A power law study of the edge influence on the perceived filling-in brightness magnitude

Detalhes bibliográficos
Autor(a) principal: Costa,Marcelo Fernandes
Data de Publicação: 2019
Outros Autores: Gaddi,Carlo Martins
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Psicologia (Universidade Federal do Rio Grande do Sul. Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-79722019000105103
Resumo: Abstract: Background: Edge plays a special role in spatial perception and as well as in determining the brightness of a surface within borders. The aim of our study was to measure threshold brightness in different levels of edges thickness. Methods: Steven's power law for circles modulating in luminance was estimated for 30 subjects (mean age 24 years, SD 3.3, 13 female). Stimuli were presented on the iMac display using the 11-bit graphic board and consisted of two circles of 3° of visual angle, separated by 10°. We tested 7 levels of Michelson contrast: 7, 8, 10, 15, 26, 50, and 100. Three edges filtering were tested (0.3, 0.8, and 1.5° of smoothing). The subjects' task was to judge the brightness of the edge filtered circle compared with the circle of the hard edge which was considered the modulus and received an arbitrary level of 50, representing the amount of brightness perception. In each trial, the same contrast level was presented in both circles. Five judgments were performed for each contrast level in edge filtering. Results: We found an increase in the power law exponent as the increase of the edge filtering (for sigma of 0.3 = 0.43, sigma of 0.8 = 0.73, and sigma 1.5 = 0.97). All power function fitting had high correlation coefficients (r2 = .94, r2 = .95, r2 = .97, respectively to sigma 0.3, 0.8, and 1.5) passing to the model's adhesion criteria. Conclusions: There was a progressive distortion on the figure brightness perception as increasing the edge filtering suggesting the control of edges on the polarity of the overall brightness. Also, perceived brightness was increasingly veridical with increased filtering, approaching 1:1 correspondence at 1.5 sigmas.
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spelling A power law study of the edge influence on the perceived filling-in brightness magnitudeBrightness perceptionBrightness magnitudeFilling-inEdge blurMagnitude estimationSpatial visionVisual psychophysicsAbstract: Background: Edge plays a special role in spatial perception and as well as in determining the brightness of a surface within borders. The aim of our study was to measure threshold brightness in different levels of edges thickness. Methods: Steven's power law for circles modulating in luminance was estimated for 30 subjects (mean age 24 years, SD 3.3, 13 female). Stimuli were presented on the iMac display using the 11-bit graphic board and consisted of two circles of 3° of visual angle, separated by 10°. We tested 7 levels of Michelson contrast: 7, 8, 10, 15, 26, 50, and 100. Three edges filtering were tested (0.3, 0.8, and 1.5° of smoothing). The subjects' task was to judge the brightness of the edge filtered circle compared with the circle of the hard edge which was considered the modulus and received an arbitrary level of 50, representing the amount of brightness perception. In each trial, the same contrast level was presented in both circles. Five judgments were performed for each contrast level in edge filtering. Results: We found an increase in the power law exponent as the increase of the edge filtering (for sigma of 0.3 = 0.43, sigma of 0.8 = 0.73, and sigma 1.5 = 0.97). All power function fitting had high correlation coefficients (r2 = .94, r2 = .95, r2 = .97, respectively to sigma 0.3, 0.8, and 1.5) passing to the model's adhesion criteria. Conclusions: There was a progressive distortion on the figure brightness perception as increasing the edge filtering suggesting the control of edges on the polarity of the overall brightness. Also, perceived brightness was increasingly veridical with increased filtering, approaching 1:1 correspondence at 1.5 sigmas.Curso de Pós-Graduação em Psicologia da Universidade Federal do Rio Grande do Sul2019-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-79722019000105103Psicologia: Reflexão e Crítica v.32 2019reponame:Psicologia (Universidade Federal do Rio Grande do Sul. Online)instname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGS10.1186/s41155-019-0130-7info:eu-repo/semantics/openAccessCosta,Marcelo FernandesGaddi,Carlo Martinseng2019-10-11T00:00:00Zoai:scielo:S0102-79722019000105103Revistahttps://www.scielo.br/j/prc/ONGhttps://old.scielo.br/oai/scielo-oai.phpprc@springeropen.com1678-71530102-7972opendoar:2019-10-11T00:00Psicologia (Universidade Federal do Rio Grande do Sul. Online) - Universidade Federal do Rio Grande do Sul (UFRGS)false
dc.title.none.fl_str_mv A power law study of the edge influence on the perceived filling-in brightness magnitude
title A power law study of the edge influence on the perceived filling-in brightness magnitude
spellingShingle A power law study of the edge influence on the perceived filling-in brightness magnitude
Costa,Marcelo Fernandes
Brightness perception
Brightness magnitude
Filling-in
Edge blur
Magnitude estimation
Spatial vision
Visual psychophysics
title_short A power law study of the edge influence on the perceived filling-in brightness magnitude
title_full A power law study of the edge influence on the perceived filling-in brightness magnitude
title_fullStr A power law study of the edge influence on the perceived filling-in brightness magnitude
title_full_unstemmed A power law study of the edge influence on the perceived filling-in brightness magnitude
title_sort A power law study of the edge influence on the perceived filling-in brightness magnitude
author Costa,Marcelo Fernandes
author_facet Costa,Marcelo Fernandes
Gaddi,Carlo Martins
author_role author
author2 Gaddi,Carlo Martins
author2_role author
dc.contributor.author.fl_str_mv Costa,Marcelo Fernandes
Gaddi,Carlo Martins
dc.subject.por.fl_str_mv Brightness perception
Brightness magnitude
Filling-in
Edge blur
Magnitude estimation
Spatial vision
Visual psychophysics
topic Brightness perception
Brightness magnitude
Filling-in
Edge blur
Magnitude estimation
Spatial vision
Visual psychophysics
description Abstract: Background: Edge plays a special role in spatial perception and as well as in determining the brightness of a surface within borders. The aim of our study was to measure threshold brightness in different levels of edges thickness. Methods: Steven's power law for circles modulating in luminance was estimated for 30 subjects (mean age 24 years, SD 3.3, 13 female). Stimuli were presented on the iMac display using the 11-bit graphic board and consisted of two circles of 3° of visual angle, separated by 10°. We tested 7 levels of Michelson contrast: 7, 8, 10, 15, 26, 50, and 100. Three edges filtering were tested (0.3, 0.8, and 1.5° of smoothing). The subjects' task was to judge the brightness of the edge filtered circle compared with the circle of the hard edge which was considered the modulus and received an arbitrary level of 50, representing the amount of brightness perception. In each trial, the same contrast level was presented in both circles. Five judgments were performed for each contrast level in edge filtering. Results: We found an increase in the power law exponent as the increase of the edge filtering (for sigma of 0.3 = 0.43, sigma of 0.8 = 0.73, and sigma 1.5 = 0.97). All power function fitting had high correlation coefficients (r2 = .94, r2 = .95, r2 = .97, respectively to sigma 0.3, 0.8, and 1.5) passing to the model's adhesion criteria. Conclusions: There was a progressive distortion on the figure brightness perception as increasing the edge filtering suggesting the control of edges on the polarity of the overall brightness. Also, perceived brightness was increasingly veridical with increased filtering, approaching 1:1 correspondence at 1.5 sigmas.
publishDate 2019
dc.date.none.fl_str_mv 2019-01-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-79722019000105103
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-79722019000105103
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1186/s41155-019-0130-7
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Curso de Pós-Graduação em Psicologia da Universidade Federal do Rio Grande do Sul
publisher.none.fl_str_mv Curso de Pós-Graduação em Psicologia da Universidade Federal do Rio Grande do Sul
dc.source.none.fl_str_mv Psicologia: Reflexão e Crítica v.32 2019
reponame:Psicologia (Universidade Federal do Rio Grande do Sul. Online)
instname:Universidade Federal do Rio Grande do Sul (UFRGS)
instacron:UFRGS
instname_str Universidade Federal do Rio Grande do Sul (UFRGS)
instacron_str UFRGS
institution UFRGS
reponame_str Psicologia (Universidade Federal do Rio Grande do Sul. Online)
collection Psicologia (Universidade Federal do Rio Grande do Sul. Online)
repository.name.fl_str_mv Psicologia (Universidade Federal do Rio Grande do Sul. Online) - Universidade Federal do Rio Grande do Sul (UFRGS)
repository.mail.fl_str_mv prc@springeropen.com
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