Bilinguals often show evidence of cross language influences, such as facilitation in processing cognates. Here we use computational methods for analyzing spontaneous English texts written by hundreds of speakers of different L1s, at different levels of English proficiency, to investigate writers’ preference for using cognates over alternative word choices. We focus on English, since a majority of its lexicon is either of Romance or Germanic origin, allowing an investigation of the preference of speakers of Germanic and Romance L1s towards cognates between their L1 and English. Results show that L2 writers tend to prefer English cognates, and that this tendency is weaker as English proficiency level increases, suggesting diminishing effects of CLI. However, a comparison of the L2 writers with native English writers shows general overuse of cognates only for the Germanic, but not the Romance, L1 speakers, most likely due to the register of argumentative writing.

The present study asked whether oral vocabulary training can facilitate reading in a second language (L2). Fifty L2 speakers of English received oral training over three days on complex novel words, with predictable and unpredictable spellings, composed of novel stems and existing suffixes (i.e., vishing, vishes, vished). After training, participants read the novel word stems for the first time (i.e., trained and untrained), embedded in sentences, and their eye movements were monitored. The eye-tracking data revealed shorter looking times for trained than untrained stems, and for stems with predictable than unpredictable spellings. In contrast to monolingual speakers of English, the interaction between training and spelling predictability was not significant, suggesting that L2 speakers did not generate orthographic skeletons that were robust enough to affect their eye-movement behaviour when seeing the trained novel words for the first time in print.

Early bilingual language experience can enhance children's social-cognitive skills for effective communication. This study examined whether individual variability in bilingual language diversity, measured by language entropy, influenced 3- to 5-year-old children's engagement of contextual information in their selective trust strategies. One-hundred-and-forty Singaporean children (58 girls, Mage = 53.64 months, 97.1% Asian) were presented with an informant who provided either accurate or inaccurate information in a context with either adequate or limited information access. Bilingual children with greater language diversity, compared to those with less language diversity, were more likely to adapt their accuracy-based selective trust strategy to the informant's circumstances (i.e, information access). Results provide new insights into the role of diverse linguistic experiences in shaping children's social cognitive development.

This study investigates bilingualism-induced neuroplastic and cognitive-reserve effects in the Caudate Nucleus (CN), a structure believed to support both bilingual language control and domain-general executive functioning. We computed a generalized bilingualism index incorporating several dimensions of bilingual experience in a sample of bilingual young adults and tested whether this index would predict behavioral executive performance (measured using a Flanker task) and volumetric differences in the CN. Moreover, we investigated whether bilingualism mitigates the relationship between CN volume and executive performance, a sign of cognitive reserve. Our results indicate that bilingualism facilitates executive performance and induces an inverted U-shaped neuroplastic trajectory in bilateral CN, consistently with the view that structural increases are replaced by functional improvements as bilingual experience progresses. The emergence of bilingualism-induced cognitive reserve effects in CN further supports the view that bilinguals rely progressively less on the availability of structural resources in the face of increased functional efficiency.

Previous studies that contrasting bilinguals with monolinguals on Theory of Mind (ToM) have shown mixed results. We present a relatively large (N = 102) study comparing Polish–English sequential bilinguals living in the UK with Polish monolinguals living in Poland. Going beyond a simple group comparison, we explored the role of language proficiency and input in ToM abilities. A battery of eight tasks was used to measure ToM, and the groups were matched on age, gender, SES, IQ and L1 word comprehension. Although bilinguals did not differ from monolinguals in accuracy in ToM tasks, they demonstrated better reasoning abilities when providing justification for ToM responses. ToM accuracy scores were best predicted by L1 proficiency, but the justification scores were best predicted by both L1 and L2 proficiency. The findings suggest that the nuances of bilingual experience provide an important scaffolding context for ToM development.

Structural and functional brain adaptations in bilingual speakers are well documented in the neurolinguistic literature. However, far less is known about neural changes evidenced in multilingual speakers. This study investigates brain plasticity in a group of highly proficient multilinguals, fluent in four or more languages, compared to a group of monolinguals. An ROI analysis used to evaluate differences in core linguistic regions and regions associated with language control revealed robust decreases for multilinguals in grey matter thickness of two brain regions within the parietal lobe (i.e., precuneus and angular gyrus), involved in lexico-semantic processing, memory retrieval, and control maintenance. We discuss our findings in the context of emerging models characterizing trajectorial changes in brain structures associated with language experience. We consider how the demands of optimal functioning within multi-linguistic environments may foster cortical changes that manifest as decreased GM thickness in highly proficient multilingual compared to monolinguals.

Listeners can use the way people speak (prosody) or what people say (semantics) to infer vocal emotions. It can be speculated that bilinguals and musicians can better use the former rather than the latter compared to monolinguals and non-musicians. However, the literature to date has offered mixed evidence for this prosodic bias. Bilinguals and musicians are also arguably known for their ability to ignore distractors and can outperform monolinguals and non-musicians when prosodic and semantic cues conflict. In two online experiments, 1041 young adults listened to sentences with either matching or mismatching semantic and prosodic cues to emotions. 526 participants were asked to identify the emotion using the prosody and 515 using the semantics. In both experiments, performance suffered when cues conflicted, and in such conflicts, musicians outperformed non-musicians among bilinguals, but not among monolinguals. This finding supports an increased ability of bilingual musicians to inhibit irrelevant information in speech.

In this behavioral and electrophysiological study, we compare novel word learning, particularly lexical form acquisition, in an immersive virtual reality (VR) context with a picture-word (PW) association context. We also test whether inhibitory control and age of second language acquisition (L2 AoA) have modulating effects. Chinese speakers of L2 English learned two sets of German words, one set in each of the contexts. Behavioral performance from a subsequent recognition task indicated that responses to VR-learned words were faster than PW-leaned words. ERPs revealed that VR-learned words elicited more negative N100 and N200 waveforms than PW-learned words. Moreover, a significant relationship between L2 AoA and N200 amplitude was observed for VR-learned words. Taken together, the results suggest that the multi-sensory, interactive experience simulated by an immersive VR context has a positive effect on early lexical form acquisition of novel words.

In two online survey studies (N = 688 and N = 247, respectively) we developed and validated a new psychometric scale for measuring emotional resonance reduction in bilinguals’ LX (“later learnt language”) relative to their L1 (“first language”). The final scale, dubbed RER-LX (for Reduced Emotional Resonance in LX), comprises 15 items and possesses a number of desirable psychometric properties. It yields good test reliability (expected alpha between 0.8 and 0.9), produces near-normally distributed test scores, and exhibits content validity in terms of its underlying factor structure. Moreover, it correlates well with the only other instrument previously used for the same purpose (BEQ subscale comprising BEQ-swearing, BEQ-feelings and BEQ-anger). However, compared to the BEQ items, RER-LX has significantly better discriminant validity in relation to LexTALE, a widely used measure of proficiency in English as a second language. Our new scale will be useful to researchers studying bilingualism and emotion.

People's judgements differ systematically while reading moral dilemmas in their native or their foreign language. This so-called Foreign Language Effect (FLE) has been found in many language pairs when tested with artificial, sacrificial moral dilemmas (i.e., Trolley and Footbridge). In Experiment 1, we investigated whether the FLE can be replicated in Turkish (native) – English (foreign) bilinguals using the same dilemmas (N = 203). These unrealistic and decontextualized dilemmas have been criticized for providing low external validity. Therefore, in Experiment 2, we (1) tested bilinguals with realistic scenarios which included the protagonist's age as a source of identity (child, adult, neutral), and (2) investigated the FLE in these scenarios (N = 467). Our results revealed that the FLE was not present in Turkish–English bilinguals, tested either on sacrificial dilemmas or realistic scenarios. Psychological distance of the scenarios, protagonists’ age and the perceived age similarity with the protagonist affected moral judgments.

This study investigated the engagement of domain-general cognitive control during the comprehension of dense code-switching sentences. Stimulus-locked event-related potentials (ERPs) were measured while L1-dominant Chinese–English bilinguals read switch and non-switch sentences. The results of the reading task revealed language dominance effects on the N400, left anterior negativity (LAN) and late positive component (LPC). The language dominance effects at lexical level (i.e., on the N400 and LAN) were modulated by individual differences in monitoring capacity. In contrast, inhibition capacity predicted code-switching costs at the sentence level (i.e., for the LPC component). The results suggest that proactive monitoring and reactive inhibition affect different processing stages during the comprehension of dense code-switching sentences. These findings partially align with processing models of code-switching incorporating a dual control mode perspective and contribute new insight into the dynamic interplay between reactive and proactive control processes.

We examined moral judgments in three types of language: a native national language (Italian), a non-native foreign language (English), and a native regional language (Venetian, oral and colloquial). We used the Moral Foundation Questionnaire to investigate cross-linguistic differences in multiple aspects of morality. Higher scores in the Harm, Purity and Fairness dimensions were obtained in the foreign and the regional language with respect to the national language. In addition, higher scores in the Ingroup dimension were obtained in the foreign language with respect to the native language. The effects of language on morality can thus be quite pervasive, involving a variety of aspects of morality. The differences we observed across these languages are explained in terms of their sociolinguistics – specifically, the greater use of national languages with moral values and beliefs. It is proposed that language effects arise because the language that is used activates information associated with it.

There exists insufficient eye-tracking evidence on the differences in emotional word processing between the first language (L1) and second language (L2) readers. This study conducted an eye-tracking experiment to investigate the emotional effects in L2 sentence reading, and to explore the modulation of L2 proficiency and individual emotional states. Adapted from Knickerbocker et al. (2015), the current study recorded eye movements at both early and late processing stages when late Chinese–English bilinguals read emotion-label and neutral target words in natural L2 sentences. Results indicated that L2 readers did not show the facilitation effects of lexical affective connotations during sentence reading, and they even demonstrated processing disadvantages for L2 emotional words. Additionally, the interaction effect between L2 proficiency and emotion was consistently significant for the measure of total reading time in positive words. Measurements of participants’ depressive and anxious states were not robustly correlated with eye movement measures. Our findings supplemented new evidence to existing sparse eye-tracking experiments on L2 emotion processing, and lent support to several theoretical frameworks in the bilingual research field, including the Emotional Contexts of Learning Theory, Lexical Quality Hypothesis and Revised Hierarchical Model.

Recent studies suggest that heterogeneous bilingual experiences implicate different executive functions (EF) in children. Using a latent profile analysis, we conducted a more nuanced investigation of multifaceted bilingual experiences. By concurrently considering numerous bilingual indicators – age of L1 and L2 acquisition, interactional contexts of verbal exchanges, L1 and L2 proficiency, balance of language use at home and school, and receptive vocabulary – we identified three latent profiles (subgroups): balanced dual-language, dominant single-language, and mixed-interaction. We found that the balanced dual-language and dominant single-language profiles predicted significantly better switching than the mixed-interaction profile. However, no profile differences were found in working memory, prepotent response inhibition, or inhibitory control. These results held true when multiple covariates (age, sex, household income, and nonverbal intelligence) were controlled for. Using a person-centered approach, our study underscores that disparate bilingual experiences asymmetrically predict the shifting facet of EF during early childhood.

Being bilingual confers certain behavioral effects. Determining their precise origin is of utmost importance given the need to avoid unjust misattribution of labels such as “bilingual (dis)advantage” to people's bilingual experiences. To this end, this systematic PRISMA-based review aims to shed light on the social and sociolinguistic origins of bilingualism-related behavioral effects. Analyzing 368 studies, we find that 73.41% of the 267 studies that report such effects attribute them either to sociolinguistic factors alone or to the interaction of sociolinguistic and cognitive factors. Linking the two fronts, type of effect and origin of effect, we find a previously unreported correlation: Studies that find evidence for bilingual disadvantages are more likely to claim a sociolinguistic origin, while studies that report advantages are more likely to link their findings to a cognitive origin. We discuss these results and present the key components of a sociolinguistic theory of the origin of bilingual effects.

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.

Studies investigating the role of dual language use in modulating executive functions have reported mixed results, with some studies reporting benefits in older adults. These studies typically focus on bilingual settings, while the role of dual language use in diglossic settings is rarely investigated. In diglossia, the two language varieties are separated by context, making it an ideal test case for the effects on cognition of Single Language Contexts, as defined by the Adaptive Control Hypothesis (Green & Abutalebi, 2013). We compare the performances of three groups of older adults, Arab diglossics (n = 28), bilinguals (n = 29), and monolinguals (n = 41), on the Flanker and Stroop tasks, measuring inhibition abilities, and the Color-shape task, measuring switching abilities. We report a diglossic benefit in inhibition as measured by the Flanker task only, and no benefits for the bilingual group. These findings are discussed with reference to conversational contexts in dual language use.

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.

We investigated the extent to which language tests developed for native speakers (L1) can be used with advanced speakers of a second language (L2). We compared the performance of Dutch–English bilinguals with that of native English speakers on a series of English language tests, looking at vocabulary knowledge, crystallized intelligence, reading comprehension, and reading speed. It was found that advanced L2 speakers know fewer L2 words than native speakers and take longer to read texts but perform equally well on text comprehension. Tests optimized for native English-speakers predicted text comprehension less well than tests better adapted to the skill level of the bilinguals (which include the Lextale test). An exploratory graphical analysis suggested that L2 users’ performance on challenging vocabulary tests, along with performance on an English author recognition test, forms a distinct cluster – arguably also measuring interest in English language and culture besides knowledge in general (also called crystallized intelligence).