Bilingualism is not a categorical variable: Interaction between language proficiency and usage

Brain correlates of attentional load processing reflect degree of bilingual engagement: Evidence from EEG

The present study uses electroencephalography (EEG) with an N-back task (0-, 1-, and 2-back) to investigate if and how individual bilingual experiences modulate brain activity and cognitive processes. The N-back is an especially appropriate task given recent proposals situating bilingual effects on neurocognition within the broader attentional control system (Bialystok and Craik, 2022). Beyond its working memory component, the N-Back task builds in complexity incrementally, progressively taxing the attentional system. EEG, behavioral and language/social background data were collected from 60 bilinguals. Two cognitive loads were calculated: low (1-back minus 0-back) and high (2-back minus 0-back). Behavioral performance and brain recruitment were modeled as a function of individual differences in bilingual engagement. We predicted task performance as modulated by bilingual engagement would reflect cognitive demands of increased complexity: slower reaction times and lower accuracy, and increase in theta, decrease in alpha and modulated N2/P3 amplitudes. The data show no modulation of the expected behavioral effects by degree of bilingual engagement. However, individual differences analyses reveal significant correlations between non-societal language use in Social contexts and alpha in the low cognitive load condition and age of acquisition of the L2/2L1 with theta in the high cognitive load. These findings lend some initial support to Bialystok and Craik (2022), showing how certain adaptations at the brain level take place in order to deal with the cognitive demands associated with variations in bilingual language experience and increases in attentional load. Furthermore, the present data highlight how these effects can play out differentially depending on cognitive testing/modalities - that is, effects were found at the TFR level but not behaviorally or in the ERPs, showing how the choice of analysis can be deterministic when investigating bilingual effects.

Negative Pragmatic Transfer in Bilinguals: Cross-Linguistic Influence in the Acquisition of Quantifiers

Building on the cross-linguistic variability in the meaning of vague quantifiers, this study explores the potential for negative transfer in Italian-Slovenian bilinguals concerning the use of quantificational determiners, specifically the translational equivalents of the English "many", that is the Slovenian "precej" and "veliko". The aim is to identify relevant aspects of pragmatic knowledge for cross-linguistic influence. The study presents the results of a sentence-picture verification task in which Slovenian native speakers and Italian-Slovenian bilinguals evaluated sentences of the form "Quantifier X are Y" in relation to visual contexts. The results suggest that Italian learners of Slovenian, unlike Slovenian native speakers, fail to distinguish between "precej" and "veliko". This finding aligns with the negative transfer hypothesis. The study highlights the potential role of pragmatic knowledge in cross-linguistic transfer, particularly in the context of vague quantifiers.

Distinct functional connectivity patterns during naturalistic learning by adolescent first versus second language speakers

Spoken lessons (lectures) are commonly used in schools as a medium for conveying educational content. In adolescence, experience-expectant maturation of language and cognitive systems supports learning; however, little is known about whether or how learners' language experiences interact with this integration process during learning. We examined functional connectivity using fMRI in 38 Spanish-English bilingual (L1-Spanish) and English monolingual (L1-English) adolescents during a naturalistic science video lesson in English. Seed analyses including the left inferior frontal gyrus (pars opercularis) and posterior middle temporal gyrus showed that L1-Spanish adolescents, when learning in their second language (L2), displayed widespread bilateral functional connectivity throughout the cortex while L1-English adolescents displayed mostly left-lateralized connectivity with core language regions over the course of the science lesson. Furthermore, we identified functional seed connectivity associated with better learning outcomes for adolescents with diverse language backgrounds. Importantly, functional connectivity patterns in L1-Spanish adolescents while learning in English also correlate with their Spanish cloze reading. Findings suggest that functional networks associated with higher-order language processing and cognitive control are differentially engaged for L1 vs. L2 speakers while learning new information through spoken language.

Early language experience and modality affect parietal cortex activation in different hemispheres: Insights from hearing bimodal bilinguals

The goal of this study was to investigate the impact of the age of acquisition (AoA) on functional brain representations of sign language in two exceptional groups of hearing bimodal bilinguals: native signers (simultaneous bilinguals since early childhood) and late signers (proficient sequential bilinguals, who learnt a sign language after puberty). We asked whether effects of AoA would be present across languages - signed and audiovisual spoken - and thus observed only in late signers as they acquired each language at different life stages, and whether effects of AoA would be present during sign language processing across groups. Moreover, we aimed to carefully control participants' level of sign language proficiency by implementing a battery of language tests developed for the purpose of the project, which confirmed that participants had high competences of sign language. Between-group analyses revealed a hypothesized modulatory effect of AoA in the right inferior parietal lobule (IPL) in native signers, compared to late signers. With respect to within-group differences across languages we observed greater involvement of the left IPL in response to sign language in comparison to spoken language in both native and late signers, indicating language modality effects. Overall, our results suggest that the neural underpinnings of language are molded by the linguistic characteristics of the language as well as by when in life the language is learnt.

Degree of multilingual engagement modulates resting state oscillatory activity across the lifespan

Multilingualism has been demonstrated to lead to a more favorable trajectory of neurocognitive aging, yet our understanding of its effect on neurocognition across the lifespan remains limited. We collected resting state EEG recordings from a sample of multilingual individuals across a wide age range. Additionally, we obtained data on participant multilingual language use patterns alongside other known lifestyle enrichment factors. Language experience was operationalized via a modified multilingual diversity (MLD) score. Generalized additive modeling was employed to examine the effects and interactions of age and MLD on resting state oscillatory power and coherence. The data suggest an independent modulatory effect of individualized multilingual engagement on age-related differences in whole brain resting state power across alpha and theta bands, and an interaction between age and MLD on resting state coherence in alpha, theta, and low beta. These results provide evidence of multilingual engagement as an independent correlational factor related to differences in resting state EEG power, consistent with the claim that multilingualism can serve as a protective factor in neurocognitive aging.

The role of embodied cognition in action language comprehension in L1 and L2

In this study we carried out a behavioral experiment comparing action language comprehension in L1 (Italian) and L2 (English). Participants were Italian native speakers who had acquired the second language late (after the age of 10). They performed semantic judgments on L1 and L2 literal, idiomatic and metaphorical action sentences after viewing a video of a hand performing an action that was related or unrelated to the verb used in the sentence. Results showed that responses to literal and metaphorical L1 sentences were faster when the action depicted was related to the verb used rather than when the action depicted was unrelated to the verb used. No differences were found for the idiomatic condition. In L2 we found that all responses to the three conditions were facilitated when the action depicted was related to the verb used. Moreover, we found that the difference between the unrelated and the related modalities was greater in L2 than in L1 for the literal and the idiomatic condition but not for the metaphorical condition. These findings are consistent with the embodied cognition hypothesis of language comprehension.

Exploring the Interplay Between Language Comprehension and Cortical Tracking: The Bilingual Test Case

Cortical tracking, the synchronization of brain activity to linguistic rhythms is a well-established phenomenon. However, its nature has been heavily contested: Is it purely epiphenomenal or does it play a fundamental role in speech comprehension? Previous research has used intelligibility manipulations to examine this topic. Here, we instead varied listeners' language comprehension skills while keeping the auditory stimulus constant. To do so, we tested 22 native English speakers and 22 Spanish/Catalan bilinguals learning English as a second language (SL) in an EEG cortical entrainment experiment and correlated the responses with the magnitude of the N400 component of a semantic comprehension task. As expected, native listeners effectively tracked sentential, phrasal, and syllabic linguistic structures. In contrast, SL listeners exhibited limitations in tracking sentential structures but successfully tracked phrasal and syllabic rhythms. Importantly, the amplitude of the neural entrainment correlated with the amplitude of the detection of semantic incongruities in SLs, showing a direct connection between tracking and the ability to understand speech. Together, these findings shed light on the interplay between language comprehension and cortical tracking, to identify neural entrainment as a fundamental principle for speech comprehension.

Examining the consistency in bilingualism and white matter research: A meta-analysis

This study aimed to systematically investigate the relationship between bilingualism, age, L2 onset age of acquisition (AoA), and white matter integrity (operationalized as fractional anisotropy, FA), addressing inconsistencies in the literature. We conducted a meta-analysis of 23 studies and used meta-regression models to assess the influence of age and L2AoA on effect sizes in studies comparing monolinguals and bilinguals. Even though the overall between-group effect size across the whole brain was unreliable, bilingualism was associated with increased white matter integrity in specific tracts and in groups with a limited range of age and L2AoA. Age had a small, negative effect on white matter integrity, with differences between monolinguals and bilinguals more pronounced in younger adults, consistent with a view of an initial increase in white matter integrity, followed by remodeling for efficiency over time. In contrast, later L2AoA was associated with greater white matter integrity in bilinguals than monolinguals, again consistent with the remodeling for efficiency model. Our findings highlight the importance of considering age and L2AoA when examining the neural basis of bilingualism on white matter in the brain and how bilingualism contributes to structural changes that stave off cognitive decline in older age.

LexCHI: A quick lexical test for estimating language proficiency in Chinese

A prominent methodological issue in cognitive research on bilingualism is the lack of consistency in measuring second language (L2) proficiency. To reduce the inconsistency in L2 proficiency measurements, brief and valid vocabulary tests have been developed as an objective measure of proficiency in a variety of languages (e.g., English, French, Spanish). Here, we present LexCHI, a valid lexical test to measure Chinese proficiency. This freely available short test consists of 60 two-character items presented in simplified Chinese. Although it only takes a few minutes to complete LexCHI, the LexCHI scores in two studies correlated significantly with L2 participants' performance in a translation task and a cloze test. We believe that LexCHI is a useful tool for researchers who need to objectively measure Chinese proficiency as part of their investigations.

Neural specificity for semantic and syntactic processing in Spanish-English bilingual children

Brain development for language processing is associated with neural specialization of left perisylvian pathways, but this has not been investigated in young bilinguals. We examined specificity for syntax and semantics in early exposed Spanish-English speaking children (N = 65, ages 7-11) using an auditory sentence judgement task in English, their dominant language of use. During functional near infrared spectroscopy (fNIRS), the morphosyntax task elicited activation in left inferior frontal gyrus (IFG) and the semantic task elicited activation in left posterior middle temporal gyrus (MTG). Task comparisons revealed specialization in left superior temporal (STG) for morphosyntax and left MTG and angular gyrus for semantics. Although skills in neither language were uniquely related to specialization, skills in both languages were related to engagement of the left MTG for semantics and left IFG for syntax. These results are consistent with models suggesting a positive cross-linguistic interaction in those with higher language proficiency.

Brain gray matter morphometry relates to onset age of bilingualism and theory of mind in young and older adults

Lifelong bilingualism may result in neural reserve against decline not only in the general cognitive domain, but also in social cognitive functioning. In this study, we show the brain structural correlates that are associated with second language age of acquisition (L2AoA) and theory of mind (the ability to reason about mental states) in normal aging. Participants were bilingual adults (46 young, 50 older) who completed a theory-of-mind task battery, a language background questionnaire, and an anatomical MRI scan to obtain cortical morphometric features (i.e., gray matter volume, thickness, and surface area). Findings indicated a theory-of-mind decline in older adults compared to young adults, controlling for education and general cognition. Importantly, earlier L2AoA and better theory-of-mind performance were associated with larger volume, higher thickness, and larger surface area in the bilateral temporal, medial temporal, superior parietal, and prefrontal brain regions. These regions are likely to be involved in mental representations, language, and cognitive control. The morphometric association with L2AoA in young and older adults were comparable, but its association with theory of mind was stronger in older adults than young adults. The results demonstrate that early bilingual acquisition may provide protective benefits to intact theory-of-mind abilities against normal age-related declines.

Mapping individual aspects of bilingual experience to adaptations in brain structure

Individual differences in using multiple languages are thought to differentially affect brain structure and function. The present study assessed the neuroanatomical predictions of an emerging theory, the Unifying the Bilingual Experience Trajectories framework, which provides the most comprehensive set of predictions of how individual differences in bilingual experiences lead to specific neural and cognitive adaptations. A total of 140 young adults with variable language experiences were scanned using magnetic resonance imaging and completed demographic questionnaires. Brain structure measures implicated in predictions of the Unifying the Bilingual Experience Trajectories model were extracted and regressed against the model's experiential factors. Consistent with the model's predictions, greater intensity and diversity of bilingual language use resulted in changes in gray matter volume in cortical regions involved in executive control (including inferior frontal gyrus, middle temporal gyrus, angular gyrus, and medial frontal gyrus), indicating adaptations toward handling increased executive control demands. Conversely, duration of bilingual engagement resulted in changes within white matter microstructure (bilateral superior longitudinal fasciculus) and increases in subcortical gray matter (left caudate), indicative of adaptations toward increased efficiency of control. Overall, this research enhances our understanding of how bilingual experiences influence brain structure and provides the first direct empirical evidence for the predictions made by the Unifying the Bilingual Experience Trajectories framework.

Brain connectivity and academic skills in English learners

English learners (ELs) are a rapidly growing population in schools in the United States with limited experience and proficiency in English. To better understand the path for EL's academic success in school, it is important to understand how EL's brain systems are used for academic learning in English. We studied, in a cohort of Hispanic middle-schoolers (n = 45, 22F) with limited English proficiency and a wide range of reading and math abilities, brain network properties related to academic abilities. We applied a method for localizing brain regions of interest (ROIs) that are group-constrained, yet individually specific, to test how resting state functional connectivity between regions that are important for academic learning (reading, math, and cognitive control regions) are related to academic abilities. ROIs were selected from task localizers probing reading and math skills in the same participants. We found that connectivity across all ROIs, as well as connectivity of just the cognitive control ROIs, were positively related to measures of reading skills but not math skills. This work suggests that cognitive control brain systems have a central role for reading in ELs. Our results also indicate that an individualized approach for localizing brain function may clarify brain-behavior relationships.

Exploring the Production Effect in Memory Reveals a Balanced Bilingual Advantage

There is evidence suggesting that bilingual individuals demonstrate an advantage over monolinguals in performing various tasks related to memory and executive functions. The characteristics of this bilingual advantage are not unanimously agreed upon in the literature, and some even doubt it exists. The heterogeneity of the bilingual population may explain this inconsistency. Hence, it is important to identify different subgroups of bilinguals and characterize their cognitive performance. The current study focuses on the production effect, a well-established memory phenomenon, in bilingual young adults differing in their English and Hebrew proficiency levels, and the possible balanced bilingual advantage. The aims of this study are (1) to evaluate the production effect in three groups of bilingual participants: English-dominant bilinguals, Hebrew-dominant bilinguals, and balanced bilinguals, and (2) to examine whether memory advantage depends on varying degrees of bilingualism. One hundred twenty-one bilingual young adults who speak English and Hebrew at different levels participated. All learned lists of familiar words, in English and Hebrew, half by reading aloud and half by silent reading, followed by free recall tests. As expected, a production effect (better memory for aloud words than for silent words) was found for all groups in both languages. Balanced bilinguals remembered more words than did dominant participants, demonstrating a memory advantage in both languages. These findings support the hypothesis that the presence of cognitive advantage in bilingualism depends on the acquisition of a good proficiency level in each of the languages, with direct implications for family language policy and bilingual education.

Touching while listening: Does infants' haptic word processing speed predict vocabulary development?

The present study examined the links between haptic word processing speed, vocabulary, and inhibitory control among bilingual children. Three main hypotheses were tested: faster haptic processing speed, measured by the Computerized Comprehension Task at age 1;11, would be associated with larger concurrent vocabulary and greater longitudinal vocabulary growth. Second, early vocabulary size would be associated with greater vocabulary growth at 3;0 and 5;0. Finally, faster haptic processing speed would be associated with greater concurrent inhibitory control, as measured by the Shape Stroop Task. The results revealed that haptic processing speed was associated with concurrent vocabulary, but not predictive of later language skills. Also, early decontextualized vocabulary was predictive of vocabulary at 3;0. Finally, haptic processing speed measured in the non-dominant language was associated with inhibitory control. These results provide insight on the mechanisms of lexical retrieval in young bilinguals and expand previous research on haptic word processing and vocabulary development.

Bilingualism Alters the Neural Correlates of Sustained Attention

The present study examined whether monolingual and bilingual language experience -- including first and second language proficiency, exposure, and age of acquisition -- modify the neural mechanisms of attention during nonverbal sound discrimination. English monolinguals and Korean-English bilinguals performed an auditory two-stimulus oddball task while their EEG was recorded. Participants heard a series of two different tones (high pitch tone versus low pitch tone), one of which occurred less frequently (deviant trials) than the other (standard trials), and were asked to mentally count the number of infrequent tones. We found that in the early time window, bilinguals had larger amplitudes than monolinguals in response to both standard and deviant trials, suggesting that bilinguals initially increased attention to identify which of the two tones they heard. In the later time window, however, bilinguals had a smaller ERP effect (deviant minus standard trials) relative to monolinguals, suggesting that bilinguals used fewer cognitive resources for the infrequent stimuli at later stages of processing. Furthermore, across the entire sample, increased exposure to the native language led to larger early, middle, and late ERP effects. These results suggest that native language exposure shapes perceptual processes involved in detection and monitoring. Knowing more than one language may alter sustained attentional processes, with implications for perception and learning.

Receptive vocabulary predicts multilinguals' recognition skills in adverse listening conditions

Adverse listening conditions are known to affect bilingual listeners' intelligibility scores more than those of monolingual listeners. To advance theoretical understanding of the mechanisms underpinning bilinguals' challenges in adverse listening conditions, vocabulary size and language entropy are compared as predictors in a sentence transcription task with a heterogeneous multilingual population representative of a speech community. Adverse listening was induced through noise type, bandwidth manipulations, and sentences varying in their semantic predictability. Overall, the results generally confirm anticipated patterns with respect to sentence type, noise masking, and bandwidth. Listeners show better comprehension of semantically coherent utterances without masking and with a full spectrum. Crucially, listeners with larger receptive vocabularies and lower language entropy, a measure of the predictability of one's language use, showed improved performance in adverse listening conditions. Vocabulary size had a substantially larger effect size, indicating that vocabulary size has more impact on performance in adverse listening conditions than bilingual language use. These results suggest that the mechanism behind the bilingual disadvantage in adverse listening conditions may be rooted in bilinguals' smaller language-specific receptive vocabularies, offering a harmonious explanation for challenges in adverse listening conditions experienced by monolinguals and multilinguals.

Speech disfluencies in bilingual Greek-English young adults

PURPOSE

The purpose of this study was to investigate the frequency and types of disfluencies in Greek-English bilingual adults across naturalistic speech samples and compare frequency and types of disfluencies between the participants' L1 and L2.

METHODS

Participants in the study included 26 Greek-English bilingual young adults. All participants were sequential bilinguals, whose first language was Greek and second language was English. Two speech samples were collected in each language, a conversational and a narrative sample, which were subsequently analyzed for the frequency and types of disfluencies.

RESULTS

Results indicated that participants produced more typical disfluencies in English compared to Greek across speaking samples. The most frequent types of disfluencies were filled pauses and vowel prolongations (without tension or struggle) across speaking samples and languages.

CONCLUSION

Our results revealed differences in the types and frequencies of disfluencies produced in participants' native compared to their second language. Results add to the growing body of literature addressing the manifestation of speech disfluencies in bilingual speakers.

Robustness of the cognitive gains in 7-month-old bilingual infants: A close multi-center replication of Kovács and Mehler (2009)

We present an exact replication of Experiment 2 from Kovács and Mehler's 2009 study, which showed that 7-month-old infants who are raised bilingually exhibit a cognitive advantage. In the experiment, a sound cue, following an AAB or ABB pattern, predicted the appearance of a visual stimulus on the screen. The stimulus appeared on one side of the screen for nine trials and then switched to the other side. In the original experiment, both mono- and bilingual infants anticipated where the visual stimulus would appear during pre-switch trials. However, during post-switch trials, only bilingual children anticipated that the stimulus would appear on the other side of the screen. The authors took this as evidence of a cognitive advantage. Using the exact same materials in combination with novel analysis techniques (Bayesian analyses, mixed effects modeling and cluster based permutation analyses), we assessed the robustness of these findings in four babylabs (N = 98). Our results did not replicate the original findings: although anticipatory looks increased slightly during post-switch trials for both groups, bilingual infants were not better switchers than monolingual infants. After the original experiment, we presented additional trials to examine whether infants associated sound patterns with cued locations, for which we did not find any evidence either. The results highlight the importance of multicenter replications and more fine-grained statistical analyses to better understand child development. HIGHLIGHTS: We carried out an exact replication across four baby labs of the high-impact study by Kovács and Mehler (2009). We did not replicate the findings of the original study, calling into question the robustness of the claim that bilingual infants have enhanced cognitive abilities. After the original experiment, we presented additional trials to examine whether infants correctly associated sound patterns with cued locations, for which we did not find any evidence. The use of novel analysis techniques (Bayesian analyses, mixed effects modeling and cluster based permutation analyses) allowed us to draw better-informed conclusions.

Disentangling dyslexia from typical L2-learning in emergent literacy

The present paper assessed how dyslexia can be identified in school children with another language than their first language. Participants were school children with Norwegian as their second language (L2), and two groups of children with Norwegian as their first language (L1): a control group (L1-Con), and a dyslexia group (L1-Dys). All were 2nd and 3rd graders who had attended Norwegian schools from 1st grade on. None of the individuals in L1-Con or the L2 group were identified with any learning disability. However, slow literacy progress was seen in some L2-children. The children were tested individually within the symptomatic and cognitive levels. Results were analysed in two steps: (1) group comparisons; (2) L2 individual profiles and tentative L2 subgrouping. An unexpected L2 profile showed language scores below norm, coupled with some scores within and some scores above norm within the cognitive domain. Case assessment of the L2 group resulted in three subgroups: one comparable to L1-Con, one comparable to L1-Dys, and one with a result in between these two groups. Low linguistic scores cannot be considered valid markers of dyslexia in L2. Within the cognitive domain, a variety of low scores can indicate dyslexia, while high scores can be compensatory.

The effect of inhibitory control and language proficiency on intra-sentential switching costs in reading comprehension

Based on the inhibition account and activation account, inhibitory control and language proficiency play big roles on language control mechanisms underlying language switching respectively. But it is still debatable whether inhibitory control and language proficiency play roles in sentential context during bilingual language comprehension, and how and when they work if they both do. The present study examined the specific roles of language proficiency and inhibitory control on modulating intra-sentential switching costs in Chinese-English bilinguals using self-paced reading task. Results indicated that language proficiency and switching direction modulated intra-sentential switching costs significantly. Switching costs were larger when switching into L1 than into L2 for the first two code-switched words due to inhibitory effect, but more costly switching into L2 than into L1 since the third code-switched words owing to the effect of relative language proficiency. During bilingual language processing, inhibition and activation of languages shaped a dynamic interplay of complementary language control processes. Specifically, inhibitory control and language proficiency work as a dynamic continuum in language switching at sentence level. Switching into L1 requires the release of inhibition to L1, but switching into L2 asks the activation and access of L2. The interaction effects of language proficiency and inhibitory control influenced the exertion and components of inhibition. This study reconciled the independent roles of language proficiency and inhibitory control on language switching and constructed a new continuum based on language proficiency.

The Impact of Interpreting Training Experience on the Attentional Networks and Their Dynamics

Interpreting, a complicated and demanding bilingual task, depends heavily on attentional control. However, few studies have focused on the interpreters' advantages in attention, and the findings so far have been inconsistent. Meanwhile, the connection between attentional networks and other cognitive abilities, such as working memory (WM), has rarely been explored in interpreters. The present study investigated whether interpreting experience (IE) contributed to the attentional networks of bilinguals and explored the link between interpreters' attention and WM. Three groups of Chinese-English bilinguals, differing only in their duration of interpreting training (the More-IE group, the Less-IE group, and the No-IE group), completed the Attention Network Test (ANT). Results showed that only the alerting network was more efficient in the More-IE group than in the Less-IE and No-IE groups; moreover, the dynamics between the alerting and executive networks were significant only in the More-IE group. Furthermore, we found a negative correlation between the executive effect and the working memory capacity (WMC) in the More-IE group. Our study validated and provided empirical support for the Attentional Control Model, stimulating further research into neurocognitive mechanisms of advanced second language learning.

The more they hear the more they learn? Using data from bilinguals to test models of early lexical development

Children have an early ability to learn and comprehend words, a skill that develops as they age. A critical question remains regarding what drives this development. Maturation-based theories emphasise cognitive maturity as a driver of comprehension, while accumulator theories emphasise children's accumulation of language experience over time. In this study we used archival looking-while-listening data from 155 children aged 14-48 months with a range of exposure to the target languages (from 10% to 100%) to evaluate the relative contributions of maturation and experience. We compared four statistical models of noun learning: maturation-only, experience-only, additive (maturation plus experience), and accumulator (maturation times experience). The best-fitting model was the additive model in which both maturation (age) and experience were independent contributors to noun comprehension: older children as well as children who had more experience with the target language were more accurate and looked faster to the target in the looking-while-listening task. A 25% change in relative language exposure was equivalent to a 4 month change in age, and age effects were stronger at younger than at older ages. Whereas accumulator models predict that the lexical development of children with less exposure to a language (as is typical in bilinguals) should fall further and further behind children with more exposure to a language (such as monolinguals), our results indicate that bilinguals are buffered against effects of reduced exposure in each language. This study shows that continuous-level measures from individual children's looking-while-listening data, gathered from children with a range of language experience, provide a powerful window into lexical development.

The ups and downs of bilingualism: A review of the literature on executive control using event-related potentials

Whether bilingualism enhances executive control (EC) is controversial. This article reviews 24 studies on the bilingual EC effect using event-related potentials (ERPs). It evaluates the evidence based on considerations of neural efficiency, different EC theories, and accounts regarding the locus of the bilingual effect. The review finds some evidence for a positive bilingual impact. This is more consistent for the P3 and response-locked ERPs. Moreover, when considering each component independently, evidence primarily supports a monitoring and secondarily an inhibition locus. Additionally, an N2/ERN (error-related negativity) dissociation (no bilingual N2 effect but positive ERN impact, evident as smaller ERN), coupled with the P3 results, suggest that monitoring may not be the (only) locus of a bilingual effect but (an)other post-monitoring mechanism(s). Attention disengagement also receives some support. Finally, results across studies are largely consistent with the Bilingualism Anterior to Posterior and Subcortical Shift model (BAPSS): Bilingual effects, when found, often manifest as shorter latencies, larger components or wider amplitude effects during earlier (N2, P3) but smaller components or narrower effects during later processing (stimulus-locked negativities and response-locked components). However, this evidence is not unequivocal. Many bilingual-monolingual comparisons reveal null or some suggest negative or opposite to prediction bilingual effects. Second, the scant evidence about which bilingual experiences impact EC is, generally, unclear, while some evidence indicates negative effects. Third, BAPSS is often not confirmed when multiple components are examined within subjects. Finally, this literature is challenged by confounds and small samples. Further research is required to conclude a positive bilingual effect on EC in ERPs.

The dynamic role of inhibitory control in language switching during number-word task performance in dominant and balanced bilinguals

Language is one of the fascinating abilities of the human species. The beauty of language becomes intriguing when we examine language processing among bilinguals. This work attempted to study the effects of language dominance among native Hindi speakers who were either Hindi dominant, English dominant, or balanced bilingual in a language switching task. The task required the participants to read aloud the number-words that were presented singly on the computer screen. The findings support the inhibitory control model's predictions as the results were indicative of asymmetrical switch cost for both the Hindi and English dominant bilinguals. In both the language dominance condition, moving back to the dominant language from a non-dominant language required more time than vice versa. The results also indicated overall reduced reaction time in the reading task performance for balanced bilinguals, further demonstrating the benefits of balanced bilingualism.

Language and communication skills in multilingual children on the autism spectrum: A systematic review

LAY ABSTRACT

Both parents and service providers have voiced concerns about the potential negative impact of exposure to multiple languages on the language and communication skills of autistic children. The current literature review summarized research that assessed the language and communication skills of multilingual autistic children in comparison with their autistic and nonautistic peers. After a comprehensive search, 22 relevant publications were identified that met the inclusion criteria of the current review. Thirteen studies used both direct (directly administered screening/diagnostic tools) and indirect language assessments (e.g. parent questionnaires). Receptive and expressive vocabulary was the most frequently assessed language skill. Available research does not support the assumption that bilingualism has negative effects on the language and communication skills of autistic children. The language and communication skills of multilingual autistic children frequently resembled their monolingual autistic peers in both strengths and areas of growth. Preliminary findings indicate that multilingual autistic children may share some advantages of multilingualism with their multilingual nonautistic peers. Studies often excluded participants with intellectual disabilities or complex communication needs, which means that a large population of autistic children is not yet represented in research about the effects of multilingualism.

Use of the first-acquired language modulates pupil size in the processing of island constraint violations

Introduction

Traditional studies of the population called "heritage speakers" (HS) have treated this group as distinct from other bilingual populations, e.g., simultaneous or late bilinguals (LB), focusing on group differences in the competencies of the first-acquired language or "heritage language". While several explanations have been proposed for such differences (e.g., incomplete acquisition, attrition, differential processing mechanisms), few have taken into consideration the individual variation that must occur, due to the fluctuation of factors such as exposure and use that characterize all bilinguals. In addition, few studies have used implicit measures, e.g., psychophysiological methods (ERPs; Eye-tracking), that can circumvent confounding variables such as resorting to conscious metalinguistic knowledge.

Methodology

This study uses pupillometry, a method that has only recently been used in psycholinguistic studies of bilingualism, to investigate pupillary responses to three syntactic island constructions in two groups of Spanish/English bilinguals: heritage speakers and late bilinguals. Data were analyzed using generalized additive mixed effects models (GAMMs) and two models were created and compared to one another: one with group (LB/HS) and the other with groups collapsed and current and historical use of Spanish as continuous variables.

Results

Results show that group-based models generally yield conflicting results while models collapsing groups and having usage as a predictor yield consistent ones. In particular, current use predicts sensitivity to L1 ungrammaticality across both HS and LB populations. We conclude that individual variation, as measured by use, is a critical factor tha must be taken into account in the description of the language competencies and processing of heritage and late bilinguals alike.

The labor market outcomes of bilinguals in the United States: Accumulation and returns effects

At least half of the world population is bilingual, but lifetime financial gains from early exposure to multiple languages are largely unknown. In this study, we analyze individual earnings of bilinguals in the US using 15 years of Census data and an augmented wage model, accounting for cognitive, manual, and interpersonal skills derived from O*NET job task descriptors via sparse principal component method. Using unconditional quantile regression, we find evidence that language skills mostly benefit individuals at the lower end of the earnings distribution. While our analysis does not establish causality, it underscores the potential of early language acquisition to mitigate income inequality by enhancing the employment prospects of low-income individuals. We also highlight the favorable cost-benefit ratio of language acquisition in childhood, when learners face no monetary opportunity costs and can achieve greater levels of fluency.

Documenting heritage language experience using questionnaires

Introduction

There exists a great degree of variability in the documentation of multilingual experience across different instruments. The present paper contributes to the "methods turn" and individual differences focus in (heritage) bilingualism by proposing a comprehensive online questionnaire building on existing questionnaires and the experience of using them to document heritage bilingualism: the Heritage Language Experience (HeLEx) online questionnaire. HeLEx is validated against and contrasted to an extended version of the Language and Social Background Questionnaire designed for heritage speakers (HSs), LSBQ-H.

Methods

We compare data elicited with both questionnaires in turn from a group of Turkish HSs (n = 174, mean age=32). Our validation focuses on traditional language background variables, including language exposure and use, language proficiency, language dominance, as well as a more novel measure of language entropy. The analyses are based on a subset of key questions from each questionnaire that capture language experience for up to five languages, four modalities, and five social contexts. In a subsequent set of analyses, we explore the impact of different types of response scales, response mechanisms, and manners of variable derivation on the informativity of the data they can provide, in terms of the scope, granularity and distributional properties of the derived measures.

Results and Discussion

Our results show that both HeLEx and LSBQ-H are successful at detecting the important distributional patterns in the data and reveal a number of advantages of HeLEx. In the discussion, we consider the impact of methodological choices regarding question phrasing, visual format, response options, and response mechanisms. We emphasize that these choices are not trivial and can affect the derived measures and subsequent analyses on the impact of individual differences on language acquisition and processing.

Monolingual and bilingual children's performance on arithmetic fluency varies by language fluency

Research has demonstrated that learning two or more languages during development (i.e., becoming bilingual) shapes children's cognition in myriad ways. However, because such studies have largely been conducted using laboratory experiments, it is unclear how bilingualism may modulate more naturalistic cognitive skills such as arithmetic fluency. Moreover, how the relationship between speaking two (or more) languages and arithmetic varies with language fluency-specifically, the degree of bilingualism-has been understudied. Therefore, this study examined third- to fifth-grade monolingual (n = 70) and bilingual (n = 51) children's performance on an arithmetic fluency task. Monolinguals' and bilinguals' performance on the arithmetic fluency task did not differ. However, individual differences in the relation between children's arithmetic fluency and their language fluency were found, suggesting that bilingual children's skill in their nondominant language was associated with arithmetic fluency. These findings point to the importance of examining individual differences in language fluency among bilinguals to understand how bilingualism may shape cognitive skills.

No bilingual advantage in children's attentional disengagement: Congruency and sequential congruency effects in a large sample of monolingual and bilingual children

According to recent accounts, bilingualism in childhood confers an advantage in a specific domain of executive functioning termed attentional disengagement. The current study tested this hypothesis in 492 children (245 boys; M_age = 10.98 years) from Canada, China, and Lebanon by testing for an association between language status and measures of attentional disengagement. Across the entire sample, monolinguals responded more quickly and accurately than bilinguals on a measure of attentional disengagement but differed in age, socioeconomic status, and general cognitive ability. Differences between monolinguals and bilinguals disappeared when the influence of these confounding variables was controlled using a matched samples analysis (ns = 105). Bayesian analyses further confirmed that the evidence was more likely under the null hypothesis than under the alternative hypothesis. In sum, there was little evidence of an association between language status and attentional disengagement in children.

Brain Engagement During a Cognitive Flexibility Task Relates to Academic Performance in English Learners

English Learners (ELs), students from non-English-speaking backgrounds, are a fast-growing, understudied, group of students in the U.S. with unique learning challenges. Cognitive flexibility-the ability to switch between task demands with ease-may be an important factor in learning for ELs as they have to manage learning in their non-dominant language and access knowledge in multiple languages. We used functional MRI to measure cognitive flexibility brain activity in a group of Hispanic middle school ELs (N = 63) and related it to their academic skills. We found that brain engagement during the cognitive flexibility task was related to both out-of-scanner reading and math measures. These relationships were observed across the brain, including in cognitive control, attention, and default mode networks. This work suggests the real-world importance of cognitive flexibility for adolescent ELs, where individual differences in brain engagement were associated with educational outcomes.

Sources of Heterogeneity in Functional Connectivity During English Word Processing in Bilingual and Monolingual Children

Diversity and variation in language experiences, such as bilingualism, contribute to heterogeneity in children's neural organization for language and brain development. To uncover sources of such heterogeneity in children's neural language networks, the present study examined the effects of bilingual proficiency on children's neural organization for language function. To do so, we took an innovative person-specific analytical approach to investigate young Chinese-English and Spanish-English bilingual learners of structurally distinct languages. Bilingual and English monolingual children (N = 152, M(SD)_age = 7.71(1.32)) completed an English word recognition task during functional near-infrared spectroscopy neuroimaging, along with language and literacy tasks in each of their languages. Two key findings emerged. First, bilinguals' heritage language proficiency (Chinese or Spanish) made a unique contribution to children's language network density. Second, the findings reveal common and unique patterns in children's patterns of task-related functional connectivity. Common across all participants were short-distance neural connections within left hemisphere regions associated with semantic processes (within middle temporal and frontal regions). Unique to more proficient language users were additional long-distance connections between frontal, temporal, and bilateral regions within the broader language network. The study informs neurodevelopmental theories of language by revealing the effects of heterogeneity in language proficiency and experiences on the structure and quality of emerging language neural networks in linguistically diverse learners.

Functional neural architecture of cognitive control mediates the relationship between individual differences in bilingual experience and behaviour

Bilinguals have often, but not always, been found to outperform monolinguals on domain-general attentional control. Inconsistent findings have been argued to stem, at least partly, from treating bilingualism as a uniform category and from not considering how neural adaptations to bilingual experiences modulate behavioural outcomes. The present study investigated how patterns of language experience, including language switching behaviour, duration and intensity/diversity of bilingual language use, influence the brain processes underlying cognitive control, and how these in turn translate to cognitive control performance. We examined reaction times and spectral dynamics of the electroencephalograms (EEG) of two-hundred-and-thirty-nine participants (about 70% bilinguals) with diverse language experiences during two cognitive control paradigms testing interference suppression (flanker and Simon task). Using structural equation modelling, we found that different bilingual experience factors were related with neurocognitive measures, which in turn were related with behavioural interference effects, for the flanker but not the Simon task. More specifically, increased frequency of language switching and intensity / diversity of bilingual language usage was negatively related to induced top-down control measures (especially midline-frontal theta), which in turn was beneficial for interference control. In contrast, duration of bilingual engagement correlated negatively with evoked bottom-up control measures (especially P3) and was therefore detrimental to interference control. We demonstrate here for the first time how the different factors of bilingual experience lead to different neural adaptations which impact behavioural outcomes. SIGNIFICANCE STATEMENT: Like other intensive experiences, bilingualism leads to brain adaptations. It results in structural changes in language areas, and, due to demands on language control, in brain areas associated with domain-general cognitive control. Related to this, bilinguals often outperform monolinguals on cognitive control tasks. But what is often ignored is that bilingualism is a multi-dimensional phenomenon, with variations such as diversity of language usage and duration of language use. The present large-scale study of neural functioning in bilingualism revealed for the first time how individual differences in bilingual experience lead to adaptations to brain functioning which in turn affect cognitive control behaviour. It exemplifies how the complexity of individual experiences plays a fundamental role in brain function.

Executive Function and Narrative Language Abilities in Emergent Bilingual Preschoolers: An Exploratory Study

PURPOSE

In light of the importance of preschool oral narrative skills as precursors to literacy, this exploratory study examined expressive language skills among emergent bilingual Latine preschoolers using a naturalistic personal narrative task. To understand the factors that support language use in the personal narrative context for this population, we examined the contribution of children's executive function (EF) skills to their narrative language abilities.

METHOD

Children completed two subtests from the Preschool Self-Regulation Assessment to measure EF and produced two personal narratives in response to conversational prompts. A series of linear regressions were used to evaluate the relation between children's EF skills and their narrative production ability, narrative organization, and expressive language skills derived from automated analyses of narrative samples.

RESULTS

EF was found to predict children's ability to produce a personal narrative but not the language skills children demonstrated in these narratives.

CONCLUSIONS

The current findings suggest that EF is implicated in emergent bilingual Latine children's narrative abilities. At the preschool age, the contribution of EF to narrative language production is apparent in the global task of producing a narrative, rather than in the organizational or linguistic features of the narrative. As such, supporting both EF and narrative skills might be an important means of facilitating preliteracy among bilingual children.

Testing the effects of congruence in adult multilingual acquisition with implications for creole genesis

Linguists from across sub-disciplines have noted that congruence (i.e., form-function mapping) across languages in contact seems to affect acquisition and play a role in language emergence (e.g. Creole genesis). However, because congruence is often confounded with other variables (e.g., frequency, language type, speakers' proficiency levels, perceptual salience, semantic transparency), it remains unclear whether congruence per se benefits learners. In this paper, we provide an experimental test of the effects of congruence on acquisition through an artificial language-learning experiment involving English (L1) and two artificial languages (Flugerdu and Zamperese). English-speakers who identified as "native" (i.e., first-language) speakers (N = 163) were randomly assigned to one of four conditions, varying which of the three languages expressed negation with congruent forms: all three languages; only Flugerdu and Zamperese; only English and Flugerdu; or none. Our findings show that participants better acquired the negation morpheme when the form was congruent with negation in English but not when the two artificial languages alone shared a congruent form. We likewise found unanticipated spillover effects in which participants better acquired the vocabulary and grammar of the artificial languages when all three languages had congruent negation forms. These findings provide insight into the effects of congruence on language acquisition in multilingual environments and Creole language formation.

The Spanish-English bilingual experience and cognitive change in Hispanics/Latinos from the Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging

INTRODUCTION

Studies suggest bilingualism may delay behavioral manifestations of adverse cognitive aging including Alzheimer's dementia.

METHODS

Three thousand nine hundred sixty-three participants (unweighted mean population age ≈56 years) at Hispanic Community Health Study/Study of Latinos baseline (2008-2011) self-reported their and their parents' birth outside the United States, Spanish as their first language, and used Spanish for baseline and comparable cognitive testing 7 years later (2015-2018). Spanish/English language proficiency and patterns of use were self-rated from 1 = only Spanish to 4 = English > Spanish. Cognitive testing included test-specific and global composite score(s) of verbal learning, memory, word fluency, and Digit Symbol Substitution (DSS). Survey linear regression models examined associations between baseline bilingualism scores and cognition.

RESULTS

Higher second-language (English) proficiency and use were associated with higher global cognition, fluency, and DSS at follow-up and better than predicted change in fluency.

DISCUSSION

The bilingual experience was more consistently related to 7-year level versus change in cognition for Hispanics/Latinos.

An intricate relationship between executive function and second-language ability in a cohort of Uyghur-Chinese bilingual children

The relationship between executive function and second-language ability remains contentious in bilingual children; thus, the current study focused on this issue. In total, 371 Uyghur-Chinese bilingual children ranging from 3 to 6 years old were assessed by a battery of tasks measuring language ability (expressive vocabulary tests, receptive vocabulary tests, and phonological awareness of both their first-language and second-language) and executive function (working memory, inhibition, and switching). Our results indicated that age is a crucial moderator of the relationship between second-language ability and executive function. Specifically, executive function unilaterally predicted second-language ability in children who were 3-4 years old, whereas second-language ability and executive function bilaterally influenced each other in children who were 4-5 and 5-6 years old. These findings suggest that executive function and second-language ability have an intertwined and causal relationship among preschool children during development. The theoretical implications of these findings are discussed. RESEARCH HIGHLIGHTS: A counterfactual model showed causality between executive function and second language ability in Uyghur-Chinese bilingual children. Executive function unilaterally predicted second language ability in the 3- to 4-year-old age group. Executive function and second language ability bilaterally influenced each other in the 4- to 5 and 5- to 6-year-old age groups.

Executive functioning during verbal fluency tasks in bilinguals: A systematic review

BACKGROUND

Bilingualism is widespread and being bilingual is more common than being monolingual. The lifelong practice bilinguals receive from managing two languages seems to lead to a cognitive benefit. Conversely, bilingualism seems to affect language ability negatively due to less use of each known language.

AIMS

This systematic review aims to summarize the results of the studies on the effect of bilingualism on executive functioning assessed by verbal fluency tasks. The verbal fluency task is a neuropsychological measure of lexical retrieval efficiency and executive functioning.

METHODS

The review was conducted according to the PRISMA statement through searches in the scientific databases PsycINFO, PsycARTICLES, MEDLINE, PubMed, Web of Science and SCOPUS. Studies included in this review had at least one bilingual and monolingual group, participants over 18 years and one verbal fluency task. Studies that considered bimodal bilingual, second language learners, trilingual or multilingual people, and clinical populations were excluded. A total of 38 studies were included in the systematic review.

MAIN CONTRIBUTION

Quantitative analysis of performance did not show significant differences between monolinguals and bilinguals. Qualitative results are mixed, and no definitive conclusions can be drawn about a bilingual advantage or disadvantage in the verbal fluency tasks.

CONCLUSIONS

Normative data based on the monolingual population are not appropriate to test a bilingual population. It is necessary to take precautions in using this task, especially in clinical practice.

WHAT THIS PAPER ADDS

What is already known on the subject Bilingualism seems to lead to a cognitive benefit due to constantly monitoring the known languages to select the most suitable one for each interactional context and to affect language ability negatively due to less use of each known language but also to language ability negatively. What this paper adds to the existing knowledge This systematic review summarizes the results of the studies on the effect of bilingualism on executive functioning assessed by verbal fluency tasks, a neuropsychological measure of lexical retrieval efficiency and executive functioning. What are the potential or actual clinical implications of this work? Normative data based on the monolingual population are not appropriate to test a bilingual population. It is necessary to take precautions in using this task, especially in clinical practice.

Language combinations of multilinguals are reflected in their first-language knowledge and processing

Consequences of multilingualism vary from offering cognitive benefits to poor educational and cognitive outcomes. One aspect of multilingualism that has not been systematically examined is the typology of multilinguals' languages: Do differences and similarities between languages multilinguals are exposed to contribute to the development of their cognition and brain? We investigated n = 162 5-6-year-olds with various language backgrounds on a monolingual-to-quintilingual continuum. Our results show that typological linguistic diversity can be related to expressive vocabulary knowledge in the dominant language. On neural level, it relates to brain activation patterns in (among others) the PGa area in the bilateral IPL, a brain region previously associated with multilingual experience, but never with language typology. We propose an ecologically valid way of describing the continuum of multilingual language experience and provide evidence for both the cognition and the brain of multilingual kindergartners to be related to the typological linguistic diversity of their environment.

Bilingual Language Experience and Its Effect on Conflict Adaptation in Reactive Inhibitory Control Tasks

We used machine-learning techniques to assess interactions between language and cognitive systems related to inhibitory control and conflict adaptation in reactive control tasks. We built theoretically driven candidate models of Simon and Number Stroop task data (N = 777 adult bilinguals ages 18-43 years living in Montréal, Canada) that differed in whether bilingual experience interacted with inhibitory control, including two forms of conflict adaptation: shorter term sequential congruency effects and longer term trial order effects. Models with continuous aspects of bilingual experience provided signal in predicting new, unmodeled data. Specifically, mixed language usage predicted trial order adaptation to conflict. This effect was restricted to Number Stroop, which overtly involves linguistic or symbolic information and relatively higher language- and response-related uncertainty. These results suggest that bilingual experience adaptively tunes aspects of the control system and offers a novel integrative modeling approach that can be used to pursue other complex individual difference questions within the psychological sciences.

Language dominance and order of acquisition affect auditory translation priming in heritage speakers

Late second language (L2) learners show translation priming from the first language (L1) to the second language (L1-L2), while L2-L1 effects are inconsistent. Late L2 learners also acquire the L2 after the L1 and are typically less dominant in the L2. As such, the relative contribution of language dominance and order of acquisition is confounded in these results. Here, Cantonese heritage and native speakers are tested in an auditory translation priming paradigm. As heritage speakers first learn Cantonese (L1) but later become dominant in English (L2), this profile allows for the potential dissociation of dominance and order of acquisition in translation priming. If order of acquisition is the primary factor, stronger priming is expected in the L1-L2 (Cantonese-English) direction; however, if dominance plays a stronger role, priming is expected in the L2-L1 (English-Cantonese) direction. Native speakers showed stronger L1-L2 priming, consistent with previous findings, while heritage speakers showed priming in both directions, and marginally larger L2-L1 priming. Treating language dominance as a continuous variable revealed that L1-L2 priming correlated with increased Cantonese dominance, while L2-L1 priming marginally correlated with increased English dominance. Collectively, these results suggest that both language dominance and order of acquisition help explain translation priming findings and bilingual lexical processing, generally. Overall, they invite a rethinking of the role of both variables in bilingual lexical access for speakers with different language dominance profiles.

The Involvement of Listening Effort in Explaining Bilingual Listening Under Adverse Listening Conditions

The current review examines listening effort to uncover how it is implicated in bilingual performance under adverse listening conditions. Various measures of listening effort, including physiological, behavioral, and subjective measures, have been employed to examine listening effort in bilingual children and adults. Adverse listening conditions, stemming from environmental factors, as well as factors related to the speaker or listener, have been examined. The existing literature, although relatively limited to date, points to increased listening effort among bilinguals in their nondominant second language (L2) compared to their dominant first language (L1) and relative to monolinguals. Interestingly, increased effort is often observed even when speech intelligibility remains unaffected. These findings emphasize the importance of considering listening effort alongside speech intelligibility. Building upon the insights gained from the current review, we propose that various factors may modulate the observed effects. These include the particular measure selected to examine listening effort, the characteristics of the adverse condition, as well as factors related to the particular linguistic background of the bilingual speaker. Critically, further research is needed to better understand the impact of these factors on listening effort. The review outlines avenues for future research that would promote a comprehensive understanding of listening effort in bilingual individuals.

Can Speaking More Than One Language Help Prevent Alzheimer's Disease?

Alzheimer's disease (AD) is an age-related neurocognitive disorder that is epidemic in the elderly population. Currently, there are limited pharmacological interventions, and this has heightened the urgency to identify potential preventable or modifiable risk factors that promote resilience to the neuropathological effects of AD. The regular use of two or more languages is one such factor that may increases cognitive reserve through the long-standing executive control involved in managing multiple languages in the brain. There is also evidence that bilingualism is associated with increased brain reserve or maintenance, particularly in frontal-executive structures and networks. This review examines the current, sometimes conflicting literature on bi/multilingualism and AD. These studies have confounding variations in the assessment of age of second language onset, language proficiency, language usage, and whether determining incidence of AD or age of symptom onset. Despite these limitations, most publications support the presence of increased frontal-executive reserve that compensates for the development of AD neuropathology and, thereby, delays the emergence of clinical symptoms of dementia by about 4-5 years. Although regularly speaking more than one language does not protect against AD neuropathology, the delay in its clinical expression has a potentially significant impact on the lifelong morbidity from this age-related disease. Learning other languages may be an important modifiable factor for delaying the clinical expression of AD in later life.

The effects of bilingualism on cognition and behaviour in individuals with attention deficits: A scoping review

Background

Weaknesses in executive function have persistently been found to be associated with Attention Deficit Hyperactivity Disorder (ADHD), while bilinguals have been argued to show advantages in executive functions. While there has been some research into how bilingualism affects cognitive skills and behaviour in individuals with attention deficits, the question is still very much open. The aim of this systematic review is to gather, synthesise and evaluate existing evidence on how bilingual language experience and attention deficits affect executive function performance and ADHD-related symptoms in children and adults.

Methods

Following PRISMA guidelines, a comprehensive literature search in relevant databases (PsycInfo, PubMed, Scopus, ERIC, Web of Science, EMBASE, MEDLINE, LLBA) was performed using search strings related to attention difficulties/ADHD and bilingualism. All quantitative studies were included that presented original empirical data on the combined effects of bilingualism and attention levels, regardless of age group and methodology. The screening procedure revealed nine relevant studies.

Results

Across the nine identified studies, a total of 2071 participants were tested. Of these, seven studies involved children and two adults. The studies varied considerably with respect to their design and methodology, the targeted executive function skills or behavioural symptoms, as well as their measure of bilingualism and attention levels. Most studies assessed aspects of executive function performance such as interference control, response inhibition, working memory or cognitive flexibility. Three studies looked at the effects of bilingualism on ADHD-related symptoms or ADHD diagnosis. Across the studies, no systematic advantage or disadvantage of bilingualism on cognitive performance or behaviour in people with attention deficits was observed.

Conclusion

The limited number of identified studies provide no consistent evidence that bilingualism alleviates or intensifies attention difficulties in adults or children with ADHD. Based on the current state of research, individuals with ADHD and their families should not be concerned that learning additional languages has a negative impact on functioning or cognitive performance.

Systematic review registration

https://doi.org/10.17605/OSF.IO/PK768.

Gray matter volume differences between early bilinguals and monolinguals: A study of children and adults

Gray matter has been shown to be greater in early bilingual adults relative to monolingual adults in regions associated with language (Mechelli et al., 2004), and executive control (EC; Olulade et al., 2016). It is not known, however, if language experience-dependent differences in gray matter volume (GMV) exist in children. Further, any such differences are likely not to be the same as those observed in early bilingual adults, as children have had relatively shorter duration of dual-language exposure and/or less development of brain regions serving EC. We tested these predictions by comparing GMV in Spanish-English early bilingual and English monolingual children, and Spanish-English early bilingual and English monolingual adults (n = 122). Comparing only children revealed relatively more GMV in the bilinguals in bilateral frontal, right inferior frontal, and right superior parietal cortices (regions associated with EC). Bilinguals, however, had less GMV in left inferior parietal cortex (region associated with language). An ANOVA including these children with bilingual and monolingual adults revealed interactions of Language Background by Age Group. There were no regions of more GMV in bilinguals relative to monolinguals that were less pronounced in children than adults, despite the children's shorter dual-language experience. There were relative differences between bilingual and monolingual children that were more pronounced than those in adults in left precentral gyrus and right superior parietal lobule (close to, but not directly in areas associated with EC). Together, early bilingual children manifest relative differences in GMV, and, surprisingly, these do not diverge much from those observed in studies of bilingual adults.

Social-Pragmatic Skills and Length of Bilingualism Predict Inhibitory Control in Children

PURPOSE

There is conflicting evidence regarding effects of bilingualism on inhibition, and the mechanisms that might underlie the effects remain unclear. A prominent account views additional demands on structural language use in bilinguals as being at the root of bilingual effects on inhibition. In this study, we tested the novel hypothesis that social-pragmatic skills (alone or together with structural language skills) are associated with inhibition in bilingual children.

METHOD

Parents of 114 typically developing 8- to 11-year-old Spanish-English bilingual children completed the Children's Communication Checklist-Second Edition to index social pragmatics and the Behavior Rating Inventory of Executive Function to index executive functioning skills. The Inhibit clinical scale score reflected children's inhibition. Children's language ability was indexed by the Clinical Evaluation of Language Fundamentals-Fourth Edition in English and Spanish. Length of bilingualism was operationalized continuously as the length of time children had been exposed to both languages in their lifetime. Moderation analyses tested the effects of structural language, social-pragmatic skills, and length of bilingual experience, and their interactions on inhibition.

RESULTS

While structural language skills were not associated with inhibition, they moderated the relation between social-pragmatic skills and inhibition, such that children with better social-pragmatic skills demonstrated better inhibition, and this effect was stronger for children with better structural language skills. Furthermore, longer length of bilingual experience was associated with better inhibition, and this effect was not moderated by any other predictor.

CONCLUSION

These results confirm a graded relationship between bilingualism and inhibition, and indicate that this association is not qualified by structural language or social-pragmatic skills.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21183916.

Assessing language background and experiences among heritage bilinguals

The language backgrounds and experiences of bilinguals have been primarily characterized using self-report questionnaires and laboratory tasks, although each of these assessments have their strengths and weaknesses. The Electronically Activated Recorder (EAR), an audio recording device, has recently become more prominent as a method of assessing real-world language use. We investigated the relationships among these three assessment tools, to understand the shared variance in how these measures evaluated various aspects of the bilingual experience. Participants were 60 Southern California heritage bilingual college students who spoke a variety of heritage languages and began to learn English between the ages of 0-to 12-years. Participants completed both self-report and laboratory-based measures of language proficiency and use, and they wore the EAR for 4  days to capture representative samples of their day-to-day heritage language (HL) use. The results indicated that self-reported HL use and English age of acquisition were significant predictors of real-world language use as measured by the EAR. In addition, self-reported HL proficiency and laboratory-based HL proficiency, as measured by verbal fluency, were mutually predictive. While some variability was shared across different assessments, ultimately, none of the measures correlated strongly and each measure captured unique information about the heritage bilingual language experience, highlighting the dissociation between language experience measured at a single point in time and an accumulated life history with a heritage language. These findings may provide guidance for bilingualism researchers about which assessment tool, or combination of tools, may be best for their specific research questions.

Phonetic and Lexical Encoding of Tone in Cantonese Heritage Speakers

Heritage speakers contend with at least two languages: the less dominant first language (L1), that is, the heritage language, and the more dominant second language (L2). In some cases, their L1 and L2 bear striking phonological differences. In the current study, we investigate Toronto-born Cantonese heritage speakers and their maintenance of Cantonese lexical tone, a linguistic feature that is absent from English, the more dominant L2. Across two experiments, Cantonese heritage speakers were tested on their phonetic/phonological and lexical encoding of tone in Cantonese. Experiment 1 was an AX discrimination task with varying inter-stimulus intervals (ISIs), which revealed that heritage speakers discriminated tone pairs with disparate pitch contours better than those with shared pitch contours. Experiment 2 was a medium-term repetition priming experiment, designed to extend the findings of Experiment 1 by examining tone representations at the lexical level. We observed a positive correlation between English dominance and priming in tone minimal pairs that shared contours. Thus, while increased English dominance does not affect heritage speakers' phonological-level representations, tasks that require lexical access suggest that heritage Cantonese speakers may not robustly and fully distinctively encode Cantonese tone in lexical memory.

Masked-Speech Recognition for Linguistically Diverse Populations: A Focused Review and Suggestions for the Future

PURPOSE

Twenty years ago, von Hapsburg and Peña (2002) wrote a tutorial that reviewed the literature on speech audiometry and bilingualism and outlined valuable recommendations to increase the rigor of the evidence base. This review article returns to that seminal tutorial to reflect on how that advice was applied over the last 20 years and to provide updated recommendations for future inquiry.

METHOD

We conducted a focused review of the literature on masked-speech recognition for bilingual children and adults. First, we evaluated how studies published since 2002 described bilingual participants. Second, we reviewed the literature on native language masked-speech recognition. Third, we discussed theoretically motivated experimental work. Fourth, we outlined how recent research in bilingual speech recognition can be used to improve clinical practice.

RESULTS

Research conducted since 2002 commonly describes bilingual samples in terms of their language status, competency, and history. Bilingualism was not consistently associated with poor masked-speech recognition. For example, bilinguals who were exposed to English prior to age 7 years and who were dominant in English performed comparably to monolinguals for masked-sentence recognition tasks. To the best of our knowledge, there are no data to document the masked-speech recognition ability of these bilinguals in their other language compared to a second monolingual group, which is an important next step. Nonetheless, individual factors that commonly vary within bilingual populations were associated with masked-speech recognition and included language dominance, competency, and age of acquisition. We identified methodological issues in sampling strategies that could, in part, be responsible for inconsistent findings between studies. For instance, disparities in socioeconomic status (SES) between recruited bilingual and monolingual groups could cause confounding bias within the research design.

CONCLUSIONS

Dimensions of the bilingual linguistic profile should be considered in clinical practice to inform counseling and (re)habilitation strategies since susceptibility to masking is elevated in at least one language for most bilinguals. Future research should continue to report language status, competency, and history but should also report language stability and demand for use data. In addition, potential confounds (e.g., SES, educational attainment) when making group comparisons between monolinguals and bilinguals must be considered.