Associations between Bilingualism and Neurocognitive Outcomes during Childhood: Does Socioeconomic Status Matter?

• In Event: 3-143 - The bilingual advantage meets big data: Results of three large-sample studies in children

Integrative Statement

Background: More than 20% of school-aged children in the United States speak a language other than English at home (U.S. Census Bureau, 2014), yet the implications of bilingualism for broader cognitive development are not clear. Variations in cognitive skills and brain structure have been attributed to dual-language exposure (Costa & Sebastián-Gallés, 2014), but bilingual differences are not always found (de Bruin, Treccani, & Della Sala, 2015; Paap & Greenberg, 2013). As a majority of the school-aged dual-language children in the U.S. come from poor or near-poor households (Federal Interagency Forum, 2011), it is important to take into account family socioeconomic status (SES) when investigating links between bilingualism and neurocognitive outcomes. Here two studies will be presented that examine the independent and potentially interactive effects of bilingualism and SES on neurocognitive skills during childhood.

Methods: In the first sample, infants from four different language and SES backgrounds (monolingual lower SES; monolingual higher SES; bilingual lower SES; bilingual higher SES) were tested at 18-months of age (M = 18.47, SD = .59; N = 82). Infants were tested on measures of cued recall, memory flexibility, and working memory (Bernier, et al., 2011; Herbert & Hayne, 2000). Measures of language skill and home language environment were also collected for a subsample of the infants. In the second sample, a subset of data from the Pediatric Imaging, Neurocognition and Genetics (PING) study was analyzed using propensity score matching to establish an equal sample (N = 562) of monolinguals and dual-language users with similar socio-demographic characteristics (Mage = 13.5, Range = 3-20 years). Outcomes for this study included both brain structure and measures of executive function and language (via NIH Toolbox).

Results: For the infant sample, preliminary analyses indicate no significant differences between monolingual and bilingual 18-month-olds on cued recall or working memory. Consistent with past studies (Brito & Barr, 2012) differences by language group were found for memory flexibility, with both low-SES and high-SES bilingual groups outperforming monolinguals. Data collection is still ongoing and links between memory and language assessments will also be discussed. In the second sample, across all ages, SES but not dual-language use was related to both brain structure and cognitive skills. When re-analyzing data using two separate age groups (early childhood: 3 - 11.9 years & adolescence: 12 - 20.0 years), dual-language use was unrelated to either brain structure or cognitive skills for the younger children. In contrast, for adolescents there was an association between both SES and dual-language use for brain structure (cortical surface area), such that these links were most pronounced among adolescents from more disadvantaged families.

Conclusion: These studies are consistent with past research reporting limited differences between monolinguals and bilinguals in executive function but add to the literature by demonstrating the specificity of bilingual neurocognitive outcomes. Family SES plays an important role in shaping developmental trajectories and studies that aim to disentangle the effects of SES and bilingualism on development are crucial for appropriately identifying mechanisms of risk and resilience for lower SES language minority children.

Authors

• Natalie Hiromi Brito, New York University
  Presenting Author

• Kimberly G. Noble, Teachers College, Columbia University
  Non-Presenting Author