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Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects

The brighter portions of a shaded complex object are in principle more informative about its lightness and are preferentially fixated during lightness judgments. In this study, we investigate whether preventing this strategy also has measurable detrimental effects on performance. Observers were pres...

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Detalles Bibliográficos
Autores principales: Toscani, Matteo, Valsecchi, Matteo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SAGE Publications 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6876175/
https://www.ncbi.nlm.nih.gov/pubmed/31803462
http://dx.doi.org/10.1177/2041669519884335
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author Toscani, Matteo
Valsecchi, Matteo
author_facet Toscani, Matteo
Valsecchi, Matteo
author_sort Toscani, Matteo
collection PubMed
description The brighter portions of a shaded complex object are in principle more informative about its lightness and are preferentially fixated during lightness judgments. In this study, we investigate whether preventing this strategy also has measurable detrimental effects on performance. Observers were presented with a reference and a comparison three-dimensional rendered object and had to choose which one was “painted with a lighter gray.” The comparison was rendered with different diffuse reflectance values. We compared precision between three different conditions: full image, 20% of the lightest pixels removed, or 20% of the darkest pixels removed. Removing the bright pixels maximally impaired performance. The results confirm that the strategy of relying on the brightest areas of a complex object in order to estimate lightness is functionally optimal, yielding more precise representations.
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spelling pubmed-68761752019-12-04 Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects Toscani, Matteo Valsecchi, Matteo Iperception Short Report The brighter portions of a shaded complex object are in principle more informative about its lightness and are preferentially fixated during lightness judgments. In this study, we investigate whether preventing this strategy also has measurable detrimental effects on performance. Observers were presented with a reference and a comparison three-dimensional rendered object and had to choose which one was “painted with a lighter gray.” The comparison was rendered with different diffuse reflectance values. We compared precision between three different conditions: full image, 20% of the lightest pixels removed, or 20% of the darkest pixels removed. Removing the bright pixels maximally impaired performance. The results confirm that the strategy of relying on the brightest areas of a complex object in order to estimate lightness is functionally optimal, yielding more precise representations. SAGE Publications 2019-11-22 /pmc/articles/PMC6876175/ /pubmed/31803462 http://dx.doi.org/10.1177/2041669519884335 Text en © The Author(s) 2019 http://creativecommons.org/licenses/by/4.0/ Creative Commons CC BY: This article is distributed under the terms of the Creative Commons Attribution 4.0 License (http://www.creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
spellingShingle Short Report
Toscani, Matteo
Valsecchi, Matteo
Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects
title Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects
title_full Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects
title_fullStr Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects
title_full_unstemmed Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects
title_short Lightness Discrimination Depends More on Bright Rather Than Shaded Regions of Three-Dimensional Objects
title_sort lightness discrimination depends more on bright rather than shaded regions of three-dimensional objects
topic Short Report
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6876175/
https://www.ncbi.nlm.nih.gov/pubmed/31803462
http://dx.doi.org/10.1177/2041669519884335
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