No compelling evidence for a bilingual advantage in switching or that frequent language switching reduces switch cost

Semantic verbal fluency in native speakers of Turkish: a systematic review of category use, scoring metrics and normative data in healthy individuals

INTRODUCTION

Semantic verbal fluency (SVF) is a widely used measure of frontal executive function and access to semantic memory. SVF scoring metrics include the number of unique words generated, perseverations, intrusions, semantic cluster size and switching between clusters, and scores vary depending on the language the test is administered in. In this paper, we review the existing normative data for Turkish, the main metrics used for scoring SVF data in Turkish, and the most frequently used categories.

METHOD

We conducted a systematic review of peer-reviewed papers using Medline, EMBASE, PsycInfo, Web of Science, and two Turkish databases, TR-Dizin and Yok-Tez. Included papers contained data on the SVF performance of healthy adult native speakers of Turkish, and reported the categories used. Versions of the SVF that required participants to alternate categories were excluded. We extracted and tabulated demographics, descriptions of groups, metrics used, categories used, and sources of normative data. Studies were assessed for level of detail in reporting findings.

RESULTS

1400 studies were retrieved. After deduplication, abstract, full text screening, and merging of theses with their published versions, 121 studies were included. 114 studies used the semantic category "animal", followed by first names (N = 14, 12%). All studies reported word count. More complex measures were rare (perseverations: N = 12, 10%, clustering and switching: N = 5, 4%). Four of seven normative studies reported only word count, two also measured perseverations, and one reported category violations and perseverations. Two normative studies were published in English.

CONCLUSIONS

There is a lack of normative Turkish SVF data with more complex metrics, such as clustering and switching, and a lack of normative data published in English. Given the size of the Turkish diaspora, normative SVF data should include monolingual and bilingual speakers. Limitations include a restriction to key English and Turkish databases.

Attention networks in multilingual adults who do and who do not stutter

This study investigated whether multilinguals who stutter differ from multilinguals who do not stutter in terms of attention networks. Towards that end, it measured (a) performance differences in attention networks between multilinguals who stutter and those who do not stutter and (b) the correlation between stuttering characteristics and attention networks. Twenty-four multilingual Dutch-English speaking adults (20-46y), half of whom were diagnosed with stuttering, completed the Attentional Network Task (ANT) that evaluates the attention networks of alerting, orienting, and executive control. A language and social background questionnaire and a lexical decision task (LexTALE) assessed the participants' language proficiency. The Stuttering Severity Instrument 4th Ed. and the Brief Version of the Unhelpful Thoughts and Beliefs About Stuttering Scale were used to evaluate stuttering characteristics. The two groups did not differ in the ANT in terms of reaction time and error rate scores. Furthermore, no differences were observed in the three attention networks between the groups. Lastly, no correlation was found between stuttering characteristics and attention networks. The results suggest that the attention abilities of multilinguals who stutter do not differ from multilinguals who do not stutter.

Bilingual Spatial Cognition: Spatial Cue Use in Bilinguals and Monolinguals

Structural plasticity changes and functional differences in executive control tasks have been reported in bilinguals compared to monolinguals, supporting a proposed bilingual 'advantage' in executive control functions (e.g., task switching) due to continual usage of control mechanisms that inhibit one of the coexisting languages. However, it remains unknown whether these differences are also apparent in the spatial domain. The present fMRI study explores the use of spatial cues in 15 bilinguals and 14 monolinguals while navigating in an open-field virtual environment. In each trial, participants had to navigate towards a target object that was visible during encoding but hidden in retrieval. An extensive network was activated in bilinguals compared to monolinguals in the encoding and retrieval phase. During encoding, bilinguals activated the right temporal and left parietal regions (object trials) and left inferior frontal, precentral, and lingual regions more than monolinguals. During retrieval, the same contrasts activated the left caudate nucleus and the right dorsolateral prefrontal cortex (DLPFC), the left parahippocampal gyrus, as well as caudate regions. These results suggest that bilinguals may recruit neural networks known to subserve not only executive control processes but also spatial strategies.

The Effect of Phonetic Similarity on Domain-General Executive Control in Color-Shape Task: Evidence from Cantonese-Mandarin and Beijing-Dialect-Mandarin Bidialectals

The present study was carried out to investigate whether bidialectals have a similar advantage in domain-general executive function as bilinguals and if so whether the phonetic similarity between two different dialects can modulate the executive function performance in the conflicting-switching task. The results showed that the latencies for switching trials in mixed block (SMs) were longest, non-switching trials in mixed block (NMs) were medium, and non-switching trials in pure block (NPs) were the shortest in the conflict-switching task in all three groups of participants. Importantly, the difference between NPs and NMs varied as a function of phonetic similarity between two dialects with Cantonese-Mandarin bidialectal speakers being the minimum, Beijing-dialect-Mandarin bidialectals medium, and Mandarin native speakers maximum. These results provide strong evidence that there is an advantage in balanced bidialectals's executive function which is modulated by the phonetic similarity between two dialects suggesting that phonetic similarity plays an important role in domain-general executive function.

The influence of bilingual experience on executive function under emotional interference: Evidence from the N1 component

The influence of bilingual education and experience on an individual’s information-processing ability has recently been a hot issue in international studies. Previous studies have found that bilingual experience affects executive function, but the results remain controversial. Executive function refers to the conscious control of purposeful behavior. It is responsible for processing high-level action controls, including such sub-functions as inhibitory control, cognitive switching, and working memory updating. Emotion, as an essential factor in daily life, also has a complex interaction with executive function. This paper explores whether the bilingual cognitive advantage effect can continue in the more complex conditions of emotional interference. To investigate the specific electrophysiological characteristics of the participants at different stages of cognitive processing, we used a combination of the behavioral and ERP experiments in which the positive, neutral, and negative emotional stimuli were selected as emotional interference conditions and the emotional Simon paradigm, the cognitive switching of emotion paradigm, and the emotional N-back paradigm was adopted. The results show that the main effect of the N1 component amplitude is significant. Specifically, the amplitude of the N1 component in the proficient bilinguals is significantly smaller than that of the non-proficient bilinguals, while the main effects of other component groups are not significant, indicating that under the condition of emotional interference, the influence of bilingual experience on executive function only exists in the early attention stage and that the bilingual experience can improve the individual’s attentional control and speed up attention processing in the early attention stage.

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.

Does bilingualism come with linguistic costs? A meta-analytic review of the bilingual lexical deficit

A series of recent studies have shown that the once-assumed cognitive advantage of bilingualism finds little support in the evidence available to date. Surprisingly, however, the view that bilingualism incurs linguistic costs (the so-called lexical deficit) has not yet been subjected to the same degree of scrutiny, despite its centrality for our understanding of the human capacity for language. The current study implemented a comprehensive meta-analysis to address this gap. By analyzing 478 effect sizes from 130 studies on expressive vocabulary, we found that observed lexical deficits could not be attributed to bilingualism: Simultaneous bilinguals (who acquired both languages from birth) did not exhibit any lexical deficit, nor did sequential bilinguals (who acquired one language from birth and a second language after that) when tested in their mother tongue. Instead, systematic evidence for a lexical deficit was found among sequential bilinguals when tested in their second language, and more so for late than for early second language learners. This result suggests that a lexical deficit may be a phenomenon of second language acquisition rather than bilingualism per se.

Assessing language background and experiences among heritage bilinguals

The language backgrounds and experiences of bilinguals have been primarily characterized using self-report questionnaires and laboratory tasks, although each of these assessments have their strengths and weaknesses. The Electronically Activated Recorder (EAR), an audio recording device, has recently become more prominent as a method of assessing real-world language use. We investigated the relationships among these three assessment tools, to understand the shared variance in how these measures evaluated various aspects of the bilingual experience. Participants were 60 Southern California heritage bilingual college students who spoke a variety of heritage languages and began to learn English between the ages of 0-to 12-years. Participants completed both self-report and laboratory-based measures of language proficiency and use, and they wore the EAR for 4  days to capture representative samples of their day-to-day heritage language (HL) use. The results indicated that self-reported HL use and English age of acquisition were significant predictors of real-world language use as measured by the EAR. In addition, self-reported HL proficiency and laboratory-based HL proficiency, as measured by verbal fluency, were mutually predictive. While some variability was shared across different assessments, ultimately, none of the measures correlated strongly and each measure captured unique information about the heritage bilingual language experience, highlighting the dissociation between language experience measured at a single point in time and an accumulated life history with a heritage language. These findings may provide guidance for bilingualism researchers about which assessment tool, or combination of tools, may be best for their specific research questions.

The perception of intonational and emotional speech prosody produced with and without a face mask: an exploratory individual differences study

Face masks affect the transmission of speech and obscure facial cues. Here, we examine how this reduction in acoustic and facial information affects a listener's understanding of speech prosody. English sentence pairs that differed in their intonational (statement/question) and emotional (happy/sad) prosody were created. These pairs were recorded by a masked and unmasked speaker and manipulated to contain audio or not. This resulted in a continuum from typical unmasked speech with audio (easiest) to masked speech without audio (hardest). English listeners (N = 129) were tested on their discrimination of these statement/question and happy/sad pairs. We also collected six individual difference measures previously reported to affect various linguistic processes: Autism Spectrum Quotient, musical background, phonological short-term memory (digit span, 2-back), and congruence task (flanker, Simon) behavior. The results indicated that masked statement/question and happy/sad prosodies were harder to discriminate than unmasked prosodies. Masks can therefore make it more difficult to understand a speaker's intended intonation or emotion. Importantly, listeners differed considerably in their ability to understand prosody. When wearing a mask, speakers should try to speak clearer and louder, if possible, and make intentions and emotions explicit to the listener.

Verbal fluency difficulties in aphasia: A combination of lexical and executive control deficits

BACKGROUND

Verbal fluency tasks are routinely used in clinical assessment and research studies of aphasia. People with aphasia produce fewer items in verbal fluency tasks. It remains unclear if their output is limited solely by their lexical difficulties and/or has a basis in their executive control abilities. Recent research has illustrated that detailed characterization of verbal fluency performance using temporal characteristics of words retrieved, clustering and switching, and pause durations, along with separate measures of executive control stands to inform our understanding of the lexical and cognitive underpinnings of verbal fluency in aphasia.

AIMS

To determine the locus of the verbal fluency difficulties in aphasia, we compared semantic and letter fluency trials between people with aphasia and healthy control participants using a wide range of variables to capture the performance between the two groups. The groups were also tested on separate measures of executive control to determine the relationship amongst these tasks and fluency performance.

METHODS & PROCEDURES

Semantic (animal) and letter (F, A, S) fluency data for 60s trials were collected from 14 people with aphasia (PWA) and 24 healthy adult controls (HC). Variables, such as number of correct responses, clustering and switching analyses, were performed along with temporal measures of the retrieved words (response latencies) and pause durations. Participants performed executive control tasks to measure inhibitory control, mental-set shifting and memory span.

OUTCOMES & RESULTS

Compared with HC, PWA produced fewer correct responses, showed greater difficulty with the letter fluency condition, were slower in getting started with the trials, showed slower retrieval times as noted in within- and between-cluster pause durations, and switched less often. Despite these retrieval difficulties, PWA showed a similar decline in the rate of recall to HC, and had similar cluster size. Executive control measures correlated primarily with the letter fluency variables: mostly for PWA and in one instance for HC.

CONCLUSIONS & IMPLICATIONS

Poorer performance for PWA is a combination of difficulties in both the lexical and executive components of the verbal fluency task. Our findings highlight the importance of detailed characterization of fluency performance in deciphering the underlying mechanism of retrieval difficulties in aphasia, and illustrate the importance of using letter fluency trials to tap into executive control processes.

WHAT THIS PAPER ADDS

What is already known on the subject PWA typically show impaired performance in verbal fluency tasks. It is debated whether this impaired performance is a result of their lexical difficulties or executive control difficulties, or a combination of both. This debate continues because previous studies have mostly used semantic fluency condition without including letter fluency condition; used a limited range of variables (e.g., number of correct responses); and not included separate executive control measures to explain the performance pattern in aphasia. This research addresses these outstanding issues to determine the specific contribution of lexical and executive control processes in verbal fluency in aphasia by including: both semantic and letter fluency conditions; a wide range of variables to identify the relative contribution of lexical and executive control mechanisms; and independent measures of executive control. What this paper adds to existing knowledge Using the multidimensional analysis approach for verbal fluency performance from both semantic and letter fluency conditions, this is the first study to systematically demonstrate that PWA had difficulties in both lexical and executive control components of the task. At the individual level, PWA had greater difficulty on the letter fluency condition compared with semantic fluency. We observed significant correlations between the executive control measures and verbal fluency measures primarily for the letter fluency condition. This research makes a significant contribution to our understanding of lexical and executive control aspects in word production in aphasia. What are the potential or actual clinical implications of this work? From a clinical perspective, this research highlights the importance of using a full range of verbal fluency and executive control measures to tap into the lexical as well as executive control abilities of PWA, and also the utility of using letter fluency to tap into the executive control processes in PWA.

Nonverbal Switching Ability of Monolingual and Bilingual Children with and without Developmental Language Disorder

Bilingualism is associated with enhanced switching skills, while a developmental language disorder (DLD) may negatively impact switching ability. However, both studies with bilinguals as well as studies including children with DLD have revealed mixed results. Moreover, the interaction of bilingualism and DLD has not been addressed and the origin of the stronger or weaker switching performance is unknown. The current study aimed to fill these gaps. Monolingual and bilingual children with and without DLD (n = 32 in each of the four groups) completed a nonverbal color/shape switching task when they were 7 to 8 years old, and a Continuous Performance Task two years earlier. The latter tapped into their response inhibition and sustained attention skills, which may underlie switching ability. No differences between monolinguals and bilinguals were found on the switching task. Children with DLD had higher mixing costs than peers without DLD, which was driven by differences in sustained attention skills. These results add to the body of research indicating that the cognitive advantages of bilingualism are unstable. Additionally, the results substantiate the hypothesis that attention processes are foundational for complex cognitive skills, such as switching, and suggest cascading effects for children with weaker attention skills, such as children with DLD.

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.

On the reliability of behavioral measures of cognitive control: retest reliability of task-inhibition effect, task-preparation effect, Stroop-like interference, and conflict adaptation effect

This study examined the reliability (retest and split-half) of four common behavioral measures of cognitive control. In Experiment 1 (N = 96), we examined N – 2 task repetition costs as a marker of task-level inhibition, and the cue-stimulus interval (CSI) effect as a marker of time-based task preparation. In Experiment 2 (N = 48), we examined a Stroop-like face-name interference effect as a measure of distractor interference control, and the sequential congruency effect (“conflict adaptation effect”) as a measure of conflict-triggered adaptation of cognitive control. In both experiments, the measures were assessed in two sessions on the same day, separated by a 10 min-long unrelated filler task. We observed substantial experimental effects with medium to large effect sizes. At the same time, split-half reliabilities were moderate, and retest reliabilities were poor, for most measures, except for the CSI effect. Retest reliability of the Stroop-like effect was improved when considering only trials preceded by congruent trials. Together, the data suggest that these cognitive control measures are well suited for assessing group-level effects of cognitive control. Yet, except for the CSI effect, these measures do not seem suitable for reliably assessing interindividual differences in the strength of cognitive control, and therefore are not suited for correlational approaches. We discuss possible reasons for the discrepancy between robustness at the group level and reliability at the level of interindividual differences.

Clear Theories Are Needed to Interpret Differences: Perspectives on the Bilingual Advantage Debate

The heated debate regarding bilingual cognitive advantages remains ongoing. While there are many studies supporting positive cognitive effects of bilingualism, recent meta-analyses have concluded that there is no consistent evidence for a bilingual advantage. In this article we focus on several theoretical concerns. First, we discuss changes in theoretical frameworks, which have led to the development of insufficiently clear theories and hypotheses that are difficult to falsify. Next, we discuss the development of looking at bilingual experiences and the need to better understand language control. Last, we argue that the move from behavioural studies to a focus on brain plasticity is not going to solve the debate on cognitive effects, especially not when brain changes are interpreted in the absence of behavioural differences. Clearer theories on both behavioural and neural effects of bilingualism are needed. However, to achieve this, a solid understanding of both bilingualism and executive functions is needed first.

Functional neuroanatomy of arithmetic in monolingual and bilingual adults and children

Prior studies on the brain bases of arithmetic have not focused on (or even described) their participants' language backgrounds. Yet, unlike monolinguals, early bilinguals have the capacity to solve arithmetic problems in both of their two languages. This raises the question whether this ability, or any other experience that comes with being bilingual, affects brain activity for arithmetic in bilinguals relative to monolinguals. Here, we used functional magnetic resonance imaging to compare brain activity in 44 English monolinguals and 44 Spanish-English early bilinguals, during the solving of arithmetic problems in English. We used a factorial design to test for a main effect of bilingual Language Experience. Based on the known modulating roles of arithmetic operation and age, we used two arithmetic tasks (addition and subtraction) and studied two age groups (adults and children). When collapsing across operations and age, we found broad bilateral activation for arithmetic in both the monolingual group and the bilingual group. However, an analysis of variance revealed that there was no effect of Language Experience, nor an interaction of Language Experience with Operation or Age Group. Bayesian analyses within regions of interest chosen for their role in arithmetic further supported the finding of no effect of Language Experience on brain activity underlying arithmetic. We conclude that early bilingualism does not influence the functional neuroanatomy of simple arithmetic.

Predictions about the Cognitive Consequences of Language Switching on Executive Functioning Inspired by the Adaptive Control Hypothesis Fail More Often than Not

The adaptive control hypothesis developed by Green and Abutalebi is the most influential theory of bilingual language control. The focus of this article is on the predictions that other researchers have derived based on the three different modes of interactional context described by the hypothesis. Foremost, that dual-language contexts should enhance domain-general executive functions more than single-language contexts. Several recent and ambitious behavioral tests of these predictions are reviewed. Although there was some evidence that dual-language contexts are associated with smaller switch costs, the evidence is inconsistent and there were no similar advantages for inhibitory control. The hypothesis also predicts neuroanatomical adaptations to the three types of interactional context. A careful evaluation of the relevant fMRI and ERP studies that take into account whether behavioral differences align with neuroscience differences and resolves valence ambiguities led to the conclusion that the neuroscience evidence for the hypothesis is, at best, inconsistent. The study also includes new analyses of two large-sample studies that enable the identification of relatively pure cases of single-language bilinguals, dual-language bilinguals, and dense-code switchers. Across nine different measures of executive functioning, the predicted advantage of the dual-language context never materialized. The hypotheses derived from the adaptive control hypothesis do not accurately predict behavioral performance on tests of executive functioning and do not advance our understanding as to what dimensions of bilingualism may lead to enhancements in specific components of executive functioning.

The executive function of bilingual and monolingual children: A technical efficiency approach

This paper introduces a novel approach to evaluate performance in the executive functioning skills of bilingual and monolingual children. This approach targets method- and analysis-specific issues in the field, which has reached an impasse (Antoniou et al., 2021). This study moves beyond the traditional approach towards bilingualism by using an array of executive functioning tasks and frontier methodologies, which allow us to jointly consider multiple tasks and metrics in a new measure; technical efficiency (TE). We use a data envelopment analysis technique to estimate TE for a sample of 32 Greek-English bilingual and 38 Greek monolingual children. In a second stage, we compare the TE of the groups using an ANCOVA, a bootstrap regression, and a k-means nearest-neighbour technique, while controlling for a range of background variables. Results show that bilinguals have superior TE compared to their monolingual counterparts, being around 6.5% more efficient. Robustness tests reveal that TE yields similar results to the more complex conventional MANCOVA analyses, while utilising information in a more efficient way. By using the TE approach on a relevant existing dataset, we further highlight TE's advantages compared to conventional analyses; not only does TE use a single measure, instead of two principal components, but it also allows more group observations as it accounts for differences between the groups by construction.

Do All Switches Cost the Same? Reliability of Language Switching and Mixing Costs

The current study examined the reliability and consistency of switching and mixing costs in the language and the color-shape tasks in three pre-existing data sets, to assess whether they are equally well suited for the study of individual differences. Specifically, we considered if the language task is as reliable as the color-shape task - an important question given the wide use of language switching tasks but little information available to address this question. Switching costs had low to moderate reliability and internal consistency, and these were similar for the language and the color-shape tasks. Mixing costs were more reliable in the language task than in the color-shape task when tested twice on the same day and trended in the same direction when tested a week apart. In addition, mixing costs were larger and more consistent than switching costs in all data sets and they were also were more reliable than switching costs in the language task when tested on the same day. These results reveal the language task to be as good as the color-shape task for measuring switching and mixing ability. Low variability of switching costs may decrease their reliability and consistency, in turn interfering with the chance of detecting cross task correlations. We advocate for exploring procedures to increase the variability of switching costs, which might increase reliability and consistency of these measures, and improve the ability to determine if bilingual language use relies on cognitive mechanisms that overlap with those underlying nonlinguistic multi-tasking.

Explaining Individual Differences in Executive Functions Performance in Multilinguals: The Impact of Code-Switching and Alternating Between Multicultural Identity Styles

This study sheds new light on the relative impact of switching between languages and switching between cultures on Executive Functions (EFs) in bilinguals. Several studies have suggested that bilingualism has a measurable impact on executive functioning, presumably due to bilinguals’ constant practice in dealing with two languages, or two cultures. Yet, the evidence on the relative contribution of culture and bilingualism to EFs is not well understood, because disentangling language, culture and immigration status is very difficult. The novelty of our approach was to keep the language pair and immigration status constant, whilst the cultural identity of participants was systematically varied, and measured at the individual level (not just at group level). Two groups of Turkish–English bilinguals, all adult immigrants to the United Kingdom, took part in the study, but one group (n = 29) originated from mainland Turkey and the other (n = 28) from Cyprus. We found that the bilinguals experienced smaller Conflict Effects on a Flanker task measuring inhibition, by comparison with monolingual British participants (n = 30). The key variable explaining EF performance variance at the individual level turned out to be bilinguals’ Multicultural Identity Style. In particular those who indicated that they attempted to alternate between different British and Turkish (Cypriot) identity styles were found to have shorter RTs on incongruent trials of the Flanker task. The two multicultural identity variables, Alternating and Hybrid Identity Styles, together explained 32% in RTs over and above Education, Working Memory and Nonverbal reasoning (overall explained variance 49%). Thus, the data provide strong evidence for the impact of culture on EFs. We suggest that, as a result of their daily practice in recognizing cultural cues which highlight the need to switch to a different cultural frame, multicultural bilinguals develop a heightened context-sensitivity, and this gives them an advantage over monolinguals in a Flankers task. Our approach, which draws on models from cross-cultural psychology, bilingualism and executive functioning, illustrates the importance of theory building in which sociolinguistic and cultural variables are integrated into models of EFs.

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.

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.

Linguistic Diversity, Multilingualism, and Cognitive Skills: A Study of Disadvantaged Children in India

Multilingualism and linguistic diversity are the norm in India. Although studies have shown a relation between bilingualism and cognitive gains, linguistic diversity has so far been ignored as a potential factor affecting cognitive skills. This study aims to fill this gap by examining how cognitive skills—as measured by the n-back and Raven’s Colored Progressive Matrices tasks—are affected by multilingualism and/or sociolinguistic diversity in a large cohort of socioeconomically disadvantaged primary school children in two urban sites of India: Delhi and Hyderabad. We present a questionnaire estimating sociolinguistic diversity and show that this measure assesses a distinct construct, as compared to a child’s multilingualism. Children were classified as growing up monolingually or bilingually, depending on whether they grew up with one or more languages in the home. Regarding cognitive performance, bilinguals were found to outperform monolinguals on the n-back task, as well as on the Raven’s task. In addition, a socially and linguistically diverse environment seems to enhance cognitive performance for children who are not multilingual themselves. Finally, several contextual factors such as city were found to influence cognitive performance. Overall, this shows that cognitive tasks are subject to contextual effects and that bilingualism and linguistic diversity can enhance cognitive performance of children in disadvantaged contexts.

The alchemy of confirmation bias transmutes expectations into bilingual advantages: A tale of two new meta-analyses

Five recent meta-analyses of the bilingual advantage in executive functioning hypothesis have converged on the outcome that the mean effect size is very small and that the incidence of statistically significant bilingual advantages is very low (about 15% of all comparisons). Those analyses that used the PET-PEESE method to correct for publication bias show mean effect sizes that are not different from zero and sometimes negative. In contrast, van den Noort and colleagues provide a sixth review of 46 studies published before October 31, 2018, that appears to produce a very different outcome, namely that more than half the studies yield clear support for the bilingual advantage hypothesis. We show that the deviance is due in part to search terms that yielded far fewer relevant studies, but more importantly to a subjective method of evaluating the results of each study that enables confirmation biases on the part of study authors and meta-analysts to substantially distort the objective pattern of results. A seventh meta-analysis, by Armstrong and colleagues, reports significant bilingual advantages of g = 0.48 for 32 samples using Simon and Stroop colour–word interference tasks that tested older adults. However, all effects were entered into the funnel plots as positive even though many were negative (bilingual disadvantages). This and other striking anomalies are consistent with the view that confirmation bias can suspend critical judgement and promulgate errors. Meta-analyses that use preregistration and a many-labs collaboration can better control for both publication and experimenter biases.

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.

Effects of bilingual language experience on basal ganglia computations: A dynamic causal modeling test of the conditional routing model

Bilingual language control is characterized by the ability to select from amongst competing representations based on the current language in use. According to the Conditional Routing Model (CRM), this feat is underpinned by basal-ganglia signal-routing mechanisms, and may have implications for cognitive flexibility. The current experiment used dynamic causal modeling of fMRI data to compare network-level brain functioning in monolinguals and bilinguals during a task that required productive (semantic decision) and receptive (language) switches. Consistent with the CRM, results showed that: (1) both switch types drove activation in the basal ganglia, (2) bilinguals and monolinguals differed in the strength of influence of dorsolateral prefrontal cortex (DLPFC) on basal ganglia, and (3) differences in bilingual language experience were marginally related to the strength of influence of the switching drives onto basal ganglia. Additionally, a task-by-group interaction was found, suggesting that when bilinguals engaged in language-switching, their task-switching costs were reduced.

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

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

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.

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.

Bilingualism and language similarity modify the neural mechanisms of selective attention

Learning and using multiple languages places major demands on our neurocognitive system, which can impact the way the brain processes information. Here we investigated how early bilingualism influences the neural mechanisms of auditory selective attention, and whether this is further affected by the typological similarity between languages. We tested the neural encoding of continuous attended speech in early balanced bilinguals of typologically similar (Dutch-English) and dissimilar languages (Spanish-English) and compared them to results from English monolinguals we reported earlier. In a dichotic listening paradigm, participants attended to a narrative in their native language while ignoring different types of interference in the other ear. The results revealed that bilingualism modulates the neural mechanisms of selective attention even in the absence of consistent behavioural differences between monolinguals and bilinguals. They also suggested that typological similarity between languages helps fine-tune this modulation, reflecting life-long experiences with resolving competition between more or less similar candidates. The effects were consistent over the time-course of the narrative and suggest that learning a second language at an early age triggers neuroplastic adaptation of the attentional processing system.

Does the Bilingual Advantage in Cognitive Control Exist and If So, What Are Its Modulating Factors? A Systematic Review

Recently, doubts were raised about the existence of the bilingual advantage in cognitive control. The aim of the present review was to investigate the bilingual advantage and its modulating factors. We searched the Medline, ScienceDirect, Scopus, and ERIC databases for all original data and reviewed studies on bilingualism and cognitive control, with a cut-off date of 31 October 2018, thereby following the guidelines of the preferred reporting items for systematic reviews and meta-analysis (PRISMA) protocol. The results of the 46 original studies show that indeed, the majority, 54.3%, reported beneficial effects of bilingualism on cognitive control tasks; however, 28.3% found mixed results and 17.4% found evidence against its existence. Methodological differences seem to explain these mixed results: Particularly, the varying selection of the bilingual participants, the use of nonstandardized tests, and the fact that individual differences were often neglected and that longitudinal designs were rare. Therefore, a serious risk for bias exists in both directions (i.e., in favor of and against the bilingual advantage). To conclude, we found some evidence for a bilingual advantage in cognitive control; however, if significant progress is to be made, better study designs, bigger data, and more longitudinal studies are needed.

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.

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.

Bidialectalism and Bilingualism: Exploring the Role of Language Similarity as a Link Between Linguistic Ability and Executive Control

The notion of bilingual advantages in executive functions (EF) is based on the assumption that the demands posed by cross-language interference serve as EF training. These training effects should be more pronounced the more cross-language interference bilinguals have to overcome when managing their two languages. In the present study, we investigated the proposed link between linguistic and EF performance using the similarity between the two languages spoken since childhood as a proxy for different levels of cross-language interference. We assessed the effect of linearly increasing language dissimilarity on linguistic and EF performance in multiple tasks in four groups of young adults (aged 18-33): German monolinguals (n = 24), bidialectals (n = 25; German and Swiss German dialect), bilinguals speaking two languages of the same Indo-European ancestry (n = 24; e.g., German-English), or bilinguals speaking two languages of different ancestry (n = 24; e.g., German-Turkish). Bayesian linear-mixed effects modeling revealed substantial evidence for a linear effect of language similarity on linguistic accuracy, with better performance for participants with more similar languages and monolinguals. However, we did not obtain evidence for the presence of a similarity effect on EF performance. Furthermore, language experience did not modulate EF performance, even when testing the effect of continuous indicators of bilingualism (e.g., age of acquisition, proficiency, daily foreign language usage). These findings question the theoretical assumption that life-long experience in managing cross-language interference serves as EF training.

Exploiting Language Variation to Better Understand the Cognitive Consequences of Bilingualism

Within the past decade, there has been an explosion of research investigating the cognitive consequences of bilingualism. However, a controversy has arisen specifically involving research claiming a "bilingual advantage" in executive function. In this brief review, we re-examine the nature of the "bilingual advantage" and suggest three themes for future research. First, there must be a theoretical account of how specific variation in language experience impacts aspects of executive function and domain general cognition. Second, efforts toward adequately characterizing the participants tested will be critical to interpreting results. Finally, designing studies that employ converging analytical approaches and sensitive methodologies will be important to advance our knowledge of the dynamics between bilingual language experience and cognition.

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.

On the Reliability of Switching Costs Across Time and Domains

Bilingual speakers are suggested to use control processes to avoid linguistic interference from the unintended language. It is debated whether these bilingual language control (BLC) processes are an instantiation of the more domain-general executive control (EC) processes. Previous studies inconsistently report correlations between measures of linguistic and non-linguistic control in bilinguals. In the present study, we investigate the extent to which there is cross-talk between these two domains of control for two switch costs, namely the n-1 shift cost and the n-2 repetition cost. Also, we address an important problem, namely the reliability of the measures used to investigate cross-talk. If the reliability of a measure is low, then these measures are ill-suited to test cross-talk between domains through correlations. We asked participants to perform both a linguistic- and non-linguistic switching task at two sessions about a week apart. The results show a dissociation between the two types of switch costs. Regarding test-retest reliability, we found a stronger reliability for the n-1 shift cost compared to the n-2 repetition cost within both domains as measured by correlations across sessions. This suggests the n-1 shift cost is more suitable to explore cross-talk of BLC and EC. Next, we do find cross-talk for the n-1 shift cost as demonstrated by a significant cross-domain correlation. This suggests that there are at least some shared processes in the linguistic and non-linguistic task.

Language balance and switching ability in children acquiring English as a second language

This study investigated whether relative lexical proficiency in Dutch and English in child second language (L2) learners is related to executive functioning. Participants were Dutch primary school pupils of three different age groups (4-5, 8-9, and 11-12 years) who either were enrolled in an early-English schooling program or were age-matched controls not on that early-English program. Participants performed tasks that measured switching, inhibition, and working memory. Early-English program pupils had greater knowledge of English vocabulary and more balanced Dutch-English lexicons. In both groups, lexical balance, a ratio measure obtained by dividing vocabulary scores in English by those in Dutch, was related to switching but not to inhibition or working memory performance. These results show that for children who are learning an L2 in an instructional setting, and for whom managing two languages is not yet an automatized process, language balance may be more important than L2 proficiency in influencing the relation between childhood bilingualism and switching abilities.

Plurilingualism as a Catalyst for Creativity in Superdiverse Societies: A Systemic Analysis

Post-industrial societies are characterized by a high degree of mobility which manifests itself through waves of migration and affects all knowledge domains and all aspects of both individual and collective lives. This situation presents challenges under the pressure of a powerfully uniformizing globalization. However, the exponential increase of diversity linked to intensified mobility is also conducive to social transformations since, when the numerous languages and cultures of the migrants encounter the languages and cultures of the host countries, they act as catalyzers of change. This article considers such social transformation in the light of the concept of plurilingualism as distinct from multilingualism, explaining the advantages of the former over the latter in such contexts, and analyzes possible synergies between plurilingualism and creativity through the lens of complexity theories and the theory of affordances, with the related concepts of 'affordance spaces' and landscape of affordances. After a brief introduction of the main tenets of complexity theories and affordances, the article builds on three complementary models of creativity, using complexity theories as a framework and discusses the specific characteristics and potential of plurilingualism by explaining how it can transform diversity from an obstacle into an opportunity, a possibility for action. The triadic relationship between creativity, plurilingualism, and complexity is considered. As a result, the article suggests that plurilingualism can create conditions conducive to creativity thanks to its multiple and flexible nature that values all forms of cross-fertilization and the uniqueness of the resulting individual trajectories. Without claiming any causal relationship between plurilingualism and creativity, the paper explains the reasons why it is crucial to nurture and foster plurilingualism in order to provide favorable conditions for creativity and change. The article explains the characteristics and implications of plurilanguaging, and the potential for individuals to embrace a holistic, complex view of languages and cultures and to experience empowerment in the process of perceiving and exploring linguistic and cultural diversity, hybridity and interconnections, thus discovering and liberating their full creative repertoire.

The Effect of Forced Language Switching during Divergent Thinking: A Study on Bilinguals' Originality of Ideas

In the present study we experimentally manipulated language switching among bilinguals who indicated to be more or less habitual language switchers in daily life. Our aim was to investigate the impact of forced language switching on originality of produced ideas during divergent thinking, conditional on the level of habitual language switching. A sample of bilinguals was randomly assigned to perform alternate uses tasks (AUT’s), which explicitly required them to either switch languages, or to use only one language while performing the tasks. We found that those who were instructed to switch languages during the AUT’s were able to generate ideas that were on average more original, than those who were instructed to use only one language during the AUT’s, but only at higher levels of habitual language switching. At low levels of habitual language switching, the effect reversed, and participants who were instructed to use only one language found ideas that were on average more original, than participants who were required to switch languages during the AUT’s. Implications and limitations are discussed.