Exposure to multiple languages may support the development of Theory of Mind (ToM) in neurotypical (NT) and autistic children. However, previous research mainly applied group comparisons between monolingual and bilingual children, and the underlying mechanism of the observed difference remains unclear. The present study, therefore, sheds light on the effect of bilingualism on ToM in both NT and autistic children by measuring language experiences with a continuous operationalization. We measure ToM with a behavioral, linguistically simple tablet-based task, allowing inclusive assessment in autistic children. Analyses revealed no difference between monolingual and bilingual NT and autistic children. However, more balanced exposure to different languages within contexts positively predicted first-order false belief understanding in NT children but not autistic children. Mediation analysis showed that the impact in NT children was a direct effect and not mediated via other cognitive skills.

Recent studies showed contradictory results with regard to the implementation of proactive language control during bilingual sentence production. To add novel evidence to this debate, the current study investigated the blocked language order effect, a measure of proactive language control that has previously only been examined in single-word production. More specifically, bilingual participants completed a network description task, using their L1 in Blocks 1 and 3 and their L2 in Block 2. Results showed increased language intrusions in Block 3 compared to Block 1. This pattern indicates that proactive language control can be implemented during bilingual sentence production.

Early language development has rarely been studied in hearing children with deaf parents who are exposed to both a spoken and a signed language (bimodal bilinguals). This study presents longitudinal data of early communication and vocabulary development in a group of 31 hearing infants exposed to British Sign Language (BSL) and spoken English, at 6 months, 15 months, 24 months and 7 years, in comparison with monolinguals (exposed to English) and unimodal bilinguals (exposed to two spoken languages). No differences were observed in early communication or vocabulary development between bimodal bilinguals and monolinguals, but greater early communicative skills in infancy were found in bimodal bilinguals compared to unimodal bilinguals. Within the bimodal bilingual group, BSL and English vocabulary sizes were positively related. These data provide a healthy picture of early language acquisition in those learning a spoken and signed language simultaneously from birth.

Research demonstrates that English- and French-speaking Canadians differ in a wide range of attitudes, including their political preferences, their vision of the Canadian federation and their national identity. In this article, we ask whether individual bilingualism is associated with a decrease in the attitudinal differences between anglophones and francophones. Using survey data collected in the summer of 2023, we attempt to determine whether knowledge of the French language is related to an increase in the responsiveness of English-speaking citizens toward issues that typically preoccupy French-speaking Canadians. Our analyses suggest that knowledge of French as a second language is strongly linked to the political preferences of Canadian citizens but does not bridge the attitudinal gap between Canada’s two main language groups. These results highlight the relevance of considering the different languages that people speak—and not just their mother tongue—to understand their political attitudes.

Prospective memory (PM) relies on switching processes to change from the ongoing activity to the future intention. Similarly, bilinguals in dual-language contexts are frequently required to switch between languages. In this study, we experimentally simulated the exposure to a dual-language context in a sample of single-language context bilinguals to explore the effect of language switching on PM. Thus, a group of bilinguals practiced language switching previous to the PM task (practice group) and were compared to a homologous group that did not receive this practice (control group). Event-related potential results indicated that the practice group showed greater wave amplitudes than the control group in the components associated to monitoring and switching processes. Whereas, this practice did not affect the retrospective components associated with the retrieval of the intention. This suggested that the interactional context in which bilinguals are immersed modulates their cognitive control strategies in charge of recalling future intentions.

Unbalanced bilinguals often exhibit reduced emotionality in their non-native language, although the underlying neural mechanisms remain poorly understood. This fMRI (functional magnetic resonance imaging) study investigated neural differences during a silent reading task where late Spanish–English bilinguals read happy, fearful and neutral fiction passages in their first (L1) and second (L2) languages. We observed a significant language-by-emotionality interaction in the left hippocampus while participants read fearful texts, indicating a stronger limbic system response in L1. Functional connectivity analyses revealed lower coupling between semantic (left anterior temporal lobe) and limbic (left amygdala) regions when reading fearful texts in L2, suggesting less integrated emotional processing. Overall, these findings show that emotional reading in unbalanced bilinguals is strongly influenced by language, with a higher emotional response and more integrated connectivity between semantic and affective areas in the native language.

A central question in foreign language (LX) learning is how vocabulary acquisition is affected by using image versus orthographic referents. According to the picture superiority effect (PSE) and bilingual/dual coding theory (b/DCT), images should lead to better novel word encoding and retrieval. We tested this prediction using behavioral and event-related potential (ERP) measures. Thirty Polish native speakers learned 40 LX (artificial language) words using either image or L1/orthographic referents. After 24 hours, participants were tested using a translational priming paradigm in congruent and incongruent training-testing modalities. Behavioral results showed higher accuracy and faster responses for LX words learned and tested with images, in line with the PSE and b/DCT. ERP results revealed smaller Late Positive Complex (LPC) amplitudes for words preceded by image compared to lexical primes, likely reflecting less cognitively demanding lexical retrieval. These results provide converging evidence that visual referents provide a more salient modality for L2 learning.

Word frequency has long been considered an essential aspect of psycholinguistic theory. However, research has shown that measures of contextual and semantic diversity provide a better fit to lexical decision and naming data than word frequency. The current study examines the role of contextual and semantic diversity in picture naming ability across aging and bilingualism. A picture naming experiment was conducted with six groups of participants: younger monolinguals, older monolinguals, younger L1 English bilinguals, older L1 English bilinguals, younger L2 English bilinguals and older L2 English bilinguals. Consistent with previous findings, the contextual diversity measure accounted for more variance in the picture naming data than word frequency. Furthermore, older adults and L1 English bilinguals were more sensitive to semantic diversity information, while younger adults and L2 English bilinguals relied more on age of acquisition in their lexical organization.

This study examined the variability of language profiles in Spanish–English bilingual children with and without developmental language disorder (DLD). The data included 529 children between the ages of 5 and 10 years. Eighty-eight of these children were identified as having DLD. A latent profile analysis was conducted based on children’s morphosyntax and semantics performance in Spanish and English. The optimal model identified five different profiles, illustrating the heterogeneity in bilingual development. Children with DLD were observed across all profiles, but most were classified in the only two profiles where lower morphosyntax than semantic performance was observed across languages. These results show the variability in both bilingual children with and without DLD. Additionally, the hallmark deficit of DLD in morphosyntax was confirmed, with the morphological weakness being observed in each of the bilingual children’s languages. Children’s background factors (age, maternal education and language exposure) were associated with profile characteristics.

Language mixing is a common phenomenon in the language input of bilingual children. However, the relation between the frequency of parental language mixing and children’s language development remains unclear. The present study investigates the relation between language mixing as observed in daylong audio recordings (LENA) and as reported by parents in the questionnaire for Quantifying Bilingual Experience (Q-BEx) and children’s language outcomes in the majority and minority language. Participants were 52 3-to-5-year-old Polish-Dutch and Turkish-Dutch children in the Netherlands and Bayesian informative hypothesis evaluations were applied. In 14 out of 15 regression analyses, the LENA and Q-BEx measures yielded similar associations with children’s language outcomes. Parental language mixing was not related to majority language outcomes, but a negative relation was found with expressive vocabulary in the minority language. Longitudinal studies are needed to pinpoint the directionality of this negative relation.

The bilingual advantage hypothesis, which associates bilingualism with benefits in executive functioning (EF), has been challenged by studies demonstrating inconsistent results. Considering explicit calls to revise the hypothesis, research has turned toward understanding which specific bilingualism-related aspects might impact bilinguals’ EF. Notably, patterns of everyday language use, referred to as interactional contexts in the adaptive control hypothesis (ACH), have emerged as a prominent factor modulating the association between bilingualism and EF. This scoping review synthesizes findings from 49 studies investigating interactional contexts and bilinguals’ EF. The results indicate that the current literature is highly heterogeneous regarding the operationalization, measurement, experimental manipulations of interactional contexts, the EF tasks employed and sample characteristics. This variability limits definitive conclusions about the adaptation of bilinguals’ EF to the demands of interactional contexts. More studies with comparable research designs and clearer predictions on the associations between EF domains and bilinguals’ language-use patterns are needed.

The purpose of this study was to examine the impact of acoustic filtering and modality on speech-in-noise recognition for Spanish-English late bilinguals (who were exposed to English after their 5th birthday) and English monolinguals. All speech perception testing was conducted in English. Speech reception thresholds (SRTs) were estimated at 50% recognition accuracy in an open-set sentence recognition task in the presence of speech-shaped noise (SSN) in both low-pass and no-filter conditions. Consonant recognition was assessed in a closed-set identification task in SSN in four conditions: low-pass and no-filter stimuli presented in auditory-only (AO) and audiovisual (AV) modalities. Results indicated that monolinguals outperformed late bilinguals in all conditions. Late bilinguals and monolinguals were similarly impacted by acoustic filtering. Some data indicated that monolinguals may be more adept at integrating auditory and visual cues than late bilinguals. Theoretical and practical implications are discussed.

We investigated which objective language proficiency tests best predict the language dominance, balance, English and Spanish proficiency scores relative to Oral Proficiency Interview (OPI) scores (averaged across 5–6 raters). Eighty Spanish–English bilinguals completed OPIs, picture naming, semantic and letter fluency, lexical decision tests and a language history questionnaire. Except for letter fluency, objective measures explained more variance than self-report variables, which seldom and negligibly improved proficiency prediction beyond objective measures in forward regression models. Picture naming (the Multilingual Naming Test (MINT) Sprint 2.0) was the strongest predictor for most purposes. Lexical decision and category fluency were next best predictors, but the latter was time-consuming to score, while the former was easiest to administer (and does not require bilingual examiners). Surprisingly, self-rated proficiency better predicted the OPI scores when averaged across modalities (i.e., including reading/writing instead of just spoken proficiency), and lexical-decision (a written test) was as powerful as picture naming for predicting spoken Spanish (but not language dominance).

Many bilinguals speak both languages proficiently and habitually; however, the contexts in which the languages are used can vary. The present study examined the effects of context variation on emotions, comparing a national language used everywhere to a regional language spoken only among family and friends. We found a higher sensitivity to disgust (Experiment 1), a greater enjoyment of humor (Experiment 2) and stronger emotions in response to endearments, reprimands and insults (Experiment 3) with the regional language. The regional language induced stronger emotional responses, even though it was used less frequently than the national language. The effects of the regional language varied depending on the frequency of its use. We propose that these effects on emotions reflect the different opportunities to use the language among family and friends, contexts critical for the acquisition and regulation of emotions and in which emotions are expressed quite vividly.

Grammatical aspect is a linguistic correlate of the temporal distribution of an event. However, aspect is not identical across languages. Crosslinguistic differences in mapping between aspect and basic temporal features such as event stage can reveal underlying language-specific criteria that guide event conceptualization. We investigated the relationship between grammatical aspect and event stage in conceptualizations of in-progress and completed events by native (L1) and non-native (L2) speakers of aspectual languages Russian and English. In L1, event stage predicted aspect in Russian but not in English. In L2s, event stage did not predict aspect. We discuss these findings in terms of crosslinguistic differences in the relevance of event stage for conceptualization in L1 as well as the role of L1 transfer in L2 aspect use.

Bilingualism delays the onset of dementia symptoms and contributes to cognitive reserve. However, the neural basis of this mechanism remains elusive. The few studies that have investigated neural mechanisms of cognitive reserve and bilingualism have focused on Alzheimer’s disease. This study investigated the neural basis of cognitive reserve among persons with frontotemporal dementia (FTD) using regional brain volumes. Sixty-eight persons with FTD (42 bilinguals and 26 monolinguals) were included. After propensity score matching for age, sex, education, FTD subtype and clinical severity, there were 26 bilinguals and 26 monolinguals. The results showed that bilinguals had reduced thalamic volume compared to monolinguals despite having similar cognitive performance. The results indicate that bilinguals were able to tolerate more severe atrophy compared to monolinguals while maintaining comparable cognitive abilities. Our study therefore suggests that bilingualism contributes to cognitive reserve in persons with FTD.