The Impact of Bilingualism on Executive Function: A Meta-Analysis

The potential cognitive benefits associated with bilingualism have garnered substantial attention in recent years. The present meta-analysis aimed to synthesize and critically evaluate the existing evidence regarding the impact of bilingualism on executive function (EF), a set of cognitive processes vital for goal-directed behavior. A comprehensive literature search was conducted across multiple databases, encompassing studies published between 2018 and 2024. Studies were included if they employed a quantitative design, compared bilingual and monolingual individuals on at least one measure of EF, and reported sufficient statistical data for effect size calculation. A total of 32 studies met the inclusion criteria, yielding a combined sample size of 3,875 participants. The overall meta-analysis revealed a small but significant positive effect of bilingualism on EF (Hedges' g = 0.18, 95% CI [0.12, 0.24], p < 0.001). Moderator analyses indicated that the effect was moderated by the type of EF assessed, with stronger effects observed for inhibitory control and cognitive flexibility than for working memory. In conclusion, our study suggests that bilingualism is associated with enhanced EF. The magnitude of the effect varies across different EF components, highlighting the need for further research to elucidate the specific mechanisms underlying the bilingual advantage in cognitive control.


Introduction
Bilingualism, proficiency in two or more languages, has been the subject of extensive research due to its potential impact on cognitive processes.Beyond the linguistic domain, bilingualism has been hypothesized to influence a range of cognitive abilities, including attention, memory, problem-solving, and decisionmaking.This potential influence stems from the unique cognitive demands associated with managing two language systems, which may lead to the development of enhanced cognitive control mechanisms and neural plasticity.Among the most investigated cognitive domains in relation to bilingualism is executive function (EF).EF is an umbrella term encompassing a set of higher-order cognitive processes crucial for goal-directed behavior (Diamond, 2013).These processes include: Inhibitory control: The ability to suppress irrelevant or distracting information and resist impulsive responses (Miyake et al., 2000); Working memory: The capacity to temporarily hold and manipulate information in mind (Baddeley, 1974); Cognitive flexibility: The ability to shift attention between different tasks or mental sets and adapt to changing demands (Diamond, 2013).
EF plays a critical role in various aspects of daily life, from academic achievement and problem-solving to social interaction and emotional regulation.Therefore, https://doi.org/10.37275/oaijss.v7i5.268

A B S T R A C T
The potential cognitive benefits associated with bilingualism have garnered substantial attention in recent years.The present metaanalysis aimed to synthesize and critically evaluate the existing evidence regarding the impact of bilingualism on executive function (EF), a set of cognitive processes vital for goal-directed behavior.A comprehensive literature search was conducted across multiple databases, encompassing studies published between 2018 and 2024.Studies were included if they employed a quantitative design, compared bilingual and monolingual individuals on at least one measure of EF, and reported sufficient statistical data for effect size calculation.A total of 32 studies met the inclusion criteria, yielding a combined sample size of 3,875 participants.The overall meta-analysis revealed a small but significant positive effect of bilingualism on EF (Hedges' g = 0.18, 95% CI [0.12, 0.24], p < 0.001).Moderator analyses indicated that the effect was moderated by the type of EF assessed, with stronger effects observed for inhibitory control and cognitive flexibility than for working memory.In conclusion, our study suggests that bilingualism is associated with enhanced EF.The magnitude of the effect varies across different EF components, highlighting the need for further research to elucidate the specific mechanisms underlying the bilingual advantage in cognitive control.
promotion of healthy aging.
The notion of a "bilingual advantage" in EF has been a subject of considerable debate and investigation.Numerous studies have explored whether bilingual individuals exhibit superior EF compared to their monolingual counterparts.Some studies have reported evidence of such an advantage, particularly in the domains of inhibitory control and cognitive flexibility (Bialystok et al., 2009;Costa et al., 2008).This advantage has been attributed to the constant need for bilinguals to manage two language systems, which may strengthen their cognitive control mechanisms and enhance their ability to suppress irrelevant information and switch between tasks (Green, 2013).However, other studies have failed to replicate these findings or have even reported null or negative effects of bilingualism on EF (Duñabeitia et al., 2014;Paap, 2013).This discrepancy in the literature has led to ongoing discussions about the superior EF in bilingual individuals (Bialystok et al., 2009).Bilinguals must continuously monitor their linguistic environment, select the appropriate language for a given context, and inhibit interference from the non-target language.These processes are thought to strengthen the executive control network in the brain, leading to improved performance on tasks requiring inhibitory control, working memory, and cognitive flexibility.The Cognitive Reserve hypothesis suggests that bilingualism may act as a protective factor against cognitive decline, potentially delaying the onset of age-related cognitive impairments (Stern, 2009).This hypothesis is based on the idea that bilingualism promotes neural plasticity and cognitive

Methods
A comprehensive and systematic literature search was conducted using the following electronic databases: PubMed; PsycINFO; Web of Science; and Scopus.The search was performed between January 1 st , 2023, and July 31 st , 2024, to ensure the inclusion of the most recent and relevant studies.Search terms were carefully selected to capture the key concepts of interest, including: Bilingualism: "bilingualism," "bilingual," "second language"; Executive Function: "executive function," "cognitive control," "working memory," "inhibitory control," "cognitive flexibility," "attention"; Meta-Analysis: "meta-analysis," "systematic review".These keywords were combined using Boolean operators (AND, OR) to create a comprehensive search string for each database.
Additionally, the reference lists of included studies and relevant review articles were manually searched to identify any potentially eligible studies that may have been missed by the electronic database searches.

Meta-regression involved
examining the relationship between the effect sizes and the moderator variables using a regression model.
Publication bias refers to the tendency for studies with statistically significant results to be more likely to be published than studies with non-significant results.
Publication bias can distort the findings of a metaanalysis by overestimating the true effect size.
Publication bias was assessed using the following methods: Funnel plot: A graphical representation of the relationship between study effect sizes and their precision (standard error).In the absence of publication bias, the funnel plot should be symmetrical; Egger's regression test: A statistical test that examines the asymmetry of the funnel plot.

Results and Discussion
Table 1 provides 1 demonstrates the heterogeneity of the included studies, which is typical in meta-analyses.This heterogeneity will be carefully considered and statistically accounted for in the subsequent analyses.how the findings of this meta-analysis fit within this framework.At its core, the BECA hypothesis hinges on the idea that bilingualism creates a unique linguistic environment where two languages are constantly vying for attention.This competition necessitates a sophisticated system of cognitive control to manage the selection, activation, and inhibition of the appropriate language at any given moment.This system is engaged not only during overt language production but also during comprehension and even internal thought processes.The constant exercise of these control mechanisms, according to the BECA hypothesis, results in their strengthening and refinement.Crucially, this enhancement is not limited to the linguistic domain; it is proposed to generalize to non-linguistic tasks that also rely on executive control, such as those involving attentional focus, conflict resolution, and task switching.The lifespan perspective on bilingualism further enriches our understanding of how bilingualism might interact with cognitive development and aging (Kroll, 2013).This perspective emphasizes that bilingualism is not a static state but a dynamic and evolving The prefrontal cortex (PFC) often referred to as the brain's "command center," plays a pivotal role in a wide array of EF processes, including planning, decision-making, and goal-directed behavior.
Bilinguals have been shown to exhibit greater PFC activation than monolinguals during tasks that require them to switch between languages or inhibit interference from the non-target language (Abutalebi et al., 2012;Luk et al., 2011).This suggests that the constant need to manage two linguistic systems necessitates increased engagement of the PFC, leading to its functional strengthening.The anterior cingulate cortex (ACC) is another critical node in the executive control network, particularly involved in conflict monitoring and error detection.Bilinguals tend to show greater ACC activation than monolinguals during tasks that involve conflicting linguistic or nonlinguistic information (Abutalebi et al., 2012;Garbin et al., 2010).This heightened ACC activity may reflect the bilingual brain's enhanced ability to detect and resolve conflicts arising from the simultaneous activation of two language systems.The increased activation of these executive control regions in bilinguals is thought to be a consequence of the continuous exercise and fine-tuning of cognitive control mechanisms required for successful bilingual language processing.The constant need to select the appropriate language, suppress the irrelevant one, and monitor for potential conflicts places significant demands on the executive control network.Over time, this may lead to functional adaptations, resulting in greater efficiency and flexibility in the recruitment of these brain regions not only for language processing but also for other cognitive tasks that rely on executive control.
In addition to functional changes, bilingualism has also been linked to structural alterations in the brain.
Several studies have reported that bilingual individuals exhibit increased gray matter volume in brain regions associated with executive control, including the PFC and ACC (Grundy et al., 2017;Mechelli et al., 2004).Gray matter consists primarily of neuronal cell bodies and dendrites, which are responsible for processing and transmitting information.The increased gray matter volume in bilinguals suggests that the experience of managing two languages may promote structural changes in the brain, potentially leading to greater neural resources and connectivity in regions critical for cognitive control.The relationship between bilingualism and gray matter volume appears to be influenced by various factors, including age of acquisition, language proficiency, and the degree of language use.Early bilinguals, who acquire both languages from infancy, tend to show more widespread structural changes compared to late bilinguals, who learn their second language later in life (Pliatsikas et al., 2015).Moreover, higher levels of language proficiency and more frequent language switching have been associated with greater gray matter volume in executive control regions (Filippi et al., 2011;Hervais-Adelman et al., 2011).These findings suggest that the structural adaptations in the bilingual brain are not fixed but rather dynamic and responsive to the specific characteristics of the bilingual experience.
The present meta-analysis did not directly examine Instead, they appear to be particularly pronounced for two key components: inhibitory control and cognitive flexibility.This observation suggests that these specific EF components may be especially sensitive to the unique cognitive demands imposed by bilingualism.Let's delve deeper into the theoretical underpinnings and implications of these findings.
Inhibitory control, at its core, refers to the ability to suppress irrelevant or distracting information and resist impulsive responses.This ability is fundamental to goal-directed behavior, enabling us to focus on relevant stimuli, filter out noise, and make deliberate choices rather than succumbing to automatic reactions.In the context of bilingualism, inhibitory control plays a pivotal role in language management.
Bilingual individuals must constantly monitor their linguistic environment, selecting the appropriate language for a given context and suppressing interference from the non-target language.This ongoing process of language control necessitates a high degree of inhibitory control, as bilinguals must actively inhibit the activation of words and grammatical structures from the language that is not currently in use.The stronger effect of bilingualism on inhibitory control observed in this meta-analysis suggests that this constant practice of language suppression and selection may lead to a refinement of inhibitory control mechanisms.In essence, the bilingual brain becomes adept at filtering out irrelevant linguistic information, and this enhanced inhibitory prowess may generalize to non-linguistic tasks as well.This generalization is supported by numerous studies demonstrating that bilinguals outperform monolinguals on tasks that require the suppression of irrelevant information or the resistance to impulsive responses, such as the Stroop task and the Simon task (Bialystok et al., 2004;Costa et al., 2008).The neural underpinnings of this bilingual advantage in inhibitory control are also beginning to be elucidated.Neuroimaging studies have shown that bilinguals exhibit greater activation in brain regions associated with inhibitory control, such as the prefrontal cortex and anterior cingulate cortex, during tasks requiring conflict resolution (Abutalebi et al., 2012).This heightened neural activity suggests that bilinguals may recruit these brain regions more efficiently or effectively to support their inhibitory control processes.perspectives or problem-solving strategies (Green, 2013).This transfer of cognitive flexibility to nonlinguistic tasks further supports the notion that bilingualism fosters a more general cognitive advantage in adapting to changing demands.
In contrast to the robust effects observed for inhibitory control and cognitive flexibility, the impact of bilingualism on working memory was relatively weaker in this meta-analysis.Working memory, the ability to temporarily hold and manipulate information in mind, is essential for a wide range of cognitive activities, from language comprehension and problemsolving to planning and decision-making.While bilingualism undoubtedly involves some degree of working memory engagement, particularly in tasks requiring simultaneous processing of both languages, the demands on working memory may not be as pronounced as those on inhibitory control and cognitive flexibility.In many everyday language situations, bilinguals may rely on contextual cues and linguistic knowledge to facilitate language processing, reducing the need for extensive working memory resources.Moreover, some studies have suggested that the relationship between bilingualism and working memory may be more complex and contextdependent.For example, bilinguals may exhibit advantages in verbal working memory tasks that involve switching between languages, but not necessarily in tasks that require maintaining and manipulating information within a single language (Morales et al., 2013).This suggests that the bilingual experience may shape working memory in specific ways, rather than leading to a general enhancement of working memory capacity.

Conclusion
The present meta-analysis provides robust evidence for a positive association between bilingualism and EF.The findings support the BECA hypothesis and the cognitive reserve hypothesis, suggesting that bilingualism may enhance cognitive control abilities and protect against cognitive decline.
The bilingual advantage in EF appears to be most pronounced for inhibitory control and cognitive flexibility and is relatively consistent across different age groups, language proficiency levels, and socioeconomic backgrounds.
have been proposed to explain the potential cognitive benefits of bilingualism.Two prominent accounts are the bilingual executive control advantage (BECA) hypothesis and the Cognitive Reserve hypothesis.The BECA hypothesis posits that the constant management of two language systems necessitates enhanced cognitive control mechanisms, which may generalize to non-linguistic tasks and contribute to A random-effects model was used to conduct the meta-analysis.This model assumes that the true effect sizes vary across studies due to both sampling error and genuine differences in study characteristics or populations.The random-effects model provides a more conservative estimate of the overall effect size compared to a fixed-effects model, which assumes that all studies share a common true effect size.Heterogeneity refers to the variability in effect sizes across studies beyond what would be expected by chance.Heterogeneity was assessed using the following statistics: Q statistic: A chi-square test that assesses whether the observed variability in effect sizes is significantly greater than what would be expected by chance; I 2 index: A measure of the proportion of total variance in effect sizes that is attributable to between-study heterogeneity.Moderator analyses were conducted to examine the potential influence of various factors on the relationship between bilingualism and executive function.The following moderators were considered: Type of Executive Function: Inhibitory control, working memory, cognitive flexibility; Age: Children, young adults, older adults; Language Proficiency: Low, medium, high; Socioeconomic Status: Low, medium, high.Moderator analyses were performed using subgroup analyses and meta-regression.Subgroup analyses involved comparing the overall effect sizes between different subgroups of studies based on the moderator variables.
a summary of the key features of the 32 studies included in the meta-analysis.It offers a snapshot of the diversity of the research landscape in terms of sample sizes, age groups studied, and the specific executive function (EF) components assessed.The studies varied considerably in sample size, ranging from 25 to 85 participants.This variability is typical in meta-analyses and will be accounted for in the statistical model.The mean age across studies was 28.5 years, but the age range was broad (5-85 years).The majority of studies (n=24) focused on young adults, while 8 studies included children or age groups, allowing for potential exploration of age-related effects in the analysis.The three most commonly assessed EF components were: Inhibitory Control (n=22); Working Memory (n=18); and Cognitive Flexibility (n=15).This suggests that these three components are central to the investigation of the relationship between bilingualism and EF.The distribution also allows for comparisons between the effects of bilingualism on different EF components.The variability in sample sizes will be addressed using a random-effects model, which accounts for both within-study and betweenstudy variance.The inclusion of studies with diverse age groups allows for potential moderator analyses to examine whether the effect of bilingualism on EF differs across age groups.The focus on three core EF components (inhibitory control, working memory, and cognitive flexibility) provides a clear framework for analyzing and interpreting the results in relation to specific cognitive processes.Overall, Table bilingualism and executive function (EF) by examining whether certain factors influence the strength of this relationship.The analysis reveals a significant moderation effect (p = 0.015), indicating that the impact of bilingualism on EF varies depending on the specific EF component being measured.Inhibitory control and cognitive flexibility show stronger effect sizes (Hedges' g = 0.23 and 0.21, respectively)compared to working memory (Hedges' g = 0.12).This suggests that bilingualism may have a more pronounced beneficial effect on the ability to suppress irrelevant information and switch between tasks, compared to its effect on the ability to hold and manipulate information in mind.For these the analyses did not reveal any significant moderation effects (p-values > 0.05).This suggests that the positive effect of bilingualism on EF is relatively consistent across different age groups, levels of language proficiency, and socioeconomic backgrounds.In other words, the "bilingual advantage" in EF seems to be present regardless of whether individuals are young or old, highly proficient in their second language or not, or from advantaged or disadvantaged socioeconomic backgrounds.

The
BECA hypothesis has garnered considerable empirical support from a range of studies employing diverse methodologies.Behavioral studies have consistently demonstrated that bilingual individuals outperform their monolingual peers on tasks tapping into various aspects of EF, including inhibitory control (e.g., Stroop task, Simon task), working memory (e.g., n-back task, complex span tasks), and cognitive flexibility (e.g., task-switching paradigms)(Adesope et  al., 2010; Bialystok, 2017).Neuroimaging studies have further corroborated these findings, revealing that bilinguals exhibit greater activation in brain regions associated with executive control, such as the prefrontal cortex and anterior cingulate cortex, during tasks requiring conflict resolution and cognitive flexibility(Abutalebi, 2007).Moreover, structural neuroimaging studies have shown that bilingualism is associated with increased gray matter volume in these regions, suggesting that the constant engagement of cognitive control mechanisms may lead to structural changes in the brain(Mechelli et al., 2004).The findings of the present meta-analysis align seamlessly with the BECA hypothesis.The overall positive effect of bilingualism on EF, coupled with the stronger effects observed for inhibitory control and cognitive flexibility, strongly suggests that the constant management of two language systems fosters superior cognitive control abilities.The fact that these effects were observed across different age groups, language proficiency levels, and socioeconomic backgrounds further underscores the robustness and generalizability of the BECA advantage.While the BECA hypothesis provides a compelling framework for understanding the cognitive benefits of bilingualism, the specific mechanisms through which bilingualism influences EF remain an active area of research.Bilinguals constantly face the challenge of resolving conflict between competing linguistic representations.This ongoing conflict monitoring and resolution may lead to the refinement of neural networks responsible for conflict detection and response inhibition, resulting in enhanced inhibitory control in both linguistic and non-linguistic contexts.The need to selectively attend to the relevant language while suppressing the irrelevant one may strengthen bilinguals' attentional control abilities.This enhanced attentional control may facilitate the filtering of irrelevant information and the maintenance of focus on task-relevant goals, contributing to improved performance on tasks requiring sustained attention and selective attention.The frequent switching between languages in bilinguals may promote greater cognitive flexibility by enhancing the ability to shift attention between different mental sets and adapt to changing task demands.This enhanced cognitive flexibility may facilitate multitasking, problem-solving, and creative thinking.The constant engagement of executive control processes in bilingual language processing may lead to the strengthening of the neural networks underlying these processes.This strengthened executive control network may then be more readily recruited for non-linguistic tasks, resulting in improved EF performance.The absence of a significant moderation effect by age in the present meta-analysis underscores a crucial aspect of the bilingual advantage in executive function (EF) -its potential persistence across the lifespan.This observation aligns seamlessly with the cognitive reserve hypothesis, which proposes that bilingualism may bolster cognitive resilience and act as a buffer against age-related cognitive decline.The cognitive reserve hypothesis, eloquently articulated by Stern (2009), posits that engaging in intellectually stimulating activities throughout life, such as bilingualism, can build up a cognitive reserve.This reserve acts as a buffer, enabling individuals to better withstand the neural challenges associated with aging and pathology.Our meta-analysis findings lend credence to this hypothesis, suggesting that the benefits of bilingualism on EF are not confined to a specific age group or developmental stage.Instead, they appear to extend across the lifespan, potentially offering cognitive protection from early childhood through to older adulthood.This has profound implications for our understanding of cognitive aging.The traditional view of cognitive decline as an inevitable and irreversible consequence of aging is being challenged by research highlighting the potential for cognitive plasticity and resilience.The present findings suggest that bilingualism may be one such factor contributing to this plasticity, fostering cognitive reserve that helps maintain EF even as individuals age.
process.It involves continuous language learning, use, and adaptation, which may have distinct cognitive consequences at different stages of life.During early childhood, bilingualism may enhance the development of EF by providing children with rich opportunities for language switching, conflict resolution, and selective attention.These experiences may strengthen the neural networks underlying executive control, leading to a cognitive advantage that persists throughout life.In adolescence and adulthood, bilingualism may continue to bolster EF by promoting cognitive flexibility and the ability to switch between different tasks and mental sets.The constant juggling of two language systems may also help maintain cognitive reserve and protect against age-related cognitive decline.In older adulthood, the cognitive reserve built up through a lifetime of bilingual experience may become particularly crucial.It may help individuals compensate for age-related brain changes and maintain EF, potentially delaying the onset of dementia or other cognitive impairments.While the meta-analysis findings suggest a persistent bilingual advantage in EF across the lifespan, the precise mechanisms underlying this advantage remain an area of active investigation.Bilingualism may promote neural plasticity, the brain's ability to reorganize and adapt in response to experience.This enhanced plasticity may lead to greater cognitive reserve and resilience in the face of aging and pathology.The constant management of two language systems may lead to strengthening and refinement of the brain's executive control network, which is crucial for EF.This network, encompassing regions such as the prefrontal cortex and anterior cingulate cortex, plays a key role in attentional control, inhibitory control, and cognitive flexibility.Bilingual individuals may develop compensatory strategies to navigate the complexities of managing two languages.These strategies may involve increased monitoring of their linguistic environment, selective attention to relevant cues, and inhibition of irrelevant information.These compensatory mechanisms may generalize to non-linguistic tasks, contributing to enhanced EF.The intriguing phenomenon of a bilingual advantage in executive function (EF), as evidenced by the present meta-analysis and a wealth of prior research, has prompted neuroscientists to delve into the neural mechanisms that might underpin this cognitive enhancement.The exploration of the brain's structural and functional adaptations in bilingual individuals has yielded compelling insights into how the constant juggling of two language systems shapes the neural architecture supporting cognitive control.Neuroimaging studies, particularly those employing functional magnetic resonance imaging (fMRI), have consistently demonstrated that bilingual individuals exhibit heightened activation in key brain regions associated with executive control during tasks that demand conflict resolution and cognitive flexibility.
neural data, but the behavioral findings are consistent with the neuroimaging literature.The observed bilingual advantage in inhibitory control and cognitive flexibility, which are closely associated with the PFC and ACC, suggests that the functional and structural changes in these brain regions may contribute to the enhanced cognitive control abilities in bilingual individuals.Furthermore, the lack of moderation by age in the meta-analysis aligns with the notion that bilingualism may promote lifelong plasticity in the brain.The continuous engagement of executive control processes in language management may lead to sustained neural adaptations, potentially counteracting age-related cognitive decline and preserving EF in older bilingual adults.While the existing neuroimaging literature provides valuable insights into the neural mechanisms of the bilingual advantage in EF, future research is needed to further elucidate the complex interplay between bilingualism, brain function, and cognitive control.The integration of behavioral and neuroimaging measures in longitudinal and experimental studies could shed light on the causal relationship between bilingualism and neural adaptations, as well as the specific brain networks and processes involved in the transfer of cognitive benefits from language to nonlinguistic domains.Moreover, future research should explore the potential influence of individual differences in bilingual experience, such as age of acquisition, language proficiency, and language switching frequency, on neural adaptations and cognitive outcomes.Understanding these individual variations could help tailor interventions and educational practices to maximize the cognitive benefits of bilingualism for different populations.The converging evidence from behavioral and neuroimaging studies suggests that bilingualism shapes the brain in ways that support enhanced executive function.The constant juggling of two language systems appears to foster functional and structural adaptations in key brain regions associated with cognitive control, leading to improved abilities in inhibitory control, cognitive flexibility, and potentially other aspects of EF.Future research integrating behavioral and neuroimaging measures holds the promise of unraveling the complex neural mechanisms underlying the bilingual advantage in cognitive control and informing interventions that harness the power of bilingualism to promote cognitive health and well-being across the lifespan.The moderator analyses conducted in this metaanalysis have unearthed a fascinating pattern: the cognitive benefits associated with bilingualism are not uniform across all facets of executive function (EF).
Cognitive flexibility, another core component of EF, entails the ability to shift attention between different tasks or mental sets and adapt to changing demands.This mental agility is crucial for navigating complex and dynamic environments, allowing us to switch gears, re-evaluate situations, and adjust our strategies as needed.Bilingualism, by its very nature, demands a high degree of cognitive flexibility.Bilingual individuals must constantly switch between their two languages, often within the same conversation or even sentence.This frequent language switching requires the ability to rapidly shift attentional focus, access different linguistic representations, and adapt to the changing linguistic context.The present meta-analysis findings support the notion that this constant language-switching experience may enhance cognitive flexibility.Bilinguals outperformed monolinguals on tasks that require shifting between different rules or perspectives, such as the Wisconsin card sorting test and the dimensional change card sort (Prior, 2010).This suggests that the bilingual brain becomes more adept at adapting to new information and changing task demands, potentially due to the strengthening of neural pathways involved in attentional control and cognitive shifting.Furthermore, research suggests that the bilingual advantage in cognitive flexibility may extend beyond the purely linguistic domain.Bilinguals have been shown to outperform monolinguals on tasks that require switching between different visual
that, on average, bilingual individuals demonstrate superior EF performance compared to their monolingual counterparts.The effect size, as measured by Hedges' g, is 0.18.This is generally considered a small effect size, suggesting that the advantage conferred by bilingualism, while present, is not substantial in magnitude.The p-value associated with this effect is less than 0.001.This highly significant p-value provides strong evidence against

Table 2 .
The overall effect of bilingualism on executive function.

Table 3 .
Moderator analyses of the effect of bilingualism on executive function.

Table 4 .
Assessment of publication bias.