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Uncovering predictors of language learning speed in two-year olds


Recent research in child language acquisition has utilized fine-grained measures of processing abilities to better characterize the underlying knowledge that children use to interpret sentences. New findings by Megan Sutton and her colleagues at the University of Maryland demonstrate that individual differences in syntactic processing speed predict individual differences in pronoun interpretation. These results support the view that pronoun interpretation is driven in large measure by syntactic factors. Not only do 2½ year-old children interpret sentences containing pronouns in the same manner that adults do, but the grammatical knowledge that leads to these interpretations is the same as adults’ as well. Sutton is a trainee in Maryland’s “Biological and Computational Foundations of Language Diversity” program, which is supported by NSF’s Integrative Graduate Education and Research Traineeship (IGERT) program. By integrating methodological and analytical techniques that span the fields of linguistics, psychology, and human development, her research is some of the first to use measures of individual differences in sentence processing to uncover the nature of young children’s syntactic development.

Sentences often present ambiguities. For example, the sentence “While she was in the garage, Jane fixed the car” can have multiple interpretations, depending on whether the pronoun ‘she’ refers to Jane or to another woman. Interestingly, the same range of possible interpretations is not available for the seemingly similar sentence “She was in the garage while Jane fixed the car,” which requires the pronoun to refer to someone other than Jane. The origins of this asymmetry have played a critical role in linguistic theory since the late 1960s, with research revealing cross-linguistic uniformity in this dimension and acquisition at least by age 3. Using data from children’s eye-movements while they hear such sentences, Sutton and her colleagues have shown that by the age of 30 months, children’s interpretations are adult-like. By exploring the time course of these eye movements and comparing with lexical and syntactic measures of processing speed, they have demonstrated the role of syntax, over and above lexical processing, in driving children’s interpretations of pronouns. This finding supports the continuity of linguistic representations across development. This work has several important implications. First, it demonstrates that is possible to correlate individual differences across several tasks in order to reason about the mental computations involved in sentence understanding. Second, it helps to establish that even infant’s linguistic representations share fundamental properties with adults’. Finally, because this work depends on measures of individual differences, it is possible to link syntactic development with features of the environment or features of the child’s extra-linguistic cognition that might be determinative of the observed variability. Ultimately, this work paves the way for understanding the origins of individual differences in normal and abnormal language development.

Address Goals

Discovery: this work advances our understanding of critical milestones in language development in young children.

Learning: this research was made possible through cross-training of PhD students in multiple scientific fields, including Linguistics, Human Development, and Psychology.