Artigo

Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways

The purpose of this study was to compare contrast sensitivity estimated from transient visual evoked potentials (VEPs) elicited by achromatic pattern-reversal and pattern-onset/offset modes. The stimuli were 2-cpd, achromatic horizontal gratings presented either as a 1 Hz pattern reversal or a 300 m...

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Autor principal: SOUZA, Givago da Silva
Outros Autores: GOMES, Bruno Duarte, LACERDA, Eliza Maria da Costa Brito, SAITO, Cézar Akiyoshi, SILVA FILHO, Manoel da, SILVEIRA, Luiz Carlos de Lima
Grau: Artigo
Idioma: eng
Publicado em: 2014
Assuntos:
Sensibilidade ao contraste
Visão espacial
Vias visuais paralelas
VEP
Acesso em linha: http://repositorio.ufpa.br/jspui/handle/2011/5182
id ir-2011-5182
recordtype dspace
spelling ir-2011-51822017-10-17T11:46:23Z Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways SOUZA, Givago da Silva GOMES, Bruno Duarte LACERDA, Eliza Maria da Costa Brito SAITO, Cézar Akiyoshi SILVA FILHO, Manoel da SILVEIRA, Luiz Carlos de Lima Sensibilidade ao contraste Visão espacial Vias visuais paralelas VEP The purpose of this study was to compare contrast sensitivity estimated from transient visual evoked potentials (VEPs) elicited by achromatic pattern-reversal and pattern-onset/offset modes. The stimuli were 2-cpd, achromatic horizontal gratings presented either as a 1 Hz pattern reversal or a 300 ms onset/700 ms offset stimulus. Contrast thresholds were estimated by linear regression to amplitudes of VEP components vs. the logarithm of the stimulus contrasts, and these regressions were extrapolated to the zero amplitude level. Contrast sensitivity was defined as the inverse of contrast threshold. For pattern reversal, the relation between the P100 amplitude and log of the stimulus contrast was best described by two separate linear regressions. For the N135 component, a single straight line was sufficient. In the case of pattern onset/offset for both the C1 and C2 components, single straight lines described their amplitude vs. log contrast relations in the medium-to-low contrast range. Some saturation was observed for C2 components. The contrast sensitivity estimated from the low-contrast limb of the P100, from the N135, and from the C2 were all similar but higher than those obtained from the high-contrast limb of the P100 and C1 data, which were also similar to each other. With 2 cpd stimuli, a mechanism possibly driven by the M pathway appeared to contribute to the P100 component at medium-to-low contrasts and to the N135 and C2 components at all contrast levels, whereas another mechanism, possibly driven by the P and M pathways, appeared to contribute to the P100 component at high contrast and C1 component at all contrast levels. 2014-06-30T12:59:55Z 2014-06-30T12:59:55Z 2013-12 Artigo de Periódico SOUZA, Givago S. et al. Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways. Psychology & Neuroscience, Rio de Janeiro, v. 6, n. 2, p. 191-198, jul./dez. 2013. Disponível em: <http://www.scielo.br/pdf/pn/v6n2/v6n2a07.pdf>. Acesso em: 12 fev. 2014. <http://dx.doi.org/10.3922/j.psns.2013.2.07>. 1983-3288 http://repositorio.ufpa.br/jspui/handle/2011/5182 eng Acesso Aberto application/pdf
institution Repositório Institucional - Universidade Federal do Pará
collection RI-UFPA
language eng
topic Sensibilidade ao contraste
Visão espacial
Vias visuais paralelas
VEP
spellingShingle Sensibilidade ao contraste
Visão espacial
Vias visuais paralelas
VEP
SOUZA, Givago da Silva
Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
topic_facet Sensibilidade ao contraste
Visão espacial
Vias visuais paralelas
VEP
description The purpose of this study was to compare contrast sensitivity estimated from transient visual evoked potentials (VEPs) elicited by achromatic pattern-reversal and pattern-onset/offset modes. The stimuli were 2-cpd, achromatic horizontal gratings presented either as a 1 Hz pattern reversal or a 300 ms onset/700 ms offset stimulus. Contrast thresholds were estimated by linear regression to amplitudes of VEP components vs. the logarithm of the stimulus contrasts, and these regressions were extrapolated to the zero amplitude level. Contrast sensitivity was defined as the inverse of contrast threshold. For pattern reversal, the relation between the P100 amplitude and log of the stimulus contrast was best described by two separate linear regressions. For the N135 component, a single straight line was sufficient. In the case of pattern onset/offset for both the C1 and C2 components, single straight lines described their amplitude vs. log contrast relations in the medium-to-low contrast range. Some saturation was observed for C2 components. The contrast sensitivity estimated from the low-contrast limb of the P100, from the N135, and from the C2 were all similar but higher than those obtained from the high-contrast limb of the P100 and C1 data, which were also similar to each other. With 2 cpd stimuli, a mechanism possibly driven by the M pathway appeared to contribute to the P100 component at medium-to-low contrasts and to the N135 and C2 components at all contrast levels, whereas another mechanism, possibly driven by the P and M pathways, appeared to contribute to the P100 component at high contrast and C1 component at all contrast levels.
format Artigo
author SOUZA, Givago da Silva
author2 GOMES, Bruno Duarte
LACERDA, Eliza Maria da Costa Brito
SAITO, Cézar Akiyoshi
SILVA FILHO, Manoel da
SILVEIRA, Luiz Carlos de Lima
author2Str GOMES, Bruno Duarte
LACERDA, Eliza Maria da Costa Brito
SAITO, Cézar Akiyoshi
SILVA FILHO, Manoel da
SILVEIRA, Luiz Carlos de Lima
title Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
title_short Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
title_full Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
title_fullStr Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
title_full_unstemmed Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
title_sort contrast sensitivity of pattern transient vep components: contribution from m and p pathways
publishDate 2014
url http://repositorio.ufpa.br/jspui/handle/2011/5182
_version_ 1832605121551269888
score 11.755432

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