esthetics, and subjective randomness

Color charts, or grids of evenly spaced multicolored dots or squares, appear in the work of modern artists and designers. Often the artist/designer distributes the many colors in a way that could be described as "random," that is, without an obvious pattern. We conduct a statistical analysis of 125 "random-looking" art and design color charts and show that they differ significantly from truly random color charts in the average distance between adjacent colors. We argue that this attribute generalizes results in subjective randomness in a black/white setting and gives further evidence supporting a connection between subjective randomness and what is esthetically pleasing.     

Flexible cue use in food-caching birds

An animal’s memory may be limited in capacity, which may result in competition among available memory cues. If such competition exists, natural selection may favor prioritization of different memory cues based on cue reliability and on associated differences in the environment and life history. Food-caching birds store numerous food items and appear to rely on memory to retrieve caches. Previous studies suggested that caching species should always prioritize spatial cues over non-spatial cues when both are available, because non-spatial cues may be unreliable in a changing environment; however, it remains unclear whether non-spatial cues should always be ignored when spatial cues are available. We tested whether mountain chickadees (Poecile gambeli), a food-caching species, prioritize memory for spatial cues over color cues when relocating previously found food in an associative learning task. In training trials, birds were exposed to food in a feeder where both spatial location and color were associated. During subsequent unrewarded test trials, color was dissociated from spatial location. Chickadees showed a significant pattern of inspecting feeders associated with correct color first, prior to visiting correct spatial locations. Our findings argue against the hypothesis that the memory of spatial cues should always take priority over any non-spatial cues, including color cues, in food-caching species, because in our experiment mountain chickadees chose color over spatial cues. Our results thus suggest that caching species may be more flexible in cue use than previously thought, possibly dependent upon the environment and complexity of available cues.     

Mapping the color space of saccadic selectivity in visual search

Color coding is used to guide attention in computer displays for such critical tasks as baggage screening or air traffic control. It has been shown that a display object attracts more attention if its color is more similar to the color for which one is searching. However, what does similar precisely mean? Can we predict the amount of attention that a display color will receive during a search for a given target color? To tackle this question, two color‐search experiments measuring the selectivity of saccadic eye movements and mapping out its underlying color space were conducted. A variety of mathematical models, predicting saccadic selectivity for given target and display colors, were devised and evaluated. The results suggest that applying a Gaussian function to a weighted Euclidean distance in a slightly modified HSI color space is the best predictor of saccadic selectivity in the chosen paradigm. Hue and intensity information by itself provides a basis for useful predictors, spanning a possibly spherical color space of saccadic selectivity. Although the current models cannot predict saccadic selectivity values for a wide variety of visual search tasks, they reveal some characteristics of color search that are of both theoretical and applied interest, such as for the design of human–computer interfaces.