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	Provedor de dados BJMBR (4) Autor Silveira,L.C.L. (4) Ventura,D.F. (3) Gomes,B.D. (2) Rodrigues,A.R. (2) Souza,G.S. (2) Barboni,M.T.S. (1) Braga,A.M. (1) Castro,A.J.O. (1) Côrtes,M.I.T. (1) Damin,E.T.B. (1) Fitzgerald,M.E.C. (1) Gomes,F.L. (1) Mello,G.A. (1) Moura,A.L.A. (1) Pinheiro,M.C.N. (1) Rodrigues,P.S.S. (1) Saito,C.A. (1) Schakelford,H.B. (1) Silveira,A.T. (1) Souza,C.R.B. (1) Mais... Palavra-chave Color vision (2) Contrast sensitivity (2) Spatial vision (2) Amazon riverside communities (1) Contrast vision (1) Magnocellular pathway (1) Mercury exposure (1) Mercury toxicity (1) Multifocal visual evoked cortical potential (1) New World primates (1) Parallel processing (1) Parvocellular pathway (1) Psychophysics (1) Signal-to-noise analysis (1) Steady-state visual evoked cortical potential (1) Visual dysfunction (1) Visual electrophysiology (1) Visual system (1) Visual thresholds (1) Mais... Tipo do documento Info:eu-repo/semantics/article (4) Ano 2013 (1) 2012 (1) 2007 (1) 2005 (1) País Brazil (4) Idioma Inglês (4)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 4 Primeira ... 1 ... Última Density, proportion, and dendritic coverage of retinal ganglion cells of the common marmoset (Callithrix jacchus jacchus) BJMBR Gomes,F.L.; Silveira,L.C.L.; Saito,C.A.; Yamada,E.S.. We performed a quantitative analysis of M and P cell mosaics of the common-marmoset retina. Ganglion cells were labeled retrogradely from optic nerve deposits of Biocytin. The labeling was visualized using horseradish peroxidase (HRP) histochemistry and 3-3'diaminobenzidine as chromogen. M and P cells were morphologically similar to those found in Old- and New-World primates. Measurements were performed on well-stained cells from 4 retinas of different animals. We analyzed separate mosaics for inner and outer M and P cells at increasing distances from the fovea (2.5-9 mm of eccentricity) to estimate cell density, proportion, and dendritic coverage. M cell density decreased towards the retinal periphery in all quadrants. M cell density was higher in the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Magnocellular pathway; Parvocellular pathway; Visual system; Parallel processing; New World primates. Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000600014 Chromatic spatial contrast sensitivity estimated by visual evoked cortical potential and psychophysics BJMBR Barboni,M.T.S.; Gomes,B.D.; Souza,G.S.; Rodrigues,A.R.; Ventura,D.F.; Silveira,L.C.L.. 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... Tipo: Info:eu-repo/semantics/article Palavras-chave: Contrast sensitivity; Color vision; Steady-state visual evoked cortical potential; Visual thresholds; Spatial vision; Psychophysics. Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000200154 Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury BJMBR Rodrigues,A.R.; Souza,C.R.B.; Braga,A.M.; Rodrigues,P.S.S.; Silveira,A.T.; Damin,E.T.B.; Côrtes,M.I.T.; Castro,A.J.O.; Mello,G.A.; Vieira,J.L.F.; Pinheiro,M.C.N.; Ventura,D.F.; Silveira,L.C.L.. We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55%) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green... Tipo: Info:eu-repo/semantics/article Palavras-chave: Mercury exposure; Mercury toxicity; Contrast sensitivity; Color vision; Visual dysfunction; Amazon riverside communities. Ano: 2007 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000300018 Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation BJMBR Souza,G.S.; Schakelford,H.B.; Moura,A.L.A.; Gomes,B.D.; Ventura,D.F.; Fitzgerald,M.E.C.; Silveira,L.C.L.. This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean luminance, was controlled by a binary m-sequence in the time domain. The signal-to-noise ratio was generally larger in the pattern reversal than in the pattern pulse mode. The number of reliable responses was similar in the central sectors for the two stimulation... Tipo: Info:eu-repo/semantics/article Palavras-chave: Multifocal visual evoked cortical potential; Contrast vision; Spatial vision; Signal-to-noise analysis; Visual electrophysiology. Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001000011 Registros recuperados: 4 Primeira ... 1 ... Última

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