Previous research suggests that child HSs’ performance in offline linguistic tasks is typically worse than their age-matched monolingual peers and is modulated by linguistic and child-level factors. This study examined the comprehension and production of three Mandarin non-canonical structures in 5- to 9-year-old Mandarin–English heritage children and Mandarin-speaking monolingual children, including an online processing task. Results showed that heritage children had different performance in production and offline comprehension across structures compared to monolinguals. In online processing, they showed sensitivity to different cues similarly to monolinguals but took longer to revise initial misinterpretations. Within heritage children, we found that presence of morphosyntactic cues facilitated performance across tasks while cross-linguistic influence was only identified in production and offline comprehension but not in online processing. Additionally, input quantity predicted their production and offline comprehension accuracy of non-canonical structures, whereas age modulated their production. Lastly, online processing was not modulated by age nor input.

Contraction of want to to wanna is sometimes possible (e.g., Who do you want to/wanna stay with ___ ?), but sometimes impossible (e.g., Who do you want ___ to/*wanna stay?). This contrast is attributable to the grammatical constraint that a wh-trace blocks the contraction of want and to. Most first language (L1) and second language (L2) acquisition studies testing learner knowledge of this constraint have used elicited production tasks and focused on adult participants, with inconsistent results. Using a child-friendly acceptability judgment task, the current study shows that children as young as 3;11 and both child and adult L2 learners have target-like knowledge of the constraint on wanna contraction. This result is in line with the position that L1 acquisition, child L2 acquisition, and adult L2 acquisition are qualitatively similar.

For bilinguals, lexical access in one language may affect, or be affected by, activation of words in another language. Research to date suggests seemingly contradictory effects of such cross-linguistic influence (CLI): in some cases CLI facilitates lexical access while in others it is a hindrance. Here we provide a comprehensive review of CLI effects drawn from multiple disciplines and paradigms. We describe the contexts within which CLI gives rise to facilitation and interference and suggest that these two general effects arise from separate mechanisms that are not mutually exclusive. Moreover, we argue that facilitation is ubiquitous, occurring in virtually all instances of CLI, while interference is not always present and depends on levels of cross-language lexical competition. We discuss three critical factors – language context, direction, and modality of CLI – which appear to modulate facilitation and interference. Overall, we hope to provide a general framework for investigating CLI in future research.

No studies have investigated the neural correlates of Number and Person agreement processing in bilinguals. Because a previous fMRI study showed difference in L1 and L2 morphosyntactic processing of L1 Turkish–L2 Persian bilinguals, it was of interest whether this difference can be specifically attributed to Number or Person processing. Therefore, we reanalyzed these data at the whole-brain level, revealing a selective response for Number Violations in the pars opercularis (PO), whereas Number and Person Violations activated the posterior superior temporal gyrus (pSTG). These results support the decomposition of agreement projections and their neuroanatomical substrates in bilinguals and confirm the involvement of systematically different feature-checking and feature-mapping mechanisms in Number and Person agreement but shared mechanisms between L1 and L2. Moreover, at variance with previous reports, Number Violations evoked more effects than Person Violations in pSTG, suggesting qualitatively different processing underlying R-expression and pronominal controllers.

In a recent study, Fernandez et al. (2021) investigated parafoveal processing in L1 English and L1 German–L2 English readers using the gaze contingent boundary paradigm (Rayner, 1975). Unexpectedly, L2 readers derived an interference from a non-cognate translation parafoveal mask (arrow vs. pfeil), but derived a benefit from a German orthographic parafoveal mask (arrow vs. pfexk) when reading in English. The authors argued that bilingual readers incurred a switching cost from the complete German word, and derived a benefit by keeping both lexicons active from the partial German word. In this registered report, we further test this finding with L1 German–L2 English participants using improved items, but with the sentences presented in German. We were able to replicate the non-cognate translation interference but not the orthographic facilitation. Follow up comparisons showed that all parafoveal masks evoked similar inhibition, suggesting that bilingual readers do not process non-cognate semantic or orthographic information parafoveally.

BAbSANT (Bilingual Abstract Semantic Associative Network Training) is a novel, theoretically motivated approach to anomia therapy for bilingual persons with aphasia (BPWA). We report on a Russian-dominant, Russian–English BPWA, who was trained on abstract English and Russian words. We hypothesized both within- and cross-language generalization when the non-dominant language was trained, and only within-language generalization when the dominant language was trained. We also hypothesized that cross-language generalization is modulated by nonverbal cognitive control. Results revealed that when English abstract words were trained, within-language generalization to concrete words and cross-language generalization to Russian abstract words was observed, confirming our first hypothesis. However, our second hypothesis was not confirmed. When Russian was trained, direct effects of treatment and within- or cross-language generalization effects were not observed. Our third hypothesis was confirmed. Results from cognitive control tasks from this individual suggest a role of nonverbal cognitive control on cross-language treatment outcomes.

Semantic feature-based treatments (SFTs) are effective rehabilitation strategies for word retrieval deficits in bilinguals with aphasia (BWA). However, few studies have prospectively evaluated the effects of key parameters of these interventions on treatment outcomes. This study examined the influence of intervention-level (i.e., treatment language and treatment sessions), individual-level (baseline naming severity and age), and stimulus-level (i.e., lexical frequency, phonological length, and phonological neighborhood density) factors on naming improvement in a treated and untreated language for 34 Spanish–English BWA who completed 40 hours of SFT. Results revealed significant improvement over time in both languages. In the treated language, individuals who received therapy in their L1 improved more. Additionally, higher pre-treatment naming scores predicted greater response to treatment. Finally, a frequency effect on baseline naming accuracy and phonological effects on accuracy over time were associated with differential treatment gains. These findings indicate that multilevel factors are influential predictors of bilingual treatment outcomes.

In a between-language lexical priming study, we examined to what extent the two languages in a simultaneous bilingual child's lexicon interact, while taking individual differences in language exposure into account. Primary-school-aged Dutch–Greek bilinguals performed a primed picture selection task combined with eye-tracking. They matched pictures to auditorily presented Dutch target words preceded by Greek prime words. Their reaction times and eye movements were recorded. We tested for effects of between-language phonological priming, translation priming, and phonological priming through translation. Priming effects emerged in reaction times and eye movements in all three conditions, at different stages of processing, and unaffected by language exposure. These results extend previous findings for bilingual toddlers and bilingual adults. Processing similarities between these populations indicate that, across different stages of development, bilinguals have an integrated lexicon that is accessed in a language-nonselective way and is susceptible to interactions within and between different types of lexical representation.

This study investigated whether non-native English speakers showed a processing advantage for high-frequency multiword units (multiword frequency effects), and whether the effects differed between native and non-native speakers. Such a difference has been identified in relation to single-word processing. Native English speakers and intermediate learners of English with languages of different scripts (native speakers of Japanese and German) judged whether English multiword units were grammatical. A significant processing advantage was identified for both native and non-native participants. More importantly, the multiword frequency effects were stronger among non-native than native speakers. The discrepancy persisted even after including individual vocabulary knowledge as a predictor in the mixed-effect models. Furthermore, there was no significant different impact of the effects between two non-native groups, even though German participants responded quicker than Japanese participants. This indicates that the varying influence between L1 and L2 could be explained by within-language, not between-language, variables.

To test effects of German on anticipation in Vietnamese, we recorded eye-movements during comprehension and manipulated i) verb constraints (different vs. similar in German and Vietnamese) and ii) classifier constraints (absent in German). In each of two experiments, participants listened to Vietnamese sentences like “Mai mặc một chiếc áo.” (‘Mai wears a [classifier] shirt.’), while viewing four objects. Between experiments, we contrasted bilingual background: L1 Vietnamese–L2 German late bilinguals (Experiment 1) and heritage speakers of Vietnamese in Germany (Experiment 2). Both groups anticipated verb-compatible and classifier-compatible objects upon hearing the verb/classifier. However, when the (verb) constraints differed (e.g., Vietnamese: mặc ‘wear (a shirt/#earrings)’ – German: tragen ‘wear (a shirt/earrings)’), the heritage speakers were distracted by the object (earrings) compatible with the German (but not the Vietnamese) verb constraints. These results demonstrate that competing information in the two languages can interfere with anticipation in heritage speakers.

The aim of the present study was to determine whether bilinguals activate the figurative meaning of an idiom that is specific to one language when they are exposed to its translation in their other language. We used a cross-modal priming task in which participants heard L2 English sentences that ended with an idiom translated from their L1. They then saw a visually presented stimulus that was either related to the meaning of the L1 idiom, a matched control word, or a nonword, and made a lexical decision. Three experiments were run, each with a different group of bilinguals (French–English, Vietnamese–English, and Indonesian–English), and each with a monolingual English control group. In all three studies, the effect of relatedness for bilinguals and monolinguals differed, demonstrating cross-language activation of idiom meanings. Evidence was obtained that suggested that culture-specific information in idioms influenced processing.

Previous developmental studies reported bilinguals’ Theory of Mind (ToM; the ability to take on another's perspective) develops differently than monolinguals. We conducted a scoping review to evaluate how researchers assess bilinguals’ ToM and whether they characterize bilinguals’ lived experiences. We analyzed 53 publications examining ToM in bilinguals, with most papers studying children (n = 42; 79%). We identified 96 different tasks used across these 53 papers. The most common are 46 (48%) cases of the false-belief task, a cognitive-focused task using story vignettes. Few tasks target other types of ToM, such as ToM in social settings or taking others’ emotional perspectives. Furthermore, only half of the papers reported language history (n = 28, 53%) and exposure (n = 25, 47%), limiting the inferrability of ToM and language experiences. Expanding how we study ToM in bilinguals will improve our understanding of the intersection of bilingualism and ToM.

Previous research has shown that bilingual speakers may be more tolerant to ambiguity, they might perceive situations of ambiguity more interesting, challenging and desirable (e.g., Dewaele & Li, 2013). To our knowledge, no data are available addressing the question whether the language in use can have an effect on the personality trait of tolerance of ambiguity (ToA). This study investigated whether and how reading statements in a second language (L2), as opposed to the native language (L1), affects ToA. 387 Italian–English bilingual adults completed a questionnaire measuring levels of ToA either in English or Italian. Results revealed that processing information in L2 promoted higher scores of ToA overall and in sentences that were related to challenging perspectives and change. Age, gender and L2 proficiency were significant predictors of higher ToA scores. This study offers new evidence that processing information in a L2 can affect tolerance of ambiguous situations.