ABSTRACT
Early malnutrition refers to inadequate nutrition during the critical period of nervous system development followed by nutritional recovery, resulting in a short stature according to age but normal weight according to short stature. We measured the effects of early malnutrition on contrast sensitivity (CS) to concentric circular gratings in 18 children of both sexes, aged 8 to 11 years (mean = 9.2 years, standard deviation = .99 years). Nine of the children were eutrophic (E group), and nine experienced early malnutrition (EM group) based on state healthcare records and Waterlow's anthropometric parameters. Contrast sensitivity to four spatial frequencies (.25, 1.0, 2.0, and 8.0 cycles per degree [cpd]) was measured using a temporal two-alternative forced-choice psychophysical method with mean luminance of 40.1 cd/m². Statistical analyses showed significant differences between groups and a group × frequency interaction. EM group was significantly less sensitive than the E group to the 8.0 cpd frequency and needed 1.49-times more contrast to detect the gratings. These results suggest that early malnutrition impairs CS to high-spatial-frequency concentric circular gratings in children. Therefore, early malnutrition, which is known to affect primary visual cortical areas, may also affect higher visual cortical areas such as V4 and the inferotemporal cortex.
Subject(s)
Humans , Male , Female , Child , Child Nutrition Disorders , Contrast SensitivityABSTRACT
We measured the effects of epilepsy on visual contrast sensitivity to linear and vertical sine-wave gratings. Sixteen female adults, aged 21 to 50 years, comprised the sample in this study, including eight adults with generalized tonic-clonic seizure-type epilepsy and eight age-matched controls without epilepsy. Contrast threshold was measured using a temporal two-alternative forced-choice binocular psychophysical method at a distance of 150 cm from the stimuli, with a mean luminance of 40.1 cd/m². A one-way analysis of variance (ANOVA) applied to the linear contrast threshold showed significant differences between groups (F[3,188] = 14.829; p < .05). Adults with epilepsy had higher contrast thresholds (1.45, 1.04, and 1.18 times for frequencies of 0.25, 2.0, and 8.0 cycles per degree of visual angle, respectively). The Tukey Honestly Significant Difference post hoc test showed significant differences (p < .05) for all of the tested spatial frequencies. The largest difference between groups was in the lowest spatial frequency. Therefore, epilepsy may cause more damage to the neural pathways that process low spatial frequencies. However, epilepsy probably alters both the magnocellular visual pathway, which processes low spatial frequencies, and the parvocellular visual pathway, which processes high spatial frequencies. The experimental group had lower visual contrast sensitivity to all tested spatial frequencies.
Subject(s)
Humans , Female , Adult , Contrast Sensitivity , Epilepsy, Tonic-Clonic , Visual PathwaysABSTRACT
Este trabalho foi um estudo de validação de duas escalas que visam verificar a relação entre a importância atribuída a questões sociais contemporâneas e o engajamento político dos jovens na sociedade. A cidadania foi definida como uma atitude heterogênea, motivada por diversos interesses que se adequam a um modelo tripartite: voto, ajudar na comunidade, e se fazer ouvir. Duzentos jovens de ambos os sexos, com idade média de 18 anos, estudantes do ensino médio de escolas públicas e privadas e de uma universidade pública responderam a três escalas objetivas: Informações Sócio-demográficas, Importância das Questões Sociais e Engajamento Social. Os resultados mostraram forte consistência interna para as escalas de importância das questões sociais (α = 0,94) e de engajamento político (α = 0,96) e uma boa adequação do modelo de três fatores da cidadania aos dados obtidos. Estudantes de escola pública mostraram um maior engajamento na sociedade do que estudantes de escolas privadas ou universitários. Em geral, os jovens mostraram maior interesse pela Ajuda na Comunidade do que por Se fazer Ouvir. O Voto recebeu a menor média de importância pelos jovens.
This study aimed at validating two scales designed to assess the relationship between the importance attached to contemporary social issues and political engagement of youth in society. Citizenship was defined as heterogeneous and motivated by various interests to suit a tripartite model: voting, helps the community and to be heard. 200 young people of both sexes with an average age of 18 years, high school students in public schools and private and a public university responded to three objective scales: Socio-demographic Information, Importance of Social Issues and Social Engagement. The results showed strong internal consistency for the scales of importance of social issues (α = 94) and political engagement (α = 96) and a good model fit of three factors of citizenship to the data obtained. Public school students showed a greater engagement in society than students from private schools or universities. In general, young people showed greater interest in the Help in the Community than by Being Heard. The Vote has received the lowest average importance by the young.