New insights on what leads bilinguals to be able to name some pictures only in their nondominant language: Immersion, dominance reversal, and balanced bilingualism.

OBJECTIVE: The present study asked if bilinguals who are immersed in their nondominant language are more likely to know some words only in their nondominant language. METHOD: The either-language scoring benefit (ELSB) reflects how many more points bilinguals get when credited for pictures named regardless of which language is used. We asked if the ELSB varies with self-rated proficiency level of the nondominant language in young English-dominant (n = 68) compared to Spanish-dominant (n = 33) bilinguals, and in older English-dominant (n = 36) compared to Spanish-dominant (n = 32) bilinguals. All bilinguals were immersed in English (in the USA) at the time of testing. RESULTS: Spanish-dominant bilinguals showed a larger ELSB than English-dominant bilinguals (in both young and older groups), but simple correlations showed that the degree of Spanish dominance was associated with a higher ELSB only in young bilinguals. Additionally, the ELSB was larger for bilinguals with more years of immersion and for more balanced bilinguals, whether measured by naming scores or self-rated balance (in both age groups). Nearly half (n = 14/33) of the young bilinguals who said they were Spanish-dominant scored higher in English than in Spanish, and on average these participants had similar naming scores in English and Spanish. CONCLUSIONS: Either-language scoring benefits bilinguals with higher proficiency level in the nondominant language, which is more likely in bilinguals with extended immersion in the nondominant language, who also tend to be more balanced bilinguals, and for young adult bilinguals who may be in the process of a switch in which language is dominant.

Does code-switching influence novel word learning?

Code-switching occurs regularly in the input to bilingual children. Yet, the effect of code-switched input on language development is unclear. To test whether word learning would be affected by code-switching, Spanish-English bilingual children (N = 45, 19 boys, MeanAge  = 5.05 years; ethnicity: 37 Hispanic/Latino, six Non-Hispanic/Latino, two unreported) were taught English-like novel words in two conditions. In the English-only condition, definitions for novel words were provided entirely in English. In the code-switch condition, definitions for novel words were provided in English and Spanish, incorporating code-switches. Children required fewer exposures to retain novel words in the code-switch than the English-only condition and this effect was not moderated by children's language ability or exposure to code-switching, suggesting that code-switched input does not pose word-learning risks to bilingual children, including children with lower levels of language ability.

Paired-associate versus cross-situational: How do verbal working memory and word familiarity affect word learning?

Word learning is one of the first steps into language, and vocabulary knowledge predicts reading, speaking, and writing ability. There are several pathways to word learning and little is known about how they differ. Previous research has investigated paired-associate (PAL) and cross-situational word learning (CSWL) separately, limiting the understanding of how the learning process compares across the two. In PAL, the roles of word familiarity and working memory have been thoroughly examined, but these same factors have received very little attention in CSWL. We randomly assigned 126 monolingual adults to PAL or CSWL. In each task, names of 12 novel objects were learned (six familiar words, six unfamiliar words). Logistic mixed-effects models examined whether word-learning paradigm, word type and working memory (measured with a backward digit-span task) predicted learning. Results suggest better learning performance in PAL and on familiar words. Working memory predicted word learning across paradigms, but no interactions were found between any of the predictors. This suggests that PAL is easier than CSWL, likely because of reduced ambiguity between the word and the referent, but that learning across both paradigms is equally enhanced by word familiarity, and similarly supported by working memory.

Does long-term dual-language immersion affect children's executive functioning?

Dual-language immersion (DLI) experience has been linked to enhanced reading and math skills in minority- and majority-language elementary school children. However, it remains unclear whether DLI experience can also enhance executive functioning. The current study took a longitudinal approach to this question and examined the effect of DLI experience on the development of executive function skills in majority-language children over a 1-year period. In total, 33 monolingual children attending English-only classrooms (Mage = 9.17 years, SD = 1.03) and 33 English-Spanish bilingual children attending DLI classrooms (Mage = 9.27 years, SD = 0.94) matched on age, gender, nonverbal IQ, and socioeconomic status were tested twice, 1 year apart, on nonverbal measures of inhibition, shifting, switching, and monitoring. Results revealed a significant interaction between group and year only on the response inhibition task, with bilinguals showing superior inhibition in Year 1 but not in Year 2. The two groups performed equivalently on all other measures at both time points. Results suggest that classroom DLI has a minimal impact on executive functions, at least as tested in the current study.

The role of bilingualism in paired-associate and cross-situational word learning.

In adulthood, novel words are commonly encountered in the context of sequential language learning, and to a lesser extent, when learning a new word in one's native language. Paired-associate (PAL) and cross-situational word learning (CSWL) paradigms have been studied separately, under distinct theoretical umbrellas, limiting the understanding of the mechanisms underlying the learning process in each. We tested 126 monolinguals and 111 bilinguals on PAL and CSWL, manipulating familiarity and measuring verbal working memory. Results revealed highly similar learning performance across groups, both demonstrating better performance in PAL than in CSWL, similar sensitivity to familiarity, and similar reliance on phonological working memory. We observed a trend such that bilinguals outperformed monolinguals in PAL but not in CSWL, but this trend was weak. Findings indicate limited effects of bilingualism on word learning in adulthood and suggest highly similar word learning mechanisms in learners with different linguistic experiences.

Revisiting which language declines more in Spanish-English bilinguals with Alzheimer's disease: Longitudinal decline patterns on the multilingual naming test.

Theories of bilingual language production predict that bilinguals with Alzheimer's disease (AD) should exhibit one of two decline patterns. Either parallel decline of both languages (if decline reflects damage to semantic representations that are accessed by both languages), or asymmetrical decline, with greater decline of the nondominant language (if decline reflects reduced ability to resolve competition from the dominant language with disease progression). Only two previous studies examined decline longitudinally with one showing parallel, and the other asymmetrical, decline. We examined decline over 2-7 years (3.9 on average) in Spanish-English bilinguals (N = 23). Logistic regression revealed a parallel decline pattern at one year from baseline, but an asymmetrical decline pattern over the longer decline period, with greater decline of the nondominant language (when calculating predicted probabilities of a correct response). The asymmetrical decline pattern was significantly greater for the nondominant language only when including item-difficulty in the model. Exploratory analyses across dominance groups looking at proportional decline relative to initial naming accuracy further suggested that decline of the nondominant language may be more precipitous if that language was acquired later in life, but the critical interaction needed to support this possibility was not statistically significant in a logistic regression analysis. These results suggest that accessibility of the nondominant language may initially be more resilient in early versus more advanced AD, and that AD affects shared semantic representations before executive control declines to a point where the ability to name pictures in single-language testing block is disrupted. Additional work is needed to determine if asymmetrical decline patterns are magnified by late age of acquisition of the nondominant language, and if more subtle impairments to executive control underlie impairments to language switching that occur in the earliest stages of AD (even preclinically).

One fish, uh, two fish: Effects of fluency and bilingualism on adults' novel word learning.

Listeners utilize speech disfluencies to anticipate novelty in spoken language, but little is known about how speech disfluencies impact novel word learning. We investigated how monolingual and bilingual adults learn novel words under disfluent speech conditions, focusing on fillers such as uh and um. If fillers highlight novelty, they might be an especially potent cue during word learning; however, because fillers also signal uncertainty, listeners may be less willing to learn in a disfluent condition. We also tested whether an effect of fillers on word learning would be moderated by bilingual experience, expecting that bilinguals would be affected differently because their exposure to distributional information within each language is reduced relative to monolinguals. In Experiments 1 and 2, where participants were exposed only to novel words, we found that participants learned words equally well in fluent and disfluent conditions, and that this effect was not moderated by bilingual experience. In Experiment 3, when novel words were embedded within a larger set of known words, we observed a bilingualism by condition interaction, wherein bilinguals benefited from fluency, but monolinguals performed equally well across conditions. These findings suggest that monolinguals' word learning-unlike word processing-may be robust to variations in speaker fluency, but that language experience may moderate the effect of fluency on learning.

Immersion in dual-language programs does not impede children's native language processing.

Aims and Objectives: The benefits of dual-language immersion (DLI) versus English-only classrooms for minority-language speakers' acquisition of English have been well documented. However, less is known about the effect(s) of DLI on majority-language speakers' native English skills. Prior studies largely used accuracy-focused measures to index children's language skills; it is possible that processing-based tasks are more sensitive to the effects of DLI experience. Methodology: Thirty-three monolingual native English-speaking children attending English-only classrooms and thirty-three English-speaking children attending English-Spanish DLI matched in age, gender, nonverbal IQ, and socio-economic status were tested twice, 1 year apart, on standardized and processing-based measures of English vocabulary and morphosyntax. Analysis: We ran linear mixed-effects models to examine the extent to which group and time would predict scores on knowledge-based measures of vocabulary and morphosyntactic knowledge, as well as accuracy and reaction times on processing-based measures of English vocabulary and morphosyntax. Findings: Results revealed comparable levels of growth in English for both groups. A subtle effect of DLI was observed on a lexical-decision task: bilinguals were slower in Year 1 but both groups were equally efficient in Year 2. These results indicate that DLI programs have minimal impact on majority-language speakers' native-language skills in the age-range tested. Originality: This study is the first to longitudinally examine processing-based native language outcomes in bilingual children in DLI classrooms. Significance: We do not find evidence that DLI exposure carries a cost to native language development, even when indexed by processing measures. This should reassure parents, educators, and policymakers in that there are no downsides to DLI.

Testing the Triggering Hypothesis: Effect of Cognate Status on Code-Switching and Disfluencies.

"Triggered switching" is the theory that code-switching happens more often with words connected to both languages, such as cognates. Corpus analyses have supported this theory; however, they do not allow testing for directional causality. Here, we test the triggering hypothesis through a picture-naming task, and examine whether cognates trigger code-switches, as well as more subtle interference effects resulting in disfluencies. Forty English-Spanish bilinguals completed a picture-cued sentence production task in three conditions: English-only, Spanish-only, and mixed. Half of the pictures represented Spanish-English cognates. Unsurprisingly, participants were more likely to code-switch when asked to use both their languages compared to only their dominant or non-dominant language. However, participants were not more likely to switch languages for cognate than for non-cognate trials. Participants tended to be more fluent on cognate trials in the dominant and the non-dominant condition, and on non-cognate trials in the mixed-language condition, although these effects were not significant. These findings suggest that both language context and cognate status are important to consider when testing both overt switches and disfluencies in bilingual speech production.