Two is better than one: bilingual education promotes the flexible mind

The impact of bilingualism on executive function in adolescents

AIMS AND OBJECTIVES/PURPOSE/RESEARCH QUESTIONS

In early childhood and older adulthood, bilinguals generally demonstrate better performance on executive function tasks than their monolingual counterparts, but in the young adult population, these differences are infrequently observed. However, few studies have examined these effects in the adolescent population, so the trajectory of these changes is unclear. The objective of the study was to compare performance on a modified flanker task for monolingual and bilingual adolescents, a time when the executive functions are still developing.

DESIGN/METHODOLOGY/APPROACH

The flanker task was adapted by including a rule-switching component and contained three blocks: (1) rule; (2) flanker; and (3) mixed. In the rule block, a single red or blue arrow (indicated by light grey or medium grey in Figure 1) denoted a response rule; for example, a blue arrow signaled pressing the button indicating the direction the arrow was pointing but a red arrow signaled pressing the button indicating the opposite direction. The flanker block was a standard flanker task consisting of congruent and incongruent trials. The mixed block manipulated both congruency and rule conditions.

DATA AND ANALYSIS

Mean reaction times and accuracy from 33 monolingual and 32 bilingual adolescents were analyzed using a repeated-measures analysis of variance with language group as the between-subjects variable and congruency and/or rule-type as the within-subjects variable depending on the block.

FINDINGS/CONCLUSIONS

Bilingual adolescents outperformed monolingual adolescents but only on the block that was most similar to the standard flanker task. The blocks with the rule-switching component yielded equivalent performance.

ORIGINALITY

Unlike previous studies, the current study adapted a simple executive control task to require greater attentional resources by manipulating task demands.

SIGNIFICANCE/IMPLICATIONS

Our findings add to the growing body of literature examining bilingualism and executive control in the adolescent population and fill in the gap in our understanding of the lifespan trajectory of these effects.

A Bilingual Advantage? An Appeal for a Change in Perspective and Recommendations for Future Research

The debate on possible cognitive advantages bilinguals have over monolinguals continues to occupy the research community. There is an ever-growing research body focusing on adjudicating whether there is, in fact, an effect of using two or more languages regularly on cognition. In this paper, we briefly review some of the more pertinent literature that has attempted to identify attenuating, modulating, and confounding factors in research comparing monolingual and bilingual populations, and we highlight issues that should be taken into account in future research to move forward as a research community. At the same time, we argue for a change in perspective concerning what is deemed an advantage and what is not and argue for more ecologically valid research that investigates real-life advantages.

The Effect of Bilingualism Level on Creative Performance during Preadolescent Period

The purpose of this study was to examine differences in the performance of creativity tasks regarding different levels of bilingualism and school grade. The sample consisted of 224 preadolescent children from fifth and sixth grades resident in the Basque Country (Spain). Evaluation included verbal and figural creativity tasks, and a linguistic proficiency questionnaire. The sample was divided into three groups depending on the bilingualism level (low, medium, and high). Results showed on the one hand, a better performance in figural creativity in the high-level group compared to medium and low-level groups, F(2, 218) = 7.22, p = .001, Ƞ2p = .062. On the other hand, the high-level group performed better in verbal creativity compared to the medium level group, F(2, 218) = 4.22, p = .016, Ƞ2p = .037. Differences in creativity between the three levels of bilingualism were different depending on the school grade. Moreover, children from fifth grade had better results in figural creativity tasks, F(1, 218) = 6.75, p = .010, Ƞ2p = .030. These results suggest that level of bilingualism is related to performance in creativity, and concretely, that a high level of bilingualism is associated with a greater creativity, while a medium level of bilingualism is related to a worse creativity performance. These are relevant results for the educational field that point out the importance of acquiring good competence in both languages.

Positive Cognitive Effects of Bilingualism and Multilingualism on Cerebral Function: a Review

A review of the current literature regarding bilingualism demonstrates that bilingualism is linked to higher levels of controlled attention and inhibition in executive control and can protect against the decline of executive control in aging by contributing to cognitive reserve. Bilinguals may also have smaller vocabulary size and slower lexical retrieval for each language. The joint activation theory is proposed to explain these results. Older trilingual adults experience more protection against cognitive decline and children and young adults showed similar cognitive advantages to bilinguals in inhibitory control. Second language learners do not yet show cognitive changes associated with multilingualism. The Specificity Principle states that the acquisition of multiple languages is moderated by multiple factors and varies between experiences. Bilingualism and multilingualism are both associated with immigration but different types of multilingualism can develop depending on the situation. Cultural cues and language similarity also play a role in language switching and multiple language acquisition.

Attentional asymmetry between visual hemifields is related to habitual direction of reading and its implications for debate on cause and effects of dyslexia

A major controversy regarding dyslexia is whether any of the many visual and phonological deficits found to be correlated with reading difficulty cause the impairment or result from the reduced amount of reading done by dyslexics. We studied this question by comparing a visual capacity in the left and right visual hemifields in people habitually reading scripts written right-to-left or left-to-right. Selective visual attention is necessary for efficient visual search and also for the sequential recognition of letters in words. Because such attentional allocation during reading depends on the direction in which one is reading, asymmetries in search efficiency may reflect biases arising from the habitual direction of reading. We studied this by examining search performance in three cohorts: (a) left-to-right readers who read English fluently; (b) right-to-left readers fluent in reading Farsi but not any left-to-right script; and (c) bilingual readers fluent in English and in Farsi, Arabic, or Hebrew. Left-to-right readers showed better search performance in the right hemifield and right-to-left readers in the left hemifield, but bilingual readers showed no such asymmetries. Thus, reading experience biases search performance in the direction of reading, which has implications for the cause and effect relationships between reading and cognitive functions.

Can Lextale-Esp discriminate between groups of highly proficient Catalan-Spanish bilinguals with different language dominances?

Researchers have recently introduced various LexTALE-type word recognition tests in order to assess vocabulary size in a second language (L2) mastered by participants. These tests correlate well with other measures of language proficiency in unbalanced bilinguals whose second language ability is well below the level of their native language. In the present study, we investigated whether LexTALE-type tests also discriminate at the high end of the proficiency range. In several regions of Spain, people speak both the regional language (e.g., Catalan or Basque) and Spanish to very high degrees. Still, because of their living circumstances, some consider themselves as either Spanish-dominant or regional-language dominant. We showed that these two groups perform differently on the recently published Spanish Lextale-Esp: The Spanish-dominant group had significantly higher scores than the Catalan-dominant group. We also showed that the noncognate words of the test have the highest discrimination power. This indicates that the existing Lextale-Esp can be used to estimate proficiency differences in highly proficient bilinguals with Spanish as an L2, and that a more sensitive test could be built by replacing the cognates.

Skills of Cognitive Flexibility in Monolingual and Bilingual Younger Adults

The current study examined skills of cognitive flexibility and sustained attention in late bilingual and monolingual younger adults. One-hundred and sixty two younger adults aged between 18 and 34 years old (M = 22.39) classified as Turkish-English late bilinguals (N = 74) and Turkish monolinguals (N = 88) completed the Trail Making Test (TMT-A and TMT-B). Results from this study showed that Turkish-English late bilinguals had shorter RTs than Turkish monolinguals on the TMT-B, however there were no significant RT differences between the groups on the TMT-A. These findings indicate that bilingualism impacts upon skills of cognitive flexibility but not sustained attention and that the amount of practice in coordinating, monitoring, and switching between languages is an important determinant of cognitive improvement.

Cognitive Consequences of Trilingualism

AIMS AND OBJECTIVES

The objectives of the present research were to examine the cognitive consequences of trilingualism and explain them relative to the cognitive consequences of bilingualism.

APPROACH

A comparison of cognitive abilities in trilinguals and bilinguals was conducted. In addition, we proposed a cognitive plasticity framework to account for cognitive differences and similarities between trilinguals and bilinguals.

DATA AND ANALYSIS

Three aspects of cognition were analyzed: (1) cognitive reserve in older adults, as measured by age of onset of Alzheimer's disease and mild cognitive impairment; (2) inhibitory control in children and younger adults, as measured by response times on behavioral Simon and flanker tasks; and (3) memory generalization in infants and toddlers, as measured by accuracy on behavioral deferred imitation tasks. Results were considered within a framework of cognitive plasticity, which took into account several factors that may affect plasticity, including the age of learning a third language and the extent to which additional cognitive resources are needed to learn the third language.

FINDINGS

A mixed pattern of results was observed. In some cases, such as cognitive reserve in older adults, trilinguals showed larger advantages than bilinguals. On other measures, for example inhibitory control in children and younger adults, trilinguals were found to exhibit the same advantages as bilinguals. In still other cases, like memory generalization in infants and toddlers, trilinguals did not demonstrate the advantages seen in bilinguals.

ORIGINALITY

This study is the first comprehensive analysis of how learning a third language affects the cognitive abilities that are modified by bilingual experience, and the first to propose a cognitive plasticity framework that can explain and predict trilingual-bilingual differences.

SIGNIFICANCE

This research shows that the cognitive consequences of trilingualism are not simply an extension of bilingualism's effects; rather, trilingualism has distinct consequences, with theoretical implications for our understanding of linguistic and cognitive processes and their plasticity, as well as applied-science implications for using second and third language learning in educational and rehabilitative contexts to foster successful cognitive development and aging.

Bilingualism as a Contributor to Cognitive Reserve? Evidence from Cerebral Glucose Metabolism in Mild Cognitive Impairment and Alzheimer's Disease

OBJECTIVE

Bilingualism is discussed as one factor contributing to "cognitive reserve" (CR), as it enhances executive control functions. To elucidate the underlying cerebral correlates, regional glucose uptake was compared between bilinguals and monolinguals with mild cognitive impairment (MCI) and beginning-stage Alzheimer's disease (AD) by using [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET).

METHODS

Thirty patients (73.2 ± 7.4) diagnosed with MCI or probable AD received physical and neuropsychological examinations, blood tests, and FDG-PET scans. Sixteen patients were classified as lifelong bilinguals, following the criterion of Bialystok et al., and groups were matched for age, sex, and mini mental state examination scores. Analyses were conducted using statistical parametric mapping version 8. The whole brain was used as reference region for intensity normalization and years of education were controlled for.

RESULTS

Bilingual patient groups showed substantially greater impairment of glucose uptake in frontotemporal and parietal regions [including Brodmann areas (BAs) 9, 47, 40, and 21] and in the left cerebellum relative to monolingual patients.

CONCLUSION

Bilingualism is likely to contribute to CR, given that bilingual patients showed more severe brain changes than monolinguals when adjusting for severity of cognitive impairment. The latter did not only comprise BAs relevant to speech and language but also structures typically involved in AD pathology, such as the temporal and the parietal cortices.