Executive Function Skills Account for Bilingual Advantage in Word Learning Among Low-income Preschoolers

• In Event: The Role of SES, Stress, and Language Input on Cognitive Development in at-risk Children

Abstract

Background: Bilingual learning experience influences children’s language development and cognitive functions, such as executive function (EF). Ample research has shown that bilingual children tend to have smaller vocabularies in each language than their monolingual peers (Calvo & Bialystok, 2014; Oller & Eilers, 2002), but that by adulthood bilinguals are better at learning new words (Bartolotti et al., 2011; Kaushanskaya & Marian, 2009). Relatively few studies have compared word learning ability among bilingual and monolingual preschool children, and even fewer have probed the process by which a bilingual advantage in word learning may emerge. Given bilingualism may positively affect children’s EF skills (Bialystok & Martin, 2004; Costa et al., 2008), and EF skills are related to word learning ability (Kapa & Erikson, 2020; White et al., 2017), it is likely that a bilingual advantage in word learning ability can be explained by EF skills. Existing research studies examining the association between bilingualism and novel word learning/EF development mostly focused on diverse socioeconomic samples, making it difficult to pinpoint potential differences in word learning attributed solely to bilingualism, but not SES. Therefore, the goal of the current study is to examine and compare economically disadvantaged bilingual and monolingual preschoolers’ performance on measures of word learning and determine if children’s EF skills account for differences in word learning ability among bilingual and monolingual children.

Methods & Results: Thirty-nine English monolinguals (Mage = 48.97 months, SD = 9.32 months) and 35 Spanish-English bilingual preschoolers (Mage = 52.06 months, SD = 8.31 months) from low-income homes (Income-to-Needs Ratio < 2) completed a battery of EF measures and the Quick Interactive Language Screener (QUILS & QUILS:ES) to gauge language abilities, including vocabulary knowledge, syntactic processing and novel word learning. Bilingual and monolingual preschoolers did not differ in their English vocabulary knowledge, t(72) =.12, p =.904, but bilingual preschoolers performed significantly better during novel word learning, t(72) =3.44, p =.001. After controlling for age, income-to-needs ratio, and English vocabulary, bilingual preschoolers still demonstrated significantly better word learning performance than their monolingual peers, ∆F (1, 69) = 12.42, p = .001.A parallel mediation model indicated that this bilingual advantage in word learning ability was mediated by working memory (95% bootstrap CI [.07, 2.82]), but not inhibition (95% bootstrap CI [-.64, 1.74]) or attention shifting (95% bootstrap CI [-.40, 2.74]; Figure 1).

Discussion: The current study is the first to demonstrate a bilingual advantage in word learning, but not vocabulary knowledge, among low-income preschoolers. Importantly, we show that discrepancies in economically disadvantaged monolingual and bilingual preschoolers’ word learning performance can be explained by the gains in working memory. These findings provide evidence that children from low-income and bilingual households have unique linguistic and cognitive strengths, and that interventions targeting working memory may be more effective for promoting vocabulary growth for this high-risk population.

Authors

• Rong Huang, University of Connecticut
  Presenting Author

• Julie M. Schneider, Louisiana State University