Previous studies suggest that bilinguals can quickly identify the language to which a word belongs in order to suppress a task-irrelevant language. The current study tested whether nontarget language suppression occurs at the lexical and/or semantic levels and whether the degree of processing differs across these representational levels. Spanish–Basque bilinguals classified words by language membership and animacy, and event-related potential (ERP) results demonstrated that task demands to attend to a single target language reduced frequency effects and eliminated concreteness effects for words in the nontarget language. Results support a partially selective mechanism of bilingual language control based on task demands such that words belonging to the nontarget language are only partially processed at the lexical level and are not processed at a deeper semantic level. These findings specify the locus of bilingual language control in comprehension and call for revisions to models of bilingual visual word recognition such as BIA+.

This study examines sentence comprehension in two in-situ heritage Slovene communities in Italy’s border-shift context, comparing the Gorizia/Trieste (N = 66) and Natisone Valley (N = 43) adult populations with monolingual Slovene speakers. While both heritage groups operate in Italian-dominant bilingual environments near the Slovenian border, they differ in Slovene exposure due to varying institutional support. Using a sentence–picture verification task, this study examines comprehension of non-canonical word order, relative clauses and cataphoric dependencies. The Gorizia/Trieste group performed comparably to monolinguals, demonstrating strong sensitivity to case morphology and syntactic processing. Conversely, the Natisone group showed reduced accuracy and longer response times across all domains, reflecting case system vulnerability and processing limitations linked to reduced exposure. These findings highlight the important role of active maintenance and institutional support, independent of geographical proximity to the mainland, in shaping heritage language grammars and their use.

Proactive language control is thought to regulate the interference from the nontarget language in bilingual contexts in a sustained way. This study examined the persistence of proactive control in cued picture naming. Participants first named pictures in L1 (German) and L2 (English) in pure blocks, then in mixed language blocks and finally again in pure blocks. In mixed blocks, there were language switch costs, and L1 responses were generally slower than L2 responses (“L1 slowing”). Critically, L1 remained slower than L2 even in postmixing single-language blocks. This persisting L1 slowing suggests overshooting control that downregulates lexical access to L1 representations in a sustained manner. Yet, this persistence of L1 slowing was found only in the first single-language block after the mixed language blocks and no longer in the second postmixing block, suggesting that proactive control has inertia but dissipates over time.

Simultaneous interpreting (SI), a challenging task enabled by bilingualism, is claimed to distinctly tax working memory (WM). However, causal designs are missing, limiting our understanding of the phenomenon. We recruited 50 Chinese-English bilinguals and assessed their WM performance (alongside inhibitory and fluency outcomes) before and after L1–L2 SI or a control task (text comprehension). WM scores (especially under high-demand, multimodal conditions) increased after text comprehension but not after SI, adjusting for age of L2 appropriation, years of L2 use, L2 proficiency and SI competence. Of note, WM was assessed immediately before and after SI, ruling out other cognitive influences. Conversely, no distinct patterns were observed on inhibitory or fluency tasks. Briefly, this activity seems to hinder practice-related WM gains – a finding that expands contemporary accounts of interpreting.

Bilingualism research has long been challenged by a lack of a unified approach to quantifying language dominance and degree of multilingualism. While numerous questionnaires (e.g., LHQ, BLP, LEAP‑Q, and LUQ) provide valuable data on language background variables, they lack a standardized formula to compute key measures from it. We introduce two formulas that synthesize critical linguistic variables to efficiently calculate language dominance and a multilingualism score that ranges from perfect monolingualism to native-like proficiency in multiple languages. Validation across two large datasets shows our dominance measure closely aligns with more complex PCA methods while being simpler and more efficient.

We examined the growth of English-L2 clausal density (CD) in narrative language samples from 129 school-age Syrian refugee children during their first 5 years of residency in Canada. First, we found that CD showed unique developmental trajectories from MLUw, and relatively rapid acquisition, consistent with studies with non-refugee participants. Second, faster growth in CD was associated with superior cognitive abilities and higher maternal education. An older-age advantage was found at Time 1, but a younger-age advantage emerged across Time 2–3. Factors more specific to the refugee experience (time in refugee camps and wellbeing difficulties) also predicted variance in CD and MLUw development but to a lesser extent. Finally, modeling performance on sentence repetition tasks revealed stronger contributions of lexical diversity and MLUw than CD. We conclude that complex syntax is relatively resilient in the L2 acquisition of refugee children and that CD in naturalistic production and SRT capture different abilities.

Bilingual experience may enhance attentional control, but little work has addressed whether monolinguals and bilinguals differ in allocating attentional resources. Focusing on speech processing, we examined listening effort via pupillometry in English monolinguals and simultaneous bilinguals, while they listened to passages in a familiar or unfamiliar language. Results demonstrated similar pupil responses across conditions in bilinguals, yet monolinguals showed significantly larger pupil size when listening to the unfamiliar language than the familiar one. Further, more English exposure (especially a longer stay in an English-speaking family) correlated with smaller pupil size in the familiar language condition. Overall, our findings suggest that bilinguals tend to exhibit greater listening effort than monolinguals, and a more cognitively demanding situation (i.e., listening to an unknown language) requires more effort in monolinguals. With this, we broadened the scope of research on bilingual cognition and demonstrated that bilingualism affects attentional resource allocation in spoken language processing.

Research on multilingualism often assumes homogeneity within monolingual and multilingual groups, overlooking diversity in language environments, such as differences in language exposure and combinations. This study examines three such diversity indicators – language entropy, context entropy and linguistic distance – and their relationship to vocabulary in 4- to 5-year-old mono- and multilingual children (N = 257). Results reveal significantly greater vocabulary in monolinguals than multilinguals when comparing one language, but multilinguals outperform monolinguals on conceptual vocabulary. Vocabulary size in multilinguals showed a quadratic relationship with language and context entropy, initially increasing but declining at higher entropy levels. Additionally, children with greater linguistic distances generally had larger dominant vocabularies. However, within the group with high linguistic distance, further increased distance was linked to smaller dominant vocabularies. These findings suggest that the applied diversity indicators capture meaningful variation in language environments, offering valuable insights about diversity in environments on vocabulary outcomes in multilingual children.

This study investigated whether differences in executive control exist between bilinguals and monolinguals who share a dual-language context. We compared functional monolingual and bilingual groups’ cognitive performance and the correlation between self-reported and objective linguistic variables and cognitive outcomes. Group comparisons revealed no significant differences between functional monolinguals and bilinguals on inhibition, task switching and updating of information. However, distinct correlational patterns were observed within groups. In functional monolinguals, participants with lower bilingualism scores showed better task-specific inhibition (Color–Word part of the Stroop task) and a better ability to monitor for conflicts (Digits Forward task). In contrast, bilinguals with higher degrees of bilingualism showed better overall inhibition outcomes (Stroop effect). Findings are discussed in terms of the importance of adopting more comprehensive methodological approaches to study bilingualism as a heterogeneous phenomenon, considering the diversity within each group and the cultural and linguistic context in which the bilingual experience takes place.

The present study examines how L1-English learners acquire Korean subject honorification – a system that is socio-pragmatic in interpretation but syntactically constrained. Using a multi-method design (corpus analysis, politeness ratings, and self-paced reading), we find that learners show increasing sensitivity to politeness norms yet limited awareness of morphosyntactic constraints. In corpus analysis, learners used subject honorification almost exclusively alongside addressee honorification, indicating limited functional differentiation. In politeness ratings, learners consistently associated the subject honorific suffix with greater politeness, regardless of subject type, diverging from native speakers’ judgments. In self-paced reading, learners were sensitive to semantic anomalies (e.g., inanimate subjects) but not to morphosyntactic violations. Together, these findings suggest that learners interpret the subject honorific suffix as a general politeness marker, likely due to its low cue validity and frequent co-occurrence with pragmatically salient features. Our results highlight how cue reliability and competition shape L2 acquisition pathways under conditions of noisy linguistic representations.

Continuous immersion in a second language causes speakers’ first language to change, a phenomenon known as L1 attrition. We explored (1) whether bilingual native Mandarin speakers display attrition-related changes in their use of referring expressions in Mandarin after exposure to English and (2) whether the severity of attrition is affected by the amount of exposure to both Mandarin (L1) and English (L2) and English proficiency. All participants completed a questionnaire to assess their language experience and a picture description task in spoken Mandarin. The results show that where more monolingual Mandarin speakers preferred null pronouns, bilingual speakers tended to use overt pronouns, suggesting attrition-related changes in their native language which favoured explicitness. Our study also shows that decreased use of L1 coupled with increased use of L2 and higher L2 proficiency are likely to result in a greater degree of attrition, although such an association is statistically unreliable in some models.

We examined how language affects moral judgments in a non-WEIRD population. Tanzanian participants (N = 103) evaluated utilitarian agents in moral dilemmas, either in native Chagga or foreign Swahili. Agents were rated significantly more moral and braver when evaluated in a foreign language. Bravery predicted morality more strongly in the foreign language than in the native language. Indirect sacrifices were judged more moral than direct ones, but equally brave. These findings extend the moral foreign language effect to informally acquired languages and highlight methodological implications for cross-cultural research.

Bilingual speakers have been found to outperform monolingual speakers in tasks which involve taking others’ perspectives. This research examined whether bilingualism improves young adults’ performance on visuospatial perspective-taking (VPT) tasks, independently of culture and executive function (EF). Sixty-three East Asian and 61 European bilingual adults, as well as 60 English monolingual adults took part in level-1 VPT tasks (judging what others can see), level-2 VPT tasks (judging how others can see something) and EF tasks. They also filled in questionnaires about their social and language background, cultural orientation and acculturation. Groups did not differ in terms of VPT, suggesting that adult VPT is not affected by bilingualism or cultural orientation. Hierarchical regression revealed that VPT performance was predicted by EF skills, but not by individual differences in bilingualism or culture.

Sentences written in Chinese are composed of continuous sequences of characters, without spaces or other visual cues to mark word boundaries. While skilled L1 readers can efficiently segment this naturally unspaced text into words, little is known about the word segmentation capabilities of L2 readers, including whether they employ the same strategies to process temporary segmental ambiguities. Accordingly, we report two eye movement experiments that investigated the processing of sentences containing temporarily ambiguous “incremental” three-character words (e.g., “体育馆,” meaning “stadium”) whose first two characters could also form a word (“体育,” meaning “sport”), comparing the performance of 48 skilled L1 Chinese readers and 48 high-proficiency L2 Chinese readers in each experiment. Our findings reveal that both groups can process this ambiguity efficiently, employing similar word segmentations strategies. We discuss our findings in relation to models of eye movement control and word recognition in Chinese reading.

Previous research has mainly explored the relationship between bilingual language control and domain-general cognitive control through behavioral correlations, often revealing epiphenomenal links rather than causality. This study utilizes transcranial magnetic stimulation (TMS) to investigate the causal roles of the left inferior frontal gyrus (LIFG) and left middle temporal gyrus (LMTG) in 33 unbalanced Chinese-English bilinguals. Continuous theta burst stimulation was applied in separate sessions to decrease cortical excitability, with vertex stimulation as a control. LIFG stimulation significantly increased switching costs in nonverbal switching tasks, highlighting its role in domain-general cognitive control. LMTG stimulation did not affect switching or mixing costs in language or nonverbal switching tasks, suggesting no causal involvement, but it reduced reaction times (RTs) during language switching tasks, underscoring its specialization in language processing. These findings highlight distinctions between the neural mechanisms of bilingual language control and domain-general cognitive control, particularly in the LIFG.

Despite abundant studies on motion events and mental simulation in first languages (L1s), research on how cross-linguistic dis/similarity – whether an L1 shares constructions with a second language (L2) – affects mental simulation during incremental L2 processing remains limited. This study used a novel self-paced reading task with video verification to investigate L1 influence on mental imagery of the dual (directional/locational) interpretation of locative prepositions. Participants included native English speakers and advanced L2 English learners whose L1s were either similar (Dutch) or dissimilar (Japanese) to English. Results revealed an L1 dis/similarity effect on the reaction times for the directional interpretation, but not for the locational interpretation, which was readily accessible across all L1 groups. Factors such as L2 proficiency and onset age of L2 acquisition were found to be constrained by L1, suggesting that L1–L2 constructional correspondence limits the influence of learner factors. These findings support the simulation-based model of L2 sentence processing.

This study examines the elicited production of Spanish infinitives versus gerunds among Spanish/English bilingual children and adolescents in the United States. We focus on three contexts: infinitives in subject position, infinitives with the phrasal verb parar de (“to stop doing something”), and infinitives with the prepositional verb parar a (“to stop to do something”). Results showed that children and adolescents produced fewer infinitives than their Spanish-dominant parents in subject position and with parar de, often overextending the gerund. By contrast, all groups performed more accurately with parar a, where English and Spanish align structurally. Language dominance and Spanish experience significantly predicted more target-like infinitive use, while chronological age and English dominance were associated with increased gerund overextension. These findings support the Bilingual Alignment Hypothesis, showing that heritage Spanish morphosyntactic development is gradual and context-sensitive, with greater accuracy in areas of crosslinguistic convergence.

Previous studies revealed structural differences in cerebellar regions between monolinguals and bilinguals. However, the effect of bilingual experiences on cerebellar functional neuroplasticity remains unclear. Using resting-state functional magnetic resonance imaging (fMRI) data, we compared cerebellar functional connectivity (FC) between monolinguals and bilinguals, and then examined how age of second language acquisition (AoA-L2), immersion of L2 (Immersion-L2), proficiency level of L2 (PL-L2) and usage of L2 (Usage-L2) influence cerebellar FC in bilinguals. We found monolinguals exhibited increased FC between lobules VI, VIIIa and superior temporal gyrus. Increased AoA-L2 was related to decreased cerebello-cortical FC involving lobules VI, CrusI and precentral gyrus. Increased Immersion-L2 was associated with decreased cerebello-orbitofrontal FC. Higher PL-L2 corresponded to stronger cerebellar FC with posterior cingulate gyrus. Bilinguals who used L2 more frequently at home exhibited decreased cerebellar FC, while increased social Usage-L2 was associated with increased FC. These findings highlight bilingualism’s impact on cerebellar functional neuroplasticity, shaped by different bilingual experiences.

The present study investigates whether L1 Spanish-L2 English instructed and immersed adult sequential bilinguals show L1 attrition effects in the oral production of subject referring expressions in topic continuity. We tested the predictions from the Pragmatic Principles Violation Hypothesis and controlled for two factors that modulate rates of overproduction, namely antecedent distance and the number of potential antecedents. The results from two oral retelling tasks showed that instructed and immersed bilinguals significantly employ more overt material where functional monolinguals resort to the use of null pronouns. Moreover, factors such as antecedent distance and the number of potential antecedents arguably influence the production of the bilingual groups more strongly. Overall, L1 attrition effects are observed in both L2-immersed and L2-instructed bilinguals. However, attrition effects appear to be milder in instructed bilinguals, who sometimes pattern with functional monolinguals. These results call for new avenues within L1 attrition.

Sound symbolism refers to a non-arbitrary relationship between speech and non-speech sounds and their meaning. We investigated whether bilingual individuals, due to their exposure to diverse linguistic systems, exhibit an advantage in this domain compared to monolinguals, or whether this ability relies on universal mechanisms independent of linguistic background. Ninety-four bilingual (spoken languages: Italian and at least another language; age ranging from 22 to 66 years, M = 35.31, SE = 1.26) and 101 monolingual participants (all Italian speakers; age ranging from 22 to 64 years, M = 36.05, SE = 1.16) were presented with 120 words from four unknown languages and asked to infer their meaning from three alternatives. Results confirmed the presence of sound symbolism, as overall performance was significantly higher than chance, but no significant differences emerged between monolinguals and bilinguals, suggesting that sound symbolism is an automatic cognitive mechanism, independent of prior linguistic experience.