Bilinguals simultaneously activate both languages during word retrieval. False cognates, words overlapping in form but not meaning across languages, typically trigger crosslinguistic interference relative to non-cognates. Crosslinguistic interference resolution can be impaired in bilinguals with stroke-induced aphasia, yet little is known about the neural dynamics supporting these interference resolution processes. We recorded scalp electroencephalography in 21 age-matched controls and five bilinguals with aphasia participating in a picture-word interference paradigm eliciting crosslinguistic interference and a nonlinguistic spatial Stroop task. Bilinguals with aphasia showed lower performance than age-matched controls and crosslinguistic interference was present across both groups. A medial frontal component peaking around 400 ms post stimulus presentation was present in controls across tasks but was absent in the linguistic task in bilinguals with aphasia. This suggests that while bilinguals typically engage the medial frontal cortex to resolve crosslinguistic interference, this mechanism is disrupted in bilinguals with aphasia.

This longitudinal study examined the cognitive development of Spanish children from monolingual backgrounds attending schools with varying levels of English exposure (13%–83%) to assess whether higher L2 exposure results in advantages over time. 229 children (ages 6–7) completed background (nonverbal reasoning (NVR), working memory (WM), L1 vocabulary, L2 vocabulary) and experimental tests measuring attentional/executive functions (selective attention, divided attention, switching, inhibition) at the beginning and end of year 1 of primary education. Generalized linear mixed-effects models, accounting for factors such as family educational level, onset of L2 exposure and language exposure outside of school, indicated that children’s cognitive skills benefit from (high) L2 exposure at school, with greater L2 exposure being linked to more enhanced attentional/executive skills as well as to a larger L2 vocabulary. These findings support the positive effects of immersion programs, suggesting that L2 exposure in school settings alone can contribute to more developed attentional/executive skills.

Reading experience provides critical input for language learning. This is typically quantified via estimates of print exposure, such as the Author Recognition Test (ART), although it may be unreliable in L2. This study introduces the Author Fluency Task (AFT) as an alternative measure, comparing with ART for assessing knowledge of English discourse connectives and collocations among 60 bilingual French/English speakers, and a comparison sample of 60 L1 English speakers. Participants completed AFT, ART, and LexTALE in both languages. Analysis of L2 measures showed AFT more accurately predicted L2 vocabulary knowledge than ART, even when controlling for proficiency (LexTALE). Conversely, ART was more effective for L1 speakers, showing a striking dissociation between the measures across language groups. Additionally, data showed limited contributions from L1 proficiency and print exposure on L2 vocabulary. These findings recommend AFT as a valuable tool for quantifying the role of L2 print exposure for language learning.

We corroborate findings showing a disparity in one’s willingness to update political beliefs in the face of counterevidence among bilinguals, examining the role of the Foreign Language effect (FLe) on belief maintenance. 133 Liberal English-Spanish bilinguals and 70 English monolinguals showed that belief change on political issues is lesser than on nonpolitical issues following counterevidence. Bilinguals, however, showed greater change in the second language (L2) compared to the first and greater belief change than the monolinguals overall. The second language also led to slower reading and rating times across all conditions, which corresponded with greater belief change. Among bilinguals using their L2, those most likely to show belief change reported having a less meaningful connection to the foreign language.

Previous studies show that bilingual toddlers who develop their first language (L1) alongside another language can show early stabilization in the L1. This study investigates grammatical development of L1 Cantonese in children with very early onset of English before age 3 (earlier-onset bilinguals/EB, n = 31), with matched later-onset bilinguals (LB, n = 21) as the baseline. Input characteristics and child development measures at 3;0 and 5;8 were derived from parental reports, caretaker–child toy play and narration tasks. Results show that at 3;0, when the LB children were monolingual, the EB children were below the LB group in general grammatical complexity and seven specific grammatical structures (‘early costs’). At 5;8, the EB children converged with the LB children across grammatical measures in Cantonese, while demonstrating superior performance in English (‘long-term gains’). Our findings reveal a distinctive velocity of L1 development in early additive bilinguals raised in a bilingual society.

People’s decisions may change when made in a foreign language (FL). Research testing this foreign language effect (FLE) has mostly used scenarios where uncertainty is expunged or reduced to a form of risk, whereas real-life decisions are usually characterized by uncertainty around outcome likelihood. In the current work, we aimed to investigate whether the FLE on decision-making extends to uncertain scenarios. Moreover, as it is still unclear what linguistic and psychological factors contribute to the FLE, we tested the effects of participants’ FL background, cognitive style and risk-taking attitude on decision processes under certain and uncertain conditions. Overall, we report null effects of language context (native versus foreign language) and problem condition (certain versus uncertain prospects) on participants’ choices. In addition, we found that both FL background and decision makers’ traits modulated participants’ choices in a FL, without emerging into the ‘classic’ FLE on decision-making. However, the direction of such effects was complex, and not always compatible with previous FLE theories. In light of these results, our study highlights the need to reconceptualize the FLE and its implications on decision-making.

Past research suggests that novel word learning is facilitated by multimodal contexts, which enrich semantic representations and strengthen memory traces. We explored whether environmental sounds (e.g., a creaking door) facilitate foreign language (FL) word learning. In all, 36 Spanish-speaking natives learned 60 written Spanish–FL word pairs, each accompanied by one of three sound conditions: a congruent sound matching the word pairs’ denotation, a meaningless tone or silence. Participants then completed a semantic priming and lexical decision task where reaction times and accuracy were collected. Performance was similar for congruent sound and tone conditions and, compared to silence, showed lower accuracy in the lexical decision task and a marginal benefit in the semantic task. These findings suggest that environmental sounds can influence learning, with varying effects depending on the task. Results are discussed in terms of current language learning models.

Previous L1 syntactic processing studies have identified the crucial left frontotemporal network, whereas research on L2 syntactic processing has shown that learner factors, such as L2 proficiency and linguistic distance, can modulate the related networks. Here, we developed a function-word-based jabberwocky sentence reading paradigm to investigate the neural correlates underlying Chinese L2 syntactic processing. Twenty Chinese L2 Korean native speakers were recruited in this fMRI study. Chinese proficiency test scores and Chinese-Korean syntactic similarity scores were measured to quantify the learner factors, respectively. The imaging results revealed an effective left frontoparietal network involving superior parietal lobule (SPL), posterior inferior frontal gyrus (pIFG) and precentral gyrus (PreCG). Moreover, the signal intensity of SPL as well as the connectivity strength between SPL and PreCG significantly correlated with the learner factors. These findings shed light on the neurobiological relationships between L1 and L2 syntactic processing and on the modulation of L2 learner factors.

Bilinguals with aphasia routinely experience anomia in one or both of their languages that may be ameliorated by language treatment. Traditionally, treatment response has been captured by binary scoring systems that measure the presence or absence of improvement without examining how word retrieval attempts may change over time as a function of treatment. This study analyzed word retrieval errors and subsequent treatment outcomes for a group of 48 Spanish-English bilinguals with aphasia to determine if longitudinal error patterns could capture language recovery. Results revealed naming improvement for trained words in the treated language and translations of trained words in the untreated language. Specific types of word errors at baseline were associated with overall improvement in both languages; furthermore, patterns of responses changed over time as a function of lexical-semantic treatment. These results demonstrate that error analyses may characterize bilingual treatment outcomes and provide new evidence for mechanisms of impaired word retrieval.

We investigated the interactive effects of bilingualism and sleep on executive functioning at the behavioral level. We conducted two experiments using two independent samples of bilingual young adults, the Flanker task to assess executive performance, the Pittsburg Sleep Quality Index to measure retrospective sleep quality over a one-month period and the Insomnia Severity Index to assess insomnia-related symptoms. In Experiment 1, we registered bilingualism effects on executive performance in poor, but not in good sleepers. In Experiment 2, the magnitude of bilingual effects increased with increasing severity of insomnia symptoms. We conclude that when poor sleep quality and insomnia negatively affect cognitive resources, bilingualism-related cognitive effects emerge more prominently. This suggests higher degrees of bilingualism may compensate detrimental effects of poor sleep quality and insomnia on executive functioning. We suggest that cognitive research in bilingualism and sleep could benefit from controlling for interindividual variability in sleep quality and vice versa.

Understanding high-variability speech is particularly challenging for second-language (L2) learners due to difficulties with extrinsic normalization, a perceptual strategy utilizing contextual cues to overcome speech variability. This study investigates the neural correlates of these difficulties among Mandarin speakers learning Cantonese, using EEG. Behaviorally, Mandarin learners demonstrated a significant yet considerably reduced ability to normalize Cantonese tone variability with contexts compared to native Cantonese speakers. EEG analysis showed that while native speakers engage multiple neural components (N1, P2, and LPC) for acoustic, phonetic/phonological, and cognitive adjustments in extrinsic normalization, Mandarin learners only activated P2, focusing on phonetic/phonological adjustments. This discrepancy underscores the multi-faceted nature of successful extrinsic normalization, which L2 learners fail to fully engage. L2 immersion significantly improves extrinsic normalization, particularly at the cognitive-adjustment stage. Overall, this study illuminates the intricate nature of poor extrinsic normalization in L2 learners and the importance of L2 immersion for effective L2 speech perception.

This study tested whether native Chinese (L1) readers whose second language (L2) was English could activate L2 translations of L1 words during L1 sentence reading. Chinese–English bilinguals read Chinese sentences silently, each containing a target word whose parafoveal preview was manipulated. To test cross-language semantic activation, each target word was paired with an identical, an unrelated and a translation-related preview that shared an L2 translation (e.g., 政黨, party as a political group) with the target word (e.g., 派對, party as a social gathering). Compared to the unrelated previews, the translation-related previews induced shorter target-word viewing times, despite no phonological/orthographic overlap. Furthermore, the highly proficient L2 readers showed earlier priming effects than did the average readers. Our results suggest that bilinguals activate lexical representations in both languages automatically and non-selectively, even when the task requires activation of one language only, and that the L2 lexical activation is modulated by L2 proficiency.

Language-switching sometimes causes delayed responses, especially when switching from the later-acquired languages (here, L2) to the dominant native language (L1). It is well-established that language proficiency plays a role in production, but what about language context (i.e., the ratio of L1 and L2)? We investigated language context within two language production processes: “top-down” (naming pictures) and “bottom-up” (reading words aloud). We suggest that switch cost asymmetry was not only affected by language context, but also by production modality. In picture naming, the degree of inhibition relies largely on the activation level of the predominant language in the language context, whereby affects the asymmetry. However, the asymmetry disappears when language processing only requires reading aloud words with orthographically unique and constrained to one language. We provide evidence with dynamics of inhibition in different language contexts, suggesting that future study should continue to explore the flexibility of production processes in bilingual speakers.

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.

Word age of acquisition (AoA) influences many aspects of language processing, including reading. However, reading studies of word AoA effects have almost exclusively focused on monolingual young adults, leaving their influence in other age and language groups little understood. Here, we investigated how age (childhood, young adulthood) and language background (monolingual, bilingual) influence word AoA effects during first-language (L1) and second-language (L2) reading. Using eye-tracking, we observed larger L1 word AoA effects in children versus adults (across both language backgrounds). Moreover, we observed larger L2 versus L1 word AoA effects in bilinguals (across both ages), with some evidence of heightened effects in bilingual adults (for late-stage reading only). Taken together, our findings suggest that word AoA exerts a stronger influence on reading during conditions of reduced lexical entrenchment, offering critical insights into how both developing and bilingual readers acquire and maintain word representations across their known languages.

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.

How does the bilingual experience affect online processing? The distribution of lexical items shared between monolinguals and bilinguals can differ greatly. One critical difference is how code-switching allows more variability in the relative co-occurrence of words. The current study uses a visual world paradigm to test whether the relative distribution between Spanish gender-marked determiners (“el,” “la”) and the non-marked English determiner (“the”) predict the Spanish–English bilingual’s ability to predict and/or integrate an incoming noun. While we replicate a previously observed asymmetry among Spanish–English bilinguals between the masculine “el” and feminine “la,” our cluster permutation test results reveal differences in how bilinguals predict and integrate nouns when preceded by “el” versus “la” or “the.” Comparing our results to existing corpus data, we argue that bilinguals rely on the distributional norms they experience across both single-language and code-switched contexts to facilitate online processing.

Although web-based data collection has become increasingly popular in (linguistic) research over the past years, many researchers are still cautious about collecting data via the internet. Thus, this study aims at comparing web-based and lab-based testing of linguistic manipulations that have resulted in robust findings in previous lab-based research on bilingual language processing. A total of 134 L1 German students of L2 English participated in two experiments in a web-based (n = 78) or lab-based setting (n = 56). The study examined potential language co-activation through cognates in an English Lexical Decision Task (Experiment 1) and the use of L2 lexical and syntactic information in English relative clause processing in a Self-paced Reading Task (Experiment 2). We found comparable evidence of lexical and syntactic processing in both groups in both experiments. Critically, this paper provides important methodological implications for web-based data collections with second language learners.

This study investigates heritage speakers (HSs) of Spanish in the U.S. and potential areas of divergence in speech from homeland speakers. To examine the relative contribution of prosody and segments in perceived heritage accent, we conducted an accent rating task with speech samples of second language learners (L2s), HSs and homeland speakers presented in three conditions: original, prosody-only and segments-only. The stimuli were rated by two groups: HSs and homeland speakers. The results revealed that HSs and homeland speakers had similar global accent perceptions, rating HSs as more native-like than L2s but less native-like than homeland speakers. We found that both rater groups aligned with a dominant language ideology of Spanish; speakers who were judged as more native-like were perceived as residing in a Spanish-speaking country. Our findings also demonstrate that prosody contributes more to perceived heritage accent than segments, while segments contribute more to L2 foreign accent than prosody.