When bilinguals produce words in one language, their translation equivalents in the other language are thought to be activated as well. A common assumption is that this parallel co-activation produces interference, which slows down word retrieval. The current study aimed to evaluate the assumption of lexical interference during word retrieval by testing whether late Portuguese–English bilinguals were slower to name pictures in their native language when they knew the word in their second language compared to when they only knew the native language label. Instead of interfering with production, knowing the second-language label facilitated speed of word retrieval in the native language for both cognate and non-cognate translation-equivalent pairs. We suggest that using the second language may provide an indirect frequency boost for translation-equivalent words in the native language. This frequency boost has both long-term and short-term effects, strengthening connections to native-language labels when the translation equivalent is retrieved.

Bilinguals usually select the right language to speak for the particular context they are in, but sometimes the nontarget language intrudes. Despite a large body of research into language selection and language control, it remains unclear where intrusion errors originate from. These errors may be due to incorrect selection of the nontarget language at the conceptual level, or be a consequence of erroneous word selection (despite correct language selection) at the lexical level. We examined the former possibility in two language switching experiments using a manipulation that supposedly affects language selection on the conceptual level, namely whether the conversational language context was associated with the target language (congruent) or with the alternative language (incongruent) on a trial. Both experiments showed that language intrusion errors occurred more often in incongruent than in congruent contexts, providing converging evidence that language selection during concept preparation is one driving force behind language intrusion.

To investigate whether similar control processes are used during single and dual language production, we compared register switching (formal and informal speech in the same language) vs. language switching (French and English). The results across two experiments showed a positive correlation of overall register- and language-switch costs and similar formal French switch costs across the two switching tasks. However, whereas increasing the cue-to-stimulus interval resulted in a reduction of language-switch costs, register-switch costs were unaffected by the interval manipulation. This difference in switch-cost pattern indicates that control processes are not entirely identical during single and dual language production.

This study addresses the question of whether and how growing up with more than one language shapes a child's language impairment. Our focus is on Specific Language Impairment (SLI) in bilingual (Turkish–German) children. We specifically investigated a range of phenomena related to the so-called CP (Complementizer Phrase) in German, the hierarchically highest layer of syntactic clause structure, which has been argued to be particularly affected in children with SLI. Spontaneous speech data were examined from bilingual children with SLI in comparison to two comparison groups: (i) typically-developing bilingual children, (ii) monolingual children with SLI. We found that despite persistent difficulty with subject-verb agreement, the two groups of children with SLI did not show any impairment of the CP-domain. We conclude that while subject-verb agreement is a suitable linguistic marker of SLI in German-speaking children, for both monolingual and bilingual ones, ‘vulnerability of the CP-domain’ is not.

Native language (L1) processing draws on implicit expectations. An open question is whether non-native learners of a second language (L2) similarly draw on expectations, and whether these expectations are based on learners’ L1 or L2 knowledge. We approach this question by studying inverse preference effects on lexical encoding. L1 and L2 speakers of Spanish described motion events, while they were either primed to express path, manner, or neither. In line with other work, we find that L1 speakers adapted more strongly after primes that are unexpected in their L1. For L2 speakers, adaptation depended on their L2 proficiency: The least proficient speakers exhibited the inverse preference effect on adaptation based on what was unexpected in their L1; but the more proficient speakers were, the more they exhibited inverse preference effects based on what was unexpected in the L2. We discuss implications for L1 transfer and L2 acquisition.

Many human infants grow up learning more than one language simultaneously but only recently has research started to study early language acquisition in this population more systematically. The paper gives an overview on findings on early language acquisition in bilingual infants during the first two years of life and compares these findings to current knowledge on early language acquisition in monolingual infants. Given the state of the research, the overview focuses on research on phonological and early lexical development in the first two years of life. We will show that the developmental trajectory of early language acquisition in these areas is very similar in mono- and bilingual infants suggesting that these early steps into language are guided by mechanisms that are rather robust against the differences in the conditions of language exposure that mono- and bilingual infants typically experience.

Multilingual children are faced with the task of selectively using the linguistic systems of their languages. Previous research has shown that although bilinguals may make more errors in production and comprehension than their monolingual peers, less cognitively demanding processing experiments may reveal target-like performance. This has been attributed to several factors, among which language transfer and processing limitations. In this study we investigate the processing of additive connectives in both languages of German–Russian bilingual children using the Visual World Paradigm. Previous research has shown that bilingual children make many errors in the production of these connectives in Russian. The results show that the processing behaviour in both languages of the bilingual children does not differ from that of their monolingual peers. This finding is compatible with the view that errors in production and in more demanding comprehension tasks are due to processing limitations.

This paper investigates whether there are changes in gesture rate when speakers of two languages with different gesture rates (Turkish-high gesture; Dutch-low gesture) come into daily contact. We analyzed gestures produced by second-generation heritage speakers of Turkish in the Netherlands in each language, comparing them to monolingual baselines. We did not find differences between bilingual and monolingual speakers, possibly because bilinguals were proficient in both languages and used them frequently – in line with a usage-based approach to language. However, bilinguals produced more deictic gestures than monolinguals in both Turkish and Dutch, which we interpret as a bilingual strategy. Deictic gestures may help organize discourse by placing entities in gesture space and help reduce the cognitive load associated with being bilingual, e.g., inhibition cost. Therefore, gesture rate does not necessarily change in contact situations but might be modulated by frequency of language use, proficiency, and cognitive factors related to being bilingual.

Matching participants (as suggested by Hope, 2015) may be one promising option for research on a potential bilingual advantage in executive functions (EF). In this study we first compared performances in three EF-tasks of a naturally heterogeneous sample of monolingual (n = 69, age = 9.0 y) and multilingual children (n = 57, age = 9.3 y). Secondly, we meticulously matched participants pairwise to obtain two highly homogeneous groups to rerun our analysis and investigate a potential bilingual advantage. The initally disadvantaged multilinguals (regarding socioeconomic status and German lexicon size) performed worse in updating and response inhibition, but similarly in interference inhibition. This indicates that superior EF compensate for the detrimental effects of the background variables. After matching children pairwise on age, gender, intelligence, socioeconomic status and German lexicon size, performances became similar except for interference inhibition. Here, an advantage for multilinguals in the form of globally reduced reaction times emerged, indicating a bilingual executive processing advantage.

This study investigates the psycholinguistic process underlying triggered codeswitching – codeswitching facilitated by the occurrence of cognates – within the context of conversational dynamics. It confirms that, in natural bilingual speech, lexical selection of cognates can facilitate codeswitching by enhancing the activation of the non-selected language. Analyses of a large-scale corpus of Welsh–English conversational speech showed that 1) producing cognates facilitated codeswitching, 2) speakers who generally produced more cognates generally codeswitched more, even in clauses that did not contain cognates, 3) larger numbers of cognates in a clause increased the likelihood of codeswitching, 4) codeswitching temporarily remained facilitated after the production of cognates, and 5) hearing rather than producing cognates did not facilitate codeswitching. The findings confirm the validity of the proposed cognitive account of triggered codeswitching, and clarify the relation between the lexical activation of cognates and consecutive language choice, in accord with current insights in lexical processing.

Research on the effects of bi- and multi-lingualism on brain structure has so far yielded variable patterns. Although it cannot be disputed that learning and using additional languages restructures grey (cortical, subcortical and cerebellar) and white matter in the brain, both increases and reductions in regional volume and diffusivity have been reported. This paper revisits the available evidence from simultaneous and sequential bilinguals, multilinguals, interpreters, bimodal bilinguals, children, patients and healthy older adults from the perspective of experience-based neuroplasticity. The Dynamic Restructuring Model (DRM) is then presented: a three-stage model accounting for, and reinterpreting, all the available evidence by proposing a time-course for the reported structural adaptations, and by suggesting that these adaptations are dynamic and depend on the quantity and quality of the language learning and switching experience. This is followed by suggestions for future directions for the emerging field of bilingualism-induced neuroplasticity.

Research has shown that bilinguals can perform similarly, better or poorly on verbal fluency task compared to monolinguals. Verbal fluency data for semantic (animals, fruits and vegetables, and clothing) and letter fluency (F, A, S) were collected from 25 Bengali–English bilinguals and 25 English monolinguals in English. The groups were matched for receptive vocabulary, age, education and non-verbal intelligence. We used a wide range of measures to characterize fluency performance: number of correct, fluency difference score, time-course analysis (1st RT, Sub-RT, initiation, slope), clustering, and switching. Participants completed three executive control measures tapping into inhibitory control, mental-set shifting and working memory. Differences between the groups were significant when executive control demands were higher such as number of correct responses in letter fluency, fluency difference score, Sub-RT, slope and cluster size for letter fluency, such that bilinguals outperform the monolinguals. Stroop performance correlated positively with the slope only for the bilinguals.

In two lexical-decision experiments, we investigated the processing of figurative and literal meaning in idioms. Dutch native and German–Dutch bilingual speakers responded to target words presented after a minimal context idiom prime (e.g., ‘He kicked the bucket’). Target words were related to the figurative meaning of the prime (‘die’), the literal word at the end of the idiom (‘water’), or unrelated to both (‘face’). We observed facilitation in RTs for figuratively and literally related targets relative to unrelated targets for both participant groups. A higher frequency idiom-final word caused inhibition in responses to the literally related target for native speakers, indicating competition between the idiom as a whole and its literal word constituents. Native speakers further showed sensitivity to transparency of the idiom's meaning and the plausibility of the idiom as a literally interpretable sentence. The results are interpreted in terms of available L1/L2 idiom comprehension models, and a more detailed processing account for literal and idiomatic sentence interpretation.

Mandarin speakers often use gestures to represent time laterally, vertically, and sagittally. Chinese Sign Language (CSL) users also exploit signs for that purpose, and can differ from the gestures of Mandarin speakers in their choices of axes and direction of sagittal movements. The effects of sign language on co-speech gestures about time were investigated by comparing spontaneous temporal gestures of late bimodal bilinguals (Mandarin learners of CSL) and non-signing Mandarin speakers. Spontaneous gestures were elicited via a wordlist definition task. In addition to effects of temporal words on temporal gestures, results showed significant effects of sign. Compared with non-signers, late bimodal bilinguals (1) produced more sagittal but fewer lateral temporal gestures; and (2) exhibited a different temporal orientation of sagittal gestures, as they were more likely to gesture past events to their back. In conclusion, bodily experience of sign language can not only impact the nature of co-speech gestures, but also spatio-motoric thinking and abstract space-time mappings.

Language switching experience is assumed to have an effect on domain-general control abilities in bilinguals, but previous studies on the relationship between these two variables have generated mixed results. The present study investigated the effects of bilingual experiences on the interaction between language switching and domain-general control. Thirty-two Dutch–French bilingual young adults executed a bilingual categorisation task to assess their language switching abilities and a Simon task to assess domain-general control. The results show that global response times on the Simon task were correlated to the forward switch cost (from L1 to L2); moreover, interestingly, the forward switch cost was found to be related to recent language exposure but not to the age of second language acquisition. We suggest a monitoring account of language switching to integrate the first finding with previous studies and we interpret the second finding as support for the adaptive control hypothesis.

Noticing the hole (NTH) occurs when speakers want to say something, but realise they do not know the right word(s). Such awareness of lacking knowledge supposedly facilitates the acquisition of the unknown word(s) from later input (Swain, 1993). We tested this claim by experimentally inducing NTH in a second language (L2) for some participants (experimental), but not others (control). Then, in a price comparison game, all participants were exposed to spoken L2 input containing the to-be-learned words. They were unaware of taking part in an L2 study. Post-tests showed that participants who had noticed holes in their vocabulary had indeed learned more words compared to participants who had not. This held both for the experimental group as well as those participants in the control group who later reported to have noticed holes. Thus, when we become aware of vocabulary holes, the first step to improve our vocabulary is already taken.

Although international students experience lower attainment at university than home students (Morrison et al., 2005), reasons are poorly understood. Some question the role of language proficiency as international students come with required language qualifications. This study investigated language and literacy of international students who successfully met language entry requirements and those of home students, matched on non-verbal cognition, studying in their native language. In a sample of 63 Chinese and 64 British students at a UK university, large and significant group differences were found at entry and eight months later. Furthermore, language and literacy indicators explained 51% of variance in the Chinese group's grades, without predicting the home students’ achievement. Thus language proficiency appears predictive of academic outcomes only before a certain threshold is reached, and this threshold does not correspond to the minimum language entry requirements. This highlights a systematic disadvantage with which many international students pursue their education.