How does the bilingual experience sculpt the brain?

Associations between Bilingualism and Memory Generalization During Infancy: Does Socioeconomic Status Matter?

Past studies have reported memory differences between monolingual and bilingual infants (Brito & Barr, 2012; Singh et al., 2015). A common critique within the bilingualism literature is the absence of socioeconomic indicators and/or a lack of socioeconomic diversity among participants. Previous research has demonstrated robust bilingual differences in memory generalization from 6- to 24-months of age. The goal of the current study was to examine if these findings would replicate in a sample of 18-month-old monolingual and bilingual infants from a range of socioeconomic backgrounds (N = 92). Results indicate no differences between language groups on working memory or cued recall, but significant differences for memory generalization, with bilingual infants outperforming monolingual infants regardless of socioeconomic status (SES). These findings replicate and extend results from past studies (Brito & Barr, 2012; Brito, Sebastián-Gallés, & Barr, 2015) and suggest possible differential learning patterns dependent on linguistic experience.

The transferability of handwriting skills: from the Cyrillic to the Latin alphabet

Do handwriting skills transfer when a child writes in two different scripts, such as the Latin and Cyrillic alphabets? Are our measures of handwriting skills intrinsically bound to one alphabet or will a child who faces handwriting difficulties in one script experience similar difficulties in the other script? To answer these questions, 190 children from grades 1-4 were asked to copy a short text using both the Cyrillic and Latin alphabets on a digital tablet. A recent change of policy in Kazakhstan gave us an opportunity to measure transfer, as the Latin-based Kazakh alphabet has not yet been introduced. Therefore, pupils in grade 1 had a 6-months experience in Cyrillic, and pupils in grades 2, 3, and 4 had 1.5, 2.5, and 3.5 years of experience in Cyrillic, respectively. This unique situation created a quasi-experimental situation that allowed us to measure the influence of the number of years spent practicing Cyrillic on the quality of handwriting in the Latin alphabet. The results showed that some of the differences between the two scripts were constant across all grades. These differences thus reflect the intrinsic differences in the handwriting dynamics between the two alphabets. For instance, several features related to the pen pressure on the tablet are quite different. Other features, however, revealed decreasing differences between the two scripts across grades. While we found that the quality of Cyrillic writing increased from grades 1-4, due to increased practice, we also found that the quality of the Latin writing increased as well, despite the fact that all of the pupils had the same absence of experience in writing in Latin. We can therefore interpret this improvement in Latin script as an indicator of the transfer of fine motor control skills from Cyrillic to Latin. This result is especially surprising given that one could instead hypothesize a negative transfer, i.e., that the finger controls automated for one alphabet would interfere with those required by the other alphabet. One interesting side-effect of these findings is that the algorithms that we developed for the diagnosis of handwriting difficulties among French-speaking children could be relevant for other alphabets, paving the way for the creation of a cross-lingual model for the detection of handwriting difficulties.

Chinese-English bilinguals show linguistic-perceptual links in the brain associating short spoken phrases with corresponding real-world natural action sounds by semantic category

Higher cognitive functions such as linguistic comprehension must ultimately relate to perceptual systems in the brain, though how and why this forms remains unclear. Different brain networks that mediate perception when hearing real-world natural sounds has recently been proposed to respect a taxonomic model of acoustic-semantic categories. Using functional magnetic resonance imaging (fMRI) with Chinese/English bilingual listeners, the present study explored whether reception of short spoken phrases, in both Chinese (Mandarin) and English, describing corresponding sound-producing events would engage overlapping brain regions at a semantic category level. The results revealed a double-dissociation of cortical regions that were preferential for representing knowledge of human versus environmental action events, whether conveyed through natural sounds or the corresponding spoken phrases depicted by either language. These findings of cortical hubs exhibiting linguistic-perceptual knowledge links at a semantic category level should help to advance neurocomputational models of the neurodevelopment of language systems.

Mood Induction Differently Affects Early Neural Correlates of Evaluative Word Processing in L1 and L2

We investigate how mood inductions impact the neural processing of emotional adjectives in one's first language (L1) and a formally acquired second language (L2). Twenty-three student participants took part in an EEG experiment with two separate sessions. Happy or sad mood inductions were followed by series of individually presented positive, negative, or neutral adjectives in L1 (German) or L2 (English) and evaluative decisions had to be performed. Visual event-related potentials elicited during word processing were analyzed during N1 (125-200 ms), Early Posterior Negativities (EPN, 200-300 ms and 300-400 ms), N400 (350-450 ms), and the Late Positive Potential (LPP, 500-700 ms). Mood induction differentially impacted word processing already on the N1, with stronger left lateralization following happy than sad mood induction in L1, but not in L2. Moreover, regardless of language, early valence modulation was found following happy but not sad mood induction. Over occipital areas, happy mood elicited larger amplitudes of the mood-congruent positive words, whereas over temporal areas mood-incongruent negative words had higher amplitudes. In the EPN-windows, effects of mood and valence largely persisted, albeit with no difference between L1 and L2. N400 amplitude was larger for L2 than for L1. On the LPP, mood-incongruent adjectives elicited larger amplitudes than mood-congruent ones. Results reveal a remarkably early valence-general effect of mood induction on cortical processing, in line with previous reports of N1 as a first marker of contextual integration. Interestingly, this effect differed between L1 and L2. Moreover, mood-congruent effects were found in perceptual processing and mood-incongruent ERP amplification in higher-order evaluative stages.

Characterizing Bilingual Effects on Cognition: The Search for Meaningful Individual Differences

A debate over the past decade has focused on the so-called bilingual advantage-the idea that bilingual and multilingual individuals have enhanced domain-general executive functions, relative to monolinguals, due to competition-induced monitoring of both processing and representation from the task-irrelevant language(s). In this commentary, we consider a recent study by Pot, Keijzer, and de Bot (2018), which focused on the relationship between individual differences in language usage and performance on an executive function task among multilingual older adults. We discuss their approach and findings in light of a more general movement towards embracing complexity in this domain of research, including individuals' sociocultural context and position in the lifespan. The field increasingly considers interactions between bilingualism/multilingualism and cognition, employing measures of language use well beyond the early dichotomous perspectives on language background. Moreover, new measures of bilingualism and analytical approaches are helping researchers interrogate the complexities of specific processing issues. Indeed, our review of the bilingualism/multilingualism literature confirms the increased appreciation researchers have for the range of factors-beyond whether someone speaks one, two, or more languages-that impact specific cognitive processes. Here, we highlight some of the most salient of these, and incorporate suggestions for a way forward that likewise encompasses neural perspectives on the topic.

Word learning in two languages: Neural overlap and representational differences

We investigated the neural basis of newly learned words in Spanish as a mother tongue (L1) and English as a second language (L2). Participants acquired new names for real but unfamiliar concepts in both languages over the course of two days. On day 3, they completed a semantic categorization task during fMRI scanning. The results revealed largely overlapping brain regions for newly learned words in Spanish and English. However, Spanish showed a heightened BOLD response within prefrontal cortex (PFC), due to increased competition of existing lexical representations. In contrast, English displayed higher activity than Spanish within primary auditory cortex, which suggests increased phonological processing due to more irregular phonological-orthographic mappings. Overall, these results suggest that novel words are learned similarly in Spanish L1 and English L2, and that they are represented in largely overlapping brain regions. However, they differ in terms of cognitive control and phonological processes.

Learning a Second Language in Adulthood Changes Subcortical Neural Encoding

Second language learning has been shown to impact and reshape the central nervous system, anatomically and functionally. Most of the studies on second language learning and neuroplasticity have been focused on cortical areas, whereas the subcortical neural encoding mechanism and its relationship with L2 learning have not been examined extensively. The purpose of this study was to utilize frequency-following response (FFR) to examine if and how learning a tonal language in adulthood changes the subcortical neural encoding in hearing adults. Three groups of subjects were recruited: native speakers of Mandarin Chinese (native speakers (NS)), learners of the language (L2 learners), and those with no experience (native speakers of foreign languages (NSFL)). It is hypothesized that differences would exist in FFRs obtained from the three language experience groups. Results revealed that FFRs obtained from L2 learners were found to be more robust than the NSFL group, yet not on a par with the NS group. Such results may suggest that in human adulthood, subcortical neural encoding ability may be trainable with the acquisition of a new language and that neuroplasticity at the brainstem level can indeed be influenced by L2 learning.

Comparison of Cognitive Performance Between Two Generations of Immigrant School-Aged Children: Child Development Change Over Time

The objective of this research is to comparatively analyze the performance of two generations of children (as first generation of immigrants) attending primary and secondary education in different geographical areas, evaluated in different decades but with equivalent age brackets. Two samples of 169 immigrant school populations in Portugal, with fair immigration criteria, were evaluated for the same verbal reasoning and auditory discrimination tasks in different periods (cohort 1—2001–2009 and cohort 2—2013–2017). The aim is to verify if age remains a differentiating variable of the performance and acuity, as maintained by the critical period hypothesis. That performance referring to two samples evaluated in second language decoding tasks, in different periods. Additionally, to evaluate the emergence of other factors that explain proficiency, cognitive and linguistic discrimination behaviors of two generations of immigrant students in Portugal. The results contribute to a new direction in the analysis and intervention for school groups that are highly diverse in terms of mother tongue and nationalities. The data point to a greater divergence of performance and difficulties not according only to the disparity of ages, but considering the nationality (country of origin and respective educational system). It is also clear, despite just the difference of a decade, how subjects are changing their immigration routes and their cognitive and social development.

Earlier age of second language learning induces more robust speech encoding in the auditory brainstem in adults, independent of amount of language exposure during early childhood

Learning a second language (L2) at a young age is a driving factor of functional neuroplasticity in the auditory brainstem. To date, it remains unclear whether these effects remain stable until adulthood and to what degree the amount of exposure to the L2 in early childhood might affect their outcome. We compared three groups of adult English-French bilinguals in their ability to categorize English vowels in relation to their frequency following responses (FFR) evoked by the same vowels. At the time of testing, cognitive abilities as well as fluency in both languages were matched between the (1) simultaneous bilinguals (SIM, N = 18); (2) sequential bilinguals with L1-English (N = 14); and (3) sequential bilinguals with L1-French (N = 11). Our results show that the L1-English group show sharper category boundaries in identification of the vowels compared to the L1-French group. Furthermore, the same pattern was reflected in the FFRs (i.e., larger FFR responses in L1-English > SIM > L1-French), while again only the difference between the L1-English and the L1-French group was statistically significant; nonetheless, there was a trend towards larger FFR in SIM compared to L1-French. Our data extends previous literature showing that exposure to a language during the first years of life induces functional neuroplasticity in the auditory brainstem that remains stable until at least young adulthood. Furthermore, the findings suggest that amount of exposure (i.e., 100% vs. 50%) to that language does not differentially shape the robustness of the perceptual abilities or the auditory brainstem encoding of phonetic categories of the language. Statement of significance: Previous studies have indicated that early age of L2 acquisition induces functional neuroplasticity in the auditory brainstem during processing of the L2. This study compared three groups of adult bilinguals who differed in their age of L2 acquisition as well as the amount of exposure to the L2 during early childhood. We demonstrate for the first time that the neuroplastic effect in the brainstem remains stable until young adulthood and that the amount of L2 exposure does not influence behavioral or brainstem plasticity. Our study provides novel insights into low-level auditory plasticity as a function of varying bilingual experience.

The temporal dynamics of first and second language processing: ERPs to spoken words in Mandarin-English bilinguals

The dynamics of bilingual spoken word recognition remain poorly characterized, especially for individuals who speak two languages that are highly dissimilar in their phonological and morphological structure. The present study compared first language (L1) and second language (L2) spoken word processing within a group of adult Mandarin-English bilinguals (N = 34; ages 18-25). Event-related potentials (ERPs) were recorded while participants completed the same cross-modal matching task separately in their L1 Mandarin and L2 English. This task consisted of deciding whether spoken words matched pictures of items. Pictures and spoken words either matched (e.g., Mandarin: TANG2-tang2; English: BELL-bell), or differed in word-initial phonemes (e.g., Mandarin: TANG2-lang2; English: BELL-shell), word-final phonemes (e.g., Mandarin: TANG2-tao2; English: BELL-bed), or whole words (e.g., Mandarin: TANG2-xia1: English: BELL-ham). Each mismatch type was associated with a pattern of modulation of the Phonological Mapping Negativity, the N400, and the Late N400 that was distinct from those of the other mismatch types yet similar between the two languages. This was interpreted as evidence of incremental processing with similar temporal dynamics in both languages. These findings support models of spoken word recognition in bilingual individuals that adopt an interactive-activation framework for both L1 and L2 processing.

Differences in Working Memory With Emotional Distraction Between Proficient and Non-proficient Bilinguals

The impact of bilingual education and bilingual experience on working memory has been an important and controversial issue in the field of psycholinguistics. Taking Chinese-English bilinguals as an example, this study aims to investigate the differences in emotional working memory between proficient and non-proficient bilinguals by using delayed matching-to-sample task paradigm and the more complex N-back task in emotional contexts. The results show that proficient bilinguals may have better performance on both of these two working memory tasks than non-proficient bilinguals, and the advantage effects can be more apparent under high memory load conditions. In addition, the negative emotion context could have a positive impact on complex N-back tasks. This study supports the notion that bilingual experience can promote the development of an individual's cognitive ability and enable individuals to possess more advantages in working memory even in the presence of emotional contexts.

Assessment of Psychiatric Symptomatology in Bilingual Psychotic Patients: A Systematic Review and Meta-Analysis

Language plays an important role in psychiatric conditions. Language disturbances are core symptoms of psychiatric ailments, and language is the main diagnostic tool to assess psychopathological severity. Although the importance of language in psychiatry, the effect of bilingualism, and more specifically of using the mother language or a later acquired language at the time of assessing psychotic symptoms, has been scarcely studied and, thus, remains unclear. We conducted a systematic review and meta-analysis to ascertain whether differences exist in the severity of psychopathology in psychotic patients when assessed either in the mother language or in an acquired language. Of 3121 retrieved references from three databases (PsycINFO, MEDLINE, Embase) and complementary searches, four studies—including 283 psychotic patients—were included in the review. The meta-analytical combined effect suggested that more overall symptomatology is detected when clinical assessment is conducted in the mother language rather than in the acquired language (very low quality evidence, random effects model standardized mean difference (SMD) 0.44, 95% CI = 0.19 to 0.69, p value = 0.0006, I² = 90%). Considering the growing migration flows and the increasing number of bilingual people in the world population, the effect of the chosen language at the time of conducting psychopathological assessments of psychotic patients is a clinically relevant issue. Based on our findings, we recommend that clinical interviews with bilingual psychotic patients should be conducted, when feasible, in the patient’s mother language.

Earlier second language acquisition is associated with greater neural pattern dissimilarity between the first and second languages

It is controversial as to how age of acquisition (AoA) and proficiency level of the second language influence the similarities and differences between the first (L1) and the second (L2) language brain networks. In this functional MRI study, we used representational similarity analysis to quantify the degree of neural similarity between L1 and L2 during sentence comprehension tasks in 26 adult Chinese-English bilinguals, who learned English as L2 at different ages and had different proficiency levels. We found that although L1 and L2 processing activated similar brain regions, greater neural pattern dissimilarity between L1 and L2 was associated with earlier AoA in the left inferior and middle frontal gyri after the effect of proficiency level was controlled. On the other hand, the association between proficiency level and the neural pattern dissimilarity between L1 and L2 was not significant when the effect of AoA was partialled out. The results suggest that the activity pattern of L2 is more distinct from that of L1 in bilingual individuals who acquired L2 earlier and that the contribution of AoA to the neural pattern dissimilarity is greater than that of proficiency level.

Bilingualism in Primary Progressive Aphasia: A Retrospective Study on Clinical and Language Characteristics

BACKGROUND

Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive deterioration of language. Being rare, reports of PPA in multilingual individuals are scarce, despite more than half of the world population being multilingual.

METHODS

We describe clinical characteristics of 33 bilingual patients with PPA, including symptom presentation and language deficits pattern in their first (L1) and second language (L2), through a systematic literature review and new cases retrospectively identified in 5 countries.

RESULTS

In total, 14 patients presented with nonfluent/agrammatic variant, 6 with semantic variant, and 13 with logopenic variant, with a median symptom onset of 2 years. Word-finding difficulties was the first symptom in 65% of all cases, initially noticed in L2, and not always the dominant language. Our group had 22 different languages as L1, and 9 as L2. At the whole-group level there was a tendency for parallel impairment in both languages, in line with the shared bilingual neural substrate hypothesis, but each PPA variant showed some heterogeneity.

DISCUSSION

Each PPA variant showed heterogeneity, showing the need for comprehensive language and cognitive assessment across languages, as well as further clarification on the role of language mediators.

The role of working memory in children's ability for prosodic discrimination

Previous research established that young children are sensitive to prosodic cues discriminating between syntactic structures of otherwise similarly sounding sentences in a language unknown to them. In this study, we explore the role of working memory that children might deploy for the purpose of the sentence-level prosodic discrimination. Nine-year old Slovenian monolingual and bilingual children (N = 70) were tested on a same-different prosodic discrimination task in a language unknown to them (French) and on the working memory measures in the form of forward and backward digit span and non-word repetition tasks. The results suggest that both the storage and processing components of the working memory are involved in the prosodic discrimination task.

One language or two? Navigating cross-language conflict in statistical word segmentation

Bilingual infants must navigate the similarities and differences between their languages to achieve native proficiency in childhood. Bilinguals learning to find individual words in fluent speech face the possibility of conflicting cues to word boundaries across their languages. Despite this challenge, bilingual infants typically begin to segment and learn words in both languages around the same time as monolinguals. It is possible that early bilingual experience may support infants' abilities to track regularities relevant for word segmentation separately across their languages. In a dual speech stream statistical word segmentation task, we assessed whether 16-month-old infants could track syllable co-occurrence regularities in two artificial languages despite conflicting information across the languages. We found that bilingual, but not monolingual, infants were able to segment the dual speech streams using statistical regularities. Although the two language groups did not differ on secondary measures of cognitive and linguistic development, bilingual infants' real-world experience with bilingual speakers was predictive of their performance in the dual language statistical segmentation task.

A comparison of temporal processing and spectral processing abilities of monolingual, bilingual and multilingual children

Objective: This study examined the effects of bilingualism and multilingualism on supra-threshold auditory processing abilities in children.Design: Cross-sectional study.Study sample: Ninety children participated in the study, based on the number of languages they know children were assigned into three groups, i.e. monolingual, bilingual and multilingual. Amplitude modulation detection threshold, gap detection threshold, pitch discrimination threshold and spectral ripple discrimination threshold were measured.Results: Results showed superior supra-threshold auditory processing abilities among multilingual and bilingual children than monolingual children. The results further showed that, the supra-threshold auditory processing of multilingual children was better than bilingual children.Conclusion: This finding suggests that knowledge of multiple languages improves supra-threshold auditory processing abilities. This study adds to the growing body of literature supporting the superior supra-threshold auditory processing abilities among bilingual and multilingual individuals.

Language Experience Impacts Brain Activation for Spoken and Signed Language in Infancy: Insights From Unimodal and Bimodal Bilinguals

Recent neuroimaging studies suggest that monolingual infants activate a left-lateralized frontotemporal brain network in response to spoken language, which is similar to the network involved in processing spoken and signed language in adulthood. However, it is unclear how brain activation to language is influenced by early experience in infancy. To address this question, we present functional near-infrared spectroscopy (fNIRS) data from 60 hearing infants (4 to 8 months of age): 19 monolingual infants exposed to English, 20 unimodal bilingual infants exposed to two spoken languages, and 21 bimodal bilingual infants exposed to English and British Sign Language (BSL). Across all infants, spoken language elicited activation in a bilateral brain network including the inferior frontal and posterior temporal areas, whereas sign language elicited activation in the right temporoparietal area. A significant difference in brain lateralization was observed between groups. Activation in the posterior temporal region was not lateralized in monolinguals and bimodal bilinguals, but right lateralized in response to both language modalities in unimodal bilinguals. This suggests that the experience of two spoken languages influences brain activation for sign language when experienced for the first time. Multivariate pattern analyses (MVPAs) could classify distributed patterns of activation within the left hemisphere for spoken and signed language in monolinguals (proportion correct = 0.68; p = 0.039) but not in unimodal or bimodal bilinguals. These results suggest that bilingual experience in infancy influences brain activation for language and that unimodal bilingual experience has greater impact on early brain lateralization than bimodal bilingual experience.

Conflict Resolution Ability in Late Bilinguals Improves With Increased Second-Language Proficiency: ANT Evidence

Experimental data supporting the claim that bilingual speakers have superior cognitive control abilities are often questioned with respect to certain methodological limitations. One such limitation is the use of between-group design, potentially confounding bilingual status with other factors (e.g., socioeconomic status). Here, we used a homogeneous sample of 57 young adult Russian-English late unbalanced bilinguals who were administrated Attention Network Task (ANT) together with an L2 proficiency task. We tested the correlation of L2 vocabulary performance with conflict and alertness measures and overall reaction times in ANT performance. Overall, participants demonstrated better conflict resolution with the increase in their second language competence, with 8% of variance in conflict resolution explained by L2 proficiency. Our results support the notion of regular correspondence between bilingualism and cognitive control.

Bilingualism for Dementia: Neurological Mechanisms Associated With Functional and Structural Changes in the Brain

As the number of older adults increases, the prevalence of dementias, such as Alzheimer’s dementia (AD), vascular dementia, dementia with Lewy bodies, and frontotemporal dementias, also increases. Despite research into pharmacological approaches for treating diverse diseases, there is still no cure. Recently, novel non-pharmacological interventions are attracting attention. Non-pharmacological approaches include cognitive stimulation, alterations in diet, physical activity, and social engagement. Cognitive stimulating activities protect against the negative effects of cognitive decline caused by age-related neurogenerative diseases. Bilingualism is one form of cognitive stimulation that requires multiple aspects of brain activity and has been shown to delay the onset of dementia symptoms in patients by approximately 4–5 years as compared with monolingual patients through cognitive reserve. The purpose of this review was to bilingualism protects against cognitive decline associated with AD and other dementias. We discuss potential underlying neurological mechanisms, including: (1) stimulating adult neurogenesis, (2) enhancing synaptogenesis, (3) strengthening functional connectivity that bilingualism may delay clinical AD symptoms, (4) protecting white matter integrity, and (5) preserving gray matter density.

A hard to read font reduces the causality bias

Previous studies have demonstrated that fluency affects judgment and decision-making. The purpose of the present research was to investigate the effect of perceptual fluency in a causal learning task that usually induces an illusion of causality in non-contingent conditions. We predicted that a reduction of fluency could improve accuracy in the detection of non-contingency and, therefore, could be used to debias illusory perceptions of causality. Participants were randomly assigned to either an easy-to-read or a hard-to-read condition. Our results showed a strong bias (i.e., overestimation) of causality in those participants who performed the non-contingent task in the easy-to-read font, which replicated the standard causality bias effect. This effect was reduced when the same task was presented in a hard-to-read font. Overall, our results provide evidence for a reduction of the causality bias when presenting the problem in a hard-to-read font. This suggests that perceptual fluency affects causal judgments.

BiLex: A computational approach to the effects of age of acquisition and language exposure on bilingual lexical access

Lexical access in bilinguals can be modulated by multiple factors in their individual language learning history. We developed the BiLex computational model to examine the effects of L2 age of acquisition, language use and exposure on lexical retrieval in bilingual speakers. Twenty-eight Spanish-English bilinguals and five monolinguals recruited to test and validate the model were evaluated in their picture naming skills in each language and filled out a language use questionnaire. We examined whether BiLex can (i) simulate their naming performance in each language while taking into account their L2 age of acquisition, use and exposure to each language, and (ii) predict naming performance in other participants not used in model training. Our findings showed that BiLex could accurately simulate naming performance in bilinguals, suggesting that differences in L2 age of acquisition, language use and exposure can account for individual differences in bilingual lexical access.

Bilingual exposure enhances left IFG specialization for language in children

Language acquisition is characterized by progressive use of inflectional morphology marking verb tense and agreement. Linguistic milestones are also linked to left-brain lateralization for language specialization. We used neuroimaging (fNIRS) to investigate how bilingual exposure influences children's cortical organization for processing morpho-syntax. In Study 1, monolinguals and bilinguals (n=39) completed a grammaticality judgment task that included English sentences with violations in earlier- (verb agreement) and later-acquired (verb tense/agreement) structures. Groups showed similar performance and greater activation in left inferior frontal region (IFG) for later- than earlier-acquired conditions. Bilinguals showed stronger and more restricted left IFG activation. In Study 2, bilinguals completed a comparable Spanish task revealing patterns of left IFG activation similar to English. Taken together, the findings suggest that bilinguals with linguistic competence at parity with monolingual counterparts have a higher degree of cortical specialization for language, likely a result of enriched linguistic experiences.

Outgroup faces hamper word recognition

The present study explores socio-cultural priming in native-language processing. Caucasian Italian native speakers completed a written lexical decision task. Written stimuli were preceded by either a prime "white" face (ingroup condition) or a prime "black" face (outgroup condition). Face priming effects were observed in three experiments using different stimuli. Participants were slower in categorizing words, but not non-words, when preceded by an outgroup face than by an ingroup face. Several psycholinguistic variables were manipulated to localize the levels of processing that are affected by socio-cultural prime. The lack of effect with non-word items excludes the possibility that the face priming effect arises at perceptual or attentive levels of processing. In addition, we observed that while the face priming effect does not interact with lexical dimensions, it does interact with a semantic dimension such as imageability. The results indicate that social categories extracted from faces may modulate lexico-semantic processing. Interestingly, such a modulation would occur in the context of a quick and automatic process like visual word recognition in a person's native language.

Actions speak louder than words: Differences in memory flexibility between monolingual and bilingual 18-month-olds

Bilingual infants from 6- to 24-months of age are more likely to generalize, flexibly reproducing actions on novel objects significantly more often than age-matched monolingual infants are. In the current study, we examine whether the addition of novel verbal labels enhances memory generalization in a perceptually complex imitation task. We hypothesized that labels would provide an additional retrieval cue and aid memory generalization for bilingual infants. Specifically, we hypothesized that bilinguals might be more likely than monolinguals to map multiple perceptual features onto a novel label and therefore show enhanced generalization. Eighty-seven 18-month-old monolingual and bilingual infants were randomly assigned to one of two experimental conditions or a baseline control condition. In the experimental conditions, either no label or a novel label was added during demonstration and again at the beginning of the test session. After a 24-hr delay, infants were tested with the same stimulus set to test cued recall and with a perceptually different but functionally equivalent stimulus set to test memory generalization. Bilinguals performed significantly above baseline on both cued recall and memory generalization in both experimental conditions, whereas monolinguals performed significantly above baseline only on cued recall in both experimental conditions. These findings show a difference between monolinguals and bilinguals in memory generalization and suggest that generalization differences between groups may arise from visual perceptual processing rather than linguistic processing. A video abstract of this article can be viewed at https://youtu.be/yXB4pM3fF2k.

Deaf Children as ‘English Learners’: The Psycholinguistic Turn in Deaf Education

The purpose of this literature review is to present the arguments in support of conceptualizing deaf children as ‘English Learners’, to explore the educational implications of such conceptualizations, and to suggest directions for future inquiry. Three ways of interpreting the label ‘English Learner’ in relationship to deaf children are explored: (1) as applied to deaf children whose native language is American Sign Language; (2) as applied to deaf children whose parents speak a language other than English; and (3) as applied to deaf children who have limited access to the spoken English used by their parents. Recent research from the fields of linguistics and neuroscience on the effects of language deprivation is presented and conceptualized within a framework that we refer to as the psycholinguistic turn in deaf education. The implications for developing the literacy skills of signing deaf children are explored, particularly around the theoretical construct of a ‘bridge’ between sign language proficiency and print-based literacy. Finally, promising directions for future inquiry are presented.

Effects of Second Language Learning on the Plastic Aging Brain: Functional Connectivity, Cognitive Decline, and Reorganization

Learning a new language requires the use of extensive neural networks and can represent a powerful tool to reorganize brain neuroplasticity. In this study, we analyze how a 4 months long second language learning program (16, 2 h sessions) can lead to functional changes in the brain of healthy elderly individuals. A large number of studies point out a decline of brain-skills with age; here it is analyzed how cognition together with functional brain organization can be improved later in life. Twenty-six older adults (59–79 years old) were enrolled in the present study. A complete neuropsychological examination was administered before and after the intervention to measure global cognition levels, short- and long-term memory, attention, language access and executive functions. At the end of the program, in the intervention group, the results showed a significant improvement in global cognition together with an increased functional connectivity in the right inferior frontal gyrus (rIFG), right superior frontal gyrus (rSFG) and left superior parietal lobule (lSPL). These findings can be added to the current neurobiological breakthroughs of reshaping brain networks with a short language learning practice in healthy elderly subjects. Therefore, learning a foreign-language may represent a potentially helpful cognitive intervention for promoting healthy aging.

The Music-In-Noise Task (MINT): A Tool for Dissecting Complex Auditory Perception

The ability to segregate target sounds in noisy backgrounds is relevant both to neuroscience and to clinical applications. Recent research suggests that hearing-in-noise (HIN) problems are solved using combinations of sub-skills that are applied according to task demand and information availability. While evidence is accumulating for a musician advantage in HIN, the exact nature of the reported training effect is not fully understood. Existing HIN tests focus on tasks requiring understanding of speech in the presence of competing sound. Because visual, spatial and predictive cues are not systematically considered in these tasks, few tools exist to investigate the most relevant components of cognitive processes involved in stream segregation. We present the Music-In-Noise Task (MINT) as a flexible tool to expand HIN measures beyond speech perception, and for addressing research questions pertaining to the relative contributions of HIN sub-skills, inter-individual differences in their use, and their neural correlates. The MINT uses a match-mismatch trial design: in four conditions (Baseline, Rhythm, Spatial, and Visual) subjects first hear a short instrumental musical excerpt embedded in an informational masker of "multi-music" noise, followed by either a matching or scrambled repetition of the target musical excerpt presented in silence; the four conditions differ according to the presence or absence of additional cues. In a fifth condition (Prediction), subjects hear the excerpt in silence as a target first, which helps to anticipate incoming information when the target is embedded in masking sound. Data from samples of young adults show that the MINT has good reliability and internal consistency, and demonstrate selective benefits of musicianship in the Prediction, Rhythm, and Visual subtasks. We also report a performance benefit of multilingualism that is separable from that of musicianship. Average MINT scores were correlated with scores on a sentence-in-noise perception task, but only accounted for a relatively small percentage of the variance, indicating that the MINT is sensitive to additional factors and can provide a complement and extension of speech-based tests for studying stream segregation. A customizable version of the MINT is made available for use and extension by the scientific community.

Neural Correlates of Enhanced Audiovisual Processing in the Bilingual Brain

Bilingualism is associated with enhancements in perceptual and cognitive processing necessary for juggling multiple languages. Recent psychophysical studies demonstrate bilinguals also show enhanced multisensory processing and more restricted temporal binding windows for integrating audiovisual information. Here, we probed the neural mechanisms of bilinguals' audiovisual benefits. We recorded neuroelectric responses in mono- and bi-lingual listeners to the double-flash paradigm in which auditory beeps concurrent with a single visual flash induces the perceptual illusion of multiple flashes. Relative to monolinguals, bilinguals showed less susceptibility to the illusion (fewer false perceptual reports) coupled with stronger and faster event-related potentials to audiovisual information. Source analyses of EEG data revealed monolinguals' increased propensity for erroneously perceiving audiovisual stimuli was attributed to increased activity in primary visual (V1) and auditory cortex (PAC), increases in multisensory association areas (BA 37), but reduced frontal activity (BA 10). Regional activations were associated with an opposite pattern of behaviors: whereas stronger V1 and PAC activity predicted slower behavioral responses, stronger frontal BA10 responses elicited faster judgments. Our results suggest bilinguals' higher precision in audiovisual perception reflects more veridical sensory coding of physical cues coupled with superior top-down gating of sensory information to suppress the generation of false percepts. Findings underscore that the plasticity afforded by speaking multiple languages shapes extra-linguistic brain regions and can enhance audiovisual brain processing in a domain-general manner.

Language experience modulates bilingual language control: The effect of proficiency, age of acquisition, and exposure on language switching

The ability to selectively access two languages characterises the bilingual everyday experience. Previous studies showed the role of second language (L2) proficiency, as a proxy for dominance, on language control. However, the role of other aspects of the bilingual experience - such as age of acquisition and daily exposure - are relatively unexplored. In this study, we used a cued language switching task to examine language switching and mixing in two groups of highly proficient bilinguals with different linguistic backgrounds, to understand how the ability to control languages is shaped by linguistic experience. Our analysis shows that the ability to switch between languages is not only modulated by L2 proficiency, but also by daily L2 exposure. Daily L2 exposure also affects language mixing. Finally, L2 age of acquisition predicts naming latencies in the L2. Together, these findings show that language dominance is characterised by multiple aspects of the bilingual experience, which modulate language control.

The independent and interacting effects of socioeconomic status and dual-language use on brain structure and cognition

Family socioeconomic status (SES) is strongly associated with children's cognitive development, and past studies have reported socioeconomic disparities in both neurocognitive skills and brain structure across childhood. In other studies, bilingualism has been associated with cognitive advantages and differences in brain structure across the lifespan. The aim of the current study is to concurrently examine the joint and independent associations between family SES and dual-language use with brain structure and cognitive skills during childhood. A subset of data from the Pediatric Imaging, Neurocognition and Genetics (PING) study was analyzed; propensity score matching established an equal sample (N = 562) of monolinguals and dual-language users with similar socio-demographic characteristics (Mage = 13.5, Range = 3-20 years). When collapsing across all ages, SES was linked to both brain structure and cognitive skills. When examining differences by age group, brain structure was significantly associated with both income and dual-language use during adolescence, but not earlier in childhood. Additionally, in adolescence, a significant interaction between dual-language use and SES was found, with no difference in cortical surface area (SA) between language groups of higher-SES backgrounds but significantly increased SA for dual-language users from lower-SES families compared to SES-matched monolinguals. These results suggest both independent and interacting associations between SES and dual-language use with brain development. To our knowledge, this is the first study to concurrently examine dual-language use and socioeconomic differences in brain structure during childhood and adolescence.

Impact of Language Experience on Attention to Faces in Infancy: Evidence From Unimodal and Bimodal Bilingual Infants

Faces capture and maintain infants' attention more than other visual stimuli. The present study addresses the impact of early language experience on attention to faces in infancy. It was hypothesized that infants learning two spoken languages (unimodal bilinguals) and hearing infants of Deaf mothers learning British Sign Language and spoken English (bimodal bilinguals) would show enhanced attention to faces compared to monolinguals. The comparison between unimodal and bimodal bilinguals allowed differentiation of the effects of learning two languages, from the effects of increased visual communication in hearing infants of Deaf mothers. Data are presented for two independent samples of infants: Sample 1 included 49 infants between 7 and 10 months (26 monolinguals and 23 unimodal bilinguals), and Sample 2 included 87 infants between 4 and 8 months (32 monolinguals, 25 unimodal bilinguals, and 30 bimodal bilingual infants with a Deaf mother). Eye-tracking was used to analyze infants' visual scanning of complex arrays including a face and four other stimulus categories. Infants from 4 to 10 months (all groups combined) directed their attention to faces faster than to non-face stimuli (i.e., attention capture), directed more fixations to, and looked longer at faces than non-face stimuli (i.e., attention maintenance). Unimodal bilinguals demonstrated increased attention capture and attention maintenance by faces compared to monolinguals. Contrary to predictions, bimodal bilinguals did not differ from monolinguals in attention capture and maintenance by face stimuli. These results are discussed in relation to the language experience of each group and the close association between face processing and language development in social communication.

Phonological Vulnerability for School-Aged Spanish-English-Speaking Bilingual Children

This study examined accuracy on syllable-final (coda) consonants in newly-learned English-like nonwords to determine whether school-aged bilingual children may be more vulnerable to making errors on English-only codas than their monolingual, English-speaking peers, even at a stage in development when phonological accuracy in productions of familiar words is high. Bilingual Spanish-English-speaking second- graders (age 7-9) with typical development (n=40) were matched individually with monolingual peers on age, sex, and speech skills. Participants learned to name sea monsters as part of five computerized word learning tasks. Dependent t-tests revealed bilingual children were less accurate than monolingual children in producing codas unique to English; however, the groups demonstrated equivalent levels of accuracy on codas that occur in both Spanish and English. Results suggest that, even at high levels of English proficiency, bilingual Spanish-English-speaking children may demonstrate lower accuracy than their monolingual English-speaking peers on targets that pattern differently in their two languages. Differences between a bilingual's two languages can be used to reveal targets that may be more vulnerable to error, which could be a result of cross-linguistic effects or more limited practice with English phonology.

Neural basis of bilingual language control

Acquiring and speaking a second language increases demand on the processes of language control for bilingual as compared to monolingual speakers. Language control for bilingual speakers involves the ability to keep the two languages separated to avoid interference and to select one language or the other in a given conversational context. This ability is what we refer with the term "bilingual language control" (BLC). It is now well established that the architecture of this complex system of language control encompasses brain networks involving cortical and subcortical structures, each responsible for different cognitive processes such as goal maintenance, conflict monitoring, interference suppression, and selective response inhibition. Furthermore, advances have been made in determining the overlap between the BLC and the nonlinguistic executive control networks, under the hypothesis that the BLC processes are just an instantiation of a more domain-general control system. Here, we review the current knowledge about the neural basis of these control systems. Results from brain imaging studies of healthy adults and on the performance of bilingual individuals with brain damage are discussed.

Learning across languages: bilingual experience supports dual language statistical word segmentation

Bilingual acquisition presents learning challenges beyond those found in monolingual environments, including the need to segment speech in two languages. Infants may use statistical cues, such as syllable-level transitional probabilities, to segment words from fluent speech. In the present study we assessed monolingual and bilingual 14-month-olds' abilities to segment two artificial languages using transitional probability cues. In Experiment 1, monolingual infants successfully segmented the speech streams when the languages were presented individually. However, monolinguals did not segment the same language stimuli when they were presented together in interleaved segments, mimicking the language switches inherent to bilingual speech. To assess the effect of real-world bilingual experience on dual language speech segmentation, Experiment 2 tested infants with regular exposure to two languages using the same interleaved language stimuli as Experiment 1. The bilingual infants in Experiment 2 successfully segmented the languages, indicating that early exposure to two languages supports infants' abilities to segment dual language speech using transitional probability cues. These findings support the notion that early bilingual exposure prepares infants to navigate challenging aspects of dual language environments as they begin to acquire two languages.

Learning across languages: bilingual experience supports dual language statistical word segmentation

Bilingual acquisition presents learning challenges beyond those found in monolingual environments, including the need to segment speech in two languages. Infants may use statistical cues, such as syllable-level transitional probabilities, to segment words from fluent speech. In the present study we assessed monolingual and bilingual 14-month-olds' abilities to segment two artificial languages using transitional probability cues. In Experiment 1, monolingual infants successfully segmented the speech streams when the languages were presented individually. However, monolinguals did not segment the same language stimuli when they were presented together in interleaved segments, mimicking the language switches inherent to bilingual speech. To assess the effect of real-world bilingual experience on dual language speech segmentation, Experiment 2 tested infants with regular exposure to two languages using the same interleaved language stimuli as Experiment 1. The bilingual infants in Experiment 2 successfully segmented the languages, indicating that early exposure to two languages supports infants' abilities to segment dual language speech using transitional probability cues. These findings support the notion that early bilingual exposure prepares infants to navigate challenging aspects of dual language environments as they begin to acquire two languages.

Thinking in a Foreign language reduces the causality bias

The purpose of this research is to investigate the impact of a foreign language on the causality bias (i.e., the illusion that two events are causally related when they are not). We predict that using a foreign language could reduce the illusions of causality. A total of 36 native English speakers participated in Experiment 1, 80 native Spanish speakers in Experiment 2. They performed a standard contingency learning task, which can be used to detect causal illusions. Participants who performed the task in their native tongue replicated the illusion of causality effect, whereas those performing the task in their foreign language were more accurate in detecting that the two events were causally unrelated. Our results suggest that presenting the information in a foreign language could be used as a strategy to debias individuals against causal illusions, thereby facilitating more accurate judgements and decisions in non-contingent situations. They also contribute to the debate on the nature and underlying mechanisms of the foreign language effect, given that the illusion of causality is rooted in basic associative processes.

Right Forceps Minor and Anterior Thalamic Radiation Predict Executive Function Skills in Young Bilingual Adults

Executive function (EF) skills enhance learning across domains, and are particularly linked to the acquisition of a second language. Previous studies have shown that bilingual individuals show enhanced EF skills in cognitive tasks where they attended a targeted dimension of a stimulus while inhibiting other competing cues. Brain imaging revealed that bilingual young adults’ performances in the Stroop color-naming task were related to the volume of anterior cingulate cortex (ACC) and inferior frontal lobe. Subjects who had greater white-matter in the frontal cortex showed enhanced performances in the same task, suggesting that brain fiber pathways connecting ACC to the frontal region may be related to the Stroop color-naming task. No studies to date have examined the tissue properties of brain fiber pathways connecting these brain regions and their association with subjects’ EF performances. Importantly, there are no data establishing whether bilingual subjects exhibit different reaction times when words are presented in their first versus second language. To study these questions, we used behavioral and unbiased whole-brain analyses, recruiting 21 Chinese students. Using the Stroop color-naming task, we measured subjects’ reaction times (RTs) in which color names were displayed using fonts that matched the named color (congruent task) or mismatched the color (incongruent task). Students performed the task twice, first in English, the subjects’ second language, then in Chinese, the subjects’ primary language. Results from whole-brain analysis showed that students’ RTs in both the English and Chinese tasks were significantly correlated with the mode of anisotropy (MO) in a brain cluster containing the forceps minor and anterior thalamic radiation in the right hemisphere. We also found that fractional anisotropy (FA) significantly predicted students’ RTs, with higher FA predicting shorter RT. Taken together, our findings demonstrate that right forceps minor and anterior thalamic radiation predict EF skills, suggesting that this brain feature may be important for young bilingual adults using their first and second languages to direct their attention when conflicting cues are present.

Investigating the Influences of Language Delay and/or Familial Risk for Dyslexia on Brain Structure in 5-Year-Olds

Early language delay has often been associated with atypical language/literacy development. Neuroimaging studies further indicate functional disruptions during language and print processing in school-age children with a retrospective report of early language delay. Behavioral data of 114 5-year-olds with a retrospective report of early language delay in infancy (N = 34) and those without (N = 80) and with a familial risk for dyslexia and those without are presented. Behaviorally, children with a retrospective report of early language delay exhibited reduced performance in language/reading-related measures. A voxel-based morphometry analysis in a subset (N = 46) demonstrated an association between reduced gray matter volume and early language delay in left-hemispheric middle temporal, occipital, and frontal regions. Alterations in middle temporal cortex in children with a retrospective report of early language delay were observed regardless of familial risk for dyslexia. Additionally, while children with isolated familial risk for dyslexia showed gray matter reductions in temporoparietal and occipitotemporal regions, these effects were most profound in children with both risk factors. An interaction effect of early language delay and familial risk was revealed in temporoparietal, occipital, and frontal cortex. Our findings support a cumulative effect of early behavioral and genetic risk factors on brain development and may ultimately inform diagnosis/treatment.