Both bilingualism and attention contribute to the development of executive functioning (EF), with higher levels of both leading to better outcomes. The present study treats bilingualism and attention as continuous variables to investigate their impact on EF. Eighty-two 9-year-olds who were attending a French school in an anglophone community completed a flanker task. Children's progress in French represented their level of bilingualism, and attention was assessed through a standard standardized instrument. Degree of bilingualism and degree of attention were both positively related to performance, but exposure to a third language in the home did not further affect outcomes.

In two experiments, we examined the hypothesis that bilingual speakers modulate their cognitive control settings dynamically in the presence of different interlocutors, and this can be captured through performance on a non-linguistic attention task. We introduced Malayalam–English bilinguals to interlocutors with varying L2 dominance through a pre-experiment familiarisation and interaction phase. Later, participants did the Flanker task while the interlocutors appeared before each trial. While in experiment one participants did the Flanker task with equal distribution of trials, in experiment two we manipulated the monitoring demands by changing the frequency of trials. Results showed that high-L2 proficient bilinguals had lower conflict effect on the Flanker task in the presence of balanced interlocutors in both the experiments. The results provide strong evidence of dynamic adaptation of control settings in bilinguals with regard to different passively present interlocutors. The results further extend the predictions of the adaptive control hypothesis with novel manipulation.

This study investigated how bilingual experience alters neural mechanisms supporting novel word learning. We hypothesised that novel words elicit increased semantic activation in the larger bilingual lexicon, potentially stimulating stronger memory integration than in monolinguals. English monolinguals and Spanish–English bilinguals were trained on two sets of written Swahili–English word pairs, one set on each of two consecutive days, and performed a recognition task in the MRI-scanner. Lexical integration was measured through visual primed lexical decision. Surprisingly, no group difference emerged in explicit word memory, and priming occurred only in the monolingual group. This difference in lexical integration may indicate an increased need for slow neocortical interleaving of old and new information in the denser bilingual lexicon. The fMRI data were consistent with increased use of cognitive control networks in monolinguals and of articulatory motor processes in bilinguals, providing further evidence for experience-induced neural changes: monolinguals and bilinguals reached largely comparable behavioural performance levels in novel word learning, but did so by recruiting partially overlapping but non-identical neural systems to acquire novel words.

This study focuses on English onset cluster production in spontaneous speech samples of 10 children aged 5;04–6;09 from Chinese and Hindi/Punjabi first language (L1) backgrounds, each with less than a year of exposure to English. The results suggest commonalities between early second language (L2) learners and both monolingual and adult L2 learners in the location of cluster repair and the sometimes-exceptional treatment of s+stop clusters. We also provide evidence that accuracy rates and repairs used in early L2 cluster production show L1 influences. We conclude that early L2 learners represent a unique learner group, whose study is crucial to the understanding of phonological development.

Bilinguals dynamically activate lexical items in one or both languages depending on a number of factors. We explored the interaction effects of semantic constraints, language context, and L2-proficiency on cross-language interaction and switch costs in bilinguals who habitually codeswitch between Algerian Arabic (AA) and French. We recorded response times to French cognates and non-cognates embedded in auditory AA or French sentences. High proficiency bilinguals could restrict selection to the target language regardless of the language context. In lower proficiency bilinguals, however, selection was specific to the target language in non-switching contexts but was nonspecific in switching contexts where cross-language interaction yielded inhibitory and facilitatory cognate effects. Results of this study therefore suggest that lexical selection in codeswitching bilinguals is dynamic and is dependent on proficiency, semantic constraints and language context. This within-subject study using auditory stimuli contributes towards a more ecological methodology in investigating sentence processing in codeswitching bilinguals.

Assessing language in sequential bilinguals (L2 children) for the identification of language impairment suffers from lack of appropriate standardized tools and from limited understanding of the developmental trajectories of these learners. This longitudinal study compares L2 children to children with SLI in order to better understand where these groups have overlapping performance and where they differ. An analysis of standardized test scores as well as frequency of clausal embedding and morphosyntactic errors in spontaneous speech was conducted with 22 English-speaking children (aged 6;9-12;7) acquiring French as an L2 in France and 19 monolingual French-speaking children with SLI (aged 6;5–12;11). The results revealed that L2 children used clausal embedding more often than the children with SLI, but both groups had similar rates of morphosyntactic accuracy. Facility with clausal embedding from early stages of development and continuing difficulty with morphosyntactic accuracy are argued to be characteristic of typical development in L2 children.

Although many studies have investigated the consequences of bilingualism on cognitive control, few have examined the impact of bilingualism on other cognitive domains, such as memory. Of these studies, most have focused on item memory and none have examined the role of bilingualism in source memory (i.e., the memory for contextual details from a previous encounter with a stimulus). In our study, young adult bilinguals and monolinguals completed a source memory test, whose different conditions were designed to stress working memory and inhibitory control. Bilinguals performed significantly faster than monolinguals across all conditions without compromising accuracy, and also showed an overall speed advantage on the Flanker task. We interpret these processing speed advantages within the context of current models of bilingual production.

To better explain various neurocognitive consequences of bilingualism, recent investigations have adopted continuous measures of bilingual experience, as opposed to binary bi/monolingual distinctions. However, few studies have considered whether bilingualism's effects on cognition are modulated by the linguistic distance (LD) between L1 and L2, and none of the existing studies has examined cognitive consequences of LD in aging populations. Here, we investigated the modulatory role of LD on the relationship between bilingualism, executive performance, and cognitive reserve (CR) in a sample of senior bilinguals. Our results show a dynamic trajectory of LD effects, with more distant language pairs exerting maximum effects at initial stages of bilingual experience – and closer language pairs at advanced stages. Bilingualism-related CR effects emerged only in the individuals with closer language pairs, suggesting that the language control stage of bilingual experience may play a key role in CR accrual, as compared to the L2 learning stage.

We evaluated the impact of exposure to a second language on infants’ emerging speech production skills. We compared speech produced by three groups of 12-month-old infants while they interacted with interlocutors who spoke to them in Spanish and English: monolingual English-learning infants who had previously received 5 hours of exposure to a second language (Spanish), English- and Spanish-learning simultaneous bilinguals, and monolingual English-learning infants without any exposure to Spanish. Our results showed that the monolingual English-learning infants with short-term exposure to Spanish and the bilingual infants, but not the monolingual English-learning infants without exposure to Spanish, flexibly matched the prosody of their babbling to that of a Spanish- or English-speaking interlocutor. Our findings demonstrate the nature and extent of benefits for language learning from early exposure to two languages. We discuss the implications of these findings for language organization in infants learning two languages.

The idea that there is a critical period (CP) for language acquisition that starts sometime after birth and ends sometime around puberty has been central to language studies since Chomsky's paradigm shift that embedded language acquisition into human biological development (for discussion, see Bialystok & Kroll, in press). From early on, the critical period argument was loosely extended to include second language (L2) acquisition, an idea buttressed largely by anecdote: “children learn foreign languages so much better than adults” in spite of evidence to the contrary (Goldberg, Paradis & Crago, 2008; Snow, 1987). The review by Mayberry and Kluender (2017) describes the existing literature on L2 acquisition and adds recent empirical evidence from investigations of individuals learning American Sign Language (ASL) at different ages, often as a first language (L1) to offer important clarifications and insights to this debate. Their argument rests on a clear distinction between processes used in L1 or L2 acquisition to re-evaluation of some of the more extreme claims of the CP view. In brief, they argue that L2 acquisition is not a good test of the CP argument, a point with which we agree. However, our view is that CP effects on language acquisition are even more limited than Mayberry and Kluender suggest and we offer two further arguments to support their own formidable evidence and conclusion.

This paper investigates “mixed” early two-word utterances by bilinguals, in order to determine whether function words match the language context less frequently than content words. Data collected in two language contexts from a child acquiring English and Spanish from birth were used to identify those two-word utterances occurring in the first two months of two-word utterances, between the ages of 1;7 and 1;9. Those utterances containing one word from each language, where one word was a function and the other a content word, were analysed quantitatively to determine whether the function word was more or less likely to match the context than the content word. The results showed that function words matched the context considerably less than content words. This finding is interpreted as suggesting that function words may not be treated as language-specific by early bilinguals, whereas content words are. It reinforces the significance of the well-established function/content distinction in language acquisition theory in a way which would not be possible with monolingual data.

For bilinguals born in an English-speaking country or who arrive at a young age, English (L2) often becomes their dominant language by adulthood. This study examines whether such adult bilinguals show equivalent performance to monolingual English native speakers on three English auditory processing tasks: phonemic awareness, spelling-to-dictation and auditory comprehension. The study contrasts three bilingual language groups differing in their L1: morphosyllabic/logographic L1 (Cantonese), morphosyllabic/alphabetic (Vietnamese) L1 and non-morphosyllabic/alphabetic L1 (Other). Particularly on the tasks that involved nonwords, the morphosyllabic bilingual groups performed most poorly, suggesting an effect of L1 phonological structure on English processing despite L1 having become subordinate to L2. The results indicate that even when a bilingual is born, raised and educated in their L2 environment, native equivalence in L2 is not assured.

A cross-linguistic structural priming experiment explores the issue of whether parallel syntactic constructions of the two languages in bilinguals share a representation when the surface word orders of the constructions differ. The target population was early balanced bilinguals of Korean and English; the tested constructions were structures relevant to the subject-to-object raising (STOR) operation, which until this study have not been used for structural priming research in cross-linguistic contexts (e.g., STOR: Mary believes Jerry to be trustworthy; non-STOR: Mary believes that Jerry is trustworthy). These syntactic structures exist in both English and Korean, but with different surface word orders. The results show that cross-linguistic priming of the STOR construction occurred, suggesting that parallel syntactic constructions of the languages in bilinguals can share a representation independent of surface word order.

We examined the association between bilingualism, executive function (EF), and brain volume in older monolinguals and bilinguals who spoke English, Spanish, or both, and were cognitively normal (CN) or diagnosed with Mild Cognitive Impairment (MCI) or dementia. Gray matter volume (GMV) was higher in language and EF brain regions among bilinguals, but no differences were found in memory regions. Neuropsychological performance did not vary across language groups over time; however, bilinguals exhibited reduced Stroop interference and lower scores on Digit Span Backwards and category fluency. Higher scores on Digit Span Backwards were associated with a younger age of English acquisition, and a greater degree of balanced bilingualism was associated with lower scores in category fluency. The initial age of cognitive decline did not differ between language groups. The influence of bilingualism appears to be reflected in increased GMV in language and EF regions, and to a lesser degree, in EF.

Most research showing that cognates are named faster than non-cognates has focused on isolated word production which might not realistically reflect cognitive demands in sentence production. Here, we explored whether cognates elicit interference by examining error rates during sentence production, and how this interference is resolved by language control mechanisms. Twenty highly proficient Spanish–English bilinguals described visual scenes with sentence structures ‘NP1-verb-NP2’ (NP = noun-phrase). Half the nouns and half the verbs were cognates and two manipulations created high control demands. Both situations that demanded higher inhibitory control pushed the cognate effect from facilitation towards interference. These findings suggest that cognates, similar to phonologically similar words within a language, can induce not only facilitation but robust interference.

We assessed language switch and mixing costs in a language-general semantic categorization task and examined how these costs relate to general inhibition and set shifting capacities. The participants were 51 native Finnish subjects with English as L2. The results showed significant symmetric language switch costs and, unexpectedly, a mixing advantage in L2: reaction times were faster in the mixed language block than in the single language block. The interactions with the general executive functions showed no consistent overall pattern. We argue that the L2 mixing advantage stems from statistical facilitation in line with a horse race model, or from opportunistic planning as suggested by the Adaptive Control hypothesis. We argue that the results overall indicate that lexical access in language reception is non-selective.

Receptive standardized vocabulary scores have been found to be much higher than expressive standardized vocabulary scores in children with Spanish as L1, learning L2 (English) in school (Gibson et al., 2012). Here we present evidence suggesting the receptive-expressive gap may be harder to evaluate than previously thought. We compared the performance of 116 six-year-old Spanish–English bilingual children in the US to 30 monolingual Spanish-speaking peers in Mexico across two Spanish-language standardized picture naming tests and one standardized picture pointing test. The performance of 134 monolingual English-speaking peers was compared using similar English-language tests. Results revealed the presence and magnitude of a receptive-expressive gap was largely dependent on the tests used. These discrepant results likely exist because widely-used standardized tests do not offer comparable normed scores. We review possible test norming practices that may have contributed to these results and suggest guidelines to determine a meaningful receptive-expressive gap for bilingual children.

Syntactic parsing plays a central role in the interpretation of sentences, but it is unclear to what extent non-native speakers can deploy native-like grammatical knowledge during online comprehension. The current eye-tracking study investigated how Chinese–English bilinguals and native English speakers respond to syntactic category and subcategorization information while reading sentences with object-subject ambiguities. We also obtained measures of English language experience, working memory capacity, and executive function to determine how these cognitive variables influence online parsing. During reading, monolinguals and bilinguals showed similar garden-path effects related to syntactic reanalysis, but native English speakers responded more robustly to verb subcategorization cues. Readers with greater language experience and executive function showed increased sensitivity to verb subcategorization cues, but parsing was not influenced by working memory capacity. These results are consistent with exposure-based accounts of bilingual sentence processing, and they support a link between syntactic processing and domain-general cognitive control.

This paper contributes to current investigations of the nature of babbling in infants raised bilingually by analyzing the babbling of a child raised in a Spanish–English environment. Examination of syllable structure shows the expected preponderance of open syllables in both language contexts while other phenomena point to important differences dependent on language context. While some of the differences relate to general features of the input languages, others coincide with individual features of the parents’ input. These results offer some evidence of distinct babbling according to language context and suggest a possible influence of the type of input.

When bilinguals produce words in one language, their translation equivalents in the other language are thought to be activated as well. A common assumption is that this parallel co-activation produces interference, which slows down word retrieval. The current study aimed to evaluate the assumption of lexical interference during word retrieval by testing whether late Portuguese–English bilinguals were slower to name pictures in their native language when they knew the word in their second language compared to when they only knew the native language label. Instead of interfering with production, knowing the second-language label facilitated speed of word retrieval in the native language for both cognate and non-cognate translation-equivalent pairs. We suggest that using the second language may provide an indirect frequency boost for translation-equivalent words in the native language. This frequency boost has both long-term and short-term effects, strengthening connections to native-language labels when the translation equivalent is retrieved.