Building on our earlier analysis of the factorial structure of bilingualism for young adults obtained from the Language and Social Background Questionnaire (LSBQ; Anderson, Mak, Keyvani Chahi & Bialystok, 2018), we analyzed responses from 675 children and 125 older adults to a similar questionnaire. Three factors accounting for 74% of the variance emerged in the analysis of children's responses: Adult Language in the Home, Non-English use for Media, Non-English use with Siblings. There were also three factors that explained the responses of older adults that accounted for 79% of the variance: Non-English Use, Non-English Proficiency, and English Proficiency. Therefore, bilingual experience is captured by different factors at different points in the lifespan. These results are discussed in conjunction with the earlier results from young adults and the implications for understanding bilingualism across the lifespan.

The language history questionnaire (LHQ) is an important tool for assessing the linguistic background and language proficiency of multilinguals or second language learners. Previously we developed a generic LHQ based on the most commonly asked questions in published studies (Li, Sepanski & Zhao, 2006) and provided a web-based interface (LHQ 2.0) that has flexibility in functionality, accuracy in data recording, and privacy for users and data (Li, Zhang, Tsai & Puls, 2014). LHQ3 (version 3) introduces new functions, developed in response to many comments/requests from users. One important improvement is the addition of an automatic scoring system, in that the new interface automatically calculates aggregated scores for language proficiency, language dominance, and language immersion levels. Finally, LHQ3 allows researchers to assign different weights to the modules when calculating the aggregated scores, addressing the issue of different focuses that different researchers put on multilingual speakers’ language usage and background.

The Language Experience and Proficiency Questionnaire (LEAP-Q) is a validated questionnaire tool for collecting self-reported proficiency and experience data from bilingual and multilingual speakers ages 14 to 80. It is available in over 20 languages, and can be administered in a digital, paper-and-pencil, and oral interview format. The LEAP-Q is used by researchers across various disciplines (Psychology, Neuroscience, Linguistics, Education, Communication Sciences & Disorders, etc.) to provide a comprehensive description of their bilingual participants, to substantiate a division of bilinguals into groups (e.g., early vs. late bilinguals), and to screen participants for adequate or threshold levels of language proficiency. Best practices for using the LEAP-Q include administration of the full questionnaire, consideration of acquisition and history of language use together with self-ratings of proficiency, and supplementation of self-reported data with objective language measures whenever possible. The LEAP-Q can be downloaded at no cost at https://bilingualism.northwestern.edu/leapq/.

Bilingual infants vary in when, how, and how often they hear each of their languages. Variables such as the particular languages of exposure, the community context, the onset of exposure, the amount of exposure, and socioeconomic status are crucial for describing any bilingual infant sample. Parent report is an effective approach for gathering data about infants’ language experience. However, its quality is highly dependent on how information is elicited. This paper introduces a Multilingual Approach to Parent Language Estimates (MAPLE). MAPLE promotes best practices for using structured interviews to reliably elicit information from parents on bilingual infants’ language background, with an emphasis on the challenging task of quantifying infants’ relative exposure to each language. We discuss sensitive issues that must be navigated in this process, including diversity in family characteristics and cultural values. Finally, we identify six systematic effects that can impact parent report, and strategies for minimizing their influence.

The diversity of experiences among bilingual children is reflected in the variability of abilities in each of their languages. This paper describes the CECER-DLL Child and Family, and Teacher Questionnaires and discusses the utility of these tools. These questionnaires were created to address the need for valid and reliable tools to document contextual characteristics and language experiences of young bilingual children in developmental and educational research. A multi-site validity study using the CECER-DLL Questionnaires demonstrates how children's language skills are influenced by language exposure at home and at school, mothers’ and teachers’ skills in each language, mother's generational status, and languages used during language and literacy activities at home.

A longstanding question in the second language acquisition literature is whether late second language (L2) learners process grammatical structures in a native-like manner. Here, we use Time Frequency Representation (TFR) analysis to test morpho-syntactic processing of clitic pronouns in native and late L2 learners of Spanish. The TFR results show overall similar power decreases in theta, alpha, and beta frequencies in both groups. Critically, the observed oscillatory effects persisted in time for native Spanish speakers, but declined earlier for L2 learners. We discuss the results using cell-assembly theory models for language processing (e.g., Pulvermüller, 1999) that posit a biphasic time-course for neural assemblies consisting of an early ignition (recognition) and a later reverberation (re-processing) phase. We propose a working hypothesis for L2 processing in tune with a cell-assembly theory suggesting that the length of the reverberation phase could be a distinguishing feature between native and L2 processing.

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.

Many language pairs chosen in language switching studies differ randomly on multiple linguistic levels, thus obscuring the nature of switching costs. Contact-induced languages, i.e., creoles (e.g., Spanish-based Palenquero) and mixed languages (e.g., Media Lengua), having arisen in intense language contact scenarios, relate systematically to their source languages by displaying high proportions of cognates or shared grammar. This configuration can speak to the relative contribution of lexicon and grammar to switching costs. Results from a production and comprehension task show that switching costs are systematically tied to a language pair's grammatical distance. This suggests that switching costs may result from the re-generation of the morphosyntactic frame on switch trials. Emphasizing the value of testing psycholinguistic theories outside of the usual Western populations, the current study provides insight into the degree of shared mental representations between contact-induced languages and their source languages.

This study aimed at identifying linguistic factors that could contribute to understanding individual differences in executive control among bilinguals. Directionality and type of natural language switching, age of second language acquisition, and language proficiency were evaluated in a sample of 112 early bilingual adults. Participants performed several computerized tasks tapping into three dimensions of executive control: inhibition of interference, working memory updating, and shifting. Regression analyses showed that frequent switching to the second language was associated with more efficient executive processing, enhanced working memory updating processes, and better shifting ability. Moreover, higher frequency of unintended language switches was associated with lower interference control abilities. Frequency of language switching behavior was the principal predictor of executive control, beyond age of second language acquisition and language proficiency. Results suggest that frequent language switching is related to enhanced executive control, while the unintended switching of languages could be associated with low interference control.

Code-switching has been found to incur a processing cost in auditory comprehension. However, listeners may have access to anticipatory phonetic cues to code-switches (Piccinini & Garellek, 2014; Fricke et al., 2016), thus mitigating switch cost. We investigated effects of withholding anticipatory phonetic cues on code-switched word recognition by splicing English-to-Mandarin code-switches into unilingual English sentences. In a concept monitoring experiment, Mandarin–English bilinguals took longer to recognize code-switches, suggesting a switch cost. In an eye tracking experiment, the average proportion of all participants' looks to pictures corresponding to sentence-medial code-switches decreased when cues were withheld. Acoustic analysis of stimuli revealed tone-specific pitch contours before English-to-Mandarin code-switches, consistent with previous work on tonal coarticulation. We conclude that withholding anticipatory phonetic cues can negatively affect code-switched recognition: therefore, bilingual listeners use phonetic cues in processing code-switches under normal conditions. We discuss the implications of tonal coarticulation for mechanisms underlying phonetic cues to code-switching.

This study used ERPs to a) assess the neural correlates of cross-linguistic, cross-modal translation priming in hearing beginning learners of American Sign Language (ASL) and deaf highly proficient signers and b) examine whether sign iconicity modulates these priming effects. Hearing learners exhibited translation priming for ASL signs preceded by English words (greater negativity for unrelated than translation primes) later in the ERP waveform than deaf signers and exhibited earlier and greater priming for iconic than non-iconic signs. Iconicity did not modulate translation priming effects either behaviorally or in the ERPs for deaf signers (except in a 800–1000 ms time window). Because deaf signers showed early translation priming effects (beginning at 400ms-600ms), we suggest that iconicity did not facilitate lexical access, but deaf signers may have recognized sign iconicity later in processing. Overall, the results indicate that iconicity speeds lexical access for L2 sign language learners, but not for proficient signers.

The present study examines whether processing a word in one language is affected by the grammatical gender of its translation equivalent in another language. To this end, a group of Catalan–Spanish bilinguals performed a translation–recognition task while event-related potentials (ERPs) were recorded. Participants were presented with Catalan and Spanish pairs of words and had to decide if they were translation equivalents. Correct translations included words that were gender congruent (estiuMAS/veranoMAS–summer) or gender incongruent (tardorFEM/otoñoMAS–autumn). The behavioral results showed that participants were faster and more accurate in the gender-congruent condition than in the incongruent condition. The ERP data showed a reduced N400 for the congruent condition. The facilitative effect of gender congruency observed in this study constitutes evidence of the obligatory access to grammatical gender information during bare noun processing and suggests that the bilinguals’ gender systems interact, even in highly proficient early bilinguals.

This study investigated the predictive effects of executive functions on bilingual language control processes. We used a flanker task, a switching task and an n-back task to investigate inhibition, shifting, and updating, respectively. We adopted a cued language switching task to investigate the language control processes during bilingual word production. Results of linear mixed effects models showed that picture naming in switch trials was significantly slower and elicited larger stimulus-locked N2 and N400-like components. The results further showed that the flanker effect alone robustly predicted the variability of the N2 but not N400-like switch effects. These findings suggest that domain-general inhibition appears to predict the intensity of inhibition exerted on the lexical items in the non-target language during bilingual word production, but bilingual language control only partially overlaps with executive functions.

This study provides a novel approach for testing the universality of perceptual biases by looking at speech processing in simultaneous bilingual adults learning two languages that support the maintenance of this bias to different degrees. Specifically, we investigated the Iambic/Trochaic Law, an assumed universal grouping bias, in simultaneous French–German bilinguals, presenting them with streams of syllables varying in intensity, duration or neither and asking them whether they perceived them as strong-weak or weak-strong groupings. Results showed robust, consistent grouping preferences. A comparison to monolinguals from previous studies revealed that they pattern with German-speaking monolinguals, and differ from French-speaking monolinguals. The distribution of simultaneous bilinguals' individual performance was best explained by a model fitting a unimodal (not bimodal) distribution, failing to support two subgroups of language dominance. Moreover, neither language experience nor language context predicted their performance. These findings suggest a special role for universal biases in simultaneous bilinguals.

The current study investigates how second language auditory word recognition, in early and highly proficient Spanish–Basque (L1-L2) bilinguals, is influenced by crosslinguistic phonological-lexical interactions and semantic priming. Phonological overlap between a word and its translation equivalent (phonological cognate status), and semantic relatedness of a preceding prime were manipulated. Experiment 1 examined word recognition performance in noisy listening conditions that introduce a high degree of uncertainty, whereas Experiment 2 employed clear listening conditions, with low uncertainty. Under noisy listening conditions, semantic priming effects interacted with phonological cognate status: for word recognition accuracy, a related prime overcame inhibitory effects of phonological overlap between target words and their translations. These findings are consistent with models of bilingual word recognition that incorporate crosslinguistic phonological-lexical-semantic interactions. Moreover, they suggest an interplay between L2-L1 interactions and the integration of information across acoustic and semantic levels of processing in flexibly mapping the speech signal onto the spoken words, under adverse listening conditions.

The psycholinguistic literature suggests that the length of a to-be-spoken phrase impacts the scope of speech planning, as reflected by different patterns of speech onset latencies. However, it is unclear whether such findings extend to first and second language (L1, L2) speech planning. Here, the same bilingual adults produced multi-phrase numerical equations (i.e., with natural break points) and single-phrase numbers (without natural break points) in their L1 and L2. For single-phrase utterances, both L1 and L2 were affected by L2 exposure. For multi-phrase utterances, L1 scope of planning was similar to what has been previously reported for monolinguals; however, L2 scope of planning exhibited variable patterns as a function of individual differences in L2 exposure. Thus, the scope of planning among bilinguals varies as a function of the complexity of their utterances: specifically, by whether people are speaking in their L1 or L2, and bilingual language experience.

Both bilingualism and attention contribute to the development of executive functioning (EF), with higher levels of both leading to better outcomes. The present study treats bilingualism and attention as continuous variables to investigate their impact on EF. Eighty-two 9-year-olds who were attending a French school in an anglophone community completed a flanker task. Children's progress in French represented their level of bilingualism, and attention was assessed through a standard standardized instrument. Degree of bilingualism and degree of attention were both positively related to performance, but exposure to a third language in the home did not further affect outcomes.