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.

This study explores the implications of Talmy's (2000) motion event typology and its subsequent articulations in relation to Slobin's (1996, 2006) thinking-for-speaking hypothesis for the early successive bilingual acquisition of Uyghur (verb-framed) and Mandarin Chinese (equipollently-framed). Specifically, it examines how 4-, 6-, 8- and 10-year-old bilingual children acquire motion expressions in their L1 and L2 respectively, and how cross-linguistic influence shapes their L2 acquisition process. Results show that, in their L1 Uyghur, bilinguals follow general developmental trajectories observed for children acquiring verb-framed languages. While sensitive to the equipollent Chinese system from early on, due to L1 and other factors, bilinguals fully converge on the Chinese pattern only at age 10, a feat in place in monolinguals from age 3. Our findings highlight that bilingual children do eventually come to develop language-specific thinking-for-speaking patterns in their L2, but they traverse a distinct developmental path.

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.

This online study investigates how first (L1) and foreign language (LX) users, and naïve (L0) listeners of Mandarin perceive the valence and arousal level of a Chinese interlocutor in various communication modalities. The 1485 participants (651 L1, 292 LX, and 542 L0 Mandarin users) were presented with 12 recordings of a Chinese actor conveying emotional events in the visual-vocal-verbal, vocal-verbal, visual-only, or vocal-only modality. Valence and arousal perceptions were collected via the 2DAFS (Lorette, 2021). Disregarding the vocal-only modality which led to neutral perceptions, bootstrapped regression models suggest that modality does not affect L1 users’ valence perceptions. LX and L0 users perceive markedly more neutral valence levels in the absence of visual cues, and in the case of positive stimuli, slightly lower arousal levels. This calls for a more nuanced conceptualisation of valence and arousal as universal features of emotions and stress the significance of modality for intercultural communication.

Little is known about the neural changes that accompany sign language learning by hearing adults. We used ERPs and a word-sign matching task to assess how learning impacted the N400 priming effect (reduced negativity for translations compared to unrelated trials). English monolinguals (N = 32) learned 100 ASL signs – half highly iconic (meaning was guessable), half non-iconic. In contrast to non-iconic signs, little learning was needed for the highly iconic signs as translation accuracy was similar pre- and post-learning. Prior to learning, an N400 priming effect was observed only for iconic signs. After learning, the size of the priming effect increased for non-iconic signs (replicating word learning studies) but decreased for iconic signs. For deaf ASL signers (N = 20), iconicity did not modulate the size of the N400 priming effect. We conclude that the impact of iconicity on lexico-semantic processing is reduced following learning, as signs are integrated into an emerging visual-manual lexicon.

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.

Learners can track word-referent co-occurrences across individually-ambiguous naming events to form correct word-referent mappings, termed statistical word learning (SWL). Prior research largely focuses on learning from a single language input, where a referent co-occurs with a single word (1:1 mapping). Here, we tested adults’ SWL from a simulated bilingual environment, where one referent co-occurred with two words (2:1 mapping) and the two words were either differentiated by a linguistic cue (Mandarin lexical tones, Cued condition) or not (Uncued condition). Results showed that in the Cued condition, Chinese–English bilinguals (N = 38) outperformed Spanish–English bilinguals (N = 56) and English monolinguals (N = 55), while Spanish–English bilinguals and English monolinguals performed similarly. The three groups did not differ in the Uncued condition. Self-reported learning confidence and strategies showed limited conscious awareness of learning. Results demonstrate that familiarity with a linguistic cue boosts overall statistical word learning from bilingual input.

This study investigates whether the cognitive reappraisal strategy is influenced by the participant's language (native/foreign) when confronting a fearful stimulus. Sixty participants with subclinical phobia of cockroaches were exposed to several phobic and neutral pictures while they used cognitive reappraisal in their native language or a foreign one. Electrodermal activity, pupil dilation, and self-reports of affective valence and arousal were collected. Results showed that participants in the foreign context were more effective at using reappraisal to reduce valence self-ratings compared to using no regulation. Also, participants in the foreign context showed greater pupil size when reappraising their emotions, compared to the non-regulation condition. Depending on the language, no differences were found for arousal self-reports or electrodermal activity when using reappraisal. These results suggest that using a foreign language could be advantageous in reducing the negative valence through reappraisal. Psychophysiological results are discussed in light of cognitive effort studies.

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.

The vocabulary of bilingual children is determined by various linguistic factors that develop depending on the language input and individual factors of these children. To understand vocabulary development and to be able to support these children accordingly, the assessment instruments essentially need to be adapted to this individual process. The current study examined factors influencing productive vocabulary performance by means of explanatory item-response models on a sample of 126 German monolingual and Turkish—German bilingual preschool children aged between 3 and 6 years. We analyzed item features with respect to lexical category, length, frequency, age of acquisition, and complexity in dependence of the language background of the children. Apart from a general delay in the development and some language specific characteristics, the results indicate a parallel shifted acquisition of vocabulary in bilingual children, which is nonetheless shaped by the same factors as in monolinguals.

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 empirical study aims to shed light on L3 initial-stage transfer and later development by investigating Q-operations in L1 English–L2 Cantonese and L1 Cantonese–L2 English bilinguals’ L3 Mandarin and L1 English speakers’ L2 Mandarin at low and high proficiency levels. Data from an online cross-modal priming task and an offline acceptability judgement task found that structural similarity determines transfer source selection. Adopting a de-compositional approach to cues of different domains, we have found both facilitative and detrimental transfer effects from Cantonese, with the latter triggered by orthographic and phonological cues. Our data also suggest that detrimental transfer effects can persist at an advanced stage and that L3 development and acquisition results can be affected by various factors such as word frequency and the nature of learning situations.

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.

Previous research suggests that bilingual language control requires domain-general cognitive control. Recent research suggests that exploration of individual differences is key for understanding the relationship between bilingual language control and cognitive control. The current study used multi-voxel pattern analysis (MVPA) to examine within-subject patterns of fMRI activity in the dorsolateral prefrontal cortex (DLPFC) during bilingual language switching and non-linguistic task-switching. We hypothesized that bilinguals would have identifiable, within-subject patterns of DLPFC activity for both types of switching and that bilinguals and monolinguals would differ in patterns of DLPFC activity for task-switching. We were unable to identify patterns of DLPFC activity associated with bilingual language switching. Task-switching was related to patterns of left DLPFC activity for both bilinguals and monolinguals, and there were identifiable patterns of right DLPFC activity for the bilinguals only. These findings suggest that the DLPFC is not the key brain structure connecting bilingual language and task-switching.

This study investigated the effect of cross-linguistic overlap in L1 and L2 auditory recognition of Spanish–English cognates. The study examined the correlation between objective and subjective measures of overlap and analyzed how these measures predict patterns in auditory recognition. 62 Spanish-speaking learners of English and 63 English-speaking learners of Spanish completed two auditory lexical decision tasks in Spanish and English and a rating task, where they rated the perceived phonological similarity of cognates. The results revealed moderate correlations between subjective and objective measures of overlap. While orthographic overlap had no effect, increased phonological overlap facilitated recognition in L1 and L2 Spanish and English and had larger effects in L2 recognition. Perceived similarity was the best predictor among the measures of overlap. The findings support models suggesting that cross-linguistic co-activation is facilitated by increased form similarity and studies reporting modality dependent effects of cross-linguistic form overlap in lexical recognition.

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.

Bilingualism is an experience that varies across a continuum and can change across the lifespan. Psychometric research is an underexplored avenue with the potential to further our understanding of the mechanisms and traits underlying bilingual experiences. Here, we developed and validated a social network questionnaire to measure sociolinguistic features in 212 individuals via personal social network. Confirmatory factor analysis examined the measurement structure of the variables. Compared to a one-factor model, the best fitting model was a two-factor model in which the language experience of the individual (i.e., ego) and the language experience of the individual's network (i.e., alters) were correlated latent factors under which aspects of the bilingual experience loaded. Additional analyses revealed other potential ways to examine the data in future analyses. These results provide the first measurement model of bilingual experiences, and provide support for theoretical accounts suggesting differential neuropsychological outcomes based on individual bilingual variability. The results also support the use of social network tools to capture differences in bilingualism.