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	Provedor de dados BJMBR (2) Autor Nogueira,R.M.T.B.L. (2) Santos,N.A. (2) Simas,M.L.B. (2) Oliveira,A.B. (1) Palavra-chave Contrast sensitivity (2) Forced-choice method (2) Angular frequency (1) Human aging (1) Radial frequency (1) Spatial frequency (1) Visual form processing (1) Mais... Tipo do documento Info:eu-repo/semantics/other (2) Ano 2006 (1) 2004 (1) País Brazil (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última Comparison of angular frequency contrast sensitivity in young and older adults BJMBR Santos,N.A.; Simas,M.L.B.; Nogueira,R.M.T.B.L.. The aim of the present study was to measure contrast sensitivity curves for angular frequencies in the range between 2 and 96 cycles/360º in older human adult volunteers and to compare these measurements with the more usual contrast sensitivity functions for sine-wave gratings. All subjects were free of identifiable ocular disease and had normal acuity. We measured the contrast thresholds for young adults (N = 6; age range, 20-26 years) and older adults (N = 6; age range, 60-67 years) using the psychophysical forced-choice method. In this paradigm the volunteers had to choose the stimulus containing a test frequency at low contrast (e.g., either a sine-wave grating or an angular frequency stimulus), or another neutral stimulus at mean luminance (without... Tipo: Info:eu-repo/semantics/other Palavras-chave: Human aging; Spatial frequency; Angular frequency; Contrast sensitivity; Forced-choice method. Ano: 2004 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000300014 Mesopic radial frequency contrast sensitivity function for young and older adults BJMBR Santos,N.A.; Oliveira,A.B.; Nogueira,R.M.T.B.L.; Simas,M.L.B.. The objective of the present study was to determine contrast sensitivity curves of concentric circular patterns with radial frequencies of 0.25, 0.5, 1.0, 2.0, and 4.0 cycles per degree in young and older adult volunteers. These parameters were also compared with sensitivity contrasts for sine-wave gratings. All participants had normal acuity vision and were free of identifiable ocular illness. Contrast sensitivity was measured in 6 young adults aged 19 to 23 years and 6 older adults aged 60 to 69 years using the psychophysical forced-choice method. In this paradigm the volunteers had to decide which of two stimuli contained the above radial frequencies at low contrast levels. The other neutral stimulus was gray with homogeneous luminance. We detected a... Tipo: Info:eu-repo/semantics/other Palavras-chave: Visual form processing; Radial frequency; Contrast sensitivity; Forced-choice method. Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000600012 Registros recuperados: 2 Primeira ... 1 ... Última

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