Bilingual brain : a review of the most important findings

Posługiwanie się więcej niż jednym językiem wiąże się z dodatkowymi wyzwaniami dla systemu poznawczego. Badania neuroobrazowe pokazują, że dwujęzyczność niesie za sobą szereg neuroplastycznych zmian zarówno w funkcjonowaniu, jak i strukturze mózgu. Zmiany te są związane z koniecznością pogodzenia dwóch systemów reprezentacji językowych oraz za angażowania systemu kontroli, dzięki czemu osoba dwujęzyczna używa języka zgodnego z intencją czy kontekstem. Artykuł jest przeglądem najważniejszych doniesień badawczych w tym zakresie. Badania neuroobrazowe wskazują, że sposób organizacji neuronalnego podłoża reprezentacji językowych zależy od ich typu. Reprezentacje konceptualne u osób dwujęzycznych mają wspólne podłoże neuronalne. Reprezentacje leksykalne, związane ze słownictwem, chociaż są przetwarzane przez te same obszary mózgu niezależnie od języka, są kodowane przez częściowo odrębne populacje neuronów. Reorganizacja systemu reprezentacji syntaktycznych drugiego języka w dużej mierze zależy od czynników związanych z indywidualnym do świadczeniem dwujęzyczności, takich jak wiek, w którym rozpoczęto naukę języka, czy osiągnięty poziom biegłości. Neuroplastyczne zmiany w mózgu osoby dwujęzycznej, zarówno funkcjonalne, jak i strukturalne, następują również w wyniku zwiększonego zaangażowania kontroli poznawczej w procesy językowe. Najnowsze doniesienia wskazują jednak, że zakres oraz nasilenie tych zmian zależą w dużej mierze od indywidualnego doświadczenia osoby dwujęzycznej.Bilingualism imposes additional requirements on the cognitive system. As such, it can be a driving force of neuroplastic changes in the brain of a person who speaks more than one language. The need to store and use two systems of representations corresponding to the two languages as well as to develop an efficient control system which allows to use the intendent, contextually appropriate language, may result in both functional and structural changes. Neuroimaging studies show that the neural organization of language representations in a bilingual brain depends to a large degree on the type of representation. Conceptual representations seem to share common neural underpinnings between the different languages. Lexical representations, related to the vocabulary and words, are processed by the same brain regions regardless of the language, however, they have been shown to be coded by distinct neuronal populations. Finally, neuroplastic reorganization of syntactic representations is highly dependent on factors related to individual experiences of bilingualism, such as age of acquisition and proficiency in the second language. Neuroplastic changes in the bilingual brain have also been linked to the increased demands that using two languages imposes on the cognitive control mechanisms. Both structural and functional changes in the brain of bilinguals were observed withing a wide network referred to as language control network. Summing up, neuroimaging studies have demonstrated that bilingualism is related to neuroplastic changes in both structure and functioning of the brain. However, the newest reports suggest the extent and intensity of the neuroplastic changes are most likely dependent on individual experiences of each bilingual speaker

The effects of bilingualism on efficiency and lateralization of attentional networks

The present study investigated the impact of bilingualism on efficiency of alerting, orienting and executive attention by means of the Lateralized Attention Network Test (LANT). Young adult bilinguals who had been exposed to their second language before the age of four years showed a reduced conflict cost and a larger alerting effect in terms of response time (RT), while no difference between bilinguals and monolinguals was observed in overall RT. Bilinguals also outperformed monolinguals on accuracy in both conflict and non-conflict trials, though the effect in the latter condition was very small. Moreover, while a left visual field advantage for accuracy of conflict resolution was present in the monolingual group, bilinguals did not show the asymmetry. The findings suggest that bilingualism enhances the efficiency of executive network while reducing its lateralization. The larger alerting effect in bilinguals is hypothesized to be related to bilinguals’ more efficient executive control, which may support processes of response anticipation or temporal orientin

Fast or accurate? : the change of goals modulates the efficiency of executive control

In the present study, we analyse the influence of goal maintenance and goal change on the efficiency of executive control. Although there is empirical evidence on the impact of goal maintenance and task-switching on executive control, little is known about the consequences of changing between processing goals (e.g., speed or accuracy goals). We assessed the influence of changing between speed and accuracy goals while performing a task-switching procedure that requires social categorization. Experiment 1 included frequent goal changes, whereas Experiment 2 included one goal change across the experimental session. The results showed that both goals influence general performance and flexibility. A comparison between experiments suggested that frequent goal change (Experiment 1) resulted in worse performance and lower flexibility overall, compared to sequential goal change (Experiment 2). Frequent goal change was also associated with increased difficulties in pursuing the accuracy goal. The implications regarding the role of goal maintenance and goal change on executive control are discussed, as well as new research possibilities

The relative balance between languages predicts the degree of engagement of global language control

After naming pictures in their second language (L2), bilinguals experience difficulty in naming pictures in their native language (L1). This phenomenon, the "L2 after-effect", is a lingering consequence of language control mechanisms regulating the activation of L1 and L2 to facilitate L2 production. Building on the Inhibitory Control model proposed by Green (1998), we propose that how much language control is applied depends on the relative balance between the current activation of L1 and L2. In two experiments, Polish-English bilinguals immersed in their L1 performed a blocked picture-naming task. This paradigm provided a continuous measure of the relative balance between the two languages and made it possible to index engagement of control by measuring the L2 after-effect. The results indicate that the higher the activation level of L1 and the lower the activation level of L2, the bigger the L2 after-effect. The results also revealed an enduring down-regulation of L1 activation level in more language-balanced speakers

Subtlex-pl: subtitle-based word frequency estimates for Polish

We present SUBTLEX-PL, Polish word frequencies based on movie subtitles. In two lexical decision experiments, we compare the new measures with frequency estimates derived from another Polish text corpus that includes predominantly written materials. We show that the frequencies derived from the two corpora perform best in predicting human performance in a lexical decision task if used in a complementary way. Our results suggest that the two corpora may have unequal potential for explaining human performance for words in different frequency ranges and that corpora based on written materials severely overestimate frequencies for formal words. We discuss some of the implications of these findings for future studies comparing different frequency estimates. In addition to frequencies for word forms, SUBTLEX-PL includes measures of contextual diversity, part-of-speech-specific word frequencies, frequencies of associated lemmas, and word bigrams, providing researchers with necessary tools for conducting psycholinguistic research in Polish. The database is freely available for research purposes and may be downloaded from the authors' university Web site at http://crr.ugent.be/subtlex-p

Sign-spoken bilingualism in hearing individuals with D/deaf parents : a questionnaire-based study on the contact between Polish Sign Language and spoken Polish

Prezentowane badanie dotyczyło dwujęzyczności migowo-fonicznej u słyszących osób mających G/głuchych rodziców (CODA, ang. child of deaf adult). W kontakcie polskiego języka migowego (PJM) i fonicznej polszczyzny może wystąpić: przełączanie się pomiędzy językami, łączenie kodów oraz symultaniczna komunikacja. Celem analizy było określenie, czy CODA dostrzegają te zjawiska w swoim doświadczeniu językowym i czy mogą określić, z jakiego powodu są one obecne w ich wypowiedziach. 32 badanych opisało swoje doświadczenia językowe za pomocą Kwestionariusza językowego dla CODA. Wyniki wskazują, że większość badanych uważa, że łączy kody, natomiast występowanie pozostałych zjawisk było deklarowane w sposób zróżnicowany w grupie osób badanych. Jako przyczyny kontaktu PJM-u i fonicznej polszczyzny wymieniano: automatyczne działanie/przyzwyczajenie, brak słów w danym języku, dostosowanie się do potrzeb interlokutora czy wygodę.Presented research concerned sign-spoken bilingualism in hearing individuals with D/deaf parents (CODA, Child of Deaf Adult). When Polish Sign Language (polski język migowy, PJM) and spoken Polish are in contact, the following phenomena can be observed: code-switching, code blending and simultaneous communication. The study aimed to investigate if CODAs observe the occurrence of the mentioned phenomena in their language experience and if they can clarify the reasons why those phenomena appear in their utterances. 32 participants described their languages’ experience in the Language Questionnaire for CODA. The findings showed that the majority of participants consider that they used code-blending, whereas the occurrence of other two phenomena was declared with more diversity within the group. Four main causes of these phenomena were reported: automatic process/habit, lack of words in a given language, adaptation to the interlocutor’s needs and comfortable communication

Patterns of bilingual language use and response inhibition : a test of the adaptive control hypothesis

Given prior studies that provided inconsistent results, there is an ongoing debate on the issue of whether bilingualism benefits cognitive control. We tested the Adaptive Control Hypothesis, according to which only the intense use of different languages in the same situation without mixing them in single utterances (called dual-language context) confers a bilingual advantage in response inhibition. In a large-scale correlational study, we attempted to circumvent several pitfalls of previous research on the bilingual advantage by testing a relatively large sample of participants and employing a more reliable and valid measurement of constructs (i.e., latent variable approach accompanied by Bayesian estimation). Our results do not support the Adaptive Control Hypothesis' prediction: the intensity of the dual-language context experience was unrelated to the efficiency of response inhibition in bilinguals. The results suggest that the Adaptive Control Hypothesis is not likely to account for the inconsistent results regarding the bilingual advantage hypothesis, at least in the case of the response-inhibition mechanism. At the same time, the study points to the problem of measuring the response-inhibition construct at the behavioral level. No evidence for a robust response-inhibition construct adds to the growing skepticism on this issue in the literature

Inhibitory Control in Bilinguals and Musicians: Event Related Potential (ERP) Evidence for Experience-Specific Effects.

Bilinguals and musicians exhibit behavioral advantages on tasks with high demands on executive functioning, particularly inhibitory control, but the brain mechanisms supporting these differences are unclear. Of key interest is whether these forms of experience influence cognition through similar or distinct information processing mechanisms. Here, we recorded event-related potentials (ERPs) in three groups – bilinguals, musicians, and controls – who completed a visual go-nogo task that involved the withholding of key presses to rare targets. Participants in each group achieved similar accuracy rates and responses times but the analysis of cortical responses revealed significant differences in ERP waveforms. Success in withholding a prepotent response was associated with enhanced stimulus-locked N2 and P3 wave amplitude relative to go trials. For nogo trials, there were altered timing-specific ERP differences and graded amplitude differences observed in the neural responses across groups. Specifically, musicians showed an enhanced early P2 response accompanied by reduced N2 amplitude whereas bilinguals showed increased N2 amplitude coupled with an increased late positivity wave relative to controls. These findings demonstrate that bilingualism and music training have differential effects on the brain networks supporting executive control over behavio

Bilingual children's phonology shows evidence of transfer, but not deceleration in their L1

Bilingual language development might be characterized by transfer, deceleration, and/or acceleration, the first two being relevant for the language impairment diagnosis. Studies on bilingual children’s productive phonology show evidence of transfer, but little is known about deceleration in this population. Here, we focused on phonological transfer and deceleration in L1 speech of typically developing Polish-English bilingual children of Polish migrants to the United Kingdom (aged 4.7-7). We analyzed L1 speech samples of 30 bilinguals and 2 groups of Polish monolinguals, matched to the bilinguals on age or vocabulary size. We found that bilingual children’ speech (both simultaneous and early sequential) was characterized by transfer, but not by deceleration, suggesting that while phonological deceleration phases out in children above the age of 4.7, transfer does not. We discuss our findings within the PRIMIR model of bilingual phonological acquisition (Curtin et al., 2011) and show their implications for SLT practices