Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia

Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.Ellison Medical FoundationMartin Richmond Memorial FundNational Institutes of Health (U.S.). (Grant UL1RR025758)National Institutes of Health (U.S.). (Grant F32EY014750-01)MIT Class of 1976 (Funds for Dyslexia Research

Intervenções para reduzir a mortalidade infantil pré-escolar e materna no Brasil Potential interventions to improve the health of mothers and children in Brazil

O presente trabalho teve como objetivo analisar o possível impacto de intervenções para reduzir a mortalidade de crianças e mães brasileiras. Através de uma combinação de métodos demográficos diretos e indiretos, avaliaram-se as tendências temporais, as variações regionais e a distribuição por causas da mortalidade de mães e crianças. Avaliou-se também a atual cobertura de programas preventivos. Com base nesses parâmetros, assim como em uma revisão da literatura sobre a efetividade das intervenções disponíveis, foram obtidas estimativas do impacto potencial de cada tipo de intervenção. A mortalidade em crianças vem sendo reduzida, mas os níveis atuais ainda são elevados e há importantes desigualdades regionais, com o Nordeste e Norte apresentando os mais altos índices. Devido à predominância de causas perinatais na mortalidade de crianças brasileiras, as medidas de maior potencial são aumentos na qualidade e cobertura do atendimento pré-natal e ao parto, seguidos pelo manejo integrado de doenças infecciosas e de problemas nutricionais. Melhorias no pré-natal e parto também contribuiriam para reduzir a mortalidade materna. É importante, ainda, garantir a sustentabilidade dos avanços já alcançados em áreas como as imunizações, a terapia de reidratação oral e o planejamento familiar, assim como investir intensamente na redução das importantes desigualdades regionais.<br>This review was aimed at analyzing the potential impact of interventions to reduce maternal and child mortality in Brazil. A combination of direct and indirect demographic methods was used to describe time trends, regional variations and cause-specific distribution of mortality. Current coverage levels of preventive interventions were also assessed. Based on these parameters, as well as on a review of the international literature on the effectiveness of different interventions, the latter were ranked according to their potential impact. Child mortality levels are falling, but current rates are still high and there are major regional differences, with the highest rates observed in the Northeastern and Northern Regions. Due to the predominance of perinatal causes in underfive child mortality, the most promising interventions include improving the quality and coverage of antenatal and delivery care, followed by the integrated management of infectious diseases and nutritional counseling. Improvement in antenatal and delivery care will also contribute to reducing maternal mortality. It is also important to ensure the sustainability of current achievements, including vaccine coverage, oral rehydration therapy and family planning, as well as to invest heavily in reducing major regional differences