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.

Bimodal bilinguals master languages in two modalities, spoken and signed, and can use them simultaneously due to the independence of the articulators. This behavior, named code-blending, is one of the hallmarks of bimodal bilingualism. Lexical experiments on production and comprehension in American Sign Language/English showed that blending is not cognitively costly and facilitates lexical access. In this work, we replicated the blending advantage in lexical comprehension for hearing bimodal bilinguals with two other language pairs, French Sign Language (LSF)–French and Italian Sign Language (LIS)–Italian, and we explored whether the facilitation is also found at the sentential level. Results show that blended utterances for languages with incongruent word order like LIS–Italian were processed slower than monolingual utterances, while no difference was found when the word orders were congruent (LSF–French). We discuss these findings in light of linguistic theories of syntactic structure derivation in bimodal bilinguals.

Subcortical structures implicated in language control and processing adapt structurally with increasing language experience. However, the adaptation patterns across different subcortical structures remain unclear. Previous findings from bilinguals and multilinguals reveal renormalisation patterns, lending support to the Dynamic Restructuring Model (Pliatsikas, 2020). These patterns are composed of increasing volumes during the initial stages of language learning, and subsequent reductions as experience increases. T1-weighted images from 14 English monolinguals, 14 bilinguals, 14 trilinguals, and 14 quadrilinguals were obtained. The volumes of five subcortical regions implicated in language control and processing were compared amongst the groups. The findings showed group differences for every structure – caudate nucleus, nucleus accumbens, putamen, globus pallidus and thalamus. Complex patterns were unveiled for each structure, suggesting expansions and renormalisations that differ in trajectory for each group. These findings highlight the dynamic progression of subcortical adaptations, and support the notion of structural renormalisation as language experience grows.

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.

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.

Emotional experiences are often dulled in one's second language. We tested whether emotion concepts are more strongly associated with first language (L1) than second language (L2) emotion words. Participants (140 L1-Swedish–L2-English bilinguals) saw a facial expression of an emotion (cue) followed by a target, which could either be another facial expression, an L1 emotion word, or an L2 emotion word. Participants indicated whether the cue and target represented the same or different emotions as fast as possible. Participants were faster and more accurate in both the L1 and L2 word conditions compared to the face condition. However, no significant differences emerged between the L1 and L2 word conditions, suggesting that emotion concepts are not more strongly associated with L1 than L2 emotion words. These results replicate prior research showing that L1 emotion words speed facial emotion perception and provide initial evidence that words (not only first language words) shape emotion perception.

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).

The goal of the current paper is to investigate effects of multilingualism regarding emotional competence (EC). We argue that there might be two paths of influence that connect multilingualism and EC. First, we assume that multilingualism represents a linguistically and culturally heterogeneous context that may stimulate the development of EC. Second, cognitions, such as executive control or divergent thinking, might be an important condition for or constituent of emotions. Since cognitive abilities are sometimes assumed to be positively influenced by multilingualism (called the cognitive resp. bilingual advantage hypothesis), multilingualism might affect EC by boosting these cognitive functions. In an initial pre-study (N = 85) we found that two EC subcomponents were significantly predicted by degree of multilingualism (DM). In a second study (N = 989), we found that DM significantly predicted EC directly and was mediated by cultural heterogeneity but not by language switching, executive functions, or divergent thinking.

Adults differ in the ease with which they acquire lexical tones in a non-native language. Individual differences have been attributed to several factors, such as the role that pitch plays in a learner's L1 to signal lexical meaning (L1 tonal status), the shape of the tones to be acquired (tone types), as well as extralinguistic factors (such as musical experience and working memory). Here, we ask whether learners from a spectrum of L1 tonal statuses (Dutch, Swedish and Japanese, and Thai) differ in their tone word learning facility, whilst we simultaneously investigate the effects of tone type, and musical experience and working memory. Our findings suggest that above and beyond L1 tonal status, the strongest predictor of tone word learning was pre-lexical tone processing (measured by a tone categorization task), although the strength of the link between pre-lexical and lexical processing may be modulated by L1 tonal status.

Bilingualism is a multifaceted experience that researchers have examined using various questionnaires to gain insights and characterize the experience. However, there are several issues related to questionnaire choice. To address this, we applied Content Overlap Analysis to seven prevalent bilingualism questionnaires, assessing their affinity. We found little overlap in these questionnaires; most had fewer than 15% of items in common, suggesting they capture different aspects of the bilingual experience and provide complementary rather than redundant data for researchers. Our investigation highlights the importance of choosing a bilingualism assessment tool to carefully fit research questions and sample language experiences.

A central finding of bilingual research is that cognates – words that share semantic, phonological, and orthographic characteristics across languages – are processed faster than non-cognate words. However, it remains unclear whether cognate facilitation effects are reliant on identical cognates, or whether facilitation simply varies along a continuum of cross-language orthographic and phonological similarity. In two experiments, German–English bilinguals read identical cognates, close cognates, and non-cognates in a lexical decision task and a sentence-reading task while their eye movements were recorded. Participants read the stimuli in their L1 German and L2 English. Converging results found comparable facilitation effects of identical and close cognates vs. non-cognates. Cognate facilitation could be described as a continuous linear effect of cross-language orthographic similarity on lexical decision accuracy and latency, as well as fixation durations. Cross-language phonological similarity modulated the continuous orthographic similarity effect in single word recognition, but not in sentence processing.

This study investigated the electrophysiological correlates of cross-language orthographic and phonological processing in unbalanced Chinese (L1)–English (L2) bilinguals using a translation recognition task. The critical L1-L2 word pairs were incorrect translation equivalents but orthographically or phonologically related through translation (orthographic or phonological translation neighbor). Compared with the unrelated control, the recognition of L2 words showed comparable reaction time and accuracies when coupled with L1 orthographic or phonological translation neighbors. However, both orthographic and phonological translation neighbors elicited more negative event-related potential (ERP) waveforms in the bulk of the N400 component (300-600 ms) than the unrelated control. These findings were interpreted in the framework of the Bilingual Interactive Activation Plus model (BIA+ model), according to which cross-language orthographic and phonological representations were non-selectively accessed during the recognition of the L2 words, and top-down inhibitory control mechanism impacted the cross-language lexical competition and confliction between the two languages.

Using a voluntary object-naming paradigm, we examined if bilinguals with high or low L2 proficiency monitor their language selection and production according to their interlocutors' L2 language proficiency. Telugu (L1)–English (L2) bilinguals were introduced to audio-visual stimuli that consisted of animated interlocutors that were high or low proficient in English. In Experiment 1, interlocutors were presented at different frequencies in each block, and in Experiment 2, the presentation of each interlocutor was blocked. We predicted that the frequency of interlocutors would modulate language activation and selection. The participants named the objects language that came to their minds to respond to interlocutors. Indeed, consistent with our predictions, monitoring contexts induced by such interlocutors influenced latencies, language choice and switch-cost. High-L2 proficient participants employed higher language control than low-L2 proficient participants. These results support the hypothesis that bilinguals are sensitive toward their interlocutors' language proficiency and employ context-appropriate cognitive control.

Language proficiency is a critically important factor in research on bilingualism, but researchers disagree on its measurement. Validated objective measures exist, but investigators often rely exclusively on subjective measures. We investigated if combining multiple self-report measures improves prediction of objective naming test scores in 36 English-dominant versus 32 Spanish-dominant older bilinguals (Experiment 1), and in 41 older Spanish–English bilinguals versus 41 proficiency-matched young bilinguals (Experiment 2). Self-rated proficiency was a powerful but sometimes inaccurate predictor and better predicted naming accuracy when combined with years of immersion, while percent use explained little or no unique variance. Spanish-dominant bilinguals rated themselves more strictly than English-dominant bilinguals at the same objectively measured proficiency level. Immersion affected young more than older bilinguals, and non-immersed (English-dominant) more than immersed (Spanish-dominant) bilinguals. Self-reported proficiency ratings can produce spurious results, but predictive power improves when combined with self-report questions that might be less affected by subjective judgements.