Caracterização da percepção visual em crianças e adolescentes com epilepsia: aspectos cognitivos e sociais

• Ano de defesa: 2009
• Autor(a) principal: Pereira, Anne Gleide Filgueira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; BR; Psicologia Social; Programa de Pós-Graduação em Psicologia Social; UFPB
• Palavras-chave em Português: Percepção visual; Epilepsia; Função de sensibilidade ao contraste; Freqüência espacial; Método psicofísico; Visual perception; Epilepsy; Contrast sensitivity function; Spatial frequency; Psychophysical forced-choice method; CIENCIAS HUMANAS::PSICOLOGIA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/6998

Epilepsy is a brain dysfunction characterized by the repeated tendency of the brain to cause epileptic crisis and by the neurobiological, cognitive, psychological and social consequences of this condition. In these terms, the aim of this work is to determine the visual sensory threshold of children and adolescents who have and who do not have epilepsy, analyzing possible alterations in the form related to this dysfunction. The sensory threshold is defined as the smallest intensity of incentive a human being is capable of detecting. The contrast sensitivity function (CSF) is the inverse of the threshold curve of contrast (1/CSF). This way, the CSF is a tool that allows us to label the answer of SV to visual patterns in low, medium and high levels of contrast and evaluate possible sensorial alterations associated with the visual processing. The main idea is that the elevation or reduction of the CSF can happen deem to sensorial, cognitive and behavioral alterations. Twenty volunteers participated on this study, from both genders, between 7 and 17 years of age, 10 of whom nonepileptic and 10 epileptic (tonic-clonic crisis). All of them presented either normal or corrected visual accuracy and were distributed in groups that were equivalent in age. The resolutions were taken from the psychophysical forced-choice method, using the static sine wave gratings with spatial frequencies of 0.25, 2.0 and 8.0 cpd (cycles per degree of visual angle). During each experimental session, there were stimulus pares presented randomly (test stimulus and neutral), and the task of the participants was to choose always the test stimulus with one of the frequencies above. The criterion used was the one of three consecutive correct answers to low the contrast in one unity and just one mistake to increase the contrast in the same unity (20%). After each session, a sheet of results with the experimental situation was released and the six values of contrast were calculated by the reversions. The values of contrast obtained to each frequency were grouped in spreadsheets separated by condition (with or without epilepsy) and the big average was used as an estimative of the sensory threshold or of the sensibility to the contrast due to each spatial frequency tested. The analysis of variance (ANOVA) to repeated measures showed significant differences between the groups [F(1,238) = 11.80); p<0.01]. The analysis obtained with the help of the test posthoc Tukey HSD revealed a relevant dissimilarity only in the 0.25cpg (p<0.01)]. In other words, the results indicated an expressive alteration in the visual perception children and adolescents with epilepsy have.