Implicit word learning in code-switched contexts by bilingual children with and without developmental language disorder (DLD)

The National Institute on Deafness and Other Communication Disorders awarded the University of Wisconsin–Madison $158,168 on December 15, 2025, under the Research Related to Deafness and Communication Disorders program (CFDA 93.173).

The project studies implicit word learning in code-switched contexts by bilingual children with and without developmental language disorder. The research targets four- to six-year-old Spanish-English bilingual children across the full range of language ability, from typical to weak skills in both languages. Two experimental studies will test the effect of code-switching on novel word learning by manipulating the placement of language switches—prior to the novel word in Study 1 and after the novel word in Study 2. Both studies will assess children's learning immediately after exposure and following a ten-minute delay. A second aim examines how language ability affects word learning in bilingual children with and without developmental language disorder, using an omnibus measure of language ability across English and Spanish.

The University of Wisconsin–Madison operates as the prime recipient at its Madison, Wisconsin campus. Performance period runs through August 31, 2027. This is a project grant, the largest funding category supported by NIDCD for biomedical research and development conducted by universities and research institutions, covering salaries, equipment, supplies, travel, and other direct and indirect costs.

Abstract

Bilingualism is common in many parts of the world and in the united states at least one-third of the population under age five speaks a language other than english at home. While there is motivation for the use of both languages in treatment for bilingual children with developmental language disorder (DLD), IT remains unclear how to optimize the integration of two languages for learning. Code-switching, or the use of multiple languages in discourse, is an especially controversial topic within bilingual language development, and the effect of code- switching on language learning is not well understood. We aim to test the effect of code-switching on bilingual children's ability to learn novel words. Our target population is four- to six-year-old spanish-english bilingual children across the full range of language ability (from typical to weak skills in both languages, i.e., DLD). We will test learning via an implicit learning task, contrasting learning between single-language and code- switched conditions. Specific aim 1 is to examine the effect of code-switching on implicit novel word learning in bilingual children with and without DLD across two time points (immediate and delayed). In two studies under this aim, we will test the effect of code-switching on novel word learning, manipulating the placement of the language switch across studies (prior to the novel word in study 1; after the novel word in study 2). Both studies will test children immediately after learning and after a 10-minute delay. Specific aim 2 is to examine the effect of language ability on word learning in bilingual children with and without DLD. Across both studies, children's language skills will be assessed via an omnibus measure of language ability measuring language skills across english and spanish. Children with DLD are characterized by processing and learning difficulties; therefore, children with lower levels of language ability might be especially sensitive to an effect of code-switching. At the same time, children with DLD demonstrate more difficulty with initial encoding than with long-term retention of information; therefore, children with lower levels of language ability may show different patterns of sensitivity to code-switching at immediate VS. Delayed testing. Specific aim 3 is to examine the effect of code-switching exposure on word learning in bilingual children. Across both studies, direct measurements of code-switching exposure collected via naturalistic parent-child interactions will be used to test the association between code- switching exposure and word learning in code-switched VS. Single-language contexts. The proposed project will contribute to the theoretical understanding of the word learning mechanisms in single- and dual-language contexts, as well as to the broader lines of inquiry into the mechanisms that support code-switching in bilinguals. These studies are the first to empirically test the effect of code-switched input on implicit word learning across time points in bilingual children with DLD. Practically, the results may provide foundational information for clinicians delivering services to bilingual children with DLD and to parents who raise them.