LangAge

While almost all children master at least one language effortlessly over the course of a few years, adults’ substantial efforts to learn a second language typically lead to less-than-perfect mastery. It seems reasonable to postulate that infants and adults have the same overall architecture for their language system. What, then, can account for the obvious differences in the final outcome of the learning process?. As language acquisition unfolds, learners apply certain processing mechanisms onto their language input, in ways that are constrained by their linguistic and cognitive biases. Logically, differences between children and adults may stem from all three of these aspects of language acquisition, i.e. 1) the input, 2) the learning mechanisms, and 3) the linguistic and cognitive biases. In each of these domains, we will compare adults and young children, in order to identify differences that may impact the end-result of the language acquisition process. In some instances, specific areas of divergence can be identified from the previous literature (e.g. the acquisition of phonetic categories); in others we offer novel avenues of research to test potential differences between infants and adults, with specific hypotheses for why they may or may not diverge (e.g. comparing the burstiness of child- vs adult-directed speech). To achieve our goals, we will rely on an interdisciplinary approach in which we combine corpora studies to describe the input, computational modeling to study the learning mechanisms and effects of learning biases in perfectly controlled situations, and psychological laboratory experiments on both young children and adults to assess whether the putative learning mechanisms and biases we attribute to learners are actually in operation. We will study the acquisition of multiple linguistic levels, and whenever possible, their interactions, ranging from the sound system to morphosyntax, through the lexicon. Overall, this project examines language acquisition, both in young children acquiring their first language, and in adults acquiring a second language, and will inform fundamental research on language learnability and acquisition. In addition, the project has a potential longer-term societal impact, in two directions: a deeper understanding of first language acquisition for early diagnosis and remediation, and improved methods for second or foreign language teaching to adults.