Bilinguals may choose to speak a language either at their own will or in response to an external demand, but the underlying neural mechanisms in the two contexts is poorly understood. In the present study, Chinese–English bilinguals named pairs of pictures in three conditions: during forced-switch, the naming language altered between pictures 1 and 2. During non-switch, the naming language used was the same. During free-naming, either the same or different languages were used at participants' own will. While behavioural switching costs were observed during free-naming and forced-switching, neuroimaging results showed that forced language selection (i.e., forced-switch and non-switch) is associated with left-lateralized frontal activations, which have been implicated in inhibitory control. Free language selection (i.e., free-naming), however, was associated with fronto-parietal activations, which have been implicated in self-initiated behaviours. These findings offer new insights into the neural differentiation of language control in forced and free language selection contexts.

Language exposure and use (LEU) are widely viewed as key factors in multilingual development, and research highlights the importance of considering not just the frequency and quantity of LEU, but also contextual factors such as when and where a language is used, with whom and why. In this study, we illustrate the complexity of LEU in two contexts (study abroad and migration) by applying sequential mixture modelling to rich Experience Sampling Method data, considering combinations of various aspects of LEU such as language choice, type of activity, quantity, interlocutor characteristics and learner engagement. We argue that together, these methods for data collection and analysis have the potential to significantly strengthen research into LEU and broader language-related development. By uncovering distinct classes of language-related activities and language user profiles, we gain deeper insight into the nature of situated LEU and its relationship to language development among migrants and in study abroad.

The present study examined whether length of bilingual experience and language ability contributed to cross-situational word learning (XSWL) in Spanish-English bilingual school-aged children. We contrasted performance in a high variability condition, where children were exposed to multiple speakers and exemplars simultaneously, to performance in a condition where children were exposed to no variability in either speakers or exemplars. Results revealed graded effects of bilingualism and language ability on XSWL under conditions of increased variability. Specifically, bilingualism bolstered learning when variability was present in the input but not when variability was absent in the input. Similarly, robust language abilities supported learning in the high variability condition. In contrast, children with weaker language skills learned more word-object associations in the no variability condition than in the high variability condition. Together, the results suggest that variation in the learner and variation in the input interact and modulate mechanisms of lexical learning in children.

Whether speaking two or more languages (multilingualism) or dialects of one language (bidialectalism) affect executive function (EF) is controversial. Theoretically, these effects may depend on at least two conditions. First, the multilingual and bidialectal characteristics; particularly, (second) language proficiency and the sociolinguistic context of language use (e.g., Green & Abutalebi, 2013). Second, the EF aspects examined; specifically, recent accounts of the locus of the multilingual effect propose a general EF effect rather than an impact on specific processes (Bialystok, 2017). We compared 52 “monolingual” (with limited additional-language/dialect experience), 79 bidialectal and 50 multilingual young adults in the diglossic context of Cyprus, where bidialectalism is widespread and Cypriot and Standard Greek are used in different everyday situations. Three EF processes were examined via seven tasks: inhibition, switching and working memory (Miyake et al., 2000). We found better multilingual and bidialectal performance in overall EF, an effect moderated by high (second) language proficiency.

Bilinguals activate both of their languages as they process written words, regardless of modality (spoken or signed); these effects have primarily been documented in single word reading paradigms. We used eye-tracking to determine whether deaf bilingual readers (n = 23) activate American Sign Language (ASL) translations as they read English sentences. Sentences contained a target word and one of the two possible prime words: a related prime which shared phonological parameters (location, handshape or movement) with the target when translated into ASL or an unrelated prime. The results revealed that first fixation durations and gaze durations (early processing measures) were shorter when target words were preceded by ASL-related primes, but prime condition did not impact later processing measures (e.g., regressions). Further, less-skilled readers showed a larger ASL co-activation effect. Together, the results indicate that ASL co-activation impacts early lexical access and can facilitate reading, particularly for less-skilled deaf readers.

Validated yes/no vocabulary tests that measure bilinguals’ language proficiency based on vocabulary knowledge have been widely used in psycholinguistic research. However, it is unclear what aspects of test takers’ vocabulary knowledge are employed in these tests, which makes the interpretation of their scores problematic. The present study investigated the contribution of bilinguals’ form-meaning knowledge to their item accuracy on a Malay yes/no vocabulary test. Word knowledge of Malay first- (N = 80) and second-language (N = 80) speakers were assessed using yes/no, meaning recognition, form recognition, meaning recall and form recall tests. The findings revealed that 59% of the variance in the yes/no vocabulary test score was explained by the accuracy of the meaning recognition, form recognition and meaning recall tests. Importantly, the item analysis indicated that yes/no vocabulary tests assess primarily knowledge of form recognition, supporting its use as a lexical proficiency measure to estimate bilinguals’ receptive language proficiency.

This study investigates how L2 proficiency contributes to creativity in relation to personality among 205 young adolescent English-as-a-foreign-language learners from rural China. Participants completed the Cambridge A2 Key for Schools English Test to assess English proficiency, the Chinese Big Five Personality Inventory to evaluate personality traits, and the Evaluation of Potential Creativity to measure creativity, operationalized as divergent and convergent thinking in verbal and graphic domains. Pearson correlation analyses revealed that L2 proficiency was positively associated with both divergent and convergent thinking across verbal and graphic domains, while Openness to Experience and Extraversion were positively linked to creativity components, albeit partially depending on the domain. Conscientiousness, Agreeableness, and Neuroticism showed no significant associations with creativity. Structural equation modeling further demonstrated that L2 proficiency, Openness, and Extraversion directly co-predicted creativity components, excluding convergent thinking in the verbal domain.

To examine the combined effects of ageing and bilingualism in language processing, we tested young and older mono- and bilingual speakers in L1 comprehension and production. In Experiment 1, bilinguals were slower to detect words than monolinguals in sentences with a low-constraint context, but not when a high-constraint context was provided. Older adults tended to outperform younger adults in high-constraint sentences. In Experiment 2, older speakers were slower than younger speakers to produce small-scope prepositional phrases (e.g., ‘the cone above the grape), suggesting more extensive planning. Bilingual disadvantages were observed in larger-scope complex phrases (e.g., ‘the cone and the pink grape’). Individual differences in language proficiency did not modulate the effects. The results support bilingual disadvantages in syntactic processing and age-preserved syntax, alongside semantic processing unaffected by either bilingualism or age. We found no interactions between age and bilingualism, suggesting that these two factors independently impact language processing.

Autobiographical memories (AMs) are partly influenced by people's ability to process and express their emotions. This study investigated the extent to which trait emotional intelligence (EI) contributed to the emotional vocabulary of 148 adolescents – 60 speakers of Spanish as a heritage language (HL) raised in Germany, 61 first-language (L1) German speakers and 27 L1 Spanish speakers – in their written AMs of anger and surprise. The results revealed that heritage speakers with high trait EI used more emotional words in their AMs. These bilinguals also used more positive, negative and high-arousal words in their HL and in their AMs of anger. Similar patterns were observed in the AMs produced in Spanish (HL and L1), but L1 Spanish speakers used more emotional words in their AMs of surprise. By contrast, L1 German speakers used more emotional words than bilinguals in their AMs in German, and AMs of anger in German included more emotional vocabulary than those addressing surprise events.

Evidence from various empirical study types have converged to show bilingualism's potential for serving as a cognitive and brain reserves contributor. In this article, I contextualize, frame the need for and offer some expanding questions in this endeavor, inclusive of empirical pathways to address them. While the set of variables and questions discussed herein are definitively incomplete, they embody a good starting point for shaping future directions in research that considers the role bilingual language engagement can have for the developing mind and brain, inclusive of how various, non-linear factors impact the descent bilinguals of various types take down the proverbial mountain of life.

Embodiment theories postulate that language processing inherently engages the sensorimotor system. This study explores the embodiment of action verbs in the second language (L2) and the effects of various L2 experiences (L2 age of acquisition, exposure, dominance, and proficiency) on L2 embodiment. Sixty-one Chinese–English bilinguals participated in two experiments judging semantic relatedness: Experiment 1 involved verb–picture pairs, while Experiment 2 focused on verb–verb pairs. Both experiments were conducted in the participants’ first language (Chinese) and second language (English), with the stimuli depicting actions performed by specific effectors (e.g., mouth, hand, and foot). Results showed that participants took longer to reject mismatched verb–picture pairs and semantic-unrelated verb–verb pairs when the actions shared the same effector (e.g., walk–run) than those involving different effectors (e.g., eat–touch). Moreover, L2 age of acquisition, exposure, and dominance correlated with the L2 embodiment effect, with L2 age of acquisition and exposure modulating this effect. This study enhances our understanding of L2 embodied semantics and illuminates the impact of multidimensional L2 experiences on embodiment.

The present paper investigates whether school-aged French-English bilingual children’s implicit and explicit knowledge of article use is affected by cross-linguistic influence (CLI) during online and offline sentence comprehension. The studies focus on the encoding of plural and mass nouns in specific and generic contexts. We also explore whether individual measures of oral proficiency, language exposure and age play a role in the children’s performance. Forty-three 8-to-10-year-old French-English bilingual children took part in a Self-Paced Reading task, a Grammaticality Judgement task and a Cloze test in their two languages. Overall, CLI was observed across tasks in English and French. These findings suggest that CLI can be bi-directional and tap into school-aged bilinguals’ implicit and explicit representations during sentence comprehension and production. The data also makes a new contribution to our understanding of the relative amount of language exposure, oral proficiency and age on CLI.

Both ageing and bilingualism can have positive as well as adverse cognitive effects. We investigated their combined impact on subcomponents of attention. We used the Attention Network Task to examine alerting, orienting, executive control and task-switching costs. Group comparisons revealed age-related declines for alerting alongside benefits for executive control, for mono- and bilinguals alike. For orienting, age-related decline was more pronounced for bilinguals than monolinguals. Task-switching was unaffected by age or language group. Within bilinguals, we found limited impact of individual differences in L2 proficiency, language switching or mixing: proficiency improves orienting and decreases switch costs, for young and older bilinguals alike; but no other individual differences effects were found. Thus, attention is a multi-faceted network, with clear adverse (alerting) and protective (executive control) ageing effects. We found these to be largely similar for mono- and bilinguals, with variability within bilinguals having only limited impact.

High-frequency words are processed faster than low-frequency words, known as the word frequency effect (FE). Although the FE has been studied in various writing systems as well as in first- (L1) and second-language (L2) reading, existing theoretical hypotheses are mainly based on findings in alphabetic languages. To date, no study has investigated theoretical explanations of the FE such as the learning hypothesis, the lexical entrenchment hypothesis and the rank hypothesis apply to Chinese–English bilinguals. The present study, therefore, compared the FEs in Chinese– and Dutch–English bilinguals during natural paragraph reading in their L1 and L2, using eye-tracking measures. Chinese bilinguals exhibited a larger FE in L2 than in L1. They displayed smaller L1 FEs and much steeper L2 FE curves than Dutch bilinguals. These findings are not entirely consistent with the existing FE hypotheses, and the present study discusses theoretical accounts in light of the observed results.

In cross-linguistic word learning, learning new knowledge based on existing knowledge is a common and lifelong process. This study investigated whether inhibitory control would be conducive to this process. We asked Chinese-English bilinguals to learn new meanings for familiar English ambiguous words within two consecutive days, manipulating semantic relatedness and word frequency to create four categories: high-frequency-unrelated, high-frequency-related, low-frequency-unrelated and low-frequency-related ambiguous words. Participants completed translation recognition and production tests immediately after learning and again one week later, with flanker and stop-signal tasks interspersed to measure their interference inhibition and response inhibition. The results indicated that inhibitory control, particularly interference inhibition, significantly aided in learning new meanings when direct knowledge transfer from existing knowledge was unfeasible. This research enhances our comprehension of individual differences in word learning, offering valuable perspectives for broader theories of word learning and targeted educational interventions.

Previous studies have reported fewer social biases in bilinguals compared to monolinguals. However, it is unclear whether the expression of social biases varies across the bilingualism spectrum. This article investigates the connections between different dimensions of bilingual experience and the expression of explicit bias. We analyzed the responses of 389 bilinguals to a battery of questionnaires on bilingual and multicultural experiences, explicit bias, internal and external motivation to respond without prejudice and executive control. The results show that more diverse language-use and language-learning experiences were associated with lower explicit bias among bilinguals who had lower internal motivation to respond without prejudice (i.e., motivation driven by personal values). This study presents novel evidence on the relationships between bilingual experiences and the expression of social biases.

The language of heritage speakers is characterized by variability and structural innovations compared to the baseline grammar of first-generation immigrants. Although many factors contribute to these differences, this study considers structural priming with structures that do not exist in the majority language as a potential mechanism for language change. The linguistic focus is accusative clitic doubling, which exists in some Spanish varieties, but which is unacceptable in others. Our research examined how flexible heritage speakers’ grammars are compared to baseline speakers, and to what extent heritage speakers adopt structures attested in the diachronic development and in other varieties of their heritage language. In two studies, we tested the acceptability of accusative clitic doubling and primed accusative clitic doubling in oral production. Results showed that heritage speakers of Spanish are somewhat accepting of innovative structures and more sensitive to structural priming compared to baseline speakers, who are generally not.

Recent conceptualisations of bilingualism are moving away from strict categorisations, towards continuous approaches. This study supports this trend by combining empirical psycholinguistics data with machine learning classification modelling. Support vector classifiers were trained on two datasets of coded productions by Italian speakers to predict the class they belonged to (“monolingual”, “attriters” and “heritage”). All classes can be predicted above chance (>33%), even if the classifier's performance substantially varies, with monolinguals identified much better (f-score >70%) than attriters (f-score <50%), which are instead the most confusable class. Further analyses of the classification errors expressed in the confusion matrices qualify that attriters are identified as heritage speakers nearly as often as they are correctly classified. Cluster clitics are the most identifying features for the classification performance. Overall, this study supports a conceptualisation of bilingualism as a continuum of linguistic behaviours rather than sets of a priori established classes.

Phoneme discrimination is believed to be less accurate in non-native languages compared to native ones. What remains unclear is whether differences in pre-attentive phonological processing emerge between the first foreign language (L2) and additional ones (L3/Ln), and whether they might be influenced by the acquisition setting (formal vs. naturalistic). We conducted an event-related brain potential oddball study with native Polish learners of English (L2) and Norwegian (L3/Ln). The results revealed a graded amplitude of the mismatch negativity (MMN) effect, which was largest in L1, smaller in L2, and smallest in L3/Ln. Considering the previously obtained results for naturalistic/mixed learners with the same language combination, we believe that the acquisition setting is an important factor influencing the perception of phonemic contrasts. In the naturalistic group, no difference was observed between L1 and L2, while the instructed group exhibited more fine-grained distinctions between all tested languages.

Socio-cognitive research on bilinguals points to a moral foreign-language effect (MFLE), with more utilitarian choices (e.g., sacrificing someone to save more people) for moral dilemmas presented in the second language (L2) relative to the first language. Yet, inconsistent results highlight the influence of subject-level variables, including a critical underexplored factor: L2 proficiency (L2p). Here we provide a systematic review of 57 bilingualism studies on moral dilemmas, showing that L2p rarely modulates responses to impersonal dilemmas, but it does impact personal dilemmas (with MFLEs proving consistent at intermediate L2p levels but unsystematic at high L2p levels). We propose an empirico-theoretical framework to conceptualize such patterns, highlighting the impact of L2p on four affective mediating factors: mental imagery, inhibitory control, prosocial behavior and numerical processing. Finally, we outline core challenges for the field. These insights open new avenues at the crossing of bilingualism and social cognition research.