Explore the vast range of titles available.

•The bilingual advantage (i.e. bilinguals having superior cognitive control) is not without controversy.•Part of this controversy relates to bilingualism being treated as a binary category, and not a continuum.•Our large-scale electrophysiological investigation focused on the impact of different facets of.•bilingual experience on cognitive-control.•We found specific aspects of bilingual experience lead to neural adaptations which impact behavioural outcomes. Bilinguals have often, but not always, been found to outperform monolinguals on domain-general attentional control. Inconsistent findings have been argued to stem, at least partly, from treating bilingualism as a uniform category and from not considering how neural adaptations to bilingual experiences modulate behavioural outcomes. The present study investigated how patterns of language experience, including language switching behaviour, duration and intensity/diversity of bilingual language use, influence the brain processes underlying cognitive control, and how these in turn translate to cognitive control performance. We examined reaction times and spectral dynamics of the electroencephalograms (EEG) of two-hundred-and-thirty-nine participants (about 70% bilinguals) with diverse language experiences during two cognitive control paradigms testing interference suppression (flanker and Simon task). Using structural equation modelling, we found that different bilingual experience factors were related with neurocognitive measures, which in turn were related with behavioural interference effects, for the flanker but not the Simon task. More specifically, increased frequency of language switching and intensity/diversity of bilingual language usage was negatively related to induced top-down control measures (especially midline-frontal theta), which in turn was beneficial for interference control. In contrast, duration of bilingual engagement correlated negatively with evoked bottom-up control measures (especially P3) and was therefore detrimental to interference control. We demonstrate here for the first time how the different factors of bilingual experience lead to different neural adaptations which impact behavioural outcomes. Like other intensive experiences, bilingualism leads to brain adaptations. It results in structural changes in language areas, and, due to demands on language control, in brain areas associated with domain-general cognitive control. Related to this, bilinguals often outperform monolinguals on cognitive control tasks. But what is often ignored is that bilingualism is a multi-dimensional phenomenon, with variations such as diversity of language usage and duration of language use. The present large-scale study of neural functioning in bilingualism revealed for the first time how individual differences in bilingual experience lead to adaptations to brain functioning which in turn affect cognitive control behaviour. It exemplifies how the complexity of individual experiences plays a fundamental role in brain function.

No two bilinguals are the same. Differences in bilingual experiences can affect language-related processes but have also been proposed to modulate executive functioning. Recently, there has been an increased interest in studying individual differences between bilinguals, for example in terms of their age of acquisition, language proficiency, use, and switching. However, and despite the importance of this individual variation, studies often do not provide detailed assessments of their bilingual participants. This review first discusses several aspects of bilingualism that have been studied in relation to executive functioning. Next, I review different questionnaires and objective measurements that have been proposed to better define bilingual experiences. In order to better understand (effects of) bilingualism within and across studies, it is crucial to carefully examine and describe not only a bilingual’s proficiency and age of acquisition, but also their language use and switching as well as the different interactional contexts in which they use their languages.

The investigation of bilingualism and cognition has been enriched by recent developments in functional magnetic resonance imaging (fMRI). Extending how bilingual experience shapes cognition, this review examines recent fMRI studies adopting executive control tasks with minimal or no linguistic demands. Across a range of studies with divergent ages and language pairs spoken by bilinguals, brain regions supporting executive control significantly overlap with brain regions recruited for language control (Abutalebi & Green). Furthermore, limited but emerging studies on resting-state networks are addressed, which suggest more coherent spatially distributed functional connectivity in bilinguals. Given the dynamic nature of bilingual experience, it is essential to consider both task-related functional networks (externally-driven engagement), and resting-state networks, such as default mode network (internal control). Both types of networks are important elements of bilingual language control, which relies on domain-general executive control.

Dual/multiple language use has been shown to affect cognition and its neural substrate, although the replicability of such findings varies, partially due to neglecting the role of interindividual variability in bilingual experience. To address this, we operationalized the main bilingual experience factors as continuous variables, investigating their effects on executive control performance and neural substrate deploying a Flanker task and structural magnetic resonance imaging. First, higher L2 proficiency predicted better executive performance. Second, neuroimaging results indicated that bilingualism-related neuroplasticity may peak at a certain stage of bilingual experience and eventually revert, possibly following functional specialization. Importantly, experienced bilinguals optimized behavioral performance independently of volumetric variations, suggesting a degree of performance gain even with lower GMV. Hence, the effects of bilingualism on cognition may evolve with experience, with improvements in functional efficiency eventually replacing structural changes. We conclude that individual differences in bilingual experience modulate cognitive and neural consequences of bilingualism.

We evaluated the impact of exposure to a second language on infants’ emerging speech production skills. We compared speech produced by three groups of 12-month-old infants while they interacted with interlocutors who spoke to them in Spanish and English: monolingual English-learning infants who had previously received 5 hours of exposure to a second language (Spanish), English- and Spanish-learning simultaneous bilinguals, and monolingual English-learning infants without any exposure to Spanish. Our results showed that the monolingual English-learning infants with short-term exposure to Spanish and the bilingual infants, but not the monolingual English-learning infants without exposure to Spanish, flexibly matched the prosody of their babbling to that of a Spanish- or English-speaking interlocutor. Our findings demonstrate the nature and extent of benefits for language learning from early exposure to two languages. We discuss the implications of these findings for language organization in infants learning two languages.

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.

We report a study that investigated executive functions in four groups of participants that varied in bilingual language experience, using a task that measured two theoretically motivated mechanisms of cognitive control (proactive and reactive control). Analyses of accuracy based on aggregated measures suggested an advantage in early highly proficient bilinguals over late passive bilinguals. However, when we factored in individual variability using mixed-model regression with a full random effect structure, we only found a marginal effect of language experience. Our results emphasise the importance of including individual variability when studying bilingualism, and highlight a fundamental consideration in research on the relation between language and attention – namely, the need for a theory-driven approach to measuring cognitive control through laboratory tasks.

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.

The purpose of the current report is to study the effects of language distance on noun and verb processing in bilingual speakers. We recruited two groups of bilingual speakers: one group spoke two typologically distant languages (Cantonese and English) and the other group spoke two typologically similar languages (Mandarin and Cantonese). Participants named object and action pictures in their first language. We controlled psycholinguistic properties of words such as frequency, AoA, imageability, name agreement, visual complexity, familiarity, and participants’ bilingual language experiences. Our findings revealed a significant role for language distance. We observed a difference between noun and verb processing in the similar language pair (Mandarin–Cantonese) due to interference induced by language similarity. However, in the distant language pair (Cantonese–English), the difference disappeared because of the lack of cross-language interference. Our findings support that current and future models of bilingual language processing should take into account the effects of language distance.

The Flanker and Number Stroop tasks, and the Wisconsin Card Sorting Test (WCST) were adopted to examine how bilingualism and public speaking training would contribute to cognitive control differences among young adults. Four groups of participants (of similar cultural and language backgrounds) were tested: monolinguals, general bilinguals, L1 public speaking bilinguals, and L2 public speaking bilinguals. Both ANOVA and multiple regression analyses showed that public speaking experience (esp. in L2) significantly contributed to conflict monitoring as tested in the global reaction times in the Flanker and Number Stroop tasks, whereas bilingualism (L2 verbal fluency, to be more specific) significantly contributed to mental set shifting as tested in the WCST. These results suggest that specific aspects of language experience, either in L1 or in L2, may incur enhancement in specific aspects of cognitive control, which has implications for bilingual advantage research.