Learning through processing: Towards an integrated approach to early word learning

Children's linguistic knowledge and the learning mechanisms by which they acquire it grow substantially in infancy and toddlerhood. And yet, theories of word learning largely fail to incorporate these shifts. Moreover, researchers' often-siloed focus on either familiar word recognition or novel word learning limits the critical consideration of how these two relate. As a step towards a mechanistic theory of language acquisition, we first present a framework of "learning through processing," and relate it to the prevailing methods used to assess children's early knowledge of words. Incorporating recent empirical work, we posit a specific, testable timeline of qualitative changes in the learning process in this interval. Finally, we conclude with several challenges and avenues for building a comprehensive theory of early word learning: better characterization of the input, reconciling results across approaches, and treating lexical knowledge in the nascent grammar with sufficient sophistication to ensure generalizability across languages and development.