The role of color in high-level vision

Traditional theories of object recognition have emphasized the role of shape information in high-level vision. However, the accumulating behavioral, neuroimaging and neuropsychological evidence indicates that the surface color of an object affects its recognition. In this article, we discuss the research that examines the conditions under which color influences the operations of high-level vision and the neural substrates that might mediate these operations. The relationship between object color and object recognition is summarized in the 'Shape+Surface' model of high-level vision.     

The indeterminacy of computation

Synthese - Do the dynamics of a physical system determine what function the system computes? Except in special cases, the answer is no: it is often indeterminate what function a given physical...     

Spatial location in color vision

Ross argues that the location problem for color-the problem of how it is represented as occupying a particular location in space-constitutes an objection to color subjectivism. There are two ways in which the location problem can be interpreted. First, it can be read as a why-question about the relation of visual experience to the environment represented: Why does visual experience represent a patch of color as located in this part of space rather than that? On this interpretation, the subjectivist can answer Ross's objection by appealing to the physical location of reflectance rather than color. Second, it can be read as a how-question about visual representation itself: How does visual experience put together the experience of a color with the experience of its being located in space? This version makes the location problem a problem about visual experience itself and renders the ontology of color irrelevant to its solution. The location problem is thus no more a problem for the color subjectivist than for the color realist.     

The measurement of factor indeterminacy

Results obtained by Guttman [1955] on the determinacy of common factors have been thought to have disturbing consequences for the common factor model. It is argued that factors must be thought of as unobservable, and uniquely defined but numerically indeterminate. It follows that Guttman's measure of indeterminacy is inconsistent with the foundations of the factor model in probability theory, and the traditional measures of factor indeterminacy used by earlier writers should be reinstated. These yield no disturbing conclusions about the model.     

Qualities of color vision in infancy.

Four-month-old infants attended differentially to eight equally bright, monochromatic spectral lights; that is, they discriminated colors. Moreover, infants showed the same pattern of differential attention regardless of experimental group (different groups of infants saw different subsets of all possible pairings of colors) or experimental method (paired comparisons or single stimulus). In general, the differential attention of infants to colors parallels the ratings of the pleasantness of those same colors by adults. Finally, infants looked significantly longer at color category centers than at color category boundaries. These results suggest that looking at this early stage of infancy can better be understood in terms of preference rather than in terms of stimulus categorization. The results also provide further evidence for a neural excitation model of early visual attention.     

Computation of cone contrasts for color vision research

Cone-contrast coordinates have proved useful for representing transient test stimuli used in color vision experiments. These representations automatically take into account the spectral absorption of cones and any Weberian adaptation to steady fields of light. Under these conditions, they also can be interpreted as being an approximation to the incremental cone response. A detailed methodology is presented for making appropriate measurements and calculations of cons contrasts for any light source, especially color monitors.     

Quantum metaphysical indeterminacy

Philosophical Studies - On a wide variety of presently live interpretations, quantum mechanics violates the classical supposition of ‘value definiteness’, according to which the...     

Schizophrenia and indeterminacy: The problem of validity

The paper attempts to account for the confusion over the validity of the concept of schizophrenia in terms of two closely related aspects of conceptual indeterminacy. Firstly, it is identified on the basis of a breakdown in intelligibility, but what constitutes such a breakdown is indeterminate. Secondly, the concept sits between the categories of natural disease or illness on the one hand, and character trait or moral failing or gift on the other. This entails an indeterminacy in attempting to define the role that physiological explanation could have. Light may be thrown on the concept by exploring a distinction between a life story in which the schizophrenic condition emerges as the conclusion of the story and a causal process in which the condition is the end result or final consequence.     

色觉疲劳、语义饱和对颜色范畴知觉的即时影响

颜色范畴知觉究竟是语言的还是知觉的, 或两者交互引起的认知冲突所致仍在探究与争议之中。本研究采用色觉疲劳和语义饱和操作分别独立地改变知觉或语义加工, 观察二者对颜色范畴知觉效应的即时影响, 以期探究语言和知觉对颜色范畴的作用。结果显示, 色觉疲劳操作导致范畴间颜色辨别反应时减少, 颜色范畴效应增强。语义饱和操作导致被饱和颜色词所属的范畴内颜色辨别反应时增加, 颜色范畴效应增强。说明单独改变知觉或语义加工能力均能影响CCP效应, 支持了语言标签对比模型, 即语言与知觉的交互作用引起颜色范畴知觉的观点。