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Campo DC | Valor | Idioma |
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dc.creator | BARBONI, Mirella Telles Salgueiro | - |
dc.creator | GOMES, Bruno Duarte | - |
dc.creator | SOUZA, Givago da Silva | - |
dc.creator | RODRIGUES, Anderson Raiol | - |
dc.creator | VENTURA, Dora Selma Fix | - |
dc.creator | SILVEIRA, Luiz Carlos de Lima | - |
dc.date.accessioned | 2014-08-11T18:01:02Z | - |
dc.date.available | 2014-08-11T18:01:02Z | - |
dc.date.issued | 2013-02 | - |
dc.identifier.citation | BARBONI, M.T.S. et al. Chromatic spatial contrast sensitivity estimated by visual evoked cortical potential and psychophysics. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 46, n. 2, p. 154-163, fev. 2013. Disponível em: <http://www.scielo.br/pdf/bjmbr/v46n2/bjb2428.pdf>. Acesso em: 12 fev. 2014. <http://dx.doi.org/10.1590/1414-431X20122428>. | pt_BR |
dc.identifier.issn | 1414-431X | - |
dc.identifier.uri | http://repositorio.ufpa.br/jspui/handle/2011/5428 | - |
dc.description.abstract | The purpose of the present study was to measure contrast sensitivity to equiluminant gratings using steady-state visual evoked cortical potential (ssVECP) and psychophysics. Six healthy volunteers were evaluated with ssVECPs and psychophysics. The visual stimuli were red-green or blue-yellow horizontal sinusoidal gratings, 5° × 5°, 34.3 cd/m2 mean luminance, presented at 6 Hz. Eight spatial frequencies from 0.2 to 8 cpd were used, each presented at 8 contrast levels. Contrast threshold was obtained by extrapolating second harmonic amplitude values to zero. Psychophysical contrast thresholds were measured using stimuli at 6 Hz and static presentation. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. ssVECP and both psychophysical contrast sensitivity functions (CSFs) were low-pass functions for red-green gratings. For electrophysiology, the highest contrast sensitivity values were found at 0.4 cpd (1.95 ± 0.15). ssVECP CSF was similar to dynamic psychophysical CSF, while static CSF had higher values ranging from 0.4 to 6 cpd (P < 0.05, ANOVA). Blue-yellow chromatic functions showed no specific tuning shape; however, at high spatial frequencies the evoked potentials showed higher contrast sensitivity than the psychophysical methods (P < 0.05, ANOVA). Evoked potentials can be used reliably to evaluate chromatic red-green CSFs in agreement with psychophysical thresholds, mainly if the same temporal properties are applied to the stimulus. For blue-yellow CSF, correlation between electrophysiology and psychophysics was poor at high spatial frequency, possibly due to a greater effect of chromatic aberration on this kind of stimulus. | pt_BR |
dc.description.provenance | Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2014-07-24T15:50:18Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Artigo_ChromaticSpatialContrast.pdf: 620417 bytes, checksum: e55dcd78e579210a87c31b6dd9adeabf (MD5) | en |
dc.description.provenance | Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2014-08-11T18:01:02Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Artigo_ChromaticSpatialContrast.pdf: 620417 bytes, checksum: e55dcd78e579210a87c31b6dd9adeabf (MD5) | en |
dc.description.provenance | Made available in DSpace on 2014-08-11T18:01:02Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Artigo_ChromaticSpatialContrast.pdf: 620417 bytes, checksum: e55dcd78e579210a87c31b6dd9adeabf (MD5) Previous issue date: 2013-02 | en |
dc.language.iso | eng | pt_BR |
dc.rights | Acesso Aberto | - |
dc.subject | Sensibilidade ao contraste | pt_BR |
dc.subject | Visão de cores | pt_BR |
dc.subject | Visão espacial | pt_BR |
dc.subject | Psicofísica visual | pt_BR |
dc.subject | Testes de avaliação da visão de cores | - |
dc.subject | Limiares visual | - |
dc.title | Chromatic spatial contrast sensitivity estimated by visual evoked cortical potential and psychophysics | pt_BR |
dc.type | Artigo de Periódico | pt_BR |
Aparece nas coleções: | Artigos Científicos - NMT |
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