Previous work indicates that 1) adults with native sign language experience produce more manual co-speech gestures than monolingual non-signers, and 2) one year of ASL instruction increases gesture production in adults, but not enough to differentiate them from non-signers. To elucidate these effects, we asked early ASL–English bilinguals, fluent late second language (L2) signers (≥ 10 years of experience signing), and monolingual non-signers to retell a story depicted in cartoon clips to a monolingual partner. Early and L2 signers produced manual gestures at higher rates compared to non-signers, particularly iconic gestures, and used a greater variety of handshapes. These results indicate susceptibility of the co-speech gesture system to modification by extensive sign language experience, regardless of the age of acquisition. L2 signers produced more ASL signs and more handshape varieties than early signers, suggesting less separation between the ASL lexicon and the co-speech gesture system for L2 signers.

The present study compared both linguistic and non-linguistic representations of motion events in Korean–English sequential bilinguals sampled at varying proficiency levels (N = 80) against each other and against those of Korean and English monolinguals (N = 15 each). The bilinguals' L2 descriptions of motion events showed that their encoding patterns were influenced by both the first language (L1) and second language (L2) and also displayed unique behaviors that were not found in either monolingual norm. The non-verbal results on a triads-matching task demonstrated that bilinguals' categorization patterns followed L1-based patterns rather than L2-based patterns. The extent to which these bilinguals employed L2 encoding patterns in their motion event descriptions was largely modulated by L2 proficiency, whereas length of immersion experience in an L2-speaking country emerged as the only predictor of their non-verbal categorization patterns. These findings suggest that the bilinguals' verbal behavior seems more susceptible to change than their non-verbal behavior.

Although there is a body of work investigating code-switching (alternation between two languages in production) in the preschool period, it largely relies on case studies or very small samples. The current work seeks to extend extant research by exploring the development of code-switching longitudinally from 31 to 39 months of age in two distinct groups of bilingual children: Spanish–English children in San Diego and French–English children in Montréal. In two studies, consistent with previous research, children code-switched more often between than within utterances and code-switched more content than function words. Additionally, children code-switched more from Spanish or French to English than the reverse. Importantly, the factors driving the rate of code-switching differed across samples such that exposure was the most important predictor of code-switching in Spanish–English children whereas proficiency was the more important predictor in French–English children.

Juggling with structurally and semantically different language systems leads to constructions that differ from the typical patterns in a language. Typical patterns in the domain of motion are characterized by more verbs encoding path in French; and more verbs encoding the manner of motion in German. An increase of manner verbs in French, for instance, can be ascribed to an influence from German. The extent of typical or reversed patterns depends on interrelated factors such as speaker-related idiosyncrasies, language dominance configurations, and – arguably – the degree of language activation. Drawing on data from 154 French–German bilinguals who described motion events in different language modes, this paper combines interrelated questions on the role of language dominance, language mode manipulation and how these factors interact. Quantitative analyses on the use of motion verbs do not show the expected effects. The null results are discussed by comparing preceding studies showing contradictory findings.

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.

The current study explored bilingual parent and child code-switching patterns over time. Concurrent and predictive models of code-switching behaviour on executive function outcomes were also examined in a sample of 29 French–English bilinguals at 36 (Wave 1) and 61 (Wave 2) months of age. We investigated whether code-switching typology in a single-language context predicted executive function performance at each wave independently, and whether growth in code-switching frequency across waves predicted executive function performance at Wave 2. At both waves, parents and children participated in two free play sessions (in English and French), followed by a battery of executive function tasks administered in the dominant language. Results indicate more frequent code-switching from the non-dominant to the dominant language in children, and that children code-switch to fill lexical gaps. Results also suggest that less frequent code-switching in a single-language context is associated with better inhibitory control skills during the preschool period.

Typically concrete words are learned better than abstract words (Kaushanskaya & Rechtzigel, 2012), and nouns are learned better than verbs (Kauschke & Stenneken, 2008). However, most studies on concreteness have not manipulated grammatical class (and vice versa), leaving the relationship between the two unclear. Therefore, in two experiments we examined the effects of grammatical class and concreteness simultaneously in foreign language vocabulary learning. In Experiment 1, English speakers learned ‘foreign language’ words (English pseudowords) mapped to concrete and abstract nouns and verbs. In Experiment 2, English speakers learned German words with the same procedure. Overall, the typical advantages for concrete words and nouns were observed. Hierarchical regression analyses provided evidence that the grammatical class effect is separable from the concreteness effect. This result challenges a strict concreteness-based source of noun/verb differences. The results also suggest that the influences of concreteness and grammatical class may vary across language measures and tasks.

This study investigates the relationship between mechanisms involved in language control within dual- and single-language contexts by examining whether they are similarly impaired in bilingual PD patients. To do so, we explored the performance of bilingual individuals affected by PD and healthy controls on two linguistic tasks: between-language and within-language switching tasks. We focused on switch and mixing costs as measures of linguistic control.

The results indicate that, whereas larger switch costs were observed in PD patients, compared to controls, solely during the between-language task, larger mixing costs appeared during both the between-language task and the within-language task. These results are discussed within the framework of the dual mechanism hypothesis, which suggests that switch and mixing costs are measures of two types of control: specifically reactive and proactive control. Therefore, we conclude that reactive control for switching between languages is domain-specific while proactive control mechanisms are more domain-general.

Most English compounds are spaced compounds, whereas spelling regulations prescribe Finnish compounds to be written in a concatenated format. However, as in English, Finnish compounds are commonly spaced nowadays (e.g., piha juhla ‘garden party’), a phenomenon that we labeled the ‘English disease’. In this eye movement study with Finnish–English bilinguals we investigate whether the reading of a concatenated or illegally spaced Finnish compound is affected by the spelling of an English translation equivalent (ETE). We found that spaced Finnish compounds were read slower than their concatenated counterparts, but this effect was attenuated when ETEs were thought to be spaced. Similarly, concatenated Finnish compounds were read faster when their ETEs were also concatenated. These backward transfer effects are in line with studies that show that processing behavior in L1 is affected by a strong concurrent L2, even when the L1 is the native language as well as the dominant community language.

There is growing evidence that the orthographic forms (spellings) of second language words affect second language (L2) speech production, but it is not known whether orthography affects L2 phonology in native users of a non-alphabetic writing system. To answer this question, this study tested the effects of number of letters on the duration of consonants and vowels in the EnglishL2 speech production of Japanese–English sequential bilinguals. JapaneseL1–EnglishL2 bilinguals and English native speakers (both n = 16) performed a delayed word repetition task, producing 16 English word pairs in which the same consonant or vowel was spelled either with a single letter or with double letters, as in city-kitty. The bilinguals produced the same English sound as longer or shorter depending on the number of letters in its spelling, confirming that L2 orthographic forms affect L2 speakers’ phonological representations of L2 words even when their L1 writing system is not alphabetical.

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.

People assume that objects labelled alike belong to the same category. Here we asked whether the role of labels in categorization depends on individuals' language experience, linguistic abilities, and/or cognitive abilities. We compared monolinguals' and bilinguals' use of phonologically licit words (zeg), illicit words (gsz), and non-linguistic frames (in addition to a baseline condition with no additional cues) in forming novel categories. For both groups, licit words affected categorization more than frames, especially in the absence of perceptual evidence for category boundaries; illicit words also shifted categorization preferences compared to frames. Furthermore, linguistic abilities predicted reliance on both licit and illicit words, and bilingualism predicted reliance on illicit words in categorization. Thus, in both monolinguals and bilinguals, novel (and even unconventional) linguistic labels act as unique category markers but their use in categorization depends on individual language processing skills (and, in some cases, exposure to a second language).

We investigated changes in self-representation depending on language in Friulian–Italian bilinguals. The Temperament and Character Inventory (TCI) and the Junior-TCI were administered respectively to 24 adults and 25 children, both in Friulian and in Italian, at a distance of two weeks from each other. Variations in TCI were detected: both adults and children scored higher in Self-Directedness (a character trait) when using Italian than Friulian. Similar findings were observed for Novelty-Seeking (a temperament trait) in children and Cooperativeness (another character trait) in adults. Results are discussed considering previous studies on bilingualism and within the frame of the Friulian sociolinguistic context.

Extending previous research that has examined the relationship between long-term memory and second language (L2) development with a primary focus on accuracy in L2 outcomes, the current study explores the relationship between declarative and procedural memory and accuracy and automatization during L2 practice. Adult English native speakers had learned an artificial language over two weeks (Morgan-Short, Faretta-Stutenberg, Brill-Schuetz, Carpenter & Wong, 2014), producing four sessions of practice data that had not been analyzed previously. Mixed-effects models analyses revealed that declarative memory was positively related to accuracy during comprehension practice. No other relationships were evidenced for accuracy. For automatization, measured by the coefficient of variation (Segalowitz, 2010), the model revealed a positive relationship with procedural memory that became stronger over practice for learners with higher declarative memory but weaker for learners with lower declarative memory. These results provide further insight into the role that long-term memory plays during L2 development.

Learning conventional verb-noun combinations in a second language is known to be highly problematic when word choices differ from those in the native language. Grounded on recent proposals of desirable difficulties in vocabulary learning (Bjork & Kroll, 2015), we tested Spanish learners of English on a new paradigm that aimed to induce interference from the native language during lexical selection in a second language, as a way to train regulation of the dominant language. Results showed that recall rates were significantly higher in the group of learners that practiced in conditions of L1-interference. Faster RTs showed more efficient lexical selection in those same learners. Additionally, RTs revealed that the more successful learners in both groups incurred a cost in accessing verb choices congruent with the native language, a finding that is consistent with an inhibitory account.

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.

As a rule, listening is easier in first (L1) than second languages (L2); difficult L2 listening can challenge even highly proficient users. We here examine one particular listening function, adaptation to novel talkers, in such a high-proficiency population: Dutch emigrants to Australia, predominantly using English outside the family, but all also retaining L1 proficiency. Using lexically-guided perceptual learning (Norris, McQueen & Cutler, 2003), we investigated these listeners’ adaptation to an ambiguous speech sound, in parallel experiments in both their L1 and their L2. A control study established that perceptual learning outcomes were unaffected by the procedural measures required for this double comparison. The emigrants showed equivalent proficiency in tests in both languages, robust perceptual adaptation in their L2, English, but no adaptation in L1. We propose that adaptation to novel talkers is a language-specific skill requiring regular novel practice; a limited set of known (family) interlocutors cannot meet this requirement.

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.