Genetic, neurological and cognitive determinants of success and failure in learning a first language. (360G-Wellcome-082498_Z_07_Z)

This research aims to identify causes of specific language impairment (SLI) at the etiological, neurobiological and cognitive levels of description, and to understand the links between SLI and other neurodevelopmental disorders. A twin study will be conducted with the goal of identifying aspects of the phenotype that are heritable and so might be useful in molecular genetic studies. In addition, bivariate genetic analyses will be conducted to explore associations between impairments, both within the domain of language, and between language and other domains. A longitudinal study following toddlers at risk of language impairment to 4 yr of age will track development of cerebral lateralisation in relation to emerging language skills. Finally, a fine- grained analysis of verbal learning will be conducted in a training study of school-aged children, with the goal of discovering why children with SLI fail to develop fluent understanding of meanings conveyed by word order. We shall consider patterns of learning on different language tasks, and procedural learning in nonlinguistic tasks, to see how far the difficulty is in abstracting rules and/or interpreting word order, or whether it reflects general problems with aspects of learning and retention.