The first part of this paper reviews research evidence for typological similarity and/or L2 status as determinants of cross-linguistic influence (CLI) in multilingual lexical production. The second part presents a model of vocabulary acquisition as a framework to explain CLI at the levels of form, (syntactic) frame, and meaning, as well as some of the developmental changes that have been reported for CLI patterns in relation to L3 learners’ proficiency. It is suggested that these patterns can be related to default processes and stages involved in the acquisition of individual word forms and their integration into networks of existing lexical triads, as described in the Parasitic Model of vocabulary acquisition. The third part of this paper points to research into the complexity and non-linearity of multilingual lexical development and the need to learn more about it.

Bilinguals often switch languages as a function of the language background of their addressee. The control mechanisms supporting bilinguals' ability to select the contextually appropriate language are heavily debated. Here we present four experiments in which unbalanced bilinguals named pictures in their first language Dutch and their second language English in mixed and blocked contexts. Immersive virtual reality technology was used to increase the ecological validity of the cued language-switching paradigm. Behaviorally, we consistently observed symmetrical switch costs, reversed language dominance, and asymmetrical mixing costs. These findings indicate that unbalanced bilinguals apply sustained inhibition to their dominant L1 in mixed language settings. Consequent enhanced processing costs for the L1 in a mixed versus a blocked context were reflected by a sustained positive component in event-related potentials. Methodologically, the use of virtual reality opens up a wide range of possibilities to study language and communication in bilingual and other communicative settings.

This study investigated the referring expressions used for first mentions of participants and entities in narratives by Mandarin heritage language (HL) and monolingual children. Referring expressions for first mentions in Mandarin comprise lexical, morphological and syntactic devices. Results showed that HL children used less adequate referring expressions for first mentions than the monolinguals, mainly due to overgeneralization of classifiers and lack of vocabulary knowledge. However, HL children did not differ from monolinguals in their use of relative clauses and post-verbal NP placement to mark first mentions. These results suggest that incomplete acquisition of the HL may vary across different linguistic subdomains (Montrul, 2008); specifically, domains requiring a great deal of input to acquire, such as vocabulary and the large repertoire of classifier morphemes, might be more vulnerable in HL speakers than syntax. Mixed modeling analyses revealed that older age of arrival, higher maternal education levels and a rich and diverse Mandarin environment at home predicted stronger narrative outcomes, also pointing to an important role for input in HL acquisition.

It has been claimed that due to their experience in controlling two languages, bilinguals exceed monolinguals in certain executive functions, especially inhibition of task-irrelevant stimuli. Here we investigated the effects of bilingualism on an executive phonological task, namely the forced-attention dichotic listening task with syllabic stimuli. In the standard non-forced (NF) condition, the participants reported all syllables they heard, be it from the right or the left ear. In the forced-right (FR) and forced-left (FL) attention conditions, they had to direct their attention to either the right- or the left-ear stimulus and inhibit information coming to the other ear. We tested Finnish monolinguals and early simultaneous Finnish–Swedish bilinguals from two age groups: (30–50-year-olds and 60–74-year-olds). The results showed that the bilinguals performed better than the monolinguals in the FR and FL conditions. This supports the idea of a bilingual advantage in directing attention and inhibiting task-irrelevant stimuli.

Research on word production in bilinguals has often shown an advantage for cognate words. According to some accounts, this cognate effect is caused by feedback from a level that represents information about phonemes (or graphemes) to a level concerned with the word. In order to investigate whether phonological feedback influences the selection of words and syntactic constructions in late bilinguals, we investigated syntactic priming between Dutch and English genitive constructions (e.g., the fork of the girl vs. the girl's fork). The head nouns of prime and target constructions were always translation equivalents. Half of these were Dutch–English cognates with a large phonological overlap (e.g., vork–fork), the other half were non-cognates that had very few phonemes in common (e.g., eend–duck). Cognate status boosted between-language syntactic priming. Further analyses showed a continuous effect of phonological overlap for cognates and non-cognates, indicating that this boost was at least partly caused by feedback from the translation equivalents’ shared phonemes.

The longitudinal study reported in the present paper examines L1 vocabulary decline by a child whose native language input effectively ceased after her immersion into the L2 environment. The subject of the study was a Russian girl adopted by an American family, brought to the USA, and completely isolated from any contact with the Russian-speaking environment. The analysis of the data was based on the results of picture naming tasks and reaction time measurements. Three groups of words showed high vulnerability to forgetting: high frequency words, cognates, and semantically convergent pairs (pairs of words lexically distinguished in L2 and non-distinguished in L1). Fast forgetting of these lexical items in L1 was related to the acquisition of their equivalents in L2. The comparison of noun versus verb retention/acquisition suggested that there might be a delay in L1 verb forgetting / L2 verb acquisition at the early stage of an extensive exposure to the second language.

Learning and using additional languages can result in structural changes in the brain. However, the time course of these changes, as well as the factors the predict them, are still not well understood. In this longitudinal study we test the effects of bilingual immersion on brain structure of adult sequential bilinguals not undergoing any language training, who were scanned twice, three years apart. We observed significant increases in grey matter volume in the lower left cerebellum, mean white matter diffusivity in the frontal cortex, and reshaping of the left caudate nucleus and amygdala and bilateral hippocampus. Moreover, both prior length of immersion and L2 age of acquisition were significant predictors of volumetric change in the cerebellum. Taken together, these results indicate that bilingualism-induced neurological changes continue to take place across the lifespan and are strongly related to the quantity and quality of bilingual immersion, even in highly-immersed adult bilingual populations.

One key issue in bilingualism is how bilinguals control production, particularly to produce words in the less dominant language. Language switching is one method to investigate control processes. Language switching has been much studied in comprehension, e.g., in lexical decision task, but less so in production. Here we first present a study of language switching in Italian–English adult bilinguals in a naming task for visually presented words. We demonstrate an asymmetric pattern of time costs to switch language, where participants incurred a greater time cost to switch into naming in their dominant language (Italian). In addition, costs were greater where the stimuli were interlingual cognates or homographs than words existing in only one language, implicating lexical competition as a source of the cost. To clarify the operation of control processes, we then present two connectionist models of bilingual naming, based on the previous models of Seidenberg and McClelland (1989), Cohen, Dunbar and McClelland (1990), Gilbert and Shallice (2002), and Karaminis and Thomas (2010). Crucially, both models acquired their differential language dominance via an experience-dependent learning process. The models embody different assumptions about the language control processes that produce the switch cost. We consider which processing assumptions are sufficient to explain asymmetric language switch costs and word class effects on language switching in individual word reading, as well as generating novel predictions for future testing.

Native speakers show rapid adjustment of their processing strategies and preferences on the basis of the structures they have recently encountered. The present study investigated the nature of priming and adaptation in second-language (L2) speakers and, more specifically, whether similar mechanisms underlie L2 and native language adaptation. Native English speakers and Korean L2 learners of English completed a written priming study probing the use of double object and prepositional phrase datives. Both groups showed cumulative adaptation effects for both types of dative, which was stronger for the structure that was initially less frequent to them (prepositional phrase datives for the native English speakers, and double object datives for the L2 learners). This supports models of priming that incorporate frequency-based modulation of long-lasting activation of structures. L2 learners and native speakers use similar processing mechanisms; differences in adaptation can be accounted for by differences in the relative frequency of structures.

Learning to read in any language requires learning to map among print, sound and meaning. Writing systems differ in a number of factors that influence both the ease and the rate with which reading skill can be acquired, as well as the eventual division of labor between phonological and semantic processes. Further, developmental reading disability manifests differently across writing systems, and may be related to different deficits in constitutive processes. Here we simulate some aspects of reading acquisition in Chinese and English using the same model for both writing systems. The contribution of semantic and phonological processing to literacy acquisition in the two languages is simulated, including specific effects of phonological and semantic deficits. Further, we demonstrate that similar patterns of performance are observed when the same model is trained on both Chinese and English as an “early bilingual”. The results are consistent with the view that reading skill is acquired by the application of statistical learning rules to mappings among print, sound and meaning, and that differences in the typical and disordered acquisition of reading skill between writing systems are driven by differences in the statistical patterns of the writing systems themselves, rather than differences in cognitive architecture of the learner.

German-English bilinguals decided whether a visually presented word, either German or English, referred to an animate or to an inanimate entity. Bilinguals were slower to respond on a language switch trial than on language non-switch trials but only if they had to make the same response as on the prior trial (e.g., two successive “animate” responses). If they had to change their response from the prior trial, a switch of language speeded responses. This interaction between language switching and response type was abolished for the translations of words previously presented. We consider the implications for theories of language control.

Bilinguals are known to perform worse than monolinguals on speech-in-noise tests. However, the mechanisms underlying this difference are unclear. By varying the amount of linguistic information available in the target stimulus across five auditory-perception-in-noise tasks, we tested if differences in language-independent (sensory/cognitive) or language-dependent (extracting linguistic meaning) processing could account for this disadvantage. We hypothesized that language-dependent processing differences underlie the bilingual disadvantage and predicted that it would manifest on perception-in-noise tasks that use linguistic stimuli. We found that performance differences between bilinguals and monolinguals varied with the linguistic processing demands of each task: early, high-proficiency, Spanish–English bilingual adolescents performed worse than English monolingual adolescents when perceiving sentences, similarly when perceiving words, and better when perceiving tones in noise. This pattern suggests that bottlenecks in language-dependent processing underlie the bilingual disadvantage while language-independent perception-in-noise processes are enhanced.

Research on the linguistic knowledge of heritage speakers has been concerned primarily with the advantages conferred by heritage language experience in production, perception, and (re)learning of the heritage language. Meanwhile, second-language speech research has begun to investigate potential benefits of first-language transfer in second-language performance. Bridging these two bodies of work, the current study examined the perceptual benefits of heritage language experience for heritage speakers of Korean in both the heritage language (Korean) and the dominant language (American English). It was hypothesized that, due to their early bilingual experience and the different nature of unreleased stops in Korean and American English, heritage speakers of Korean would show not only native-like perception of Korean unreleased stops, but also better-than-native perception of American English unreleased stops. Results of three perception experiments were consistent with this hypothesis, suggesting that benefits of early heritage language experience can extend well beyond the heritage language.

Dutch–English bilinguals performed a generalized lexical decision task on triplets of items, responding with “yes” if all three items were correct Dutch and/or English words, and with “no” if one or more of the items was not a word in either language. Sometimes the second item in a triplet was an interlingual homograph whose English meaning was semantically related to the third item of the triplet (e.g., HOUSE – ANGEL – HEAVEN, where ANGEL means “sting” in Dutch). In such cases, the first item was either an exclusively English (HOUSE) or an exclusively Dutch (ZAAK) word. Semantic priming effects were found in on-line response times. Event-related potentials that were recorded simultaneously showed N400 priming effects thought to reflect semantic integration processes. The response time and N400 priming effects were not affected by the language of the first item in the triplets, providing evidence in support of a strong bottom-up role with respect to bilingual word recognition. The results are interpreted in terms of the Bilingual Interactive Activation model, a language nonselective access model assuming bottom-up priority.

Executive control abilities and lexical access speed in Stroop performance were investigated in English monolinguals and two groups of bilinguals (English–Chinese and Chinese–English) in their first (L1) and second (L2) languages. Predictions were based on a bilingual cognitive advantage hypothesis, implicating cognitive control ability as the critical factor determining Stroop interference; and two bilingual lexical disadvantage hypotheses, focusing on lexical access speed. Importantly, each hypothesis predicts different response patterns in a Stroop task manipulating stimulus onset asynchrony (SOA). There was evidence for a bilingual cognitive advantage, although this effect was sensitive to a number of variables including proficiency, language immersion, and script. In lexical access speed, no differences occurred between monolinguals and bilinguals in their native languages, but there was evidence for a delay in L2 processing speed relative to the L1. Overall, the data highlight the multitude of factors affecting executive control and lexical access speed in bilinguals.

Can transfer occur in child bilingual syntax when surface overlap does not involve the syntax-pragmatics interface? Twenty-three Spanish/English bilingual children participated in an elicited imitation study of clitic placement in Spanish restructuring contexts, where variable word order is not associated with pragmatic or semantic factors. Bilingual children performed poorly with preverbal clitics, the order that does not overlap with English. Distinct bilingual patterns emerged: backward repositioning, omissions (for simultaneous bilinguals) and a reduction in forward repositioning bias. We conclude that transfer should be defined in lexical terms as the result of priming effects leading to shifts in lexical items.

This study assesses the impact of internal and external factors on very young EFL learners in an instructional setting. 71 child English learners in China (onset age: 2;0 - 5;6) were involved: their receptive vocabulary, productive vocabulary and receptive grammar were taken as outcome variables, and age of onset, short-term memory, nonverbal intelligence, English input quantity and quality, English use, and maternal English level were taken as predictive variables. Multiple regression analyses, verified by Bayes factor comparisons, revealed that the total amount of school input and home English media environment were significant predictors for all of three aspects of English proficiency, with each aspect having different additional significant predictors. Both internal factors (e.g., age of onset) and external factors (e.g., English input quantity) played an important role, but in contrast to similar studies (e.g., Paradis, 2011) focusing on a L2 naturalistic setting, external factors explained more variance of English proficiency measures.

Cross-linguistic transfer can be explained by structural ambiguity in a bilingual child's two languages (Döpke, 1998; Hulk and Müller, 2000). This study examined the effect of morphological ambiguity in transfer of deverbal compounds in English and French. English-speaking children go through a stage of producing ungrammatical verb-object compounds in their acquisition of object-verb-er compounds. In French, verb-object compounds are productive. If structural ambiguity predicts when transfer occurs, French-English bilingual children should use more ungrammatical verb-object compounds than English-speaking children and more grammatical verb-object compounds than French-speaking children. This study focused on 36 French-English bilingual children's production and comprehension of novel deverbal compounds in both languages. The results supported these predictions for production but not for comprehension. It is concluded that cross-linguistic transfer is a language production phenomenon and that structural ambiguity can predict when morphological transfer can occur.

Simultaneous interpretation is a cognitively demanding process that requires a high level of language management. Previous studies on bilinguals have suggested that extensive practice managing two languages leads to enhancements in cognitive control. Thus, interpreters may be expected to show benefits beyond those seen in bilinguals, either as an extension of previously-seen benefits or in areas specific to interpretation. The present study examined professional interpreters (N = 23) and matched multilinguals (N = 21) on memory tests, the color-word Stroop task, the Attention Network Test, and a non-linguistic task-switching paradigm. The interpreters did not show advantages in conflict resolution or switching cost where bilingual benefits have been noted. However, an interpretation-specific advantage emerged on the mixing cost in the task-switching paradigm. Additionally, the interpreters had larger verbal and spatial memory spans. Interpreters do not continue to garner benefits from bilingualism, but they do appear to possess benefits specific to their experience with simultaneous interpretation.

This paper investigates the shared or independent nature of grammatical gender representations in the bilingual mental lexicon and the role word form similarity (as in the case of cognates) plays in these representations. In a translation task from Greek (L1) to German (L2), nouns that had the same gender in both languages were translated faster than nouns with different genders, but only when the L2 target utterance required computation of gender agreement (adjective + noun). This tendency held for both cognates and noncognates. Unlike noncognates, however, gender-incongruent cognates yielded more errors than gender-congruent cognates. These results are interpreted as evidence for a shared L1–L2 gender system with L2 cognates relying more heavily on the L1 gender value than noncognates.