Shining a light on cultural neuroscience: Recommendations on the use of fNIRS to study how sociocultural contexts shape the brain

Functional near-infrared spectroscopy (fNIRS) is a portable neuroimaging technique that may serve as a methodological tool for studying how sociocultural contexts can shape the human brain and impact cognition and behavior. The use of fNIRS in community-based research may (a) advance theoretical knowledge in psychology and neuroscience, particularly regarding underrepresented ethnic-racial communities; (b) increase diversity in samples; and (c) provide neurobiological evidence of sociocultural factors supporting human development. The review aims to introduce the use of fNIRS, including its practicalities and limitations, to new adopters inquiring how sociocultural inputs affect the brain. The review begins with an introduction to cultural neuroscience, and a review on the use of fNIRS follows. Next, benefits and guidelines to the design of fNIRS research in naturalistic environments (in the community or in the field) using a cultural lens are discussed. Strengths-based and community-based approaches in cultural neuroscience are recommended throughout. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Increasing diversity in developmental cognitive neuroscience: A roadmap for increasing representation in pediatric neuroimaging research

Understanding of human brain development has advanced rapidly as the field of developmental cognitive neuroscience (DCN) has matured into an established scientific discipline. Despite substantial progress, DCN lags behind other related disciplines in terms of diverse representation, standardized reporting requirements for socio-demographic characteristics of participants in pediatric neuroimaging studies, and use of intentional sampling strategies to more accurately represent the socio-demographic, ethnic, and racial composition of the populations from which participants are sampled. Additional efforts are needed to shift DCN towards a more inclusive field that facilitates the study of individual differences across a variety of cultural and contextual experiences. In this commentary, we outline and discuss barriers within our current scientific practice (e.g., research methods) and beliefs (i.e., what constitutes good science, good scientists, and good research questions) that contribute to under-representation and limited diversity within pediatric neuroimaging studies and propose strategies to overcome those barriers. We discuss strategies to address barriers at intrapersonal, interpersonal, community, systemic, and structural levels. Highlighting strength-based models of inclusion and recognition of the value of diversity in DCN research, along with acknowledgement of the support needed to diversify the field is critical for advancing understanding of neurodevelopment and reducing health inequities.

Person-specific connectivity mapping uncovers differences of bilingual language experience on brain bases of attention in children

Bilingualism influences children's cognition, yet bilinguals vary greatly in their dual-language experiences. To uncover sources of variation in bilingual and monolingual brain function, the present study used standard analysis and innovative person-specific connectivity models combined with a data-driven grouping algorithm. Children (ages 7-9; N = 52) completed a visuo-spatial attention task while undergoing functional near-infrared spectroscopy neuroimaging. Both bilingual and monolingual groups performed similarly, and engaged bilateral frontal and parietal regions. However, bilinguals showed greater brain activity than monolinguals in left frontal and parietal regions. Connectivity models revealed two empirically-derived subgroups. One subgroup was composed of monolinguals and bilinguals who were more English dominant, and showed left frontal-parietal connections. The other was composed of bilinguals who were balanced in their dual-language abilities and showed left frontal lobe connections. The findings inform how individual variation in early language experiences influences children's emerging cortical networks for executive function, and reveal efficacy of data-driven approaches.

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.

Culturally relevant stressors as moderators of intergenerational transmission of mother-adolescent executive function in Mexican immigrant families

The intergenerational transmission of executive function may be enhanced or interrupted by culturally salient environmental stressors that shape the practice of executive function in the family. Building upon past research, the current study tests whether culturally relevant stressors such as economic stress and foreigner stress have a direct effect on adolescent executive function, as well as whether they modify the intergenerational transmission of mother–child executive function (i.e., working memory, inhibitory control, and shifting) in low-income Mexican immigrant families. The sample consists of 179 Mexican American adolescents (M_age = 17.03 years; SD_age = 0.83; 58% females) and their Mexico-born mothers (M_age = 43.25 years; SD_age = 5.90). Results show that mothers’ perceived economic stress is associated with poor inhibitory control in adolescents. Low levels of mothers’ perceived foreigner stress related to a stronger association between mothers’ and adolescents’ working memory, while high levels of mothers’ perceived foreigner stress related to enhanced intergenerational transmission of poor shifting ability. Study findings demonstrate the prominence of perceived foreigner stress as a contextually relevant factor moderating the intergenerational transmission of mother–child executive function in low-income Mexican immigrant families.

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.

The Simon effect in bilingual language brokers: A role for emotion and proficiency

Aims and objectives/purpose/research questions

Language brokering (LB) is an informal translation experience where bilinguals serve as linguistic and cultural intermediaries for family members. LB may have long-term socio-emotional and cognitive outcomes, yet little is known about its effects on executive functions (EFs). This study examines how first language (L1) proficiency and negative emotions tied to language brokering experiences affect EF performance on a Simon task (ST).

Design/methodology/approach

Fifty-three Mexican American Spanish-English bilinguals with LB experience performed a ST, and reported their feelings towards LB for their mother.

Data and analysis

Mean reaction times (RTs) and accuracy rates for correct ST trials were analyzed using linear mixed effects modeling, with trial type, proficiency and negative emotions tied to LB experience as factors and their interactions as additional predictors.

Findings/conclusions

The L1 proficiency and negative emotions tied to brokering experiences have divergent, but combined effects on EF. Contrary to our hypotheses, low L1 proficiency predicted better performance and the smallest Simon effect was found for brokers with low L1 proficiency and low negative emotional brokering experiences. However, high L1 proficiency predicted better performance (smallest RTs) regardless of negative emotions tied to brokering experiences.

Originality

This study takes a different perspective on the examination of individual differences among bilinguals, in which we examine how negative emotions tied to brokering experiences coupled with L1 proficiency relates to EF performance.

Significance/implications

Our results provide support for the need to understand how individual differences in bilingual language experiences, such as L1 proficiency and negative emotions tied to LB, interact with performance on the ST.

The Role of Audiovisual Speech in Fast-Mapping and Novel Word Retention in Monolingual and Bilingual 24-Month-Olds

Three experiments examined the role of audiovisual speech on 24-month-old monolingual and bilinguals’ performance in a fast-mapping task. In all three experiments, toddlers were exposed to familiar trials which tested their knowledge of known word–referent pairs, disambiguation trials in which novel word–referent pairs were indirectly learned, and retention trials which probed their recognition of the newly-learned word–referent pairs. In Experiment 1 (n = 48), lip movements were present during familiar and disambiguation trials, but not retention trials. In Experiment 2 (n = 48), lip movements were present during all three trial types. In Experiment 3 (bilinguals only, n = 24), a still face with no lip movements was present in all three trial types. While toddlers succeeded in the familiar and disambiguation trials of every experiment, success in the retention trials was only found in Experiment 2. This work suggests that the extra-linguistic support provided by lip movements improved the learning and recognition of the novel words.

Comparison of motion correction techniques applied to functional near-infrared spectroscopy data from children (Erratum)

The erratum concerns amendment of Section 2.5 of the published article.

More than meets the eye: The neural development of emotion face processing during infancy

This study explored the impact of infant temperament and maternal stress on the development of the infant medial prefrontal cortex (mPFC) among sixteen 6-8-month-old infants. Functional Near Infrared Spectroscopy (fNIRS) was used to measure activation of the infant mPFC in response to angry, happy, and sad faces. Infant temperament and dimensions of maternal stress were measured with the Infant Behavior Questionnaire and the Parenting Stress Index Respectively. Infants with high negative emotionality demonstrated increased mPFC activation in association with all emotion face conditions. Negative emotionality moderated the effect of total maternal stress on mPFC activation to angry and sad faces. Mother-infant dysfunctional interaction was related to increased mPFC activation associated with happy faces, supporting the "novelty hypothesis", in which the mPFC responds more strongly to unique experiences. Therefore, this study provides additional evidence that infant temperament and the quality of the mother-infant relationship influence the development of the mPFC and how infants process emotions.

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.

Early Executive Function: The Influence of Culture and Bilingualism

Evidence suggests that cultural experiences and learning multiple languages have measurable effects on children's cognitive development (EF). However, the precise impact of how bilingualism and culture contribute to observed effects remains inconclusive. The present study aims to investigate how these factors shape the development of early EF constructs longitudinally, between monolingual and bilingual children at ages 3, 3 ½ and 4 years, with a set of EF tasks that are uniquely relevant to the effects of bilingualism and cultural practices. We hypothesize that the effects of bilingualism and cultural backgrounds (i.e., Eastern) are based on different, though related, cognitive control processes associated with different EF constructs. Results revealed a significant bilingualism effect on cognitive control processes measuring selective attention, switching, and inhibition; while an effect of culture was most pronounced on behavioral regulation/response inhibition. Contributions of bilingualism and cultural experiences on individual EF constructs across development are discussed.

Bilingual effects on lexical selection: A neurodevelopmental perspective

When a listener hears a word, multiple lexical items may come to mind; for instance, /kæn/ may activate concepts with similar phonological onsets such as candy and candle. Acquisition of two lexicons may increase such linguistic competition. Using functional Near-Infrared Spectroscopy neuroimaging, we investigate whether bilingualism impacts word processing in the child's brain. Bilingual and monolingual children (N = 52; ages 7-10) completed a lexical selection task in English, where participants adjudicated phonological competitors (e.g., car/cat vs. car/pen). Children were less accurate and responded more slowly during competing than non-competing items. In doing so, children engaged top-down fronto-parietal regions associated with cognitive control. In comparison to bilinguals, monolinguals showed greater activity in left frontal regions, a difference possibly due to bilinguals' adaptation for dual-lexicons. These differences provide insight to theories aiming to explain the role of experience on children's emerging neural networks for lexical selection and language processing.

Brain bases of morphological processing in Chinese-English bilingual children

Can bilingual exposure impact children's neural circuitry for learning to read? To answer this question, we investigated the brain bases of morphological awareness, one of the key spoken language abilities for learning to read in English and Chinese. Bilingual Chinese-English and monolingual English children (N = 22, ages 7-12) completed morphological tasks that best characterize each of their languages: compound morphology in Chinese (e.g. basket + ball = basketball) and derivational morphology in English (e.g. re + do = redo). In contrast to monolinguals, bilinguals showed greater activation in the left middle temporal region, suggesting that bilingual exposure to Chinese impacts the functionality of brain regions supporting semantic abilities. Similar to monolinguals, bilinguals showed greater activation in the left inferior frontal region [BA 45] in English than Chinese, suggesting that young bilinguals form language-specific neural representations. The findings offer new insights to inform bilingual and cross-linguistic models of language and literacy acquisition.

Do Varieties of Spanish Influence U.S. Spanish-English Bilingual Children's Friendship Judgments?

Latinos are the largest minority group in the United States (U.S. Census, 2014), yet this term comprises individuals from multiple ethnicities who speak distinct varieties of Spanish. We investigated whether Spanish-English bilingual children (N = 140, ages 4-17) use Spanish varieties in their social judgments. The findings revealed that children distinguished varieties of Spanish but did not use Spanish dialects to make third-person friendship judgments until 10-12 years; this effect became stronger in adolescence. In contrast, young children (4-6 years) made friendship judgments based on a speaker's language (English, Spanish). Thus, using language varieties as a social category and as a basis for making social inferences is a complex result of multiple influences for Spanish-speaking children growing up bilingual in the United States.

Simultaneous acquisition of English and Chinese impacts children's reliance on vocabulary, morphological and phonological awareness for reading in English

The developmental process of reading acquisition is frequently conceptualized as a self-organizing mental network consisting of lexico-semantic, phonological and orthographical components. The developmental nature of this network varies across languages and is known to impact second language learners of typologically different languages. Yet, it remains largely unknown whether such cross-linguistic differences interact within young bilingual learners of two typologically different languages. In the present study, we compared Chinese-English bilinguals and English monolinguals (ages 6-12, N=134) born and raised in the US on their English language and reading skills including vocabulary, phonological and morphological awareness, and word reading. We conducted whole group and subgroup analyses on younger participants to examine the extent of the effect. In monolinguals, phonological abilities directly predicted English word reading. In contrast, in bilinguals, both phonological and morphological abilities made an indirect contribution to English literacy via vocabulary knowledge, even though bilinguals had monolingual-like language and reading abilities in English. These findings offer new insights into the flexibility of the phonological and lexical pathways for learning to read.

Understanding the Impact of Heritage Language on Ethnic Identity Formation and Literacy for u.s. Latino Children

Studies show positive associations between ethnic identity, socio-emotional health and academic success. However, most work is carried out with adolescents and few have examined how young children develop an ethnic identity, particularly u.s. Latino children. The present study represents a first-pass investigation of children’s ethnic identity mechanisms and their relation to academic success. We carried out semi-structured interviews in Spanish with 25 Latino children (ages 5–12). Open-ended questions addressed items on the Multigroup Ethnic Identity Measure and Ethnic Identity Scale, incorporating a mixed qualitative (i.e., themes) and quantitative (i.e., scoring) analysis. Results revealed that children provide great detail when discussing their ethnic background. Additionally, Latino children’s bilingualism and Spanish-language proficiency were significant markers of ethnic identity formation, which in turn were positively associated with affect and Spanish literacy. These findings shed light on the complexities of ethnic identity construction during children’s early years, and establish a path for further investigation of Latino children’s socio-emotional health and academic achievement.

Bilingualism alters children's frontal lobe functioning for attentional control

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children's cognitive and brain development. Theories of bilingualism suggest that early dual-language acquisition can improve children's cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children's frontal lobe development. Using functional near-infrared spectroscopy (fNIRS), the findings suggest that Spanish-English bilingual children (n = 13, ages 7-13) had greater activation in left prefrontal cortex during a non-verbal attentional control task relative to age-matched English monolinguals. In contrast, monolinguals (n = 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of children's prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.

Brain bases of morphological processing in young children

How does the developing brain support the transition from spoken language to print? Two spoken language abilities form the initial base of child literacy across languages: knowledge of language sounds (phonology) and knowledge of the smallest units that carry meaning (morphology). While phonology has received much attention from the field, the brain mechanisms that support morphological competence for learning to read remain largely unknown. In the present study, young English-speaking children completed an auditory morphological awareness task behaviorally (n = 69, ages 6-12) and in fMRI (n = 16). The data revealed two findings: First, children with better morphological abilities showed greater activation in left temporoparietal regions previously thought to be important for supporting phonological reading skills, suggesting that this region supports multiple language abilities for successful reading acquisition. Second, children showed activation in left frontal regions previously found active in young Chinese readers, suggesting morphological processes for reading acquisition might be similar across languages. These findings offer new insights for developing a comprehensive model of how spoken language abilities support children's reading acquisition across languages.

Differential effects of bilingualism and culture on early attention: a longitudinal study in the U.S., Argentina, and Vietnam

A large body of literature suggests that bilingualism strongly influences attentional processes among a variety of age groups. Increasing studies, however, indicate that culture may also have measurable effects on attentional processes. Bilinguals are often exposed to multiple cultural backgrounds, therefore, it is unclear if being exposed to multiple languages and culture together influence attentional processes, or if the effect themselves are uniquely linked to different attentional processes. The present study explores the relevancy of different attentional processes-alerting, orienting, and executive control-to language and to culture. In the present study, 97 3-years-old (Mean age = 38.78 months) monolingual and bilingual children from three countries (the U.S., Argentina, and Vietnam) were longitudinally tested for a total of five time points on a commonly used non-linguistic attentional paradigm-the Attention Network Test. Results demonstrate that when other factors are controlled (e.g., socio-economic status, vocabulary knowledge, age), culture plays an important role on the development of the alerting and executive control attentional network, while language status was only significant on the executive control attentional network. The present study indicates that culture may interact with bilingualism to further explain previous reported advantages, as well as elucidate the increasing disparity surrounding cognitive advantages in bilingual literature.

Brain bases of morphological processing in young children

How does the developing brain support the transition from spoken language to print? Two spoken language abilities form the initial base of child literacy across languages: knowledge of language sounds (phonology) and knowledge of the smallest units that carry meaning (morphology). While phonology has received much attention from the field, the brain mechanisms that support morphological competence for learning to read remain largely unknown. In the present study, young English-speaking children completed an auditory morphological awareness task behaviorally (n = 69, ages 6-12) and in fMRI (n = 16). The data revealed two findings: First, children with better morphological abilities showed greater activation in left temporoparietal regions previously thought to be important for supporting phonological reading skills, suggesting that this region supports multiple language abilities for successful reading acquisition. Second, children showed activation in left frontal regions previously found active in young Chinese readers, suggesting morphological processes for reading acquisition might be similar across languages. These findings offer new insights for developing a comprehensive model of how spoken language abilities support children's reading acquisition across languages.

Comparison of motion correction techniques applied to functional near-infrared spectroscopy data from children

Motion artifacts are the most significant sources of noise in the context of pediatric brain imaging designs and data analyses, especially in applications of functional near-infrared spectroscopy (fNIRS), in which it can completely affect the quality of the data acquired. Different methods have been developed to correct motion artifacts in fNIRS data, but the relative effectiveness of these methods for data from child and infant subjects (which is often found to be significantly noisier than adult data) remains largely unexplored. The issue is further complicated by the heterogeneity of fNIRS data artifacts. We compared the efficacy of the six most prevalent motion artifact correction techniques with fNIRS data acquired from children participating in a language acquisition task, including wavelet, spline interpolation, principal component analysis, moving average (MA), correlation-based signal improvement, and combination of wavelet and MA. The evaluation of five predefined metrics suggests that the MA and wavelet methods yield the best outcomes. These findings elucidate the varied nature of fNIRS data artifacts and the efficacy of artifact correction methods with pediatric populations, as well as help inform both the theory and practice of optical brain imaging analysis.