Color opponency in synaesthetic experiences

Grapheme-color synaesthesia is a rare condition in which perception of a letter or a digit is associated with concurrent perception of a color. Synaesthetes report that these color experiences are vivid and realistic. We used a Stroop task to show that synaesthetically induced color, like real color, is processed in color-opponent channels (red-green or blue-yellow). Synaesthetic color produced maximal interference with the perception and naming of the real color of a grapheme if the real color was opponent to the synaesthetic color. Interference was reduced considerably if the synaesthetic and real colors engaged different color channels (e.g., synaesthetic blue and real red). No dependence on color opponency was found for semantic conflicts between shape and color (e.g., a blue lemon). Thus, the neural representation of synaesthetic colors closely resembles that of real colors. This suggests involvement of early stages of visual processing in color synaesthesia and explains the vivid and realistic nature of synaesthetic experiences.     

Color diagnosticity in object recognition.

Does color influence object recognition? In the present study, the degree to which an object was associated with a specific color was referred to as color diagnosticity. Using a feature listing and typicality measure, objects were identified as either high in color diagnosticity or low in color diagnosticity. According to the color diagnosticity hypothesis, color should more strongly influence the recognition of high color diagnostic (HCD) objects (e.g., a banana) than the recognition of low color diagnostic (LCD) objects (e.g., a lamp). This prediction was supported by results from classification, naming, and verification experiments, in which subjects were faster to identify color versions of HCD objects than they were to identify achromatic versions and incongruent color versions. In contrast, subjects were no faster to identify color versions of LCD objects than they were to identify achromatic and incongruent color versions. Moreover, when shape information was degraded but color information preserved, subjects were less impaired in their recognition of degraded HCD objects than of degraded LCD objects, relative to their nondegraded versions. Collectively, these results suggest that color plays a role in the recognition of HCD objects.     

Color diagnosticity in object recognition

Does color influence object recognition? In the present study, the degree to which an object was associated with a specific color was referred to ascolor diagnosticity. Using a feature listing and typicality measure, objects were identified as either high in color diagnosticity or low in color diagnosticity. According to the color diagnosticity hypothesis, color should more strongly influence the recognition of high color diagnostic (HCD) objects (e.g., a banana) than the recognition of low color diagnostic (LCD) objects (e.g., a lamp). This prediction was supported by results from classification, naming, and verification experiments, in which subjects were faster to identify color versions of HCD objects than they were to identify achromatic versions and incongruent color versions. In contrast, subjects were no faster to identify color versions of LCD objects than they were to identify achromatic and incongruent color versions. Moreover, when shape information was degraded but color information preserved, subjects were less impaired in their recognition of degraded HCD objects than of degraded LCD objects, relative to their nondegraded versions. Collectively, these results suggest that color plays a role in the recognition of HCD objects.     

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.     

Test of a convergence model for color transparency perception

Models of color transparency suggest that a region in which colors of surfaces converge in color space will appear transparent. The convergence is described by a transparency parameter alpha and a target of convergence. To test such models psychophysically, observers were presented a display with four colored areas. The colors of three of the areas were chosen in advance by the experimenter. The task of the observer was to choose the color of the fourth area to make a central region appear transparent. Settings for the fourth color were collected for a total of twenty-four color combinations chosen from three planes in color space. Observers' settings agreed well with the model, which predicts that choices for the fourth color lie along a line segment in color space that is parameterized by alpha. The results suggest further that color discriminability and color opponency also influence transparency judgment.     

Likelihood of attending to the color word modulates Stroop interference

Three experiments investigated whether the Stroop color-naming effect is modulated by the likelihood of a color word capturing visual attention. In Experiment 1, a bar or a neutral word was presented at fixation as a color carrier, along with a color word randomly appearing in either an achromatic color (white in the main experiment, gray in a follow-up) or purple. Reduction of the Stroop effect (known as Stroop dilution) occurred when the color word was achromatic but not (or to a lesser extent) when it was in purple. In Experiment 2, the color of the color word remained constant throughout trial blocks, and Stroop dilution was equally evident when the word was always in purple and when it was always in white. In Experiment 3, a color bar was presented as the color carrier with both a color word and a neutral word. In this case, the Stroop effect was larger when the color word appeared in purple, and smaller when the neutral word appeared in purple, than when neither word did. These results imply that the extent to which processing of a color word occurs is determined by the likelihood of the word capturing attention.     

人类颜色视觉的计算理论

该文有机地结合了计算视觉理论和生态学视觉理论,指出颜色信息处理的根本任务是检测环境中的光不变量。在此基础上,作者提出了颜色视觉的计算理论以及计算理论本身的生物学标准。初级视觉计算是典型的不适定问题,动物的视觉系统则利用视环境中存在的条件将该不适定问题转化为定解问题。本文引入颜色视觉计算的免要条件,客观性约束,以及颜色认知的神经表象,证明了上述约束下颜色算法的存在性。本文给出了构造颜色知觉的基本假设。同时,该文还讨论了与上述问题密切相关的几个基本问题:神经表象的完备性,主观色觉的客观性,明度知觉和颜色知觉的统一,人类主观色觉的实现方式。     

颜色词与颜色认知的关系

颜色词作为一个特殊词类,是探讨语言与认知关系的重要途径。文章综述了颜色知觉和颜色词分类等领域的研究,重点介绍了有关颜色词与认知的两种理论：颜色词的普遍进化理论和语言关联性假设,前者认为颜色词与颜色认知是相对独立的,后者认为语言与认知相互影响。文章综述了与这两种理论有关的一些最新研究进展,并对该领域研究提出一些新的研究思路,如研究颜色词的联想意义、颜色词与民族心理、复合颜色词的加工及对认知的影响、通感现象、颜色词的概念组织等。     

右视野颜色范畴知觉是长期习得语言范畴还是即时分类颜色的结果?

本研究探讨了右视野颜色范畴知觉是由长期习得语言范畴还是即时分类颜色引起的。实验1让被试先将深绿、浅绿、浅蓝和深蓝四种颜色分为四种范畴,再接受视觉搜索任务。结果发现,视觉搜索任务中出现了与颜色分类相应的右视野颜色范畴知觉,且这一效应在任务的早段就表现出来,提示右视野颜色范畴知觉并非由分类颜色所引起。实验2让被试将四种渐进的蓝色分为两种范畴,并在之前与后接受视觉搜索任务。结果表明,分类后的视觉搜索中并未出现右视野颜色范畴知觉。先前研究表明,习得语言范畴使四种颜色为两种范畴后,颜色辨别会出现右视野范畴效应。因此,这一结果提示右视野颜色范畴知觉并非由分类颜色,而是由习得语言范畴所引起的。总体上,本研究提示右视野颜色范畴知觉是由长期习得语言范畴,而非即时分类颜色引起的,进一步揭示了语言与颜色知觉的关系。     

基于计算机仿真的颜色认知实验方法研究

近年来计算机仿真的实验研究方法逐渐成为颜色认知研究的主流方法,该方法克服了传统方法的诸多缺陷。本研究在现有技术的基础上构建了颜色研究仿真系统,并改进了CIE规定的有关CRT显示器颜色标定的方法。笔者通过颜色匹配实验考察了人对CRT显示器上仿真照明体颜色外观的辨别精度,结果表明上述颜色仿真系统在颜色认知实验中具有良好的适用性,并发现被试在计算机模拟颜色刺激的条件下,可进行精确的颜色匹配;不同照明条件下的色差有所不同。这些结果也为建立颜色认知模型提供了人的基准匹配数据。     

Influence of color word availability on the Stroop color-naming effect

Three experiments tested whether the Stroop color-naming effect is a consequence of word recognition's being automatic or of the color word's capturing visual attention. In Experiment 1, a color bar was presented at fixation as the color carrier, with color and neutral words presented in locations above or below the color bar; Experiment 2 was similar, except that the color carrier could occur in one of the peripheral locations and the color word at fixation. The Stroop effect increased as display duration increased, and the Stroop dilution effect (a reduced Stroop effect when a neutral word is also present) was an approximately constant proportion of the Stroop effect at all display durations, regardless of whether the color bar or color word was at fixation. In Experiment 3, the interval between the onsets of the to-be-named color and the color word was manipulated. The Stroop effect decreased with increasing delay of the color word onset, but the absolute amount of Stroop dilution produced by the neutral word increased. This study's results imply that an attention shift from the color carrier to the color word is an important factor modulating the size of the Stroop effect.     

A demonstration of direct access to colored stimuli following cueing by color

To test whether cueing by color can affect orienting without first computing the location of the cued color, the impact of reorienting on the validity effect was examined. In Experiment 1 subjects were asked to detect a black dot target presented at random on either of two colored forms. The forms started being presented 750 ms before the onset of a central cue (either an arrow or a colored square). In some proportion of the trials the colors switched locations 150 ms after cue onset, simultaneously with target onset. The color switch was not found to retard responses following a color cue more than following a location cue. Furthermore, it did not reduce the validity effect of the color cue: Though the validity effect of the location cue was quite larger than the validity effect of the color cue, both effects were additive with the presence/absence of a color switch. In Experiment 2, subjects were rather asked to detect a change in shape of one of the colored forms. In this case, color switch was found to affect performance even less following a color cue. The fact that across experiments, color switch did not retard neither responding nor orienting selectively in the color cue condition, indicates that when attention is set to a certain color, reorienting to a new object following color switch does not require re-computing the address of the cued color. That finding is argued to embarrass a strong space-based view of visual attention.     

The relation between children's conceptual functioning with color and color term acquisition

Young children experience considerable difficulty in learning their first few color terms. One explanation for this difficulty is that initially they lack a conceptual representation of color sufficiently abstract to support word meaning. This hypothesis, that prior to learning color terms children do not represent color as an abstraction, was tested in two experiments using samples of 25- to 39-month-olds and 20- to 32-month-olds. Children's ability to conceptually represent color and their knowledge of color terms were assessed, and a strong association was found between the ability to make inferences based on color and the comprehension of color words. Children who did not comprehend color terms were unsuccessful at a conceptual task that required them to represent color as a property independent of the particular objects that displayed it. The results suggest that the initial absence of an abstract representation of color contributes to the difficulty that young children encounter when first learning color words.     

The reverse Stroop effect

In classic Stroop interference, manual or oral identification of sensory colors presented as incongruent color words is delayed relative to simple color naming. In the experiment reported here, this effect was shown to all but disappear when the response was simply to point to a matching patch of color. Conversely, strong reverse Stroop interference occurred with the pointing task. That is, when the sensory color of a color word was incongruent with that word, responses to color words were delayed by an average of 69 msec relative to a word presented in gray. Thus, incongruently colored words interfere strongly with pointing to a color patch named by the words, but little interference from incongruent color words is found when the goal is to match the color of the word. These results suggest that Stroop effects arise from response compatibility of irrelevant information rather than automatic processing or habit strength.     

On the development of color naming in young children: data and theory

Among the semantics of different common attributes of the environment, consistent and correct color naming seems to develop paradoxically late in children, for even young infants discriminate and categorize colors well, color is a salient feature of the child's world, and children are aware of color as a separate domain, know color terms, and respond to color questions with color names. Several specific anomalies characterize early linguistic development in this domain: Errors in beginning color naming are perseverative or random, there seems to be a minimum age for correct and consistent color naming, developmental rate shows wide individual differences, and acquisition among girls is generally faster than among boys. This essay reviews data that support these observations, and evaluates three traditional explanations for them--including the perceptual salience of color for children, experience and learning in the child, and cognitive development--against a fourth new possibility. It is hypothesized that appropriate color naming may depend on the maturation and integration of specific cortical neurological structures; among several interpretations, the neurological one accounts best for diverse characteristics of early color naming.     

The interaction of synesthetic and print color and its relation to visual imagery

Synesthetic color induced by graphemes is well understood to be an automatic perceptual phenomenon paralleling print color in some ways, but also differing in others. We addressed this juxtaposition by asking how synesthetes are affected by synesthetic and print colors that are the same. We tested two groups of grapheme–color synesthetes using a basic color-priming method in which a grapheme prime was presented, followed by a color patch (probe), the color of which was to be named as quickly and accurately as possible. The primes induced either no color, print color only, synesthetic color only, or both forms of color (e.g., a letter “A” printed in red that also triggered synesthetic red). As expected, responses to name the probe color were faster if it was congruent with the prime color than if it was incongruent. The new finding (Exp. 1) was that a prime that induced the same print and synesthetic colors led to substantially larger priming effects than did either type of color individually, an effect that could not be attributed to semantic priming (Exp. 2). In addition, the synesthesia effects correlated with a standard measure of visual imagery. These findings are discussed as being consistent with the hypothesis that print and synesthetic color converge on similar color mechanisms.     

Color, consciousness, and the isomorphism constraint

The relations among consciousness, brain behavior, and scientific explanation are explored in the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke's "inverted spectrum argument" about the undetectability of color transformations. A symmetry analysis of color space shows that the literal interpretation of this argument--reversing the experience of a rainbow--would not work. Three other color to color transformations might work, however, depending on the relevance of certain color categories. The approach is then generalized to examine behavioral detection of arbitrary differences in color experiences, leading to the formulation of a principled distinction, called the "isomorphism constraint," between what can and cannot be determined about the nature of color experience by objective behavioral means. Finally, the prospects for achieving a biologically based explanation of color experience below the level of isomorphism are considered in light of the limitations of behavioral methods. Within-subject designs using biological interventions hold the greatest promise for scientific progress on consciousness, but objective knowledge of another person's experience appears impossible. The implications of these arguments for functionalism are discussed.     

Qualia Compression

Color qualia inversion scenarios have played a key role in various philosophical debates. Most notably perhaps, they have figured in skeptical arguments for the fundamental unknowability of other persons’ color experiences. For these arguments to succeed, it must be assumed that a person's having inverted color qualia may go forever unnoticed. This assumption is now generally deemed to be implausible. The present paper defines a variant of color qualia inversion—termed ‘‘color qualia compression’’—and argues that the possibility of undetectable color qualia compression is immune to the objections that have been levelled against color qualia inversion arguments, and that color qualia compression scenarios support full‐blown skepticism regarding other people's color experiences.     

A conjoint grassmann structure for testing the additivity of binocular color mixtures

A measurement structure for binocular color mixtures is developed, based on the principles that explain monocular matches of additive mixtures of color stimuli. Binocular color mixtures are created by presenting different stimuli to two eyes, such that they fuse and result in a single impression of color. The measurement structure makes it possible to compare binocular color mixtures with physical mixtures of color stimuli. The two types of mixture are characterized as compatible, if the binocular mixture creates a color, which is identical to the vectorial sum of the colors of the respective monocular components. The axioms of the measurement structure are experimental question, suitable for testing the addivity of binocular color mixtures.     

短期习得的语言范畴使成人大脑右半球颜色范畴知觉转为左半球颜色范畴知觉

本研究探讨了色词与颜色重组训练能否让被试习得与真实情境相似的色词与颜色范畴联结, 并引起相应的偏侧化颜色范畴知觉, 从而进一步揭示语言编码对颜色范畴知觉的影响。采用六种蓝色作为材料。B1与B2为先前研究的两种蓝色。B11和B12, B21和B22分别为使B1, B2变浅和变深所得, 四者是连续的蓝色。训练被试分别用“duān”和“kěn”命名B1和B2。由于被试可能习得色词与颜色范畴的联结, 因此B12与B21为可能变范畴间颜色, B11和B12, B21和B22为可能变范畴内颜色。训练前后分别让被试完成一个视觉搜索测验。结果发现：前测中可能变范畴间颜色的辨别优于可能变范畴内颜色, 且在左视野呈现时更显著; 后测中可能变范畴间颜色的辨别同样优于可能变范畴内颜色, 但在右视野呈现时更显著。这提示：(1)人们在知觉同一语言范畴的不同颜色时可能会区分深浅范畴, 并因此引发右半球颜色范畴知觉; (2)短期习得的语言范畴能引起偏左半球颜色范畴知觉, 且使右半球颜色范畴知觉转为左半球颜色范畴知觉; (3)被试在训练中习得了色词与颜色范畴的联结; (4)范畴学习可以在仅学习一个样例的条件下自动发生。