Monday, September 19, 2005
Factors influencing the origins of colour categories
Factors influencing the origins of colour categories
author: Tony Belpaeme
"In the evolution of language field a large body of work exists on mapping meaning to form, but little attention has been paid to the formation of meaning itself. Nevertheless, the debate on the nature of perceptually grounded concepts such as colour categories, and the impact of language on this, is central to cognitive science and linguistics. One point of view considers perceptual concepts as universal to all humans and argues that genetical determinism is responsible for this. Opponents adhere to a relativist account, which claims that concepts are learned and thus are ecologically and culturally specific.
Colour categorisation presents an opportunity for testing both perspectives. Berlin and Kay, in the late sixties, and Rosch, in the early seventies, provided convincing evidence for the universalist position through linguistic and memory experiments. Field data collected and interpreted over the last decades show a remarkable agreement between colour categories from different cultures. The relativist position, it is argued, is unable to account for these phenomena. Backed up by results from neuropsychology on the opponent character of colour perception the universalist stance has held strongly. Only recently, evidence from anthropology and close scrutiny of experimental results and the deductions based on these undermine the authority of the universalist model. The question arises if the relativist position can account for the strong facts brought forward by experimental data. This work investigates outstanding issues in the colour categorisation debate using computational modelling. It reports new insights on the plausibility of accounts of the origins of colour categories. Four simulations have been constructed, two in which colour categories are evolved through a process of natural selection, the other two in which colour categories are formed with a learning approach using environmental, ecological and cultural constraints. Both genetic evolution and learning are studied with and without the influence of language.
The basic entity of the simulations is the agent. The colour perception of an agent is modelled as a mapping from spectral measurements to an internal three-dimensional colour space. Categories are defined on this internal space as adaptive network. These adaptive networks consist of locally tuned receptors sensitive to small region in the space. The output of a network is the weighted sum of the reactions of all its locally tuned receptors. Categories can also be associated with words, needed for communicating colour meaning to other agents. The association between a category and a word is modelled by a scalar value representing the strength of the association."
author: Tony Belpaeme
"In the evolution of language field a large body of work exists on mapping meaning to form, but little attention has been paid to the formation of meaning itself. Nevertheless, the debate on the nature of perceptually grounded concepts such as colour categories, and the impact of language on this, is central to cognitive science and linguistics. One point of view considers perceptual concepts as universal to all humans and argues that genetical determinism is responsible for this. Opponents adhere to a relativist account, which claims that concepts are learned and thus are ecologically and culturally specific.
Colour categorisation presents an opportunity for testing both perspectives. Berlin and Kay, in the late sixties, and Rosch, in the early seventies, provided convincing evidence for the universalist position through linguistic and memory experiments. Field data collected and interpreted over the last decades show a remarkable agreement between colour categories from different cultures. The relativist position, it is argued, is unable to account for these phenomena. Backed up by results from neuropsychology on the opponent character of colour perception the universalist stance has held strongly. Only recently, evidence from anthropology and close scrutiny of experimental results and the deductions based on these undermine the authority of the universalist model. The question arises if the relativist position can account for the strong facts brought forward by experimental data. This work investigates outstanding issues in the colour categorisation debate using computational modelling. It reports new insights on the plausibility of accounts of the origins of colour categories. Four simulations have been constructed, two in which colour categories are evolved through a process of natural selection, the other two in which colour categories are formed with a learning approach using environmental, ecological and cultural constraints. Both genetic evolution and learning are studied with and without the influence of language.
The basic entity of the simulations is the agent. The colour perception of an agent is modelled as a mapping from spectral measurements to an internal three-dimensional colour space. Categories are defined on this internal space as adaptive network. These adaptive networks consist of locally tuned receptors sensitive to small region in the space. The output of a network is the weighted sum of the reactions of all its locally tuned receptors. Categories can also be associated with words, needed for communicating colour meaning to other agents. The association between a category and a word is modelled by a scalar value representing the strength of the association."
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