Bilingual advantages in executive functioning: problems in convergent validity, discriminant validity, and the identification of the theoretical constructs

Examining the relation between bilingualism and age of symptom onset in frontotemporal dementia

Bilingualism is thought to confer advantages in executive functioning, thereby contributing to cognitive reserve and a later age of dementia symptom onset. While the relation between bilingualism and age of onset has been explored in Alzheimer's dementia, there are few studies examining bilingualism as a contributor to cognitive reserve in frontotemporal dementia (FTD). In line with previous findings, we hypothesized that bilinguals with behavioral variant FTD would be older at symptom onset compared to monolinguals, but that no such effect would be found in patients with nonfluent/agrammatic variant primary progressive aphasia (PPA) or semantic variant PPA. Contrary to our hypothesis, we found no significant difference in age at symptom onset between monolingual and bilingual speakers within any of the FTD variants, and there were no notable differences on neuropsychological measures. Overall, our results do not support a protective effect of bilingualism in patients with FTD-spectrum disease in a U.S. based cohort.

Bilingual neurocognitive resiliency, vulnerability, and Alzheimer's disease biomarker correlates in Latino older adults enrolled in the Health and Aging Brain Study - Health Disparities (HABS-HD)

INTRODUCTION

The effects of bilingualism on neuropsychological test performance in bilinguals with and without cognitive impairment are not well-understood and are relatively limited by small sample sizes of Latinos.

METHODS

Using analysis of covariance (ANCOVA), we explored patterns of cognitive performance and impairment across a large sample of community-dwelling bilingual and monolingual Latino older adults with (n = 180) and without (n = 643) mild cognitive impairment (MCI) enrolled in HABS-HD.

RESULTS

Bilinguals demonstrated cognitive resiliency in the form of significantly better performance on the Trail Making Test and Digit Symbol Substitution Test, observed across the cognitively unimpaired and MCI groups. In contrast, bilinguals demonstrated cognitive vulnerability in the form of significantly poorer performance and higher impairment rates on phonemic fluency in the MCI phase, only. Follow-up analyses revealed less balanced bilinguals demonstrated poorer performance and higher impairment rates on this measure, supported by lower levels of plasma Aβ 42/40.

DISCUSSION

Patterns of cognitive performance and impairment differ as a function of bilingualism. Bilingualism must be considered when evaluating cognitive and biomarker outcomes in Latino older adults.

Highlights

Latino bilinguals perform better on measures of processing speed and coding.Latino bilinguals with MCI demonstrate cognitive vulnerability in verbal fluency.Less balanced bilinguals demonstrate greatest vulnerability anchored by Aβ 42/40.

The Development of Flexible Problem Solving: An Integrative Approach

Flexible problem solving, the ability to deal with currently goal-irrelevant information that may have been goal-relevant in previous, similar situations, plays a prominent role in cognitive development and has been repeatedly investigated in developmental research. However, this research, spanning from infancy to the school years, lacks a unifying framework, obscuring the developmental timing of flexible problem solving. Therefore, in this review paper, previous findings are gathered, organized, and integrated under a common framework to unveil how and when flexible problem solving develops. It is showed that the development of flexible problem solving coincides with increases in executive functions, that is, inhibition, working memory and task switching. The analysis of previous findings shows that dealing with goal-irrelevant, non-salient information received far more attention than generalizing in the presence of goal-irrelevant, salient information. The developmental timing of the latter can only be inferred from few transfer studies, as well as executive functions, planning and theory of mind research, to highlight gaps in knowledge and sketch out future research directions. Understanding how transfer in the presence of seemingly relevant but truly irrelevant information develops has implications for well-balanced participation in information societies, early and lifespan education, and investigating the evolutionary trajectory of flexible problem solving.

Language athletes: Dual-language code-switchers exhibit inhibitory control advantages

Recent studies have begun to examine bilingual cognition from more nuanced, experienced-based perspectives. The present study adds to this body of work by investigating the potential impact of code-switching on bilinguals’ inhibitory control abilities. Crucially, our bilingual participants originated from a predominantly dual-language environment, the interactional context which is believed to require (and therefore, potentially train) cognitive control processes related to goal-monitoring and inhibition. As such, 266 French Canadian bilinguals completed an online experiment wherein they were asked to complete a domain-general (Flanker) and a language-specific (bilingual Stroop) inhibitory control task, as well as extensive demographic and language background questionnaires. Stepwise multiple regressions (including various potential demographic and linguistic predictors) were conducted on the participants’ Flanker and Stroop effects. The results indicated that the bilinguals’ propensity to code-switch consistently yielded significant positive (but unidirectional) inhibitory control effects: dual-language bilinguals who reported more habitual French-to-English switching exhibited better goal-monitoring and inhibition abilities. For the language-specific task, the analysis also revealed that frequent unintentional code-switching may mitigate these inhibition skills. As such, the findings demonstrate that dual-language code-switchers may experience inhibitory control benefits, but only when their switching is self-reportedly deliberate. We conclude that the bilinguals’ interactional context is thus of primary importance, as the dual-language context is more conducive to intentional code-switching. Overall, the current study highlights the importance of considering individualistic language experience when it comes to examining potential bilingual executive functioning advantages.

Bilingualism can cause enhanced monitoring and occasional delayed responses in a flanker task

Complex cognitive tasks require different stages of processing (i.e. conflict monitoring, attentional resource allocation and stimulus categorisation). Performance differences between bilinguals and monolinguals on conflict tasks can be affected by the balance of these sub-processes. The current study investigated the effect of bilingualism on these sub-processes during a conflict task with medium monitoring demand. Behavioural responses and evoked potentials from bilinguals and monolinguals were examined during a flanker task with 25% incongruent trials. Behavioural differences were analysed by means of averaged response times and exponentially modified Gaussian analyses of response time distributions. For evoked potentials, the study focussed on N2 (reflecting conflict monitoring) and P3 responses (reflecting allocation of attentional resources for cognitive control). Bilinguals had significantly longer response distribution tails compared to monolinguals. Bilinguals were shown to have a more pronounced N2 and smaller P3 compared to monolinguals, independent of condition, suggesting a different balance of sub-processes for the two groups. This suggests that bilinguals were engaged more strongly in monitoring processes, leading to the allocation of fewer attentional resources during stimulus categorisation. Additionally, the P3 amplitudes were negatively related with the length of response distribution tails for bilinguals. These results are consistent with enhanced conflict monitoring in bilinguals that led to reduced engagement of attentional resources for stimulus categorisation. This enhanced conflict monitoring could lead to occasional extremely slow responses. Thus, the bilingual experience appears to impact the balance of cognitive control processes during conflict tasks, which might only be reflected in a minority of responses.

What Is a Language? Who Is Bilingual? Perceptions Underlying Self-Assessment in Studies of Bilingualism

Research on the cognitive consequences of bilingualism typically proceeds by labeling participants as "monolingual" or "bilingual" and comparing performance on some measures across these groups. It is well-known that this approach has led to inconsistent results. However, the approach assumes that there are clear criteria to designate individuals as monolingual or bilingual, and more fundamentally, to determine whether a communication system counts as a unique language. Both of these assumptions may not be correct. The problem is particularly acute when participants are asked to classify themselves or simply report how many languages they speak. Participants' responses to these questions are shaped by their personal perceptions of the criteria for making these judgments. This study investigated the perceptions underlying judgments of bilingualism by asking 528 participants to judge the extent to which a description of a fictional linguistic system constitutes a unique language and the extent to which a description of a fictional individual's linguistic competence qualifies that person as bilingual. The results show a range of responses for both concepts, indicating substantial ambiguity for these terms. Moreover, participants were asked to self-classify as monolingual or bilingual, and these decisions were not related to more objective information regarding the degree of bilingual experience obtained from a detailed questionnaire. These results are consistent with the notion that bilingualism is not categorical and that specific language experiences are important in determining the criteria for being bilingual. The results impact interpretations of research investigating group differences on the cognitive effects of bilingualism.

Words Versus Pictures: Bilingual Performance on Verbal and Pictorial Measures of Executive Functions

PURPOSE

This study examined bilinguals' performance on functional executive function map tasks such as the Zoo Map from the Behavioural Assessment of the Dysexecutive Syndrome and the extent to which working memory, set-shifting, and inhibition measures predicted bilinguals' performance on these tasks. Additionally, we explored the utility of pictorial map tasks as a measure of complex executive function in bilinguals. We hypothesized that bilinguals would perform better on the pictorial map tasks due to the reduced language processing demand.

METHOD

The analyses included 131 bilingual young adults who completed a comprehensive language history questionnaire, an English proficiency test, a battery of working memory and executive function tasks, and verbal and pictorial map tasks.

RESULTS

Contrary to predictions, bilinguals' performance on the verbal maps did not differ significantly from that on the pictorial maps. Two multiple regression models significantly predicted performance on the verbal and pictorial maps, accounting for 7%-25% of the variance in the map scores. Working memory and interference control were the most prominent predictors within these models.

CONCLUSIONS

In our study, bilinguals' performance on the verbal maps did not differ significantly from that on the pictorial maps. Additionally, English proficiency did not correlate with the participants' verbal map scores. These results suggest that executive function map tasks (e.g., the Zoo Map) are a useful clinical tool for assessing executive function in bilinguals. The findings of this study are discussed in light of the current literature on executive functions in bilinguals.

Second Language Proficiency Modulates the Dependency of Bilingual Language Control on Domain-General Cognitive Control

The relationship between bilingual language control and domain-general cognitive control has been a hot topic in the research field of bilingualism. Previous studies mostly examined the correlation between performances of bilinguals in language control tasks and that in domain-general cognitive control tasks and came to the conclusions that they overlap, partially overlap, or are qualitatively different. These contradictory conclusions are possibly due to the neglect of the moderating effect of second language (L2) proficiency, that is, the relationship between bilingual language control and domain-general cognitive control might vary with the L2 proficiency of bilinguals. To examine this hypothesis, we recruited 36 unbalanced Chinese-English bilinguals to perform the Simon task (to assess domain-general cognitive control), Oxford Placement Test (to assess L2 proficiency), and picture naming tasks in single-and dual-language contexts (to evoke local and global language control). We find that Simon scores positively predicted switching costs in bilinguals with low L2 proficiency, but not in bilinguals with high L2 proficiency. Furthermore, Simon scores positively predicted mixing costs in bilinguals with high L2 proficiency, but not in bilinguals with low L2 proficiency. These results verify the moderating effect of L2 proficiency on the relationship between bilingual language control and domain-general cognitive control, that is, bilinguals with more proficient L2 rely on domain-general cognitive control less for local language control and more for global language control. This may imply a shift from local to global for the dependency of bilingual language control on domain-general cognitive control during the L2 development of bilinguals.

How does bilingualism modify cognitive function? Attention to the mechanism

It has been claimed that bilingual experience leads to an enhancement of cognitive control across the lifespan, a claim that has been investigated by comparing monolingual and bilingual groups performing standard executive function (EF) tasks. The results of these studies have been inconsistent, however, leading to controversy over the essential assumptions underlying the research program, namely, whether bilingualism produces cognitive change. We argue that the source of the inconsistency is not in the evidence but rather in the framework that has typically been used to motivate the research and interpret the results. We examine the componential view of EF with its central role for inhibition and argue that it provides a poor fit to both bilingual experience and the results of these studies. As an alternative, we propose a more holistic account based on attentional control that overrides the processes in the componential model of EF and applies to a wider range of tasks. The key element in our account is that behavioral differences between monolingual and bilingual individuals reflect differences in the efficiency and deployment of attentional control between the two language groups. In support of this point we show how attentional control provides a more satisfactory account for a range of findings that cannot reasonably be attributed to inhibition. We also suggest that group differences will emerge only when the attentional demands of a task exceed the control abilities of one of the groups, regardless of the EF components involved. We then review literature from across the lifespan to evaluate the extent to which this account is consistent with existing evidence, and conclude with some suggestions on how the field may be advanced by new lines of empirical enquiry.

Do Bilinguals Outperform Monolinguals in Switching Tasks? Contrary Evidence for Nonlinguistic and Linguistic Switching Tasks

The benefits of bilingualism in executive functions are highly debated. Even so, in switching tasks, these effects seem robust, although smaller than initially thought (Gunnerud et al., 2020; Ware et al., 2020). By handling two languages throughout their lifespan, bilinguals appear to train their executive functions and show benefits in nonlinguistic switching tasks compared to monolinguals. Nevertheless, because bilinguals need to control for the interference of another language, they may show a disadvantage when dealing with task-switching paradigms requiring language control, particularly when those are performed in their less dominant language. The present work explored this issue by studying bilingualism's effects on task switching within the visual and language domains. On the one hand, our results show that bilinguals were overall faster and presented reduced switch costs compared to monolinguals when performing perceptual geometric judgments with no time for task preparation. On the other hand, no bilingual advantage was found when a new sample of comparable bilinguals and monolinguals completed a within-language switching task. Our results provide clear evidence favoring the bilingual advantage, yet only when the task imposes greater executive demands and does not involve language control.

Expertise, ecosystem, and emergentism: Dynamic developmental bilingualism

Bilingual language representation and cognitive control effects may reflect the dynamic interactions among the complex learning environment, genotype of the individual, and developing cognitive abilities. In this paper we propose a framework considering such interactions. Specifically, we present a nonlinear, developmentally-oriented perspective in which each individual represents a developmental trajectory in multidimensional space. These trajectories focus on the cognitive ecosystem (and how said ecosystem changes over time) and individual expertise (which affects and is affected by the ecosystem). The interactions between ecosystem and expertise lead to the emergence of a system that is built to handle the communicative needs of the individual.

Absence of a bilingual cognitive flexibility advantage: A replication study in preschoolers

Some studies have found a bilingual advantage in children's executive function and some failed to find a bilingual advantage. For example, the results of a previous study by Bialystok & Martin (2004) indicated that Chinese-English bilingual preschool children outperformed English monolingual children in solving the dimensional change card sort (DCCS). The goal of our study was to replicate this study using the same dimensional change card sort task. We also tested our participants on vocabulary and digit span. Our participants were 40 English monolingual and 40 Mandarin-English bilingual children and were within the same age range as the children in Bialystok & Martin's (2004) study. Our results showed no difference between bilinguals and monolinguals. Both groups of children in the present study performed better than those in Bialystok and Martin (2004), but the bigger difference was between the two groups of monolinguals. These results suggest that it could be important to attend to monolingual children's performance, in addition to bilinguals', when testing for a bilingual advantage. Our replication study is important because it helps with clarifying the validity of studies finding a bilingual advantage and to help future researchers know whether to build on their findings or not.

Is Oral Bilingualism an Advantage for Word Learning in Children With Hearing Loss?

Purpose The purpose of this study was to examine whether oral bilingualism could be an advantage for children with hearing loss when learning new words. Method Twenty monolingual and 13 bilingual children with hearing loss were compared with each other and with 20 monolingual and 20 bilingual children with normal hearing on receptive vocabulary and on three word-learning tasks containing nonsense words in familiar (English and Spanish) and unfamiliar (Arabic) languages. We measured word learning on the day of the training and retention the next day using an auditory recognition task. Analyses of covariance were used to compare performance on the word learning tasks by language group (monolingual vs. bilingual) and hearing status (normal hearing vs. hearing loss), controlling for age and maternal education. Results No significant differences were observed between monolingual and bilingual children with and without hearing loss in any of the word-learning task. Children with hearing loss performed more poorly than their hearing peers in Spanish word retention and Arabic word learning and retention. Conclusions Children with hearing loss who grew up being exposed to Spanish did not show higher or lower word-learning abilities than monolingual children with hearing loss exposed to English only. Therefore, oral bilingualism was neither an advantage nor a disadvantage for word learning. Hearing loss negatively affected performance in monolingual and bilingual children when learning words in languages other than English (the dominant language). Monolingual and bilingual children with hearing loss are equally at risk for word-learning difficulties and vocabulary size matters for word learning.

Poorer clinical outcomes for older adult monolinguals when matched to bilinguals on brain health

Previous studies have reported bilingualism to be a proxy of cognitive reserve (CR) based on evidence that bilinguals express dementia symptoms ~ 4 years later than monolinguals yet present with greater neuropathology at time of diagnosis when clinical levels are similar. The current study provides new evidence supporting bilingualism's contribution to CR using a novel brain health matching paradigm. Forty cognitively normal bilinguals with diffusion-weighted magnetic resonance images recruited from the community were matched with monolinguals drawn from a pool of 165 individuals in the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. White matter integrity was determined for all participants using fractional anisotropy, axial diffusivity, and radial diffusivity scores. Propensity scores were obtained using white matter measures, sex, age, and education as predictive covariates, and then used in one-to-one matching between language groups, creating a matched sample of 32 participants per group. Matched monolinguals had poorer clinical diagnoses than that predicted by chance from a theoretical null distribution, and poorer cognitive performances than matched bilinguals as measured by scores on the MMSE. The findings provide support for the interpretation that bilingualism acts as a proxy of CR such that monolinguals have poorer clinical and cognitive outcomes than bilinguals for similar levels of white matter integrity even before clinical symptoms appear.

Characterizing Bilingual Effects on Cognition: The Search for Meaningful Individual Differences

A debate over the past decade has focused on the so-called bilingual advantage-the idea that bilingual and multilingual individuals have enhanced domain-general executive functions, relative to monolinguals, due to competition-induced monitoring of both processing and representation from the task-irrelevant language(s). In this commentary, we consider a recent study by Pot, Keijzer, and de Bot (2018), which focused on the relationship between individual differences in language usage and performance on an executive function task among multilingual older adults. We discuss their approach and findings in light of a more general movement towards embracing complexity in this domain of research, including individuals' sociocultural context and position in the lifespan. The field increasingly considers interactions between bilingualism/multilingualism and cognition, employing measures of language use well beyond the early dichotomous perspectives on language background. Moreover, new measures of bilingualism and analytical approaches are helping researchers interrogate the complexities of specific processing issues. Indeed, our review of the bilingualism/multilingualism literature confirms the increased appreciation researchers have for the range of factors-beyond whether someone speaks one, two, or more languages-that impact specific cognitive processes. Here, we highlight some of the most salient of these, and incorporate suggestions for a way forward that likewise encompasses neural perspectives on the topic.

Autism Traits Predict Self-reported Executive Functioning Deficits in Everyday Life and an Aversion to Exercise

Are Autism Quotient (AQ) scores related to executive functioning (EF)? We sampled 200 students of normal intelligence and examined the relationship between AQ scores and: (a) 5 self-ratings of EF, (b) 5 performance-based measures of EF, and (c) 5 types of activities or experiences that are assumed to recruit EF and sometimes enhance EF. Our findings reveal that as AQ scores increase, self-rated EF ability decreases. AQ scores and self-reported EF measures do not correlate with objective EF task performance. Furthermore, AQ scores were shown to be negatively associated with many specific types of physical activity. As AQ scores increase, individuals report fewer positive reasons for exercise and more rationalizations for not engaging in more exercise.

Cognitive Persistence and Executive Function in the Multilingual Brain During Aging

Researchers have debated the extent to which the experience of speaking more than two languages induces long-term neuroplasticity that protects multilinguals from the adverse cognitive effects of aging. In this review, I propose a novel theory that multilingualism affects cognitive persistence, the application of effort to improve performance on challenging tasks. I review recent evidence demonstrating that the cingulo-opercular network, consisting of the bilateral inferior frontal gyrus (IFG) and dorsal anterior cingulate cortex (dACC), supports cognitive persistence. I then show that this same network is involved in multilingual language control and changes with multilingual language experience. While both early and late multilinguals exhibit differences in the cingulo-opercular network compared to monolinguals, I find that early multilinguals have a pattern of decreased dACC activity and increased left IFG activity that may enable more efficient cognitive control, whereas late multilinguals show larger dACC responses to conflict that may be associated with higher cognitive persistence. I further demonstrate that multilingual effects on the cingulo-opercular network are present in older adults and have been implicated in the mitigation of cognitive symptoms in age-related neurodegenerative disorders. Finally, I argue that mixed results in the literature are due, in part, to the confound between cognitive persistence and ability in most executive function tasks, and I provide guidance for separating these processes in future research.

Meta-Analysis Reveals a Bilingual Advantage That Is Dependent on Task and Age

Debate continues on whether a bilingual advantage exists with respect to executive functioning. This report synthesized the results of 170 studies to test whether the bilingual advantage is dependent on the task used to assess executive functioning and the age of the participants. The results of the meta-analyses indicated that the bilingual advantage was both task- and age-specific. Bilinguals were significantly faster than monolinguals (Hedges' g values ranged from 0.23 to 0.34), and significantly more accurate than monolinguals (Hedges' g values ranged between 0.18 and 0.49) on four out of seven tasks. Also, an effect of age was found whereby the bilingual advantage was larger for studies comprising samples aged 50-years and over (Hedges' g = 0.49), compared to those undertaken with participants aged between 18 and 29 years (Hedges' g = 0.12). The extent to which the bilingual advantage might be due to publication bias was assessed using multiple methods. These were Egger's Test of Asymmetry, Duval and Tweedie's Trim and Fill, Classic Fail-Safe N, and PET-PEESE. Publication bias was only found when using Egger's Test of Asymmetry and PET-PEESE method, but not when using the other methods. This review indicates that if bilingualism does enhance executive functioning, the effects are modulated by task and age. This may arise because using multiple languages has a highly specific effect on executive functioning which is only observable in older, relative to younger, adults. The finding that publication bias was not uniformly detected across the different methods raises questions about the impact that unpublished (or undetected) studies have on meta-analyses of this literature.

No Bilingual Benefits Despite Relations Between Language Switching and Task Switching

Previous research has shown that bilingual children outperform monolinguals on tasks testing cognitive control. Bilinguals' enhanced cognitive control is thought to be caused by the necessity to exert more language control in bilingual compared to monolingual settings. Surprisingly, between-group research of cognitive effects of bilingualism is hardly ever combined with within-group research that investigates relationships between language control and cognitive control. The present study compared 27 monolingual Dutch and 27 bilingual Turkish-Dutch children matched on age and fluid intelligence on their performance in a nonverbal switching task. Within the group of bilinguals, the relationship between nonverbal switching and language switching was examined. The results revealed no between-group differences on nonverbal switching. Within the bilingual sample, response times in the language switching and nonverbal switching tasks were related, although no relationships were found between accuracy, switching cost and mixing cost on both tasks. The results support the hypothesis that children utilize domain-general cognitive control in language switching, but this relationship does not entail that bilinguals have better cognitive control than monolinguals.

Cognitive control regions are recruited in bilinguals' silent reading of mixed-language paragraphs

When switching languages, bilinguals recruit a language control network that overlaps with brain regions known to support general cognitive control, but it is unclear whether these same regions are recruited in passive comprehension of language switches. Using fMRI with a blocked design, 24 Spanish-English bilinguals silently read 36 paragraphs in which the default language was Spanish or English, and that had either (1) no switches, (2) function word switches or (3) content word switches. Relative to no switches, function switches activated the right IFG, bilateral MFG, and left IPL/SMG. In contrast, switching on content words produced limited neural switching costs observed only in the left IFG. Switching into the dominant language was more costly in the right SMG than switching into the nondominant language, and neural switching costs were correlated with switching costs in the dominant language in cued picture-naming. Seemingly passive reading comprehension involves brain regions known to support cognitive control in active switching during production, possibly reflecting the operation of a modality-general switch mechanism.

Interference scores have inadequate concurrent and convergent validity: Should we stop using the flanker, Simon, and spatial Stroop tasks?

BACKGROUND

Two-hundred one college undergraduates completed four nonverbal interference tasks (Simon, spatial Stroop, vertical Stroop, and flanker) and trait scales of self-control and impulsivity. Regression analyses tested 11 predictors of the composite interference scores derived from three of the four tasks and each task separately. The purpose of the study was to examine the relationships between laboratory measures of self-control, self-report measures, and the degree to which control might be related to extensive experience in activities that logically require self-control.

RESULTS

Fluid intelligence and sex were significant predictors of the composite measure, but bilingualism, music training, video gaming, mindfulness/meditation, self-control, impulsivity, SES, and physical exercise were not.

CONCLUSIONS

Common laboratory measures of inhibitory control do not correlate with self-reported measures of self-control or impulsivity and consequently appear to be measuring different constructs. Bilingualism, mindfulness/meditation, playing action video games, and music training or performance provide weak and inconsistent improvements to laboratory measures of interference control. Flanker, Simon, and spatial Stroop effects should not be used or interpreted as measures of domain-general inhibitory control.

Is there a bilingual advantage on interference-control tasks? A multiverse meta-analysis of global reaction time and interference cost

A contentious issue in contemporary psycholinguistics is whether bilingualism enhances executive functions. Here, we report a meta-analysis of 80 studies (253 effect sizes) comparing performance of monolinguals and bilinguals on non-verbal interference-control tasks, while examining potential moderators of effects on two dependent variables (DVs): global reaction time (RT) and interference cost. We used a multiverse approach to determine how robust conclusions were to several dataset construction and analysis decisions. In our "preferred" analysis, using a broad definition of bilinguals and standard versions of interference-control tasks, there was a very small but significant bilingual advantage for global RT (g =.13), which became non-significant once corrected for publication bias. For interference cost, there was a very small but significant bilingual advantage (g =.11). Effects were not significantly moderated by task or participant age, but were moderated by an interaction between age of second language acquisition (AoA) and the DV. Unexpectedly, larger effect sizes for interference cost were observed for studies involving bilinguals with late as opposed to early AoA. The multiverse analysis produced results largely consistent with the preferred analysis, confirming our conclusion that evidence for a bilingual advantage on interference-control tasks is weak.

The effects of dual language exposure on executive function in Spanish-English bilingual children with different language abilities

The current study examined the effects of dual language exposure on executive function in 5- to 11-year-old Spanish-English bilingual children with different language skills. Dual language exposure was measured via parent report and was operationalized as the proportion of time spent in an environment where both English and Spanish were present. Executive function was measured via the Dimensional Change Card Sort (DCCS) task. Shifting costs, switching costs, and mixing costs were derived to index executive function performance. A significant interaction between extent of dual language exposure and language skills was observed such that children showed smaller shifting and mixing costs with increased dual language input as their language skills increased. The results suggest a graded effect of dual language exposure on executive function, where a robust language system may be required for dual language exposure to influence executive function.

On the ambiguity regarding the relationship between sequential congruency effects, bilingual advantages in cognitive control, and the disengagement of attention

Grundy, Bialystok, and colleagues have reported that at short response-stimulus intervals bilinguals have smaller sequential congruency effects in flanker tasks compared to monolinguals. They interpret these differences to mean that bilinguals are more efficient at disengaging attentional control. Ten empirical studies are presented that show no differences between bilinguals and monolinguals under conditions that produced robust sequential congruency effects. These null results are discussed with respect to the rate at which sequential congruency effects dissipate and the fact these effects are not adaptive in the sense of improving overall performance. Arguments made by Goldsmith and Morton [1] that smaller sequential congruency effects should not be interpreted as "advantages" are extended. Evidence is also presented that neither simple congruency effects, nor sequential congruency effects, correlate across tasks. This lack of convergent validity is inconsistent with the hypothesis that either provides a measure of domain-general control that could underlie an advantage accrued through experience in switching languages. Results from other tasks purporting to show bilingual advantages in the disengagement of attention are also reviewed. We conclude that sequential congruency effects in nonverbal interference tasks and differences in the rate of disengaging attention are unlikely to contribute to our understanding of bilingual language control and that future research might productively examine differences in proactive rather than reactive control.

The Bidirectional in Bilingual: Cognitive, Social and Linguistic Effects of and on Third-Age Language Learning

Bilingualism has been put forward as a life experience that, similar to musical training or being physically active, may boost cognitive performance and slow down age-related cognitive decline. In more recent years, bilingualism has come to be acknowledged not as a trait but as a highly individual experience where the context of use strongly modulates any cognitive effect that ensues from it (cf. van den Noort et al., 2019). In addition, modulating factors have been shown to interact in intricate ways (Pot, Keijzer and de Bot, 2018). Adding to the complexity is the fact that control processes linked to bilingualism are bidirectional-just as language control can influence cognitive control, individual differences in cognitive functioning often predict language learning outcomes and control. Indeed, Hartsuiker (2015) posited the need for a better understanding of cognitive control, language control as well as the transfer process between them. In this paper, we aim to shed light on the bidirectional and individual cognitive, social and linguistic factors in relation to bilingualism and second language learning, with a special focus on older adulthood: (1) we first show the intricate clustering of modulating individual factors as deterministic of cognitive outcomes of bilingual experiences at the older end of the lifespan; (2) we then present a meta-study of work in the emergent field of third-age language learning, the results of which are related to lifelong bilingualism; (3) objectives (1) and (2) are then combined to result in a blueprint for future work relating cognitive and social individual differences to bilingual linguistic outcomes and vice versa in the context of third-age language learning.

Sequential Multilingualism and Cognitive Abilities: Preliminary Data on the Contribution of Language Proficiency and Use in Different Modalities

This exploratory study focuses on sequential bi-/multilinguals (specifically, nonimmigrant young Dutch native speakers who learned at least one foreign language (FL) at or after the age of 5) and investigates the impact of proficiency-based and amount-of-use-based degrees of multilingualism in different modalities (i.e., speaking, listening, writing, reading) on inhibition, disengagement of attention, and switching. Fifty-four participants completed a comprehensive background questionnaire, a nonverbal fluid intelligence task, a Flanker task, and the Trail Making Test. Correlational and regression analyses considering multilingualism related variables and other variables that may contribute to the cognitive abilities under investigation (e.g., years of formal education, socioeconomic status, physical activity, playing video-games) revealed that only proficiency-based degrees of multilingualism impacted cognitive abilities. Particularly, mean FL writing proficiency affected inhibition (i.e., significant positive flanker effect) and L2 listening proficiency influenced disengagement of attention (i.e., significant negative sequential congruency effect). Our findings suggest that only those speakers who have reached a certain proficiency threshold in more than one FL show a cognitive advantage, which, in our sample, emerged in inhibition only. Furthermore, our study suggests that, regarding the impact of proficiency-based degrees of multilingualism on cognitive abilities, for our participants the writing and listening modalities mattered most.

Attentional Control in Bilingualism: An Exploration of the Effects of Trait Anxiety and Rumination on Inhibition

Bilingual individuals have been reported to show enhanced executive function in comparison to monolingual peers. However, the role of adverse emotional traits such as trait anxiety and rumination in bilingual cognitive control has not been established. Attentional Control Theory holds that anxiety disproportionately impacts processing efficiency (typically measured via reaction time) in comparison to accuracy (performance effectiveness). We administered eye tracking and behavioural measures of inhibition to young, healthy monolingual and highly proficient bilingual adults. We found that trait anxiety was a reliable risk factor for decreased inhibitory control accuracy in bilingual but not monolingual participants. These findings, therefore, indicate that adverse emotional traits may differentially modulate performance in monolingual and bilingual individuals, an interpretation which has implications both for ACT and future research on bilingual cognition.

Training in Language Switching Facilitates Bilinguals' Monitoring and Inhibitory Control

In the present study, we use a training design in two experiments to examine whether bilingual language switching facilitates two components of cognitive control, namely monitoring and inhibitory control. The results of Experiment 1 showed that training in language switching reduced mixing costs and the anti-saccade effect among bilinguals. In Experiment 2, the findings revealed a greater decrease of mixing costs and a smaller decrease of the anti-saccade effect from pre- to post-training for the language switching training group compared to the second language training group. Overall, the results suggest that extensive exercise in monitoring and inhibitory control in an experimental setting may enhance the corresponding components of cognitive control. We discuss these findings in the context of the relationship between bilingual language control and executive control.

Other Language Proficiency Predicts Unique Variance in Verbal Fluency Not Accounted for Directly by Target Language Proficiency: Cross-Language Interference?

The purpose of the study was to investigate cross-language effects in verbal fluency tasks where participants name in English as many exemplars of a target as they can in one minute. A series of multiple regression models were used that employed predictors such as self-rated proficiency in English, self-rated proficiency in a language other than English, a picture naming task used to measure productive vocabulary, the percentage of English use, and the frequency of language switching. The main findings showed that self-rated proficiency in the non-English language accounted for unique variance in verbal fluency that was not accounted for directly by self-rated proficiency in English. This outcome is consistent with cross-language interference, but is also consistent with an account that assumes bilingual disadvantages in verbal fluency and picture naming are due to bilinguals having weaker links between semantic concepts and their phonological form. The present study is also discussed in terms of a broader framework that questions whether domain-general inhibition exists and also whether it plays an important role in bilingual language control.

Predicting attention shifting abilities from self-reported media multitasking

Media multitasking is an increasingly prominent behavior in affluent societies. However, it still needs to be established if simultaneous use of several modes of media content has an influence on higher cognitive functions, such as divided attention. In this study, attention shifting was the primary focus, since switching between tasks is assumed to be necessary for media multitasking. Two tasks, the number-letter and local-global task, were used as measures of switching ability. The cognitive reflections task was included to control for possible effects of intelligence. Results from linear regression analyses showed that higher levels of media multitasking was related to lower switching costs in the two attention-shifting tasks. These findings replicate previous findings suggesting that heavy media multitaskers perform better on select measures of task switching. We suggest two possible explanations for our results: media multitasking may practice skills needed for switching between tasks, or high media multitaskers are choosing this style of technology use due to a dominating personality trait in this group.

The impact of bilingualism on executive functions and working memory in young adults

A bilingual advantage in a form of a better performance of bilinguals in tasks tapping into executive function abilities has been reported repeatedly in the literature. However, recent research defends that this advantage does not stem from bilingualism, but from uncontrolled factors or imperfectly matched samples. In this study we explored the potential impact of bilingualism on executive functioning abilities by testing large groups of young adult bilinguals and monolinguals in the tasks that were most extensively used when the advantages were reported. Importantly, the recently identified factors that could be disrupting the between groups comparisons were controlled for, and both groups were matched. We found no differences between groups in their performance. Additional bootstrapping analyses indicated that, when the bilingual advantage appeared, it very often co-occurred with unmatched socio-demographic factors. The evidence presented here indicates that the bilingual advantage might indeed be caused by spurious uncontrolled factors rather than bilingualism per se. Secondly, bilingualism has been argued to potentially affect working memory also. Therefore, we tested the same participants in both a forward and a backward version of a visual and an auditory working memory task. We found no differences between groups in either of the forward versions of the tasks, but bilinguals systematically outperformed monolinguals in the backward conditions. The results are analysed and interpreted taking into consideration different perspectives in the domain-specificity of the executive functions and working memory.

Different Features of Bilingualism in Relation to Executive Functioning

The notion that the long-term practice of managing two languages is beneficial for the executive control system is an ongoing debate. Criticism have been raised that studies demonstrating a bilingual advantage often suffer from small sample sizes, and do not control for fluid intelligence as a possible confound. Taking those suggested factors into account, focusing on older bilingual age groups and investigating the potential effects of linguistic distances, this study aimed to improve the interpretations of the bilinguals' advantages. Measures of inhibition (Flanker, Stroop, Simon task) and switching (Number-letter, Color-Shape, Local-global task) were collected in participants in the ages 50-75 years (n = 193). Despite a large study sample, results did not support any beneficial effects related to improve processing costs in executive functioning. Sub-analyses of the two different language groups (Swedish-Finnish / Swedish-English) intended to investigate the effect of linguistic distances did not change this outcome. Future studies exploring the potential long-term term effects of bilingualism would benefit from identifying tests of cognitive control with greater ecological validity and include other measures of cognitive functioning. Language learning interventions may also be a promising tool for future research.

Neuroemergentism: A Framework for Studying Cognition and the Brain

There has been virtual explosion of studies published in cognitive neuroscience primarily due to increased accessibility to neuroimaging methods, which has led to different approaches in interpretation. This review seeks to synthesize both developmental approaches and more recent views that consider neuroimaging. The ways in which Neuronal Recycling, Neural Reuse, and Language as Shaped by the Brain perspectives seek to clarify the brain bases of cognition will be addressed. Neuroconstructivism as an additional explanatory framework which seeks to bind brain and cognition to development will also be presented. Despite sharing similar goals, the four approaches to understanding how the brain is related to cognition have generally been considered separately. However, we propose that all four perspectives argue for a form of Emergentism in which combinations of smaller elements can lead to a greater whole. This discussion seeks to provide a synthesis of these approaches that leads to the emergence of a theory itself. We term this new synthesis Neurocomputational Emergentism (or Neuromergentism for short).

Effect of language proficiency on proactive occulo-motor control among bilinguals

We examined the effect of language proficiency on the status and dynamics of proactive inhibitory control in an occulo-motor cued go-no-go task. The first experiment was designed to demonstrate the effect of second language proficiency on proactive inhibitory cost and adjustments in control by evaluating previous trial effects. This was achieved by introducing uncertainty about the upcoming event (go or no-go stimulus). High- and low- proficiency Hindi-English bilingual adults participated in the study. Saccadic latencies and errors were taken as the measures of performance. The results demonstrate a significantly lower proactive inhibitory cost and better up-regulation of proactive control under uncertainty among high- proficiency bilinguals. An analysis based on previous trial effects suggests that high- proficiency bilinguals were found to be better at releasing inhibition and adjustments in control, in an ongoing response activity in the case of uncertainty. To further understand the dynamics of proactive inhibitory control as a function of proficiency, the second experiment was designed to test the default versus temporary state hypothesis of proactive inhibitory control. Certain manipulations were introduced in the cued go-no-go task in order to make the upcoming go or no-go trial difficult to predict, which increased the demands on the implementation and maintenance of proactive control. High- proficiency bilinguals were found to rely on a default state of proactive inhibitory control whereas low- proficiency bilinguals were found to rely on temporary/transient proactive inhibition. Language proficiency, as one of the measures of bilingualism, was found to influence proactive inhibitory control and appears to modulate the dynamics of proactive inhibitory control.

Exploring Different Types of Inhibition During Bilingual Language Production

Multilinguals have to control their languages constantly to produce accurate verbal output. They have to inhibit possible lexical competitors not only from the target language, but also from non-target languages. Bilinguals' training in inhibiting incongruent or irrelevant information has been used to endorse the so-called bilingual advantage in executive functions, assuming a transfer effect from language inhibition to domain-general inhibitory skills. Recent studies have suggested that language control may rely on language-specific inhibitory control mechanisms. In the present study, unbalanced highly proficient bilinguals completed a rapid naming multi-inhibitory task in two languages. The task assessed three types of inhibitory processes: inhibition of the non-target language, inhibition of lexical competitors, and inhibition of erroneous auditory feedback. The results showed an interaction between lexical competition and erroneous auditory feedback, but no interactions with the inhibition of the non-target language. The results suggested that different subcomponents of language inhibition are involved during bilingual language production.

Bilingualism and working memory performance: Evidence from a large-scale online study

The bilingual executive advantage (BEA) hypothesis has attracted considerable research interest, but the findings are inconclusive. We addressed this issue in the domain of working memory (WM), as more complex WM tasks have been underrepresented in the previous literature. First, we compared early and late bilingual vs. monolingual WM performance. Second, we examined whether certain aspects of bilingual experience, such as language switching frequency, are related to bilinguals' WM scores. Our online sample included 485 participants. They filled in an extensive questionnaire including background factors such as bilingualism and second language (L2) use, and performed 10 isomorphic verbal and visuospatial WM tasks that yielded three WM composite scores (visuospatial WM, verbal WM, n-back). For verbal and visuospatial WM composites, the group comparisons did not support the BEA hypothesis. N-back analysis showed an advantage of late bilinguals over monolinguals and early bilinguals, while the latter two groups did not differ. This between-groups analysis was followed by a regression analysis relating features of bilingual experience to n-back performance, but the results were non-significant in both bilingual groups. In sum, group differences supporting the BEA hypothesis were limited only to the n-back composite, and this composite was not predicted by bilingualism-related features. Moreover, Bayesian analyses did not give consistent support for the BEA hypothesis. Possible reasons for the failure to find support for the BEA hypothesis are discussed.

Low and variable correlation between reaction time costs and accuracy costs explained by accumulation models: Meta-analysis and simulations

The underpinning assumption of much research on cognitive individual differences (or group differences) is that task performance indexes cognitive ability in that domain. In many tasks performance is measured by differences (costs) between conditions, which are widely assumed to index a psychological process of interest rather than extraneous factors such as speed-accuracy trade-offs (e.g., Stroop, implicit association task, lexical decision, antisaccade, Simon, Navon, flanker, and task switching). Relatedly, reaction time (RT) costs or error costs are interpreted similarly and used interchangeably in the literature. All of this assumes a strong correlation between RT-costs and error-costs from the same psychological effect. We conducted a meta-analysis to test this, with 114 effects across a range of well-known tasks. Counterintuitively, we found a general pattern of weak, and often no, association between RT and error costs (mean r = .17, range -.45 to .78). This general problem is accounted for by the theoretical framework of evidence accumulation models, which capture individual differences in (at least) 2 distinct ways. Differences affecting accumulation rate produce positive correlation. But this is cancelled out if individuals also differ in response threshold, which produces negative correlations. In the models, subtractions between conditions do not isolate processing costs from caution. To demonstrate the explanatory power of synthesizing the traditional subtraction method within a broader decision model framework, we confirm 2 predictions with new data. Thus, using error costs or RT costs is more than a pragmatic choice; the decision carries theoretical consequence that can be understood through the accumulation model framework. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Does Extreme Language Control Training Improve Cognitive Control? A Comparison of Professional Interpreters, L2 Teachers and Monolinguals

There is currently a lively debate in the literature whether bilingualism leads to enhanced cognitive control or not. Recent evidence suggests that knowledge of more than one language does not always suffice for the manifestation of a bilingual cognitive control advantage. As a result, ongoing research has focused on modalities of bilingual language use that may interact with the bilingual advantage. In this study, we explored the cognitive control performance of simultaneous interpreters. These highly proficient bilinguals comprehend information in one language while producing in the other language, which is a complex skill requiring high levels of language control. In a first experiment, we compared professional interpreters to monolinguals. Data were collected on interference suppression (flanker task), prepotent response inhibition (Simon task), and short-term memory (digit span task). The results showed that the professional interpreters performed similarly to the monolinguals on all measures. In Experiment 2, we compared professional interpreters to monolinguals and second language teachers. Data were collected on interference suppression (advanced flanker task), prepotent response inhibition (advanced flanker task), attention (advanced flanker task), short-term memory (Hebb repetition paradigm), and updating (n-back task). We found converging evidence for our finding that experience in interpreting may not lead to superior interference suppression, prepotent response inhibition, and short-term memory. In fact, our results showed that the professional interpreters performed similarly to both the monolinguals and the second language teachers on all tested cognitive control measures. We did, however, find anecdotal evidence for a (small) advantage in short-term memory for interpreters relative to monolinguals when analyzing composite scores of both experiments together. Taken together, the results of the current study suggest that interpreter experience does not necessarily lead to general cognitive control advantages. However, there may be small interpreter advantages in short-term memory, suggesting that this might be an important cognitive control aspect of simultaneous interpreting. The results are discussed in the light of ongoing debates about bilingual cognitive control advantages.

Changes in executive function over time in bilingual and monolingual school-aged children

We examined the development of 3 executive function (EF) components-inhibition, updating, and task shifting-over time in monolingual and bilingual school-age children. We tested 41 monolingual and 41 simultaneous bilingual typically developing children (ages 8-12) on nonverbal tasks measuring inhibition (the Flanker task), updating (the Corsi blocks task), and task shifting (the Dimensional Change Card Sort task; DCCS) at 2 time points, 1 year apart. Three indexes of task shifting (shifting, switching, and mixing costs) were derived from the DCCS task. The 2 groups did not differ in their development of updating, but did demonstrate distinct patterns of development for inhibition. Specifically, while the bilingual group demonstrated a steep improvement in inhibition from Year 1 to Year 2, the monolingual group was characterized by stable inhibition performance over this time period. The 2 groups did not differ in their developmental patterns for shifting and switching costs, but for mixing costs, the bilingual children outperformed the monolingual children in both years. Together, the findings indicate that bilingual experience may modulate the developmental rates of some components of EF but not others, resulting in specific EF performance differences between bilinguals and monolinguals only at certain developmental time points. (PsycINFO Database Record

Evidence against a cognitive advantage in the older bilingual population

Recent evidence has challenged long-standing claims that multi-language acquisition confers long-term advantages in executive function and may protect against age-related cognitive deterioration. We assessed evidence for a bilingual advantage in older monolingual and bilingual residents matched on age, gender, and socioeconomic status. A comprehensive battery of tests was administered to measure non-verbal reasoning, working memory capacity, visuo-spatial memory, response inhibition, problem solving, and language proficiency. Analyses, including Bayes factors, revealed comparable performance in both groups, with no significant differences on any task (and the only trend, found for the Tower of London task performance, indicated a monolingual advantage). Overall, therefore, our findings run counter to the bilingual advantage hypothesis. We consider the implications of our study and offer suggestions for future work in this area.

Bilingual Advantages in Inhibition or Selective Attention: More Challenges

A large sample (N = 141) of college students participated in both a conjunctive visual search task and an ambiguous figures task that have been used as tests of selective attention. Tests for effects of bilingualism on attentional control were conducted by both partitioning the participants into bilinguals and monolinguals and by treating bilingualism as a continuous variable, but there were no effects of bilingualism in any of the tests. Bayes factor analyses confirmed that the evidence substantially favored the null hypothesis. These new findings mesh with failures to replicate language-group differences in congruency-sequence effects, inhibition-of-return, and working memory capacity. The evidence that bilinguals are better than monolinguals at attentional control is equivocal at best.

Language and cognitive control networks in bilinguals and monolinguals

Neuroimaging studies have reported overlapping neural circuits for cognitive control when engaging in tasks that involve verbal and nonverbal stimuli in young adult bilinguals. However, no study to date has examined the neural basis of verbal and nonverbal task switching in both monolinguals and bilinguals due to the inherent challenge of testing verbal task switching with monolinguals. Therefore, it is not clear whether the finding for overlapping networks is unique to bilingualism or indicative of general cognitive control. To address this question, the current study compared functional neural activation for young adults who were bilingual speakers of English and French or monolingual English speakers who had limited French learning experience ("functional monolinguals") on verbal and nonverbal task switching. Analyses showed common variance explaining general cognitive control in task switching across verbal and nonverbal domains for both groups, in line with the explanation that task switching involves general cognitive control, as well as unique brain regions recruited by monolinguals and bilinguals. Specifically, beyond the processing common to the tasks, monolinguals also recruited distinct networks for each of verbal and nonverbal switching but bilinguals used a common shared network. Thus, the domain-general aspect of switching is different for monolinguals and bilinguals.

Low foreign language proficiency reduces optimism about the personal future

Optimistic estimates about the personal future constitute one of the best-described and most-debated decision biases related to emotion. Nevertheless, it has been difficult to isolate manipulations that reduce optimistic estimates. Eliciting estimates in a foreign language is a promising candidate manipulation because foreign language use alters decision biases in scenarios with emotional components. Consequently, we tested whether foreign language use reduces optimistic estimates. In a laboratory experiment, participants ( n = 45) estimated their probability of experiencing life events either in their native language or a foreign language, in which they were highly proficient. We found no differences in these estimates or in the updating of these estimates after receiving feedback about the population baseline probability. Importantly, three online experiments with large sample sizes ( ns = 706, 530, and 473) showed that using a foreign language with low proficiency reduced comparative optimism. Participants in the online experiments had diverse proficiency levels and were matched on a variety of control metrics. Fine-grained analyses indicated that low proficiency weakens the coupling between probability estimates and rated arousal. Overall, our findings suggest that an important decision bias can be reduced when using a foreign language with low proficiency.

Another bilingual advantage? Perception of talker-voice information

A bilingual advantage has been found in both cognitive and social tasks. In the current study, we examine whether there is a bilingual advantage in how children process information about who is talking (talker-voice information). Younger and older groups of monolingual and bilingual children completed the following talker-voice tasks with bilingual speakers: a discrimination task in English and German (an unfamiliar language), and a talker-voice learning task in which they learned to identify the voices of three unfamiliar speakers in English. Results revealed effects of age and bilingual status. Across the tasks, older children performed better than younger children and bilingual children performed better than monolingual children. Improved talker-voice processing by the bilingual children suggests that a bilingual advantage exists in a social aspect of speech perception, where the focus is not on processing the linguistic information in the signal, but instead on processing information about who is talking.