Percepção viso-motora de escolares com Transtorno do Déficit de Atenção com Hiperatividade

PURPOSE: The aim of this study was to characterize and to compare the visual-motor perception of students with Attention Deficit with Hyperactivity Disorder (ADHD) with students with good academic performance. METHODS: Forty students from 2nd to 5th grades of an elementary public school, male gender (100%), aged between 7 and 10 years and 8 months old participated, divided into: GI (20 students with ADHD) and GII (20 students with good academic performance), paired according to age, schooling and gender with GI. The students were submitted to Developmental Test of Visual Perception (DTVP-2). RESULTS: The students of GI presented low performance in spatial position and visual closure (reduced motor) and inferior age equivalent in reduced motor perception, when compared to GII. CONCLUSION: The difficulties in visual-motor perception presented by students of GI cannot be attributed to a primary deficit, but to a secondary phenomenon of inattention that interferes directly in their visual-motor performance.OBJETIVO: Caracterizar e comparar as habilidades de percepção viso-motoras de escolares com Transtorno do Déficit de Atenção com Hiperatividade (TDAH) com escolares com bom desempenho acadêmico. MÉTODOS: Participaram deste estudo 40 escolares na faixa etária de 7 anos a 10 anos e 8 meses, do 2º ao 5º ano do Ensino Fundamental de escolas públicas, divididos em GI (20 escolares com diagnóstico interdisciplinar de TDAH) do gênero masculino (100%) e GII (20 escolares com bom desempenho escolar), pareados com o GI em idade, escolaridade e gênero. Os escolares foram submetidos ao Teste Evolutivo de Percepção Visual (DTVP-2). RESULTADOS: Os escolares de GI apresentaram desempenho inferior na função de posição no espaço e closura visual (motricidade reduzida) e equivalente de idade inferior para percepção de motricidade reduzida em relação ao GII. CONCLUSÃO: As dificuldades em percepção viso-motora apresentadas pelos escolares de GI podem ser atribuídas não a um déficit primário, mas a um fenômeno secundário à desatenção que interfere de forma direta em seu desempenho de percepção viso-motora.Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Filosofia e Ciências Departamento de FonoaudiologiaUniversidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Filosofia e CiênciasUniversidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Filosofia e Ciências Departamento de FonoaudiologiaUniversidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Filosofia e Ciência

Temporal properties of shape processing across visual areas: a combined fMRI and MEG study

Recent studies have shown that global information about shapes is processed in both early ventral (i.e. V1, V2, Vp, V4) and higher occipitotemporal visual areas (i.e. Lateral Occipital Complex-LOC). However, the temporal properties of shape processing across visual areas in the human brain are not known. We addressed this question in a combined fMRI and MEG study that made use of the complimentary spatial and temporal resolution of the two techniques. We used an event-related adaptation paradigm in which lower neural responses are observed for two identical than two different consecutively-presented stimuli. The stimuli were closed contours that consisted of collinear Gabor elements. We manipulated the interstimulus interval (ISI: 100 vs. 400 msec) between the two consecutively-presented stimuli. The fMRI results showed adaptation for both the short and the long ISI in the LOC but only for the short ISI in early visual areas. The MEG data showed similar patterns of response amplitude to the fMRI data and differences in latencies for the different ISIs across visual areas. These findings suggest sustained shape processing in higher visual areas compared to more transient visual analysis in early visual areas. Further studies test the analysis of local vs. global shape features across areas with different temporal processing properties

Temporal Properties of Shape Processing Across Visual Areas: a Combined fMRI and MEG Study

Recent studies have shown that global information about shapes is processed in both early ventral (i.e. V1, V2, Vp, V4) and higher occipitotemporal visual areas (i.e. Lateral Occipital Complex-LOC). However, the temporal properties of shape processing across visual areas in the human brain are largely unknown. We addressed this question in a combined fMRI and MEG study that made use of the high spatial resolution of fMRI and the temporal resolution of MEG. We used an event-related adaptation paradigm in which lower neural responses are observed for two identical than two different consecutively-presented stimuli. The stimuli were closed contours that consisted of collinear Gabor elements. We manipulated the interstimulus interval (ISI: 100 vs. 400 msec) between the two consecutively-presented stimuli in each trial. To ensure comparability between fMRI and MEG results, subjects participated in both parts of the study. The fMRI results for 11 subjects showed adaptation for both the short and the long ISI in the LOC but only for the short ISI in early visual areas. The MEG data showed similar patterns of response amplitude to the fMRI data and dierences in latencies for the dierent ISIs across visual areas ranging between 70 and 160 ms. These ndings suggest sustained shape processing in higher visual areas compared to more transient visual analysis in early visual areas. Further studies test the analysis of local vs. global shape features across areas with dierent temporal processing properties