A Comparative Study of Shifting Ability,Inhibitory Control and Working Memory in Monolingual and Bilingual Children

It is now well documented that the linguistic development of bilingual children is, in many respects, different from that of their monolingual peers. Yet, there is substantial evidence in cognitive psychology that the effect of bilingualism is not merely restricted to the linguistic competence of individuals. Recent literature on bilingualism suggests that certain aspects of children’s cognitive development can be positively affected by the bilingual experience. The aim of the present study was to investigate the potential effects of bilingual experience on young children’s executive processing. A total of 67 preschool children belonging to two groups including 36 Persian–Turkish bilingual children and 31 Persian monolingual children participated in the study. They were matched for their verbal proficiency and then were compared on three executive function tasks including shifting ability, inhibitory control and working memory. Results showed that bilingual children outperformed monolinguals on both shifting and inhibitory control tasks. However, both groups performed similarly on working memory tasks. The findings are interpreted in terms of the enhanced ability of bilingual children in various executive functions processing.     

Developmental associations between bilingual experience and inhibitory control trajectories in Head Start children

Children from lower socioeconomic (SES) backgrounds tend to be at‐risk for executive function (EF) impairments by the time they are in preschool, placing them at an early disadvantage for academic success. The present study examined the potentially protective role of bilingual experience on the development of inhibitory control (IC) in 1146 Head Start preschoolers who were followed for an 18‐month period during the transition to kindergarten as part of the longitudinal Family and Child Experiences Survey (FACES) 2009 study. Using three waves of data, we predicted individual variation in developmental trajectories of IC for three groups that differed in bilingual experience—English monolinguals, Spanish‐English bilinguals, and a group of children who transitioned from being Spanish monolingual to Spanish‐English bilinguals during the course of the study. Compared to their English monolingual peers, bilingual children from Spanish‐speaking homes showed higher IC performance at Head Start entry, as well as steeper IC growth over time. Children who were Spanish monolingual at the beginning of Head Start showed the lowest IC performance at baseline. However, their rate of IC growth exceeded that of children who remained English monolingual and did not differ from that of their peers who entered Head Start being bilingual. These results suggest that acquiring bilingualism and continued bilingual experience are associated with more rapid IC development during the transition from preschool to kindergarten in children from lower SES backgrounds.     

Independent effects of bilingualism and socioeconomic status on language ability and executive functioning

One hundred and seventy-five children who were 6-years old were assigned to one of four groups that differed in socioeconomic status (SES; working class or middle class) and language background (monolingual or bilingual). The children completed tests of nonverbal intelligence, language tests assessing receptive vocabulary and attention based on picture naming, and two tests of executive functioning. All children performed equivalently on the basic intelligence tests, but performance on the language and executive functioning tasks was influenced by both SES and bilingualism. Middle-class children outperformed working-class children on all measures, and bilingual children obtained lower scores than monolingual children on language tests but higher scores than monolingual children on the executive functioning tasks. There were no interactions with either group factors or task factors. Thus, each of SES and bilingualism contribute significantly and independently to children’s development irrespective of the child’s level on the other factor.     

Socioeconomic gradients predict individual differences in neurocognitive abilities

Socioeconomic status (SES) is associated with childhood cognitive achievement. In previous research we found that this association shows neural specificity; specifically we found that groups of low and middle SES children differed disproportionately in perisylvian/language and prefrontal/executive abilities relative to other neurocognitive abilities. Here we address several new questions: To what extent does this disparity between groups reflect a gradient of SES‐related individual differences in neurocognitive development, as opposed to a more categorical difference? What other neurocognitive systems differ across individuals as a function of SES? Does linguistic ability mediate SES differences in other systems? And how do specific prefrontal/executive subsystems vary with SES? One hundred and fifty healthy, socioeconomically diverse first‐graders were administered tasks tapping language, visuospatial skills, memory, working memory, cognitive control, and reward processing. SES explained over 30% of the variance in language, and a smaller but highly significant portion of the variance in most other systems. Statistically mediating factors and possible interventional approaches are discussed.     

Musical Training,Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual‐Task Performance

This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual‐task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non‐musician, or monolingual non‐musician) were matched on age and socioeconomic status and administered task switching and dual‐task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non‐musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual‐task performance, musicians also outperformed non‐musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long‐term musical training is associated with improvements in task switching and dual‐task performance.     

The missing explanation of the false‐belief advantage in bilingual children: a longitudinal study

Bilingual preschoolers often perform better than monolingual children on false‐belief understanding. It has been hypothesized that this is due to their enhanced executive function skills, although this relationship has rarely been tested or supported. The current longitudinal study tested whether metalinguistic awareness was responsible for this advantage. Further, we examined the contributions of both executive functioning and language ability to false‐belief understanding by including multiple measures of both. Seventy‐eight children (n = 40 Spanish‐English bilingual; age M = 49.29, SD = 7.38 and, n = 38 English monolingual; age M = 47.75, SD = 6.86) were tested. A year later the children were tested again (n = 22 bilingual, n = 25 monolingual). The results indicated that language and executive function (inhibitory control) at time 1 were related to false belief in monolinguals at time 2. In contrast, bilinguals' metalinguistic performance at time 1 was the sole predictor of false belief at time 2. The different linguistic and cognitive profiles of monolinguals and bilinguals may create different pathways for their development of false‐belief understanding. A video abstract of this article can be viewed at: https://youtu.be/vILn2gKjFxw     

Monolingual but not bilingual infants demonstrate racial bias in social cue use

Bilingualism exerts early and pervasive effects on cognition, observable in infancy. Thus far, investigations of infant bilingual cognition have focused on sensitivity to visual memory, executive function, and linguistic sensitivity. Much less research has focused on how bilingualism impacts processing of social cues. The present study sought to investigate whether bilingualism modulates the expression of one aspect of social processing: early racial bias. Using a gaze‐following paradigm, we investigated whether 18‐ to 20‐month‐old monolingual and bilingual infants favored their own race. Results demonstrated that monolingual infants favored their own race in following a model whose direction of gaze signaled an event. In contrast, bilingual infants demonstrated race‐neutral gaze‐following patterns, relying more heavily on the reliability of the behavior of the model over race. Findings suggest that bilingualism may have protective effects against the early emergence of racial bias.     

Effects of classroom bilingualism on task‐shifting,verbal memory,and word learning in children

We examined the effects of classroom bilingual experience in children on an array of cognitive skills. Monolingual English‐speaking children were compared with children who spoke English as the native language and who had been exposed to Spanish in the context of dual‐immersion schooling for an average of 2 years. The groups were compared on a measure of non‐linguistic task‐shifting; measures of verbal short‐term and working memory; and measures of word learning. The two groups of children did not differ on measures of non‐linguistic task‐shifting and verbal short‐term memory. However, the classroom‐exposure bilingual group outperformed the monolingual group on the measure of verbal working memory and a measure of word learning. Together, these findings indicate that while exposure to a second language in a classroom setting may not be sufficient to engender changes in cognitive control, it can facilitate verbal memory and verbal learning.     

Word Mapping and Executive Functioning in Young Monolingual and Bilingual Children

The effect of bilingualism on the cognitive skills of young children was investigated by comparing performance of 162 children who belonged to one of two age groups (approximately 3- and 4.5-year-olds) and one of three language groups on a series of tasks examining executive control and word mapping. The children were monolingual English speakers, monolingual French speakers, or bilinguals who spoke English and one of a large number of other languages. Monolinguals obtained higher scores than bilinguals on a receptive vocabulary test and were more likely to demonstrate the mutual exclusivity constraint, especially at the younger ages. However, bilinguals obtained higher scores than both groups of monolinguals on three tests of executive functioning: Luria's tapping task measuring response inhibition, the opposite worlds task requiring children to assign incongruent labels to a sequence of animal pictures, and reverse categorization in which children needed to reclassify a set of objects into incongruent categories after an initial classification. There were no differences between the groups in the attentional networks flanker task requiring executive control to ignore a misleading cue. This evidence for a bilingual advantage in aspects of executive functioning at an earlier age than previously reported is discussed in terms of the possibility that bilingual language production may not be the only source of these developmental effects.     

Neural correlates of socioeconomic status in the developing human brain

Socioeconomic disparities in childhood are associated with remarkable differences in cognitive and socio-emotional development during a time when dramatic changes are occurring in the brain. Yet, the neurobiological pathways through which socioeconomic status (SES) shapes development remain poorly understood. Behavioral evidence suggests that language, memory, social-emotional processing, and cognitive control exhibit relatively large differences across SES. Here we investigated whether volumetric differences could be observed across SES in several neural regions that support these skills. In a sample of 60 socioeconomically diverse children, highly significant SES differences in regional brain volume were observed in the hippocampus and the amygdala. In addition, SES × age interactions were observed in the left superior temporal gyrus and left inferior frontal gyrus, suggesting increasing SES differences with age in these regions. These results were not explained by differences in gender, race or IQ. Likely mechanisms include differences in the home linguistic environment and exposure to stress, which may serve as targets for intervention at a time of high neural plasticity.     

Neurocognitive correlates of socioeconomic status in kindergarten children

Socioeconomic status (SES) is strongly associated with cognitive ability and achievement during childhood and beyond. Little is known about the developmental relationships between SES and specific brain systems or their associated cognitive functions. In this study we assessed neurocognitive functioning of kindergarteners from different socioeconomic backgrounds, using tasks drawn from the cognitive neuroscience literature in order to determine how childhood SES predicts the normal variance in performance across different neurocognitive systems. Five neurocognitive systems were examined: the occipitotemporal/visual cognition system, the parietal/spatial cognition system, the medial temporal/memory system, the left perisylvian/language system, and the prefrontal/executive system. SES was disproportionately associated with the last two, with low SES children performing worse than middle SES children on most measures of these systems. Relations among language, executive function, SES and specific aspects of early childhood experience were explored, revealing intercorrelations and a seemingly predominant role of individual differences in language ability involved in SES associations with executive function.     

Enhanced music sensitivity in 9-month-old bilingual infants

This study explores the influence of bilingualism on the cognitive processing of language and music. Specifically, we investigate how infants learning a non-tone language perceive linguistic and musical pitch and how bilingualism affects cross-domain pitch perception. Dutch monolingual and bilingual infants of 8–9 months participated in the study. All infants had Dutch as one of the first languages. The other first languages, varying among bilingual families, were not tone or pitch accent languages. In two experiments, infants were tested on the discrimination of a lexical (N = 42) or a violin (N = 48) pitch contrast via a visual habituation paradigm. The two contrasts shared identical pitch contours but differed in timbre. Non-tone language learning infants did not discriminate the lexical contrast regardless of their ambient language environment. When perceiving the violin contrast, bilingual but not monolingual infants demonstrated robust discrimination. We attribute bilingual infants’ heightened sensitivity in the musical domain to the enhanced acoustic sensitivity stemming from a bilingual environment. The distinct perceptual patterns between language and music and the influence of acoustic salience on perception suggest processing diversion and association in the first year of life. Results indicate that the perception of music may entail both shared neural network with language processing, and unique neural network that is distinct from other cognitive functions.     

Bilingual experience and executive functioning in young children

Advanced inhibitory control skills have been found in bilingual speakers as compared to monolingual controls (Bialystok, 1999). We examined whether this effect is generalized to an unstudied language group (Spanish-English bilingual) and multiple measures of executive function by administering a battery of tasks to 50 kindergarten children drawn from three language groups: native bilinguals, monolinguals (English), and English speakers enrolled in second-language immersion kindergarten. Despite having significantly lower verbal scores and parent education/income level, Spanish-English bilingual children's raw scores did not differ from their peers. After statistically controlling for these factors and age, native bilingual children performed significantly better on the executive function battery than both other groups. Importantly, the relative advantage was significant for tasks that appear to call for managing conflicting attentional demands (Conflict tasks); there was no advantage on impulse-control (Delay tasks). These results advance our understanding of both the generalizability and specificity of the compensatory effects of bilingual experience for children's cognitive development.     

The effects of bilingualism on toddlers' executive functioning

Bilingual children have been shown to outperform monolingual children on tasks measuring executive functioning skills. This advantage is usually attributed to bilinguals’ extensive practice in exercising selective attention and cognitive flexibility during language use because both languages are active when one of them is being used. We examined whether this advantage is observed in 24-month-olds who have had much less experience in language production. A battery of executive functioning tasks and the cognitive scale of the Bayley test were administered to 63 monolingual and bilingual children. Native bilingual children performed significantly better than monolingual children on the Stroop task, with no difference between groups on the other tasks, confirming the specificity of bilingual effects to conflict tasks reported in older children. These results demonstrate that bilingual advantages in executive control emerge at an age not previously shown.     

Bilingual infants excel at foreign‐language talker recognition

Bilingual and monolingual infants differ in how they process linguistic aspects of the speech signal. But do they also differ in how they process non‐linguistic aspects of speech, such as who is talking? Here, we addressed this question by testing Canadian monolingual and bilingual 9‐month‐olds on their ability to learn to identify native Spanish‐speaking females in a face‐voice matching task. Importantly, neither group was familiar with Spanish prior to participating in the study. In line with our predictions, bilinguals succeeded in learning the face‐voice pairings, whereas monolinguals did not. We consider multiple explanations for this finding, including the possibility that simultaneous bilingualism enhances perceptual attentiveness to talker‐specific speech cues in infancy (even in unfamiliar languages), and that early bilingualism delays perceptual narrowing to language‐specific talker recognition cues. This work represents the first evidence that multilingualism in infancy affects the processing of non‐linguistic aspects of the speech signal, such as talker identity.     

Working memory in multilingual children: Is there a bilingual effect?

This research investigates whether early childhood bilingualism affects working memory performance in 6- to 8-year-olds, followed over a longitudinal period of 3 years. The study tests the hypothesis that bilinguals might exhibit more efficient working memory abilities than monolinguals, potentially via the opportunity a bilingual environment provides to train cognitive control by combating interference and intrusions from the non-target language. A total of 44 bilingual and monolingual children, matched on age, sex, and socioeconomic status, completed assessments of working memory (simple span and complex span tasks), fluid intelligence, and language (vocabulary and syntax). The data showed that the monolinguals performed significantly better on the language measures across the years, whereas no language group effect emerged on the working memory and fluid intelligence tasks after verbal abilities were considered. The study suggests that the need to manage several language systems in the bilingual mind has an impact on children's language skills while having little effects on the development of working memory.     

Working memory in multilingual children: is there a bilingual effect?

This research investigates whether early childhood bilingualism affects working memory performance in 6- to 8-year-olds, followed over a longitudinal period of 3 years. The study tests the hypothesis that bilinguals might exhibit more efficient working memory abilities than monolinguals, potentially via the opportunity a bilingual environment provides to train cognitive control by combating interference and intrusions from the non-target language. A total of 44 bilingual and monolingual children, matched on age, sex, and socioeconomic status, completed assessments of working memory (simple span and complex span tasks), fluid intelligence, and language (vocabulary and syntax). The data showed that the monolinguals performed significantly better on the language measures across the years, whereas no language group effect emerged on the working memory and fluid intelligence tasks after verbal abilities were considered. The study suggests that the need to manage several language systems in the bilingual mind has an impact on children's language skills while having little effects on the development of working memory.     

Brain lateralization of phonological awareness varies by maternal education

Socioeconomic status (SES) has been shown to influence language skills, with children of lower SES backgrounds performing worse on language assessments compared to their higher SES peers. While there is abundant behavioral research on the effects of SES, whether there are differences in the neural mechanisms used to support language skill is less established. In this study, we examined the relation between maternal education (ME), a component of SES, and neural mechanisms of language. We focused on Kindergarten children, at the beginning of formal reading education, and on a pre‐reading skill, phonological awareness—the ability to distinguish or manipulate the sounds of language. We determined ME‐related differences in neural activity by examining a skill‐matched sample of typically achieving 5‐year‐old children as they performed a rhyme judgment task. We examined brain lateralization in two language processing regions, the inferior frontal gyrus (IFG) and superior temporal gyrus (STG). In the IFG, lateralization was related to ME but not skill: children with low ME showed bilateral activation compared to children with higher ME who showed leftward lateralization. In the STG, there was a skill by ME interaction on lateralization, such that children with high ME showed a positive relation between rightward lateralization and skill and children with low ME showed a positive relation between leftward lateralization and skill. Thus, we demonstrated ME is related to differences in neural recruitment during language processing, yet this difference in recruitment is not indicative of a deficit in linguistic processing in Kindergarten children.     

Reading,syntactic, orthographic,and working memory skills of bilingual Arabic-English speaking Canadian children

This study assessed the reading, language, and memory skills of 56 bilingual Arab-Canadian children age's 9-14. English was their main instructional language, and Arabic was the language spoken at home. All children attended a Heritage Language Program in Toronto where they were taught to read and write Arabic. The children were administered word and pseudo-word reading, language, and working memory tests in English and Arabic. The majority of the children showed at least adequate proficiency in both languages. There was a significant relationship between the acquisition of word and pseudo-word reading working memory, and syntactic awareness skills in the two languages. The poor readers in Arabic had lower scores on all linguistic tasks, except the visual task. There were no significant differences between bilingual English Arabic children and monolingual English-speaking children on the reading, language, and memory tasks. However, bilingual English Arabic children who had reading problems in English had higher scores on English pseudo-word reading and spelling tasks than monolingual English-speaking children with reading disabilities, probably because of positive transfer from the regular nature of Arabic orthography. In this case, bilingualism does not appear to have negative consequences for the development of language reading skills in both languages—Arabic and English—despite the different nature of the two orthographies.     

“各说各话”的语言经验对景颇族大学生执行功能的影响

在中国云南的景颇族中,相当多的家庭是由不同支系的人组成的,家庭成员交际时存在着"各说各话"的现象。"各说各话"对讲话者的执行功能有无影响?采用抑制控制、注意转换和记忆刷新任务测量各说各话和非各说各话的景颇族大学生的抑制能力、转换能力和刷新能力。结果表明,各说各话与非各说各话的景颇族大学生在色词干扰和数字转换中差异显著,各说各话者的Stroop效应量小,停止信号的反应时短。各说各话与非各说各话的景颇族大学生在数字转换和图形转换中差异显著,各说各话者反应快,转换代价小。各说各话与非各说各话的景颇族大学生在活动记忆刷新与色点位置刷新任务中差异不显著。这表明,各说各话者比非各说各话者在抑制能力与转换能力上具有优势。语言经验对执行功能的影响具有功能特异性。