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1.
Three hundred unsophisticated Os judged the lightness of a gray, reflectance 44%, against a white, reflectance 83%. Half gave a numerical estimate calling the white 100. The remainder marked a 100 mm line labeled 100 at one end and zero at the other. Both distributions of estimates were skewed with a mode around 60. The linear estimates tended to avoid the middle of the line (p<.01).The numerical estimates tended to end in zero or five (p<.001). The two distributions were not quite reliably different, but the medians of subgroups of 10 Os drawn from the two distributions were reliably different (p<.05).  相似文献   

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Bob Hale 《Axiomathes》2010,20(4):399-422
How are philosophical questions about what kinds of things there are to be understood and how are they to be answered? This paper defends broadly Fregean answers to these questions. Ontological categories—such as object, property, and relation—are explained in terms of a prior logical categorization of expressions, as singular terms, predicates of varying degree and level, etc. Questions about what kinds of object, property, etc., there are are, on this approach, reduce to questions about truth and logical form: for example, the question whether there are numbers is the question whether there are true atomic statements in which expressions function as singular terms which, if they have reference at all, stand for numbers, and the question whether there are properties of a given type is a question about whether there are meaningful predicates of an appropriate degree and level. This approach is defended against the objection that it must be wrong because makes what there depend on us or our language. Some problems confronting the Fregean approach—including Frege’s notorious paradox of the concept horse—are addressed. It is argued that the approach results in a modest and sober deflationary understanding of ontological commitments.  相似文献   

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The term simultaneous lightness constancy describes the capacity of the visual system to perceive equal reflecting surfaces as having the same lightness despite lying in different illumination fields. In some cases, however, a lightness constancy failure occurs; that is, equal reflecting surfaces appear different in lightness when differently illuminated. An open question is whether the luminance profile of the illumination edges affects simultaneous lightness constancy even when the ratio invariance property of the illumination edges is preserved. To explore this issue, we ran two experiments by using bipartite illumination displays. Both the luminance profile of an illumination edge and the luminance ratio amplitude between the illumination fields were manipulated. Results revealed that the simultaneous lightness constancy increases when the luminance profile of the illumination edge is gradual (rather than sharp) and homogeneous (rather than inhomogeneous), whereas it decreases when the luminance ratio between the illumination fields is enlarged. The results are interpreted according to the layer decomposition schema, stating that the visual system splits the luminance into perceived lightness and apparent illumination components. We suggest that illumination edges having gradual and homogeneous luminance profiles facilitate the luminance decomposition process, whereas wide luminance ratios impede it.  相似文献   

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As has been observed by Wallach (1948), perceived lightness is proportional to the ratio between the luminances of adjacent regions in simple disk-annulus or bipartite scenes. This psychophysical finding resonates with neurophysiological evidence that retinal mechanisms of receptor adaptation and lateral inhibition transform the incoming illuminance array into local measures of luminance contrast. In many scenic configurations, however, the perceived lightness of a region is not proportional to its ratio with immediately adjacent regions. In a particularly striking example of this phenomenon, called White's illusion, the relationship between the perceived lightnesses of two gray regions is the opposite of what is predicted by local edge ratios or contrasts. This paper offers a new treatment of how local measures of luminance contrast can be selectively integrated to simulate lightness percepts in a wide range of image configurations. Our approach builds on a tradition of edge integration models (Horn, 1974; Land & McCann, 1971) and contrast/filling-in models (Cohen & Grossberg, 1984; Gerrits & Vendrik 1970; Grossberg & Mingolla, 1985a, 1985b). Our selective integration model (SIM) extends the explanatory power of previous models, allowing simulation of a number of phenomena, including White's effect, the Benary Cross, and shading and transparency effects reported by Adelson (1993), as well as aspects of motion, depth, haploscopic, and Gelb induced contrast effects. We also include an independently derived variant of a recent depthful version of White's illusion, showing that our model can inspire new stimuli.  相似文献   

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Many models of color constancy assume that the visual system estimates the scene illuminant and uses this estimate to determine an object's color appearance. A version of this illumination-estimation hypothesis, in which the illuminant estimate is associated with the explicitly perceived illuminant, was tested. Observers made appearance matches between two experimental chambers. Observers adjusted the illumination in one chamber to match that in the other and then adjusted a test patch in one chamber to match the surface lightness of a patch in the other. The illumination-estimation hypothesis, as formulated here, predicted that after both matches the luminances of the light reflected from the test patches would be identical. The data contradict this prediction. A second experiment showed that manipulating the immediate surround of a test patch can affect perceived lightness without affecting perceived illumination. This finding also falsifies the illumination-estimation hypothesis.  相似文献   

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In this article I explore the relationship between feelings of superiority, White privilege, White guilt, and a denied White racial identity and how these dynamics are enacted in therapy between White therapist and client. I discuss the concepts of White privilege, White guilt, color-blind racial ideology, and the invisibility of Whiteness and their importance in understanding problems in White identity development. Throughout this discussion I draw implications for clinical practice and training. I conclude by suggesting a process for identifying the dynamics of privilege and power in cross-cultural interactions through the use of self-reflection.  相似文献   

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The specific gray shades in a visual scene can be derived from relative luminance values only when an anchoring rule is followed. The double-anchoring theory I propose in this article, as a development of the anchoring theory of Gilchrist et al. (1999), assumes that any given region (a) belongs to one or more frameworks, created by Gestalt grouping principles, and (b) is independently anchored, within each framework, to both the highest luminance and the surround luminance. The region's final lightness is a weighted average of the values computed, relative to both anchors, in all frameworks. The new model accounts not only for all lightness illusions that are qualitatively explained by the anchoring theory but also for a number of additional effects, and it does so quantitatively, with the support of mathematical simulations.  相似文献   

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In this paper it is argued that the overwhelming majority of gamete donors are amongst those who treat decisions about bringing children into existence too lightly. The argument proceeds through the following stages.
1) People have a presumptive responsibility for rearing children who result from their gametes. 2) The responsibility people have to rear their offspring is a responsibility not merely to provide a minimum of care, but also to attend to the details of nurturing children and fostering their flourishing. 3) Gamete donors transfer their responsibilities for raising their genetic offspring to those who will raise it. 4) Responsibilities for rearing children are weighty ones. 5) Treating weighty responsibilities too lightly is morally wrong. 6) Gamete donors' decisions to transfer their responsibilities for rearing their offspring to others, almost always involves treating parental responsibilities too lightly. 7) Therefore, gamete donation is almost always morally wrong.  相似文献   

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Anchoring theory (Gilchrist et al, 1999 Psychological Review 106 795-834) predicts a wide range of lightness errors, including failures of constancy in multi-illumination scenes and a long list of well-known lightness illusions seen under homogeneous illumination. Lightness values are computed both locally and globally and then averaged together. Local values are computed within a given region of homogeneous illumination. Thus, for an object that extends through two different illumination levels, anchoring theory produces two values, one for the patch in brighter illumination and one for the patch in dimmer illumination. Observers can give matches for these patches separately, but they can also give a single match for the whole object. Anchoring theory in its current form is unable to predict these object matches. We report eight experiments in which we studied the relationship between patch matches and object matches. The results show that the object match represents a compromise between the match for the patch in the field of highest illumination and the patch in the largest field of illumination. These two principles are parallel to the rules found for anchoring lightness: highest luminance rule and area rule.  相似文献   

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Abstract— Visible surfaces in a natural environment often have multiple components of reflectance, including a diffuse component, by which light is scattered isotropically in all possible directions, and a specular component, by which light is reflected anisotropically within a limited range of directions. The research described in the present article was designed to investigate how these different components of reflectance influence the perception of lightness. Human observers were presented with shaded images of smoothly curved surfaces and asked to compare the relative lightness of different surface regions whose diffuse and specular components of luminance were independently manipulated. The results revealed that observers are able to discount the presence of specular highlights so that the relative lightness among different regions is determined almost entirely by the diffuse component of surface reflectance.  相似文献   

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选取88名大班儿童(43名女童和45名男童)及90名在校大学生(42名男生和48名女生)为实验被试,通过心理量表评分,探讨面部特征空间关系、肤色和亮度对儿童卡通面孔吸引力影响。结果显示:(1)幼儿与成人对卡通面孔最佳面部特征空间关系评价存在差异;(2)幼儿评价女童卡通面孔眼嘴间距离占面长24%时吸引力最优,两眼间距离占面宽41%时吸引力最优,但未达显著。成人评价女童卡通面孔也存在纵向“黄金比例(19%)”现象;(3)男童卡通面孔不存在最佳比例;(4)幼儿偏爱偏白肤色,而成人偏好白里透红;(5)受众性别与卡通形象性别均对肤色偏好有影响;(6)亮度高的儿童卡通面孔更具吸引力。结论:卡通面孔吸引力受面部特征空间关系、肤色与亮度等因素显著影响,卡通设计需针对不同年龄、性别受众来设定面部特征空间关系与肤色等要素。  相似文献   

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Changes of annulus luminance in traditional disk-and-annulus patterns can be perceived to be either reflectance or illuminance changes. In the present experiments, we examined the effect of varying annulus reflectance. In Experiment 1, we placed test and standard patch-and-surround patterns in identical Mondrian patchworks. Only the luminance of the test surround changed from trial to triaL., appearing as reflectance variation under constant illumination. Lightness matches were identical to brightness matches, as expected. In Experiment 2, we used only the patch and surround (no Mondrian). Instructions said that the illumination would change from trial to trial. Lightness and brightness-contrast data were identical; illumination gradients were indistinguishable from reflectance gradients. In Experiment 3, the patterns were the same, but the instructions said that the shade of gray of the test surround would change from trial to trial. Lightness matches were identical to brightness matches, again confirming the ambiguity of disk-and-annulus patterns.  相似文献   

17.
Changes of annulus luminance in traditional disk-and-annulus patterns are perceptually ambiguous; they could be either reflectance or illuminance changes. In more complicated patterns, apparent reflectances are less ambiguous, letting us place test and standard patchesjnpxsurrounds perceived to be different grays. Our subjects matched the apparent amounts of light coming from the patches (brightnesses), their apparent reflectances (lightnesses), or the brightness differences between the patches and their surrounds (brightness contrasts). The three criteria produced quantitatively different results. Brightness contrasts matched when the patch/surround luminance ratio of the test was approximately equal to that of the standard. Lightness matches were illumination invariant but were not exact reflectance matches; the different surrounda of test and standard produced a small illumination-invariant error. This constant error was negligible for increments, but, for decrements, it was approximately 1.5 Munsell value steps. Brightness matches covaried substantially with illuminance.  相似文献   

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A striking finding reported by Beck, Sutter, and Ivry (1987) was that, in textures composed of regions differentiated by the arrangement (checks and stripes) of two texture elements (light and dark squares), a large lightness difference between the squares could fail to yield segregation between the regions, whereas a smaller lightness difference could sometimes yield strong segregation. In the experiments reported here, we compared the segregation of striped and checked arrangements of light and dark squares into regions with the segregation of two randomly interspersed populations of light and dark squares into subpopuiations. Perceived lightnesses are the same for a given set of squares, whether they are arranged in regions or in intermixed populations. Perceived population segregation is approximately a single-valued function of the lightness differences of the squares, but perceived region segregation is not. The reason for the difference between population segregation and region segregation may be that region segregation is mediated by detectors’ having large oriented receptive fields (large bar detectors) that are sensitive to the fundamental spatial frequency and orientation of the texture region as defined by the arrangement of the squares (Beck et al., 1987; Sutter, Beck, & Graham, 1989). These detectors cannot be responsible for population segregation, because the light and dark squares are distributed randomly throughout these patterns and therefore do not define a consistent arrangement of any particular spatial frequency or orientation. The light and dark squares in the population patterns fall equally on excitatory and inhibitory regions of large bar detectors. A plausible explanation for population segregation is to suppose that the segregation is the result of similarity grouping of the light and dark squares.  相似文献   

19.
Background data, or life history measures, ask people to recall and report prior behavior and experiences. Although these measures have been found to be effective predictors of performance, little is known about the characteristics of items contributing to accurate reporting and good recall. Accordingly, 153 undergraduates were asked to work on a complex, computer-based ‘in-basket’ task. In working through this task, objective indices of their activities were obtained. After completing this task, subjects were asked to answer a set of background data items describing their behavior and experiences during task performance. Additionally, they were asked to return one week later and, again, answer the background data questions. Indices of accuracy and recall consistency were obtained for various item types. In accordance with the literature of autobiographical memory, it was found that people could consistency recall and accurately report general summaries of activities and their reactions to the task. More specific actions or behaviors that were not linked to goals were not accurately and consistently recalled. The implications of these findings for the development and application of background data measures are discussed.  相似文献   

20.
Effects of Defendant Background and Remorse on Sentencing Judgments   总被引:2,自引:0,他引:2  
Previous evidence that subject sentencing judgments are mediated by considerations of equity led to the hypothesis that defendant remorse and an impoverished defendant background would each reduce subject sentencing judgments. Results from 48 male and 48 female student subjects showed that remorse had the predicted effect ( p < .02) but background did not. Regardless of the initial manipulation, sentences shifted significantly toward leniency ( p < .02) after subjects had engaged in group discussion. The effect for remorse is consistent with the contention that the equity principle extends to psychological factors, while the leniency shift raises the possibility that jury deliberations tend to favor the defendant.  相似文献   

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