2018 Friday Poster 6360

Friday, November 2, 2018 | Poster Session I, Metcalf Small | 3pm

Language mixing affects bilingual toddlers’ word learning
K. Byers-Heinlein, E. Fourakis, C. Lew-Williams

Language mixing – the use of more than one language in the same sentence or conversation – is a common part of bilingual children’s everyday language environments (Bail et al., 2014; Byers- Heinlein 2013). How do bilingual infants and toddlers navigate the complexities inherent in the everyday use of two languages? Previous eye-tracking and pupillometry research has demonstrated that toddlers are slower to process familiar words presented in mixed-language than in single-language sentences (Byers-Heinlein, Morin-Lessard, & Lew-Williams, 2017; Potter et al., accepted). This may signal an efficient processing strategy: young bilinguals adapt to their unique environments by monitoring and switching between their two languages during comprehension. But critically, this small (yet reliable) processing delay could double as a problem for learning: young bilinguals may be less able to encode or learn information presented moments after a switched. In this cross-lab, international study, we asked whether language mixing affects learning of a novel word that follows the moment of a language switch.

In an eye-tracking paradigm (see Figure 1), 3-year-old French-English bilingual children from high-SES Canadian families (n=20) were taught two novel words, one presented in single language sentences (“Look at the pig on the teelo!”), and another presented in mixed-language sentences (“Look at the chien [dog] on the walem!”). At test, children were significantly less accurate in recognizing the novel word taught in mixed-language sentences (M =.43, SD = .28) than the word taught in single-language sentences (M = .62, SD = .26), t(19) = 2.85, p = .01, d =.52. This was not due differences in total amount of time spent looking toward the novel object during the learning trials. Thus, interestingly, switching affected downstream learning even when in-the-moment processing of the novel object was unaffected.

In a nearly identical paradigm, 3-year-old Spanish-English bilingual children from low-SES American families (n=20) were taught the same two novel words (teelo, walem), one in single- language sentences and one in mixed-language sentences. At test, children did not demonstrate learning in either condition (mixed-language sentences: M = .50, SD = .32; single-language sentences: M = .51, SD = .34), and there was no significant difference between the conditions (t(19) = -.114, p = .91, d = -.03). However, there were very strong item effects, potentially indicating weaker (and more easily derailed) processing and learning overall in this participant sample.

These results from the high-SES, French-English bilingual participants suggest that bilingual children either implicitly or explicitly experience mixed-language sentences as less optimal opportunities for encoding novel words than single-language sentences, despite identifying the relevant target in both cases. Thus, we end with the prediction that young bilinguals avoid learning new words at the moment of a language switch even in simple referential contexts.

These results have implications for the types of language input that best support language learning, and for understanding children’s developing expertise as bilingual learners. We will discuss this in tandem with socioeconomic, linguistic, and demographic differences between the two samples, and point to the crucial puzzle of cross-population generalizability in bilingualism research.

References

Bail, A., Morini, G., & Newman, R. S. (2014). Look at the gato! Code-switching in speech to toddlers. doi: 10.1017/S0305000914000695

Byers-Heinlein, K. (2013). Parental language mixing: Its measurement and the relation of mixed input to young bilingual children’s vocabulary size. Bilingualism: Language and Cognition, 16(1), 32–48. doi: 10.1017/S1366728911000010

Byers-Heinlein, K., Morin-Lessard, E., & Lew-Williams, C. (2017). Bilingual infants control their languages as they listen. Proceedings of the National Academy of Sciences, 114(34), 9032–9037. doi: 10.1073/pnas.1703220114

Potter, C., Fourakis, E., Morin-Lessard, E., Byers-Heinlein, K., & Lew-Williams, C. (accepted). Bilingual infants process mixed sentences differently in their two languages. Proceedings of the Cognitive Science Society.