Contrast sensitivity function of sine-wave gratings in children with acute malnutrition
The aim of this study was to determine the contrast sensitivity curves of sine-wave gratings with spatial frequencies of 0.25, 1.0, 2.0 and 8.0 cycles per degree (cpd) of visual angle in 16 female subjects aged 7 to 9 years old, eight well-nourished and eight with acute protein-energy malnutrition (PEM). All participants had normal visual acuity and were free of identifiable ocular illness. Contrast threshold was measured using a temporal two-alternative forced-choice psychophysical method, at a distance of 150 cm of the stimuli, binocularly, with mean luminance of 40.1 cd/m2. We detected a general decline in contrast sensitivity for children with acute malnutrition at all spatial frequencies compared to well-nourished children. The malnourished group needed in average 1.37 times more contrast to detect the stimulus in comparison with the well-nourished one. Differences between the groups were statistically significant at all spatial frequencies (p < .001). These results suggest that acute PEM changes the visual perception for sine-wave gratings.
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Pontificia Universidade Católica do Rio de Janeiro
2009
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oai:scielo:S1983-328820090001000032011-01-17Contrast sensitivity function of sine-wave gratings in children with acute malnutritionSantos,Natanael Antonio dosAlencar,Caroline Costa GomesDias,Yuri Henrique Nunes visual perception contrast sensitivity spatial frequency malnourished children psychophysical method The aim of this study was to determine the contrast sensitivity curves of sine-wave gratings with spatial frequencies of 0.25, 1.0, 2.0 and 8.0 cycles per degree (cpd) of visual angle in 16 female subjects aged 7 to 9 years old, eight well-nourished and eight with acute protein-energy malnutrition (PEM). All participants had normal visual acuity and were free of identifiable ocular illness. Contrast threshold was measured using a temporal two-alternative forced-choice psychophysical method, at a distance of 150 cm of the stimuli, binocularly, with mean luminance of 40.1 cd/m2. We detected a general decline in contrast sensitivity for children with acute malnutrition at all spatial frequencies compared to well-nourished children. The malnourished group needed in average 1.37 times more contrast to detect the stimulus in comparison with the well-nourished one. Differences between the groups were statistically significant at all spatial frequencies (p < .001). These results suggest that acute PEM changes the visual perception for sine-wave gratings.info:eu-repo/semantics/openAccessPontificia Universidade Católica do Rio de JaneiroUniversidade de BrasíliaUniversidade de São PauloPsychology & Neuroscience v.2 n.1 20092009-06-01info:eu-repo/semantics/articletext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1983-32882009000100003en10.3922/j.psns.2009.1.03 |
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Santos,Natanael Antonio dos Alencar,Caroline Costa Gomes Dias,Yuri Henrique Nunes |
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Santos,Natanael Antonio dos Alencar,Caroline Costa Gomes Dias,Yuri Henrique Nunes Contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
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Santos,Natanael Antonio dos Alencar,Caroline Costa Gomes Dias,Yuri Henrique Nunes |
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Santos,Natanael Antonio dos |
title |
Contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
title_short |
Contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
title_full |
Contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
title_fullStr |
Contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
title_full_unstemmed |
Contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
title_sort |
contrast sensitivity function of sine-wave gratings in children with acute malnutrition |
description |
The aim of this study was to determine the contrast sensitivity curves of sine-wave gratings with spatial frequencies of 0.25, 1.0, 2.0 and 8.0 cycles per degree (cpd) of visual angle in 16 female subjects aged 7 to 9 years old, eight well-nourished and eight with acute protein-energy malnutrition (PEM). All participants had normal visual acuity and were free of identifiable ocular illness. Contrast threshold was measured using a temporal two-alternative forced-choice psychophysical method, at a distance of 150 cm of the stimuli, binocularly, with mean luminance of 40.1 cd/m2. We detected a general decline in contrast sensitivity for children with acute malnutrition at all spatial frequencies compared to well-nourished children. The malnourished group needed in average 1.37 times more contrast to detect the stimulus in comparison with the well-nourished one. Differences between the groups were statistically significant at all spatial frequencies (p < .001). These results suggest that acute PEM changes the visual perception for sine-wave gratings. |
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Pontificia Universidade Católica do Rio de Janeiro |
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2009 |
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http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1983-32882009000100003 |
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AT santosnatanaelantoniodos contrastsensitivityfunctionofsinewavegratingsinchildrenwithacutemalnutrition AT alencarcarolinecostagomes contrastsensitivityfunctionofsinewavegratingsinchildrenwithacutemalnutrition AT diasyurihenriquenunes contrastsensitivityfunctionofsinewavegratingsinchildrenwithacutemalnutrition |
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