The Case for Measuring and Reporting Bilingualism in Developmental Research

Speech Sound Production in Australian English-Dutch Bilingual Children

PURPOSE

Determining if suspected speech errors in bilingual children are due to bilingual language acquisition or a speech sound disorder is challenging for speech-language pathologists (SLPs). This study investigates how the productions of nonword imitation (NWI) tasks of English-Dutch bilingual children differ from other speech tasks, both in direct comparison and relative to norm data.

METHOD

Seventy-seven typically developing Australian English-Dutch bilingual children aged 4-12 years participated in this study. All children completed the Dutch test battery called the Computer Articulation Instrument. Data on language exposure were collected through parent/caregiver questionnaires.

RESULTS

The English-Dutch bilingual children scored lower than the norm data on the picture-naming and consistency task but not on NWI and diadochokinesis tasks. Specific phonological processes were more evident in bilingual children, and these patterns differed according to the task. The consistency task revealed a unique pattern of production in bilingual children.

CONCLUSIONS

The results confirm that the NWI task may be the most language neutral. Detailed phonological error analysis indicates that SLPs assessing English-Dutch bilingual children should pay attention to voice onset time, fricatives, and vowels.

Language experience influences performance on the NIH Toolbox Cognition Battery: A cluster analysis

Studies investigating the effects of bilingualism on cognitive function have often yielded conflicting results, which may stem in part from the use of arbitrary criteria to categorize participants into groups based on language experience. The present study addresses this limitation by using a machine learning algorithm, known as cluster analysis, to identify naturally occurring subgroups of participants with similar language profiles. In a sample of 169 participants with varying degrees of first- and second-language proficiencies and ages of acquisition, the cluster analysis yielded four bilingual subgroups: late-unbalanced, early-unbalanced, late-balanced, and early-balanced. All participants completed the NIH Toolbox Cognition Battery. Results revealed that early-balanced and early-unbalanced bilinguals scored higher than late-unbalanced bilinguals on the cognitive flexibility and inhibitory control subtests of the NIH Toolbox Cognition Battery, whereas late-unbalanced bilinguals scored higher than early-balanced bilinguals on the verbal working memory subtest of the NIH Toolbox Cognition Battery. Bilingual language experience did not impact performance on measures of processing speed, episodic memory, and English vocabulary. These findings demonstrate the utility of data-driven approaches to capture the variability in language experience that exists in the real world. We conclude that different bilingual experiences can shape a wide range of cognitive abilities, from working memory to inhibitory control.

Hablando at home: Examining the interactional resources of a bilingual autistic child

Daily language interactions predict child outcomes. For multilingual families who rear neurodiverse children and who may be minoritized for their language use, a dearth of research examines families' daily language interactions. Utilizing a language socialization framework and a case study methodology, 4,991 English and Spanish utterances from a 5-year old autistic child and his family were collected during naturally occurring interactions over 10 days. Utterances were analyzed for patterns of code-switching by speaker, activity setting, English or Spanish initial language, and code-switch function. Spanish was spoken in most activities. For reading, both languages were equally employed by the father. While participants used both languages across all activity settings, significant variations in code-switching type and function were observed by activity setting and speaker. We discuss implications for how home language resources can be integrated into autism interventions.

Exposure to bilingual or monolingual maternal speech during pregnancy affects the neurophysiological encoding of speech sounds in neonates differently

Introduction

Exposure to maternal speech during the prenatal period shapes speech perception and linguistic preferences, allowing neonates to recognize stories heard frequently in utero and demonstrating an enhanced preference for their mother's voice and native language. Yet, with a high prevalence of bilingualism worldwide, it remains an open question whether monolingual or bilingual maternal speech during pregnancy influence differently the fetus' neural mechanisms underlying speech sound encoding.

Methods

In the present study, the frequency-following response (FFR), an auditory evoked potential that reflects the complex spectrotemporal dynamics of speech sounds, was recorded to a two-vowel /oa/ stimulus in a sample of 129 healthy term neonates within 1 to 3 days after birth. Newborns were divided into two groups according to maternal language usage during the last trimester of gestation (monolingual; bilingual). Spectral amplitudes and spectral signal-to-noise ratios (SNR) at the stimulus fundamental (F0) and first formant (F1) frequencies of each vowel were, respectively, taken as measures of pitch and formant structure neural encoding.

Results

Our results reveal that while spectral amplitudes at F0 did not differ between groups, neonates from bilingual mothers exhibited a lower spectral SNR. Additionally, monolingually exposed neonates exhibited a higher spectral amplitude and SNR at F1 frequencies.

Discussion

We interpret our results under the consideration that bilingual maternal speech, as compared to monolingual, is characterized by a greater complexity in the speech sound signal, rendering newborns from bilingual mothers more sensitive to a wider range of speech frequencies without generating a particularly strong response at any of them. Our results contribute to an expanding body of research indicating the influence of prenatal experiences on language acquisition and underscore the necessity of including prenatal language exposure in developmental studies on language acquisition, a variable often overlooked yet capable of influencing research outcomes.

The Necessity of Taking Culture and Context into Account When Studying the Relationship between Socioeconomic Status and Brain Development

Decades of research has revealed a relationship between childhood socioeconomic status (SES) and brain development at the structural and functional levels. Of particular note is the distinction between income and maternal education, two highly correlated factors which seem to influence brain development through distinct pathways. Specifically, while a families' income-to-needs ratio is linked with physiological stress and household chaos, caregiver education influences the day-to-day language environment a child is exposed to. Variability in either one of these environmental experiences is related to subsequent brain development. While this work has the potential to inform public policies in a way that benefits children, it can also oversimplify complex factors, unjustly blame low-SES parents, and perpetuate a harmful deficit perspective. To counteract these shortcomings, researchers must consider sociodemographic differences in the broader cultural context that underlie SES-based differences in brain development. This review aims to address these issues by (a) identifying how sociodemographic mechanisms associated with SES influence the day-to-day experiences of children, in turn, impacting brain development, while (b) considering the broader cultural contexts that may differentially impact this relationship.

Language-Dependent Reminiscing: Bilingual Mother-Child Autobiographical Conversations Differ Across Thai and English

Cross-linguistic differences in narrative patterns were examined in bilingual mother-preschooler dyads. Twenty-six Thai-English bilingual mothers and their four-year-old children completed a reminiscing task where they jointly recalled autobiographical memories in response to word prompts. Bilingual mothers and children exhibited different reminiscing styles in each of their languages. Specifically, bilinguals adopted high-elaborative and child-centered styles (e.g., use of evaluative feedback) when speaking English and low-elaborative and adult-centered styles (e.g., use of directives) when speaking Thai. Additionally, positive associations between maternal and child narrative patterns in both languages suggested that mothers' scaffolding strategies influenced children's own emerging linguistic skills. Findings from the present study show that bilingual mothers socialize their children differently across languages. In turn, children learn to present themselves in distinct ways depending on the linguistic and social contexts. We conclude that language can cue culture-specific communicative and behavioral norms as early as preschool.

Examining the consistency in bilingualism and white matter research: A meta-analysis

This study aimed to systematically investigate the relationship between bilingualism, age, L2 onset age of acquisition (AoA), and white matter integrity (operationalized as fractional anisotropy, FA), addressing inconsistencies in the literature. We conducted a meta-analysis of 23 studies and used meta-regression models to assess the influence of age and L2AoA on effect sizes in studies comparing monolinguals and bilinguals. Even though the overall between-group effect size across the whole brain was unreliable, bilingualism was associated with increased white matter integrity in specific tracts and in groups with a limited range of age and L2AoA. Age had a small, negative effect on white matter integrity, with differences between monolinguals and bilinguals more pronounced in younger adults, consistent with a view of an initial increase in white matter integrity, followed by remodeling for efficiency over time. In contrast, later L2AoA was associated with greater white matter integrity in bilinguals than monolinguals, again consistent with the remodeling for efficiency model. Our findings highlight the importance of considering age and L2AoA when examining the neural basis of bilingualism on white matter in the brain and how bilingualism contributes to structural changes that stave off cognitive decline in older age.

Cortical mapping in multilinguals undergoing awake brain surgery for brain tumors: Illustrative cases and systematic review

BACKGROUND

Awake brain mapping in multilingual patients with brain tumors presents unique challenges to the neurosurgeon. Knowledge of potential eloquent sites is vital to preserve language function.

METHODS

We present two cases of pars opercularis glioma and perform a systematic review in accordance with PRISMA guidelines.

RESULTS

Our review yielded 7 studies, with a total of 25 multilingual brain tumor patients who underwent awake brain mapping. The age ranged from 25 to 62 years. Majority were female (56.5%). Most (52%) were trilingual, while 20% were quadrilingual and 28% were pentalingual. All tumors were left-sided, mostly in the frontal lobe. These were predominantly gliomas. Extent of resection was gross total in 61%. The brain mapping findings were heterogeneous. Some authors reported a greater number of cortical sites for the first language compared to others. Others found that the first and second languages shared cortical sites whereas the third and subsequent languages were located in distant sites. The peri-Sylvian area was also found to be involved in language that was learned at an earlier age. Subsequent languages thus involved more distant sites. A larger number of cortical areas were also activated for languages that were learned later in life. In terms of language disturbance and recovery, there were mixed results.

CONCLUSION

Cortical mapping in multilingual brain tumor patients showed heterogeneity in terms of the location and number of language areas in the face of pathology. These findings may influence neurosurgical and oncological management of tumors in the speech area but emphasize the need to tailor surgical approaches and intraoperative testing to the patient.

Bilingualism alters infants' cortical organization for attentional orienting mechanisms

A bilingual environment is associated with changes in the brain's structure and function. Some suggest that bilingualism also improves higher-cognitive functions in infants as young as 6-months, yet whether this effect is associated with changes in the infant brain remains unknown. In the present study, we measured brain activity using functional near-infrared spectroscopy in monolingual- and bilingual-raised 6- and 10-month-old infants. Infants completed an orienting attention task, in which a cue was presented prior to an object appearing on the same (Valid) or opposite (Invalid) side of a display. Task performance did not differ between the groups but neural activity did. At 6-months, both groups showed greater activity for Valid (> Invalid) trials in frontal regions (left hemisphere for bilinguals, right hemisphere for monolinguals). At 10-months, bilinguals showed greater activity for Invalid (> Valid) trials in bilateral frontal regions, while monolinguals showed greater brain activity for Valid (> Invalid) trials in left frontal regions. Bilinguals' brain activity trended with their parents' reporting of dual-language mixing when speaking to their child. These findings are the first to indicate how early (dual) language experience can alter the cortical organization underlying broader, non-linguistic cognitive functions during the first year of life.

Attentional orienting abilities in bilinguals: Evidence from a large infant sample

A key question in studies of cognitive development is whether bilingual environments impact higher-cognitive functions. Inconclusive evidence in search of a "bilingual cognitive advantage" has sparked debates on the reliability of these findings. Few studies with infants have examined this question, but most of them include small samples. The current study presents evidence from a large sample of 6- and 10-month-old monolingual- and bilingual-exposed infants (N = 152), which includes a longitudinal subset (n = 31), who completed a cueing attentional orienting task. The results suggest bilingual infants showed significant developmental gains in latency performance during the condition that was most cognitively demanding (Incongruent). The results also revealed bilingual infants' performance was associated with their parents' dual-language switching behavior. Taken together, these results provide support that bilingual experiences (i.e., dual-language mixing) influence infants' shifting and orienting of attention.

Bilingual children judge moral, social, and language violations as less transgressive than monolingual children

Learning the rules and expectations that govern our social interactions is one of the major challenges of development. The current study examined whether bilingualism is associated with differences in children's developing social knowledge. We presented 54 4- to 6-year-old monolingual and bilingual children with vignettes of moral transgressions (e.g., hitting), social transgressions (e.g., wearing pants on one's head), and language transgressions (e.g., calling a common object by a nonsense word) and asked about their permissibility. In line with previous research findings, results demonstrate that all children evaluated moral violations more harshly than conventional violations. Notably, however, bilingual children were more permissive of violations across moral, social, and language domains than monolingual children. These findings yield new insights into the role of early experience in the development of social knowledge. We propose that bilinguals' unique linguistic and social experiences influence their understanding of moral and conventional rules.

Measuring Bilingualism: The Quest for a "Bilingualism Quotient"

The study of bilingualism has a history that extends from deciphering ancient multilingual texts to mapping the structure of the multilingual brain. The language experiences of individual bilinguals are equally diverse and characterized by unique contexts of acquisition and use that can shape not only sociocultural identity, but also cognitive and neural function. Perhaps unsurprisingly, this variability in scholarly perspectives and language experiences has given rise to a range of methods for defining bilingualism. The goal of this paper is to initiate a conversation about the utility of a more unified approach to how we think about, study, and measure bilingualism. Using concrete case studies, we illustrate the value of enhancing communication and streamlining terminology across researchers with different methodologies within questions, different questions within domains, and different domains within scientific inquiry. We specifically consider the utility and feasibility of a Bilingualism Quotient (BQ) construct, discuss the idea of a BQ relative to the well-established Intelligence Quotient (IQ), and include recommendations for next steps. We conclude that though the variability in language backgrounds and approaches to defining bilingualism presents significant challenges, concerted efforts to systematize and synthesize research across the field may enable the construction of a valid and generalizable index of multilingual experience.

Linguistic Diversity, Multilingualism, and Cognitive Skills: A Study of Disadvantaged Children in India

Multilingualism and linguistic diversity are the norm in India. Although studies have shown a relation between bilingualism and cognitive gains, linguistic diversity has so far been ignored as a potential factor affecting cognitive skills. This study aims to fill this gap by examining how cognitive skills—as measured by the n-back and Raven’s Colored Progressive Matrices tasks—are affected by multilingualism and/or sociolinguistic diversity in a large cohort of socioeconomically disadvantaged primary school children in two urban sites of India: Delhi and Hyderabad. We present a questionnaire estimating sociolinguistic diversity and show that this measure assesses a distinct construct, as compared to a child’s multilingualism. Children were classified as growing up monolingually or bilingually, depending on whether they grew up with one or more languages in the home. Regarding cognitive performance, bilinguals were found to outperform monolinguals on the n-back task, as well as on the Raven’s task. In addition, a socially and linguistically diverse environment seems to enhance cognitive performance for children who are not multilingual themselves. Finally, several contextual factors such as city were found to influence cognitive performance. Overall, this shows that cognitive tasks are subject to contextual effects and that bilingualism and linguistic diversity can enhance cognitive performance of children in disadvantaged contexts.