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.

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.

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.

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.

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.

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.

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.