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Does bilingualism shape inhibitory control in the elderly?
Abstract
Bilingualism has been argued to benefit executive functioning. However, recent research suggests that this advantage may stem from uncontrolled factors or incorrectly matched samples. In this study we test the effects of bilingualism on elderly lifelong bilinguals whose cognitive abilities are in decline, thus making any benefits more salient. Firstly we compare 24 bilinguals and 24 carefully matched monolinguals on verbal and the numerical Stroop tasks, obtaining no differences in monitoring or inhibitory measures. Secondly we explore the modulations that the proficiency in the L2 might cause to executive control functions, as measured by the same tasks, by testing 70 elderly bilinguals who vary in their L2 mastery from very low to perfectly fluent. Results show no modulation in any of the indices due to L2 proficiency. These results add to the growing body of evidence showing that the bilingual advantages might indeed be due to other factors rather than bilingualism.
... Regarding the languages of the bilinguals, only in six studies did bilingual participants speak the same languages as their L1 and L2 (Ansaldo et al., 2015;Bialystok et al., 2004, Study 1;Billig & Scholl, 2011;de Bruin, Bak, et al., 2015;Kousaie & Phillips, 2012;Sundaray et al., 2018), while in the rest of the studies bilinguals differed in their L1s or L2s. Among these 18 studies, nine did not indicate which of the languages was the L1 or L2 of the bilinguals (Anderson et al., 2017;Anton et al., 2016;Bialystok et al., 2004, Study 2;Grady et al., 2015;Houtzager et al, 2017;Kirk et al., 2014;Kousaie & Phillips, 2017;Sullivan et al., 2016;Zunini et al., 2019). Moreover, in 14 studies monolingual and bilingual participants differed in their L1 (Bialystok et al., 2004, Study 1;Bialystok et al., 2006, Study 2;Bialystok et al., 2008Bialystok et al., , 2014, Studies 1 and 2; Billig & Scholl, 2011;Blumenfeld et al., 2016;Clare et al., 2016;de Bruin, Bak, et al., 2015;Houtzager et al., 2017;Luo et al., 2013;Massa et al., 2020;Schroeder & Marian, 2012;Sundaray et al., 2018). ...
... Overall, only two studies clearly stated that the L1 was the same for all monolinguals and bilinguals included (Ansaldo et al., 2015;Kousaie & Phillips, 2012). Moreover, the testing language was only reported in three studies (Anderson et al., 2017;Ansaldo et al., 2015;Anton et al., 2016). In another study, although not reported by the research team, the testing language could be estimated (Kousaie & Phillips, 2012). ...
... Bak, et al., 2015;Houtzager et al., 2017;Luo et al., 2013;Sundaray et al., 2018). Moreover, except for nine studies (Anderson et al., 2017;Anton et al., 2016;Bialystok et al., 2006, Study 2;Billig & Scholl, 2011;Houtzager et al., 2017;Kirk et al., 2014;Massa et al., 2020;Sullivan et al., 2016;Zunini et al., 2019), the rest of the studies also assessed language abilities by conducting standardized verbal tests. Controlled confounders. ...
Aims and Objectives:
Bilinguals have been claimed to develop superior executive functioning compared to monolinguals due to their continuous experience of controlling two languages. Given the developmental trajectory of executive functions, a bilingual advantage could be more pronounced at an advanced age. To gain a clearer understanding, we reviewed the effect of bilingualism executive functions in healthy older adults.
Methodology:
The present paper systematically examines the methods and the results of 24 studies from 22 articles comparing healthy older monolinguals and bilinguals in at least one domain of executive functions.
Data and Analysis:
Data of each study were extracted for sample characteristics, country, language background and measures, controlled confounders and task paradigms. Study quality was also calculated for each study.
Findings and Conclusions:
In general, nine out of the 24 studies fully supported the notion of a bilingual advantage. Four studies showed a bilingual disadvantage. The rest of the studies challenged the existence of a bilingual advantage, as neither full support for bilingual advantages nor bilingual disadvantages were seen in various domains. The available data did not clearly support the widespread notion that bilingualism is related to a general advantage in executive control. However, when looking at the domains of executive functions separately, bilingualism was reliably associated with an advantage in inhibition, especially in two commonly applied tasks: the Stroop test and the Simon task.
Originality:
This is the first systematic review aimed at exploring the link between bilingualism and executive functions in healthy older adults.
Significance/Implications:
Heterogeneity in study characteristics and control of confounding variables may partially explain some of the inconsistencies found between studies. Therefore, well-designed studies that measure all core domains of executive functions and consider confounding variables are urgently needed.
... Bilinguals should select the most appropriate language according to the context in which they are exposed, being careful with not merging words from both spoken languages, which is not the case with monolinguals. This need stimulates the execu-tive functions, especially aspects of inhibition, such as the suppression of dominant responses, task switching and monitoring (ANTÓN et al., 2016). ...
... Simon (stimuli presented to the computer, being squares of two different colors in which the sample must associate each color to a specific key) and Flanker task (similar to Simon, however with arrows pointing to the left or right side); this processing is done by the executive functions. Its stimulation reflects on the alteration of this system, generating prolonged effects on cognition (ANTÓN et al., 2016;BIALYSTOK et al., 2009;BIALYSTOK, 2016;COSTA;SEBASTIÁN-GALLÉS, 2014;MINDT et al., 2008). ...
... In this study they found that bilinguals obtained benefits. Antón et al. (2016) rigorously selected bilingual and monolingual elders within the same methodological factors (demographic factors, schooling, IQ percentage, level of proficiency for comprehension and production of both languages, age of acquisition of L2) and within that study they found no meaningful differences between the performance of bilinguals and monolinguals, concluding that bilingual exposure does not represent advantages in executive functions in healthy elderly people. A study conducted in 2004 by the Bialystok group to assess cognitive decline in bilingual and monolingual adults and seniors evaluated a population aged 30 to 80 years old. ...
... As the results became substantial after the inclusion of two variables of proficiency and mixing, the results may also become significant if different modules of proficiency, domination, usage, and mixing of LHQ 3, were used along with the number of languages spoken. Multilingualism and cognition domain has multiple influencing factors, often producing inaccurate findings [87] . Involvement of the multiple influencing variables and unfitting inclusion of various modules of language questionnaires can be the chief reason for inconsistent findings in the multilingualism and cognition domain. ...
... In the present research, a few influencing factors were controlled using LHQ 3, such as age, educational background, linguistic proficiency, and the number of languages spoken. However, pinpointing the exact influencing factors is a complicated task that necessitates thorough research on the interrelation of the executive functions [13,87] . In addition, another prevailing variable that was not accounted for was the IQ of the participants. ...
In recent years, the phenomenon of multilingualism has spread throughout the world. Pakistan offers an intriguing picture of multilingualism, yet little research has been done in this domain. The previous body of research in the multilingualism and cognition domain had produced inconsistent findings. This study aimed to investigate the positive impact of multilingualism on executive functions of inhibitory control and working memory in undergraduate students. Twenty participants were hired from a call center organization. A language history questionnaire (LHQ3) was administered along with the Simon and Corsi experimental tasks to measure inhibition and working memory. A simple linear regression analysis was run to find the impact of multilingualism. The data findings showed no impact of multilingualism on inhibitory control and working memory. The results showed insufficient statistical evidence to prove the multilingual advantage. Moreover, the results also projected the involvement of multiple confounding variables that may be the principal reason for inconsistent findings in this field of research. Hence, the bilingual advantage hypothesis is rejected because the findings could not predict the generalizability of the positive effect of multilingualism on the executive functions in the larger population of undergraduates. The study suggests that a multiple hierarchical regression model may be more productive, including multiple confounding variables.
... In processing their two languages, bilinguals have to selectively attend to the target language and context and reduce interference from the non-target language. Bilinguals gain a lot of practice using executive functioning to reduce the interference of the non-target language, thereby potentially leading to an advantage over monolinguals (Antón et al., 2016;Bialystok, 2011;Bialystok et al., 2005;Pelham & Abrams, 2014;Poulin-Dubois et al., 2011). Executive functions (EFs), also known as executive control or cognitive control, refer to a set of top-down cognitive abilities that are required to control individuals' thoughts, actions and underlie goal-directed behavior (Diamond, 2013;Miyake et al., 2000). ...
... Many studies have found that bilinguals performed better on tasks tapping EF (Bialystok et al., 2008;Brito et al., 2016;Grundy & Timmer, 2017;Hernández et al., 2010;Morales et al., 2013). However, other studies have not found these cognitive consequences of bilingual language experience (Antón et al., 2016;Blumenfeld & Marian, 2014;Desjardins et al., 2020;Filippi et al., 2020;Hilchey & Klein, 2011;Kousaie et al., 2014;Lee Salvatierra & Rosselli, 2011;Massa et al., 2020;Mor et al., 2014;Morrison & Taler, 2020;Morton & Harper, 2007;Papageorgiou et al., 2019). Further, a series of large-scale studies (e.g., Dick et al., 2019;Nichols et al., 2020) and exhaustive meta-analyses (like those by Anderson et al., 2020;Donnelly et al., 2019;Gunnerud et al., 2020;Lehtonen et al., 2018;Lowe et al., 2021) have found minimal or null effects of bilingualism on cognitive functioning. ...
In processing their two languages, bilinguals have to selectively attend to the target language and reduce interference from the non-target language. This experience may have specific cognitive consequences on Executive Functions (EF) through bilingual language processing. Some studies found cognitive consequences in executive functioning skills. However, other studies did not replicate these findings or found a bilingual disadvantage. The aim of this study was to test for the cognitive consequences of bilingualism in EF among a large number of young adults using a latent variable approach, to rule out non-EF task differences as an explanation for inconsistency across studies. Also, we were interested in testing the EF structure using the Confirmatory Factor Analysis (CFA) approach. The results did not support a cognitive consequence of bilingualism and also the EF structure was the same for both groups. We discuss other possible variables that might contribute to the mixed results across studies.
... The generally accepted explanation for the positive effects of bilingualism on domain-general non-linguistic skills is based on the assumption that the continuous use and control of, as well as the need to switch between, two languages provides speakers with additional cognitive training that improves the executive control system. Assuming that both languages are constantly active in bilinguals, even if only one of them is actually spoken in a given setting, attention needs to be focused on the target language and the non-target language must be inhibited to avoid interference that could harm effective communication (see Luk et al. 2011;Antón et al. 2016). ...
... It is worth noting that the fast-growing literature on bilingualism and executive control has been qualified by failures to replicate bilingual advantages. These null results lead several independent research groups to call into question the validity of the putative cognitive benefits of bilingualism and to conclude that the so-called bilingual advantage is either non-existent or might only occur under very specific circumstances (e.g., Antón et al. 2016;Cox et al. 2016;Clare et al. 2016Clare et al. , 2010De Bruin et al. 2015a;Duñabeitia et al. 2014;Gathercole et al. 2014;Hilchey and Klein 2011;Klein 2016;Kousaie and Phillips 2012a, b;Lawton et al. 2015;Morton and Harper 2007;Paap 2014;Paap and Greenberg 2013;Paap et al. , 2015aYeung et al. 2014;Zahodne et al. 2014). According to Kenneth R. Paap, one of the most prominent of the critics, and his colleagues (Paap 2015;Paap et al. 2015bPaap et al. , 2016, previous research relied on small sample sizes and neglected the role of potentially confounding socio-demographic factors such as immigrant status, educational level, and socio-economic status. ...
This chapter provides an overview of the development of research on the effects of bilingualism on cognitive performance from the beginning of the twentieth century until today. It presents the different stances that research has taken toward bilingualism at different moments in time and in different countries.
... Studies by Puric et al. (2017) and Javan and Ghonsooly (2017) were also unable to find an advantage in inhibitory control following second-language immersion learning in children. Anton et al. (2016), who compared elderly monolinguals and bilinguals on verbal and numerical Stroop tasks, found no differences in monitoring or inhibitory measures between the two groups. In the present and the above-discussed studies, there was no cross-domain advantage, and this is found irrespective of the age of the participants. ...
... First are studies that compared the performance of adults-who learned a new language-with that of a control group. Some studies find a positive influence of language training on behavioral measures of executive function (Bak et al. 2016; but see Anton et al. 2016). Second, studies that compared children in dual immersion programs show that there is some degree of improvement but not in all aspects (Javan and Ghonsooly 2017;Nicolay and Poncelet 2013). ...
This study investigated whether a short training (8 weeks) in the second-language (English) has any facilitative effect on components of executive functions in young adults. A pre-post design was used with two groups of participants: one group (experimental group) of students received English language training for eight weeks, and another group (control group) matched on age and background did not. Executive function tasks (Flanker, Stroop, and color-shape switching task) along with the object naming and working memory tasks were administered before and after the training. We observed that the experimental group demonstrated significant improvement in task switching, working memory capacity, and language skills. Findings from the study provide evidence that short training in second-language can enhance some components of executive functions besides improving language skills in young adult students. This finding contributes to a better understanding of language training and executive function among young adult bilinguals.
... In the last decade, however, many studies failed to find evidence for EF differences favouring multilinguals over monolinguals. This holds for children, young, and older adults (e.g., Antón et al., 2016;Gathercole et al., 2014;Nichols et al., 2020;Studenica et al., 2022). Reflecting this, recent meta-analyses on the multilingual EF impact across the lifespan typically report smaller effect sizes (see also systematic reviews and quantitative analyses of, for example, Degirmenci et al., 2022, for older adults;Grundy, 2020, for young adults;Planckaert et al., 2023 andYurtsever et al., 2023, for children). ...
Whether speaking two or more languages (multilingualism) or dialects of one language (bidialectalism) affect executive function (EF) is controversial. Theoretically, these effects may depend on at least two conditions. First, the multilingual and bidialectal characteristics; particularly, (second) language proficiency and the sociolinguistic context of language use (e.g., Green & Abutalebi, 2013). Second, the EF aspects examined; specifically, recent accounts of the locus of the multilingual effect propose a general EF effect rather than an impact on specific processes (Bialystok, 2017). We compared 52 “monolingual” (with limited additional-language/dialect experience), 79 bidialectal and 50 multilingual young adults in the diglossic context of Cyprus, where bidialectalism is widespread and Cypriot and Standard Greek are used in different everyday situations. Three EF processes were examined via seven tasks: inhibition, switching and working memory (Miyake et al., 2000). We found better multilingual and bidialectal performance in overall EF, an effect moderated by high (second) language proficiency.
... This finding is interesting, as literature regarding the effects of L2 proficiency on inhibition is highly controversial. In a study on elderly bilinguals, no effect of L2 proficiency was found, either on a numerical or on a verbal Stroop task (Antón et al. 2016). Neuroimaging evidence suggests that higher L2 proficiency is associated with more automatic and efficient inhibitory control on a Simon task (Jia 2022). ...
Most studies regarding the relationship between multilingualism and cognitive control reduce linguistic diversity to a dichotomous comparison, viz., monolinguals vs. bilinguals, failing to capture the multifactorial nature of multilingualism. Language research is largely restricted to the Global North, albeit most of the world’s population resides in the Global South, limiting the interpretability of the existing literature. Cognitive performance is assessed using very few tasks, yielding unreliable measurements. In this study, we identify the manner in which multilingual experiences influence cognitive performance in diverse sociolinguistic contexts. Young adults from the UK (n = 51, mean age = 24.0, SD = 3.18) and Singapore (n = 36, mean age = 21.3, SD = 2.15) were tested using an extensive battery of cognitive tasks, including cognitive flexibility (CF), working memory (WM), inhibition, and structure learning (SL). Information on language proficiency, use, age of acquisition, and frequency of switching was collected. The effects of various linguistic factors on the cognitive performance of each group were assessed using multiple linear regression models. The UK and Singapore samples exhibited significantly different linguistic profiles, which in turn dissimilarly influenced their cognitive performance. Our study underscores the necessity for more research in the Global South, challenging the prevailing Northern-centric focus on the multilingualism–cognition relationship.
... Nilsson and colleagues interpreted these results as an indication of the gradual loss of the brain's ability to adapt its structure as we age. Such findings echo behavioral studies that also did not find effects of bilingual experiences in seniors on inhibitory control (Antón et al., 2016) and switching (Ramos et al., 2017; but see Bak et al., 2014). It also prompts the DRM and other models of neuroplasticity to incorporate the age at which a new experience is exercised into the models' predictions (effects of age on L2 are further discussed in Fromont, this volume). ...
... On the other hand, along with the positive findings supporting the bilingual cognitive advantage, numerous studies have failed to obtain compatible results (Duñabeitia et al., 2014;Antón et al., 2016). Furthermore, sharing one brain's capacity across several languages means using each lexical item less frequently and accurately, potentially, building weaker lexical connections as captured by the weaker links hypothesis (Gollan et al., 2008;; but see Bylund et al. (2022) for the language learning history account). ...
Persistent non-target language co-activation in spoken and visual language comprehension has been found both at the word-level and at the level of a sentence, although in the latter case, sentence bias has been observed to modulate the co-activation which can create lexical competition. In the case of trilingual speakers, both non-target languages may potentially compete with the third language (L3). The current study aimed to investigate how cross-linguistic (or interlingual) competition across three languages is modulated by sentence bias while listening to the L3. Of particular interest was whether top-down sentential information would modulate not only single but also double bottom-up driven cross-linguistic competition.
A picture-word recognition task was given to 44 L1 Russian L2 English late L3 Swedish learners, listening to Swedish sentences online while their reaction times and accuracy were collected. The results revealed shorter processing times and higher accuracy for high- compared to low-constraint sentences and overall lower accuracy (and slower reactions in high-constraint sentences) when an L1 Russian competitor’s translation phonological onset overlapped with a Swedish target word. The findings suggest that when trilinguals were processing their L3 speech, top-down information from the sentential context did not modulate the bottom-up guided L1 phonological competition. However, the effect of an L2 English L3 Swedish cognate competitor was not significant. This pattern of results is in line with BLINCS (Shook & Marian, 2013), which assumes gradual co-activation decay (i.e., a strong cross-linguistic competition effect might be observed in the end-course reaction times) and a direct visual information influence on linguistic processing. It is, however, inconsistent with the BIA+ model (Dijkstra and Van Heuven, 2002), which predicts that a high-constraint sentence context can modulate cross-linguistic competition, particularly, at later processing stages.
The full text is available at https://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-217738
... Moreover, some research teams were unable to find any cognitive benefit from bilingualism. It is reported that there was no difference between older monolinguals and bilinguals in the numerical Stroop task (Antón et al., 2016), Sustained Attention to Response Task (Kousaie et al., 2014) and the Simon task (Kirk et al., 2014). A selective attention task was reported to find no difference between monolinguals and bilinguals young students (Paap et al., 2018). ...
Full text available here: https://theses.lib.polyu.edu.hk/handle/200/12383
Bilingualism has been attracting interest from the cognitive science field for years as it is suggested to be a protective factor against cognitive decline in ageing. It is often reported that bilinguals performed better than monolinguals in inhibitory control tasks. The mechanism behind the better inhibitory control was that bilinguals would have to suppress the interference from the unwanted language all the time, and such linguistic control is thought to be, at least partially, overlapped with the general inhibitory control network. However, inconsistent results have been reported. It is common for the literature to compare monolinguals with bilinguals as two homogenous groups without considering the individual variations between and among them. Moreover, as the Adaptive Control Hypothesis (Green & Abutalebi, 2013) suggested, the interaction context affects the cognitive demand in controlling the languages. Three experiments were designed to explore how different aspects of bilingualism contribute to cognition and the bilingual advantage effect.
The first experiment recruited older adults to complete a comprehensive set of cognitive tests together with questionnaires on their language and demographic profiles. Comparing the monolinguals and bilinguals, we found the classic bilingual advantage effect: bilinguals scored higher in the Montreal Cognitive Assessment (MoCA), indicating better cognitive status. Moreover, within the bilinguals, the scores in the cognitive battery were predicted with demographic and linguistic variables using linear regression analysis. We found that L2 proficiency predicts better inhibitory control and verbal ability performance in lifelong bilinguals. We propose that, because our participants are L1-dominant speakers, only the sufficiently proficient L2 would provide enough interference in the practice of linguistic inhibition control.
The second experiment investigated the cognitive changes in older foreign language learners. Older adults were recruited to study in an elementary English course for six weeks, with cognitive tests taken before and after the course. Although the statistical results between the intervention group and the active and passive control groups were not significant, the language learning-induced differences were observed in some tasks, including the accuracy of Picture Naming and the Conflicting Effect in the Attention Network Task. Correlation analysis suggested that successful language learners showed an improvement in inhibitory control and a decline in verbal fluency.
The third experiment investigated the organisation of the mental lexicon through an interesting language phenomenon in Hong Kong: dense code-switching. Whereas the literature often suggested that the comprehension of code-switching requires a switch in lexicon and is therefore challenging, we found that switching lexicon was needed only in the case of non-habitual word usage, regardless of whether it was unilingual and code-switching. From the result of this experiment, we proposed that the language input from the community had formed the bilingual prefabs, which integrated into the dominantly Cantonese lexicon.
Collectively, we suggest that the environment, language and cognition form a looping circle in that each component is interrelated. Moreover, they each affect the organisation of the bilingual mental lexicon and the retrieval of concepts from the lexicon. In view of that, we propose the Experience-based Bilingual Mental Lexicon Model, which is modified based on the Revised Hierarchical Model (Kroll & Stewart, 1994). Two critical assumptions are incorporated into the existing model: (1) the language lexicon is organised by experience but not by language origin, and (2) language dominance is dynamic. We believe the proposed model could better capture the dynamic change of language by experience. It could explain how individual differences contribute to the bilingual advantage effect.
References:
Green, D. W., & Abutalebi, J. (2013). Language control in bilinguals: The adaptive control hypothesis. Journal of Cognitive Psychology, 25(5), 515-530. https://doi.org/10.1080/20445911.2013.796377
Kroll, J. F., & Stewart, E. (1994). Category interference in translation and picture naming: Evidence for asymmetric connections between bilingual memory representations. Journal of Memory and Language, 33(2), 149-174. https://doi.org/10.1006/jmla.1994.1008
... These non-replications raise the possibility that any bilingual advantage is too small or unreliable to be of practical significance, or perhaps even an illusion. It should be noted that many of these non-replications of a bilingual advantage (though not all; e.g., Antón et al., 2016) have been obtained with undergraduate or healthy adult participants. The cognitive reserve framework explicitly argues that the "protective" or "beneficial" effects of bilingualism should be most apparent in situations where cognitive resources are heavily taxed or drained. ...
The relation between linguistic experience and cognitive function has been of great interest, but recent investigations of this question have produced widely disparate results, ranging from proposals for a “bilingual advantage,” to a “bilingual disadvantage,” to claims of no difference at all as a function of language. There are many possible sources for this lack of consensus, including the heterogeneity of bilingual populations, and the choice of different tasks and implementations across labs. We propose that another reason for this inconsistency is the task demands of transferring from linguistic experience to laboratory tasks can differ greatly as the task is modified. In this study, we show that task modality (visual, audio, and orthographic) can yield different patterns of performance between monolingual and multilingual participants. The very same task can show similarities or differences in performance, as a function of modality. In turn, this may be explained by the distance of transfer – how close (or far) the laboratory task is to the day to day lived experience of language usage. We suggest that embodiment may provide a useful framework for thinking about task transfer by helping to define the processes of linguistic production and comprehension in ways that are easily connected to task manipulations.
... Only a few studies have tried to assess all three aspects of multifactoriality (Keijzer and Schmid, 2016;Incera and McLennan, 2017;Dash et al., 2019Dash et al., , 2022. The multifactorial nature of bilingualism is established by using the measure of bilingualism on a continuum (Incera and McLennan, 2017;Dash et al., 2019Dash et al., , 2022 or by including subjective and multiple objective measures of bilingualism (Abutalebi et al., 2015;Keijzer and Schmid, 2016;Anderson et al., 2018) or my correlation L2 proficiency differences within the bilingual group with cognitive performance (Abutalebi et al., 2015;Antón et al., 2016;Clare et al., 2016). Dash et al. (2019Dash et al. ( , 2022 created the continuum of bilingualism by using four objective measures of language proficiency and self-reported information using LEAP-Q; and assessed the impact of bilingualism using factor scores on cognitive and neural processes. ...
A better understanding and more reliable classification of bilinguals has been progressively achieved through the fine-tuning methodology and simultaneously optimizing the measurement tools. However, the current understanding is far from generalization to a larger population varying in different measures of bilingualism—L2 Age of acquisition (L2 AOA), L2 usage and exposure, and L2 proficiency. More recent studies have highlighted the importance of modeling bilingualism as a continuous variable. An in-depth look at the role of bilingualism, comparing groups, may be considered a reductionist approach, i.e., grouping based on one measure of bilingualism (e.g., L2 AOA) may not account for variability in other measures of bilingualism (L2 exposure, L2 use or L2 proficiency, amongst others) within and between groups. Similarly, a multifactorial dimension is associated with cognitive performance, where not all domains of cognition and subcomponents are equally influenced by bilingualism. In addition, socio-cultural and demographical factors may add another dimension to the impact of bilingualism on cognitive performance, especially in older adults. Nevertheless, not many studies have controlled or used the multiple socio-cultural and demographical factors as a covariate to understand the role of different aspects of bilingualism that may influence cognitive performance differently. Such an approach would fail to generalize the research findings to a larger group of bilinguals. In the present review paper, we illustrate that considering a multifactorial approach to different dimensions of bilingual study may lead to a better understanding of the role of bilingualism on cognitive performance. With the evolution of various fine-tuned methodological approaches, there is a greater need to study variability in bilingual profiles that can help generalize the result universally.
... For example, Anastasi and Cordova (1953: 3) and Anastasi and Cruz (1953: 357) categorically state that "[t]he native language of the Puerto Rican is Spanish." Still today, many researchers uncritically classify participants on the basis of their nationalities or place of residence (e.g., Costa et al. 2008Costa et al. , 2009Costa and Sebastián-Gallés 2014;Antón et al. 2016). In a similar vein, adjectives that refer to nationality or religion are frequently used to refer to membership in a linguistic group, for example, Jewish or Brazilian, when the authors actually refer to speakers of Yiddish or Brazilian Portuguese, respectively, such as Pintner and Arsenian (1937) and Rutkoski Rodrigues and Zimmer (2016). ...
This chapter is devoted to a widespread and deeply entrenched narrative that metonymically links languages to nations and to issues of national identity and belonging. It is argued that the nation-state myth has had a profound and long-lasting impact on (mainly negative) attitudes toward bilingualism, which becomes manifest to this day in the terminology used to refer to linguistic issues. In line with the basic assumptions of nineteenth-century nationalism and imperialism, the metonymic conflation of languages, language components, speakers, and nations paved the way for the understanding of bilingualism in terms of conflict and rivalry in speakers’ brains: Since languages and their speakers were identified with nations, and nations were considered to be constantly involved in war, it was assumed that interactions between languages in the mind should also be understood in terms of war.
... Another measure that improved equally in both intervention groups, and significantly more than in the Control group, was the time taken to complete the Incongruent Color Naming condition of the Color Word Interference Test (aka Stroop test). A classic test of inhibitory function, the Stroop task is a sensitive measure of executive function, and has been linked to improved performance in bilinguals among older adults in several studies (Bialystok et al., 2004;Bialystok, Poarch et al., 2014;Incera & McLennan, 2018;Kousaie & Phillips, 2017), although findings are mixed (Antón et al., 2016;Kousaie & Phillips, 2012). Notably, this is a timed test, and overall processing speed would be expected to play a role. ...
Bilingualism has been linked to improved executive function and delayed onset of dementia, but it is unknown whether similar benefits can be obtained later in life through deliberate intervention. Given the logistical hurdles of second language acquisition in a randomized trial for older adults, few interventional studies have been done thus far. However, recently developed smartphone apps offer a convenient means to acquire skills in a second language and can be compared with brain training apps specifically designed to improve executive function. In a randomized clinical trial, 76 adults aged 65–75 were assigned to either 16 weeks of Spanish learning using the app Duolingo 30 minutes a day, an equivalent amount of brain training using the app BrainHQ, or a waitlist control condition. Executive function was assessed before and after the intervention with preregistered (NCT03638882) tests previously linked to better performance in bilinguals. For two of the primary measures: incongruent Stroop color naming and 2-back accuracy, Duolingo provided equivalent benefits as BrainHQ compared to a control group. On reaction time for N-back and Simon tests, the BrainHQ group alone experienced strong gains over the other two groups. Duolingo was rated as more enjoyable. These results suggest that app-based language learning may provide some similar benefits as brain training in improving executive function in seniors but has less impact on processing speed. However, future advancements in app design may optimize not only the acquisition of the target language but also the side benefits of the language learning experience.
... Scientists argued that this advantage resulted from bilinguals' life-long practice in inhibiting their non-target language during conversation (Bialystok et al., 2004). However, subsequent studies (e.g., Kirk et al., 2014;Antón et al., 2016) failed to replicate these early findings. Later studies claimed that bilingualism mainly enhanced attentional switching, since bilinguals need to switch attention in order to use different languages in different contexts. ...
... However, these findings are challenged by a number of studies that did not find cognitive control advantages in bilinguals (e.g. Antón et al., 2016;Paap & Greenberg, 2013; see the review by van den Noort et al.,2019). In view of this inconsistency, we set out to explore whether a particular bilingual experience-the studying abroad bilingual experience in an L2 immersion context-moderates performance on cognitive control tasks, especially when participants are very closely matched on confounding variables. ...
Aims and objectives/purpose/research questions
This study investigated whether the studying abroad bilingual experience among unevenly balanced Chinese–English bilinguals exerted influence on cognitive control.
Design/methodology/approach
We compared cognitive control differences between a group of Chinese–English bilinguals (n = 30) studying abroad in the USA and a control bilingual group (n = 30) studying at home in mainland China by administering the Flanker task and the Wisconsin Card Sorting Test (WCST). The two groups were matched on demographic variables including age, socioeconomic status (SES), intelligence, etc.
Data and analysis
A mixed ANOVA was applied to the Flanker task data, with the task condition as the within-subject variable and the participant group as the between-subject variable. Independent t-test analyses were used to compare performance differences between groups on the WCST.
Findings/conclusions
The two groups performed similarly on the Flanker task, whereas the group studying abroad fared better on the WCST, indicating better mental set shifting.
Originality
This is the first study to show that the experience of studying abroad brings about cognitive control advantage in mental set shifting.
Significance/implications
The current research provides the first evidence that the experience of studying abroad is related to the enhancement of cognitive control, which has implications for both cognitive development and international education.
... Several early studies comparing bilinguals and monolinguals showed enhanced performance in bilinguals on various tasks assumed to measure executive functioning (e.g., Bialystok, Craik, & Luk, 2008;Bialystok & Martin, 2004;Costa, Hernández, Costa-Faidella, & Sebastián-Gallés, 2009;Costa, Hernández, & Sebastián-Gallés, 2008). In contrast, there are also many studies reporting no differences between bilinguals and monolinguals on executive control tasks (e.g., Antón et al., 2014Antón et al., , 2016Duñabeitia et al., 2014;Gathercole et al., 2014;Paap & Greenberg, 2013), especially in studies using larger sample sizes (e.g., Antón, Carreiras, & Duñabeitia, 2019;Duñabeitia et al., 2014;Nichols et al., 2020;Paap & Greenberg, 2013). ...
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 paper 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.
... As a result of the correlation analysis, it was found that the accuracy of performing tasks in the language is significantly related to the level of proficiency of respondents in the main foreign language. It is important to note that the level of language proficiency is closely related to the time of the beginning of learning it, so the training itself for several years may not bring significant changes in the effectiveness of cognitive control, as was shown in studies of the impact of late learning a foreign language on the indicators of cognitive aging [21]. ...
Cognitive control plays an important role in regulating attention and behavior. Research has shown a cognitive advantage in bilinguals, however whether these results apply to people learning a foreign language later in life using formal education is not entirely clear. Due to globalization processes more people tend to communicate in multiple languages. Learning foreign languages has become a part of the compulsory education curriculum worldwide. In this work we investigate the relation between foreign language proficiency and the efficacy of the cognitive control functions: inhibition and task switching. Computerized cognitive control tasks were completed by 63 participants (45 women, aged 19–33). The acquired data was factorized resulting in 3 measures of cognitive control efficacy: general efficacy, accuracy of inhibition, and accuracy of task switching. Using the Spearman’s correlation analysis, we found that the accuracy of task switching is significantly linked with the level of language proficiency. These results are in line with the previous findings suggesting that code switching strongly involves the cognitive control functions in bilinguals.
... Overall, in line with many recent studies (e.g., Antón et al., 2016;Duñabeitia et al., 2014;Ladas et al., 2015;Paap et al., 2015;Vivas et al., 2017;Von Bastian et al., 2016) and meta-analyses (e.g., Lehtonen et al., 2018), we did not find consistent and substantial evidence in support of a bilingual cognitive advantage, when grouping participants based on either acculturation strategy (bicultural vs. monocultural), or bilingual profile (balanced vs. unbalanced). In the last decade, many authors have supported that specific factors related to bilingualism, such as bilingualism onset (e.g., Luk et al., 2011), language switching frequency (e.g., Prior & Gollan, 2011;Soveri et al., 2011;Verreyt et al., 2016;, bilingualism type in terms of how balanced language development is (in terms of proficiency; e.g., Bialystok et al., 2006;Yow & Li, 2015), or type of interactional context (e.g., Guerrero et al., 2015;Hartanto & Yang, 2016), may account for discrepancies in the findings regarding the bilingual advantage. ...
The idea that being bilingual benefits one’s cognitive development and performance has been greatly challenged over the last years. If such an effect exists, as some studies continue to show, it might actually be restricted to particular contexts and bilingual profiles; not unlikely, considering the enormous diversity in the latter across the world. In this study, we assessed four different bilingual populations (N = 201) and two monolingual populations (N = 105), in the Balkan region. We formed bilingual groups based on (a) acculturation strategy (Bicultural vs Monocultural), (b) linguistic distance, as well as (c) bilingual profile (balanced vs unbalanced), based on linguistic, affective, and acculturation measures and cluster analysis. Beyond prior work, this allowed us to explore the specific conditions under which any cognitive advantage may be observed in bilinguals. We did not find systematic evidence for positive effects of bilingualism, biculturalism, or a balanced bilingual profile on inhibitory control, cognitive flexibility, monitoring, and proactive-reactive control management. The only evidence pointing to an advantage was restricted to Bosnian-Albanian bilinguals (linguistic distance analyses) and their conflict monitoring and general monitoring capacities. Acculturation strategy though, played an important role in shaping the bilinguals’ language profile, and appeared to have independent effects on cognition from bilingualism. On this basis, acculturation should be considered in future explorations of bilingual cognitive development.
... Several studies have shown that the bilingual advantage increases with task difficulty (Bialystok, 2006;Costa et al., 2009;Hernández et al., 2013;Qu et al., 2015). However, other studies have failed to find evidence for a cognitive benefit of bilingualism (Paap and Greenberg, 2013;Antón et al., 2016;Scaltritti et al., 2017). Different factors have been proposed as contributing to the inconsistencies found in the literature, such as task impurities when assessing EF (Hartanto and Yang, 2020), as well as differences in study designs, assessment tasks, and insufficient assessment of other variables known to modulate cognition such as physical exercise and cognitive stimulation (Calvo et al., 2016). ...
Findings suggest a positive impact of bilingualism on cognition, including the later onset of dementia. However, it is not clear to what extent these effects are influenced by variations in attentional control demands in response to specific task requirements. In this study, 20 bilingual and 20 monolingual older adults performed a task-switching task under explicit task-cuing vs. memory-based switching conditions. In the cued condition, task switches occurred in random order and a visual cue signaled the next task to be performed. In the memory-based condition, the task alternated after every second trial in a predictable sequence without presenting a cue. The performance of bilinguals did not vary across experimental conditions, whereas monolinguals experienced a pronounced increase in response latencies and error rates in the cued condition. Both groups produced similar switch costs (difference in performance on switch trials as opposed to repeating trials within the mixed-task block) and mixing costs (difference in performance on repeat trials of a mixed-task block as opposed to trials of a single-task block), but bilinguals produced them with lower response latencies. The cognitive benefits of bilingualism seem not to apply to executive functions per se but to affect specific cognitive processes that involve task-relevant context processing. The present results suggest that lifelong bilingualism could promote in older adults a flexible adjustment to environmental cues, but only with increased task demands. However, due to the small sample size, the results should be interpreted with caution.
... Given well-established age-related declines in such cognitive abilities (see section 2.1.2), one implication of these models might be that L1/L2 grammatical processing differences should increase with agingat least to the extent that L2 speakers' cognitive abilities decline to the same extent and in a similar manner as L1 speakers', which some evidence suggests (Anderson, Saleemi & Bialystok, 2017;Antón, García, Carreiras & Duñabeitia, 2016;Cox et al., 2016;Gathercole et al., 2014;Kirk, Fiala, Scott-Brown & Kempe, 2014;Kousaie & Phillips, 2012;Kousaie, Sheppard, Lemieux, Monetta & Taler, 2014;Nichols, Wild, Stojanoski, Battista & Owen, 2020). In this case, we would expect that older L2 speakers' grammatical processing differs more from that of age-matched L1 speakers, as compared to L1/L2 differences found at younger age. ...
Substantial research has examined cognition in aging bilinguals. However, less work has investigated the effects of aging on language itself in bilingualism. In this article I comprehensively review prior research on this topic, and interpret the evidence in light of current theories of aging and theories of bilingualism. First, aging indeed appears to affect bilinguals' language performance, though there is considerable variability in the trajectory across adulthood (declines, age-invariance, and improvements) and in the extent to which these trajectories resemble those found in monolinguals. I argue that these age effects are likely explained by the key opposing forces of increasing experience and cognitive declines in aging. Second, consistent with some theoretical work on bilingual language processing, the grammatical processing mechanisms do not seem to change between younger and older bilingual adults, even after decades of immersion. I conclude by discussing how future research can further advance the field.
... While there are a considerable number of behavioural studies showing evidence for a bilingual advantage in inhibition or the ability to suppress irrelevant information (Bialystok et al., 2004(Bialystok et al., , 2008Bialystok et al., 2014) and in switching abilities or the ability to disengage attention from one stimulus or set of features and deploy it to others (Grundy et al., 2017b;Prior and Macwhinney, 2010;Vega-Mendoza et al., 2015), there are also a substantial number of studies showing no behavioural differences in inhibition (Antón et al., 2016;Kirk et al., 2014) or switching (Mor et al., 2015;Ramos et al., 2017). Several studies have also investigated other executive functions, specifically, working memory and conflict monitoring. ...
... This implies that the bilingual cognitive advantage would emerge as a result of actively using two languages and switching between them during the processes of speech comprehension and production, whereby bilinguals constantly put their inhibition skills into practice to suppress one of their languages. Recent evidence, however, has not supported this explanation as bilinguals do not consistently outperform monolinguals in tasks that assess solely response inhibition skills Antón, Carreiras, & Duñabeitia, 2019;Antón, García, Carreiras, & Duñabeitia, 2016;Barac, Moreno, & Bialystok, 2016;Carlson & Meltzoff, 2008;Duñabeitia et al., 2014;Esposito, Baker-Wand, & Mueller, 2013;Martin-Rhee & Bialystok, 2008;Paap, Johnson, & Sawi, 2015). Instead, more recent accounts have emphasised the role of attentional flexibility rather than inhibition (Bialystok, 2017), specifically bilinguals' ability to selectively allocate their attentional resources in cognitively demanding or effortful tasks such as tasks that involve conflicting cues or require participants to switch attention from one cue to another (Costa, Hernández, Costa-Feidella, & Sebastián-Gallés, 2009). ...
Bilingualism is a powerful experiential factor, and its effects have been proposed to extend beyond the linguistic domain by boosting the development of executive functioning skills. Crucially, recent findings suggest that this effect can be detected in bilingual infants before their first birthday indicating that it emerges as a result of early bilingual exposure and the experience of negotiating two linguistic systems in infants’ environment. However, these conclusions are based on only two research studies from the last decade (Comishen, Bialystok, & Adler, 2019; Kovács & Mehler, 2009), so to date, there is a lack of evidence regarding their replicability and generalisability. In addition, previous research does not shed light on the precise aspects of bilingual experience and the extent of bilingual exposure underlying the emergence of this early bilingual advantage. The present study addressed these two questions by assessing attentional control abilities in seven‐month‐old bilingual infants in comparison to same‐age monolinguals and in relation to their individual bilingual exposure patterns. Findings did not reveal significant differences between monolingual and bilingual infants in the measure of attentional control and no relation between individual performance and degree of bilingual exposure. Bilinguals showed different patterns of allocating attention to the visual rewards in this task compared to monolinguals. Thus, this study indicates that bilingualism modulates attentional processes early on, possibly as a result of bilinguals’ experience of encoding dual‐language information from a complex linguistic input, but it does not lead to significant advantages in attentional control in the first year of life.
Aims and objectives
The paper describes a study whose objective was to find whether there are any differences in inhibitory control measured with the Stroop test between Swedish early childhood (EC) monolingual and EC (bi-) multilingual university students in the language which is not their EC language and whether one can observe a relationship between the perceived proficiency in the subjects’ mother tongues and their Stroop Effect.
Methodology
The analyses were conducted on a cohort of 105 students (41 EC monolinguals and 64 EC multilinguals) who took the Stroop test, the results of which (Stroop Effect) were compared for both the groups. A comparison was also made for multilinguals’ perceived proficiency in their mother tongues.
Data and analysis
The data obtained via questionnaires and from a computerized version of the Stroop test were compared for EC monolinguals/EC multilinguals and evaluated statistically.
Findings/conclusion
The results show no statistically significant difference in the inhibitory control measured by the Stroop test between the EC monolinguals and EC multilinguals. The only significant difference the analysis found between the groups is in reaction times, as the EC multilinguals reacted faster in both congruent and incongruent conditions. The analysis conducted among the EC multilinguals does not indicate any relationship between the perceived proficiency in their mother tongues and Stroop effect.
Originality and implication
The findings contribute to a recent debate questioning cognitive early adulthood advantages of being an EC multilingual. Unlike the majority of other studies investigating inhibitory control, the Stroop test in this study was conducted in young adults and in the language (learnt at school and through extracurricular activities) in which all the students were on approximately the same proficiency level. The findings also bear relevance to future research on the relationship between inhibitory control and academic performance in young adults.
This collection brings together two areas of research that are currently receiving great attention in both scientific and public spheres: cognitive aging and bilingualism. With ongoing media focus on the aging population and the need for activities to forestall cognitive decline, experiences that appear effective in maintaining functioning are of great interest. One such experience is lifelong bilingualism. Moreover, research into the cognitive effects of bilingualism has increased dramatically in the past decade, making it an exciting area of study. This volume combines these issues and presents the most recent research and thinking into the effects of bilingualism on cognitive decline in aging. The contributors are all leading scholars in their field. The result is a state-of-the art collection on the effect of bilingualism on cognition in older populations for both healthy aging and aging with dementia. The papers will be of interest to researchers, students, and health professionals.
While previous research has identified executive functions as predictors of academic performance in school children, similar studies conducted among adults show mixed results. One of the reasons given for executive functions having a limited effect on academic achievements in adulthood is that they are usually fully developed by that time. Since these executive functions are at their peak at that age, the individual differences in these as well as their influence on academic performance in adults are harder to trace. The paper describes a study conducted among 107 university students the goal of which was to find out whether there is any relationship between the adult students’ inhibitory control values measured with the Stroop Test and their academic achievements. Although the results indicate a weak correlation between the Stroop Effect and the students’ academic performance of low statistical significance, which seems to confirm the outcomes of the previous studies focusing on adults, the study reveals an unexpected statistically significant correlation between the students’ grade averages and the number of their incorrect color identifications. This phenomenon appears to be worth pursuing in future research since it suggests the existence of another, relatively quickly measurable, variable possibly reflecting other predictors of academic performance in adults such as a degree of their manifested conscientiousness, their ability to concentrate on an assigned, relatively short, one-off task and their attitude to fulfilling this task. The Stroop Test, despite not being originally designed for this purpose, might thus be used as a simple tool suitable for providing information about these variables via the subject’s number of color identification errors. Such information can subsequently inform the activities that educators may include in their curricula to foster conscientiousness and concentration in the students lacking these.
Background and Objectives
Bilingualism has been suggested to protect older adults from cognitive aging and delay the onset of dementia. However, no studies have systematically explored bilingual usage as a tool to mitigate age-related cognitive decline. We developed the Dual-Language Intervention in Semantic memory—Computerized (DISC), a novel cognitive training program with three training tasks (object categorization, verbal fluency, and utility of things) designed specifically for older adults that featured two modes: single-language (SL) exposure mode and dual-language (DL) exposure mode.
Research Design and Methods
The final sample included 50 cognitively healthy (CH; 33 female, Mage = 72.93 years, range = 53.08–87.43 years) and 48 cognitively impaired (CI; 35 female, Mage = 80.93 years, range = 62.31–96.67 years) older adults, randomly assigned them into one of three groups: SL group, DL group, and control group (no training). Participants in SL and DL groups used DISC in either SL mode (i.e., training instructions were spoken in only one language throughout the entire training) or DL mode (i.e., training instructions alternated between two languages), respectively, for 24 sessions. Participants in the control group were asked to continue with their normal daily activities (e.g., playing bingo and reading newspapers).
Results
For CH older adults, we found significant improvements in the Rey Auditory Verbal Learning Test (RAVLT) Trial 5 score and the Clock Drawing Test score in the DL group but not in the SL and control groups posttraining compared with pretraining. For CI older adults, there was a delayed improvement in the RAVLT Trial 1, six months later.
Discussion and Implications
Our findings provided novel evidence that implementing DL cognitive training benefits CH older adult’s late verbal learning and visuospatial construction skills, and a delayed improvement in CI older adults’ early verbal learning abilities.
The protective effects of multiple language knowledge on the maintenance of cognitive functions in older adults have been discussed controversially, among others, because of methodological inconsistencies between studies. In a sample of N = 528 German monolinguals and multilinguals (speaking two or more languages) older than 60 years, this study examined (1) whether speaking multiple languages is positively related to performance on tasks of interference suppression, working memory, concept shifting, and phonemic and semantic fluency, and (2) whether language proficiency and age of second language acquisition (AoA) are associated with cognitive performance of multilinguals. Controlling for education and daily activity, we found small cognitive benefits of speaking multiple languages on interference suppression, working memory, and phonemic fluency, but not on concept shifting and semantic fluency. Furthermore, no substantive correlations were found between language proficiency or AoA and cognitive performance. In conclusion, multilingualism appears to have small incremental effects on cognitive performance beyond education and daily activity in older age that are task-specific and widely independent of proficiency and AoA.
In our increasingly multilingual modern world, understanding how languages beyond the first are acquired and processed at a brain level is essential to design evidence-based teaching, clinical interventions and language policy. Written by a team of world-leading experts in a wide range of disciplines within cognitive science, this Handbook provides a comprehensive overview of the study of third (and more) language acquisition and processing. It features 30 approachable chapters covering topics such as multilingual language acquisition, education, language maintenance and language loss, multilingual code-switching, ageing in the multilingual brain, and many more. Each chapter provides an accessible overview of the state of the art in its topic, while offering comprehensive access to the specialized literature, through carefully curated citations. It also serves as a methodological resource for researchers in the field, offering chapters on methods such as case studies, corpora, artificial language systems or statistical modelling of multilingual data.
Bilingualism is a ubiquitous global phenomenon. Beyond being a language experience, bilingualism also entails a social experience, and it interacts with development and learning, with cognitive and neural consequences across the lifespan. The authors of this volume are world renowned experts across several subdisciplines including linguistics, developmental psychology, and cognitive neuroscience. They bring to light bilingualism’s cognitive, developmental, and neural consequences in children, young adults, and older adults. This book honors Ellen Bialystok, and highlights her profound impact on the field of bilingualism research as a lifelong experience. The chapters are organized into four sections: The first section explores the complexity of the bilingual experience beyond the common characterization of “speaking multiple languages.” The next section showcases Ellen Bialystok’s earlier impact on psychology and education; here the contributors answer the question “how does being bilingual shape children’s development?” The third section explores cognitive and neuroscientific theories describing how language experience modulates cognition, behavior, and brain structures and functions. The final section shifts the focus to the impact of bilingualism on healthy and abnormal aging and asks whether being bilingual can stave off the effects of dementia by conferring a “cognitive reserve.”
Elebidun izateak baditu ondorioak, hizkuntza baten baino gehiagotan komunikatzeko gaitasuna izateaz gain. Hori horrela, elebidunen eta elebakarren arteko alderaketek zientzialari askoren interesa piztu dute aspalditik. Artikulu honetan, ondorio linguistikoei eta kognitiboei erreparatuko diegu, ondorio positiboei zein negatiboei, eta horretarako hainbat ikerketaren emaitzetan oinarrituko gara. Halaber, “abantaila elebidunaren” hipotesia aurkeztuko dugu.
We report a systematic review and exploratory meta-regression to investigate the hypothesis that the effects of bilingualism on cognitive aging are modulated by the linguistic distance (LD) between the pair of languages a bilingual uses. The protocol was pre-registered on PROSPERO (CRD42021238705) and the Open Science Framework (DOI 10.17605/OSF.IO/VPRBU). Results suggest that healthy bilingual seniors speaking more distant language pairs show improved monitoring performance on cognitive tasks. Evidence regarding a modulatory influence of LD on the age of dementia diagnosis was inconclusive due to the small number of published studies meeting our inclusion criteria. We recommend more detailed reporting of individual differences in bilingual experience to assess the impact of LD and other variables on typical cognitive aging and the development of dementia. Linguistic differences in samples should also be considered as a constraint on bilingual advantage in future studies.
Drawing on the adaptive control hypothesis, we examined whether older adults’ bilingual interactional contexts of conversational exchanges would predict important indices of executive functions (EF). We assessed participants’ engagement in each bilingual interactional context – single-language, dual-language, and dense code-switching – and their performance on a series of nonverbal EF measures. Sixty-nine healthy older adults (M age = 70.39 years; ages 60–93) were recruited from local community centers. We found that the dense code-switching context was associated with enhanced overall EF, but not individual facets of EF (inhibitory control, shifting, and updating). These findings held true when we controlled for a host of covariates. Our findings shed light on aging bilinguals’ interactional contexts as crucial bilingual experiences that modulate overall EF. Given that bilingualism is a multidimensional construct, rather than a unidimensional variable, our study underscores the importance of more fine-grained operationalisation of bilingualism when studying its impacts on EF.
This chapter situates the previous findings within a broader context of knowledge production in research and society. It is argued that the archetype of Cognitive Psychology’s metaphorical models of bilingualism is the life-as-a-struggle metaphor, which is historically and ideologically linked to Darwin’s evolutionary theory. To the extent that this metaphor became a dominant paradigm in a broad range of disciplines from the Sciences and Humanities, it was also able to spread into public thinking and discourse, and to become an epochal-making, overarching explanatory pattern of our time. Once being established in experimental research on bilingualism and cognition, the life-as-a-struggle metaphor received different interpretations according to changing mainstream beliefs and attitudes toward bilingualism that evolved in the course of the twentieth century, under the successive influence of imperialism and nationalism, postmodernity, and neoliberal multiculturalism. All this reveals that research is not an objective search for “truth,” but a socio-culturally situated practice of knowledge production, whose results are strongly influenced by context and ideological stance.
This chapter discusses two metaphors that academic discourse relied on at different moments in time to describe human brains and mental activities: the mind is an organism and the mind is a machine. In the course of the investigation period, researchers increasingly moved away from an organic understanding of language as being intimately interconnected with emotions, ways of thinking, as well as individual and collective identity, in order to adopt a mechanistic or computational view of mental processes and speech production. This shift allowed speed and efficiency to become core values in scientific discourse on bilinguals’ cognitive performance.
Significance
Given that using multiple languages incorporates cognitive functions that require a harmony of the whole brain, can we tell whether a child is monolingual or multilingual by only looking at the pattern of functional connectivity? Here, we show that the multilingual experience modulates the functional connections of multilinguals enough to be distinguished from monolinguals. The pattern is distinctive when children are performing an emotional n-back task and even at rest. Furthermore, we found that multilingual children have a stronger relationship between their working-memory functional connectivity and behavior performance than monolinguals. Along with the result that multilingual children outperformed in measures of working memory, we highlight that using multiple languages in early life shapes executive function and functional connections.
Adopting a different theoretical framework from the one dominating the field, this study explored bilingualism influences on the development and differentiation of mental abilities. Albanian-Turkish bilingual (N = 122) and Albanian-speaking monolingual (N = 129) children, adolescents, and adults were assessed on monitoring, inhibitory control, processing efficiency, fluid reasoning, and vocabulary, and were asked to specify their own language efficiency (a cognizance index). Analyses showed a bilingual advantage in monitoring—adjusting for any fluid reasoning effects—which was larger in children. Moreover, a more pronounced bilingual benefit was observed for the incongruent condition RT of the attention task. Structural equation modelling showed though that the difference between language groups does not lie within the executive function domain (inhibitory control); it rather regards processing efficiency. Analyses also revealed increased differentiation of mental abilities in bilinguals, reflecting enhanced cognitive flexibility. Implications for cognitive developmental and individual differences theories are discussed.
Previous research diverges regarding the role of bilingualism in enhancing executive functions and also whether bilingualism affects the whole executive function system or specific components of it. The present study investigated the effects of bilingualism on the executive functions (inhibitory control and monitoring processes) of bilinguals who had acquired their L2 through formal instruction and lived in an L1-dominant context. The sample included two groups of bilinguals (children and adolescents) and two groups of monolinguals matched for age, gender, mother tongue, parents’ language, handedness, and vision. Child and adult versions of flanker task were administered to the participants. The behavioral data were collected on accuracy rates and reaction times for each trial of the tasks. The results indicated that compared to monolinguals, the two groups of bilinguals showed faster reaction times on incongruent trials and smaller flanker effects, indicating their superiority in inhibitory control and conflict resolution. However, the bilinguals were not generally faster than monolinguals, which showed that they did not possess enhanced monitoring processes. These results point to the modulating effects of interactional context and mode of L2 acquisition on the magnitude and scope of bilingual advantage in executive functions.
The question of cognition in second language (L2) acquisition later in life is of importance inasmuch as L2 learning is largely mediated by domain‐general cognitive capacities. While a number of these capacities have been shown to decline with age, individual differences in cognition increase over the lifespan. This microdevelopment study investigates the L2 trajectories of 28 older German‐speaking adults (age 64+) who participated in a combined computer‐assisted and classroom‐instructed 7‐month Spanish training for beginners. We made use of generalized additive mixed models (GAMMs) to quantify linear and nonlinear learner trajectories as well as any predictors thereof. Participants were assessed on a range of behavioral, L2, socioaffective, and background variables. We found a significant (linear and nonlinear) increase across all measures of L2 proficiency. Between‐subject cognitive, socioaffective, and background variables significantly predicted the overall level of L2 proficiency as well as developmental patterns over time. Daily variances in cognitive performance and socioaffect had little impact on fluctuations in L2 performance. Findings are discussed against the backdrop of complex dynamic systems theory and highlight the necessity for dense longitudinal research designs to capture nonlinearity in third‐age L2 learning.
The controversy over whether bilingualism has consequences for mind and brain shows no sign of abating. A steady stream of research reporting both positive results supporting the claim for beneficial effects of bilingualism and null results finding no significant differences between monolingual and bilingual groups continues to be published. With the number of null results that are produced, it is tempting to conclude that the positive effects are not reliable and that there is in fact no effect of bilingualism. However, research results, both positive and null, need to be interpreted in the larger context of factors that describe the experimental paradigm, the linguistic context, and the individual differences of the participants and not reduced to a simple binary question. The present article discusses some of the factors that must be considered in evaluating the interpretation of these research results.
Background and Objectives
The effect bilingualism has on older adults’ inhibitory control has been extensively investigated, yet there is continued controversy regarding whether older adult bilinguals show superior inhibitory control compared with monolinguals. The objective of the current meta-analysis was to examine the reliability and magnitude of the bilingualism effect on older adults’ inhibitory control as measured by the Simon and Stroop tasks. In addition, we examined whether individual characteristics moderate the bilingual advantage in inhibition, including age (young–old vs old–old), age of second language acquisition, immigrant status, language proficiency, and frequency of language use.
Research Design and Methods
A total of 22 samples for the Simon task and 14 samples for the Stroop task were derived from 28 published and unpublished articles (32 independent samples, with 4 of these samples using more than 1 task) and were analyzed in 2 separate meta-analyses.
Results
Analyses revealed a reliable effect of bilingualism on older adults’ performance on the Simon (g = 0.60) and Stroop (g = 0.27) tasks. Interestingly, individual characteristics did not moderate the association between bilingualism and older adults’ inhibitory control.
Discussion and Implications
The results suggest there is a bilingual advantage in inhibitory control for older bilinguals compared with older monolinguals, regardless of the individual characteristics previously thought to moderate this effect. Based on these findings, bilingualism may protect inhibitory control from normal cognitive decline with age.
Several researchers have suggested that learning and using a second language requires domain-general executive functions, and many have shown that bilinguals outperform monolinguals on tasks that tap into these processes. However, recent behavioral studies and meta-analyses reporting failed replications have called into question whether or not bilingualism leads to changes in domain-general executive functions. The present paper argues that there are several reasons, often overlooked, that lead to failed replications, and that when group differences do appear on EF tasks, despite these issues, performance favors bilinguals far more often than monolinguals. The present paper reports a Bayesian analysis of 167 independent studies to support this claim with a Bayes Factor classified as “decisive” evidence for the alternative (BF10 = 2.91 × 10e8), ruling out chance outcomes that would predict an equal number of studies favoring monolinguals to studies favoring bilinguals. These findings could not be explained by publication bias, year of publication, or sample size. Critically, these findings are not at odds with recent meta-analyses examining overall effect sizes, but rather, highlight the need to determine when, rather than if, bilinguals outperform monolinguals on EF tasks.
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.
We examined if bilinguals are sensitive to contextual factors with regard to the presence of interlocutors and if this reflects in how they modulate their executive control. First, we introduced Telugu–English bilinguals to monolingual, bilingual and neutral interlocutors in the form of cartoon characters through an interactive session. Following this, they performed the attention network task (ANT) with the image of interlocutors appearing on every trial before the flankers. High proficient bilinguals (in L2) were overall faster on the ANT (indicating higher executive control) when different interlocutors appeared randomly in a mixed block compared to the low proficient bilinguals. However, this effect was not found when the appearance of the interlocutors along-side the ANT task was blocked. These data demonstrate that high proficient bilinguals brought in higher executive control when the context required higher monitoring (different interlocutors appearing randomly) compared to the low proficient bilinguals. We interpret the findings with regard to the adaptive control hypothesis.
Acquiring a second alphabetic language also entails learning a new set of orthographic rules and specific patterns of grapheme combinations (namely, the orthotactics). The present longitudinal study aims to investigate whether orthotactic sensitivity changes over the course of a second language learning programme. To this end, a group of Spanish monolingual old adults completed a Basque language learning course. They were tested in different moments with a language decision task that included pseudowords that could be Basque-marked, Spanish-marked or neutral. Results showed that the markedness effect varied as a function of second language acquisition, showing that learning a second language changes the sensitivity not only to the orthographic patterns of the newly acquired language, but to those of the native language too. These results demonstrate that the orthographic representations of the native language are not static and that experience with a second language boosts markedness perception in the first language.
Objectives:
Experience-related neuroplasticity suggests that bilinguals who actively manage their two languages would develop more efficient neural organization at brain regions related to language control, which also overlap with areas involved in executive control. Our aim was to examine how active bilingualism-manifested as the regular balanced use of two languages and language switching-may be related to the different domains of executive control in highly proficient healthy older adult bilinguals, controlling for age, processing speed, and fluid intelligence.
Methods:
Participants were 76 community-dwelling older adults who reported being physically and mentally healthy and showed no signs of cognitive impairment. They completed a self-report questionnaire on their language background, two computer measures for previously identified covariates (processing speed as measured by two-choice reaction time (RT) task and fluid intelligence as measured by the Raven's Progressive Matrices), as well as a battery of computerized executive control tasks (Color-shape Task Switching, Stroop, Flanker, and Spatial 2-back task).
Results:
Regression analyses showed that, even after controlling for age, processing speed, and fluid intelligence, more balanced bilingualism usage and less frequent language switching predicted higher goal maintenance (non-switch trials RT in Color-shape Task Switching) and conflict monitoring abilities (global RT in Color-shape Task Switching and Flanker task).
Discussion:
Results suggest that active bilingualism may provide benefits to maintaining specific executive control abilities in older adult bilinguals against the natural age-related declines.
Previous research has suggested that bilinguals may exhibit cognitive advantages over those who are monolingual, although conflicting results have been reported. This advantage may be heightened in older adults, because of age-related cognitive decline. However, the effects of bilingualism on working memory performance in older adults remain unknown. The current study uses electroencephalography to measure brain activity (event-related potential; ERP) differences between young and older monolinguals and bilinguals during a delayed matching-to-sample task. Although there were no effects of bilingualism in behavioral measures, differences were observed in electrophysiological measures. While, no Age by Language interaction was observed, several main effects were identified. Compared to young adults, older adults exhibited smaller N2 amplitudes and larger P2 and P3b amplitudes in the medium and high load condition. Older adults also displayed an increased slow wave amplitude that occurred in conjunction with increased reaction time. ERP differences during difficult tasks in older adults suggest the use of compensatory mechanisms to maintain similar performance to the young adults. Bilinguals exhibited smaller N2 and larger P2 and P3b amplitudes than monolinguals. ERP differences observed in bilinguals may reflect differences in cognitive processing. However, in the absence of performance differences between monolinguals and bilinguals, interpreting a bilingual advantage in working memory processing is difficult.
This paper compiles several studies that show the relationship between bilingualism and Alzheimer's disease. Studies here compiled were independently carried out between 1991 and 2012 in the United States, in Canada, in the United Kingdom, in India and in Sweden. The paper reviews the results of studies that show that the time elapsed between early Alzheimer's diagnosis and the actual appearance of telltale symptom is up to five years longer in elderly bilinguals than in elderly monolinguals. Cradle bilinguals benefit most from bilingualism but language learning in adulthood can also benefits speakers. These and related scientific facts are compiled. Reports of scientific research are presented, and its conclusions are summarized.
RESUMEN Este paper recompila estudios que muestran la relación existente entre el bilingüismo y el mal de Alzheimer. Los estudios se realizaron independientemente entre 1991 y 2012 en Estados Unidos, en el Canadá, en el Reino Unido, en la India y en Suecia. El paper revisa los resultados de estos estudios que muestran que el tiempo que transcurre entre el diagnóstico precoz de Alzheimer's y la presentación de los primeros síntomas es hasta cinco años más demorado en ancianos bilingües que en ancianos monolingües. Quienes más se benefician del bilingüismo son los que han sido bilingües desde la cuna pero también se ha demostrado que se benefician los hablantes que aprenden idiomas en la adultez. Tanto estos como otros hechos científicos relacionados se presentan y se resumen sus conclusiones.
The current study investigated the effects of bilingualism on the clinical manifestation of Alzheimer's disease (AD) in a European sample of patients. We assessed all incoming AD patients in two university hospitals within a specified timeframe. Sixty-nine monolinguals and 65 bilinguals diagnosed with probable AD were compared for time of clinical AD manifestation and diagnosis. The influence of other potentially interacting variables was also examined. Results indicated a significant delay for bilinguals of 4.6 years in manifestation and 4.8 years in diagnosis. Our study therefore strengthens the claim that bilingualism contributes to cognitive reserve and postpones the symptoms of dementia.
The hypothesis that managing two languages enhances general executive functioning is examined. More than 80% of the tests for bilingual advantages conducted after 2011 yield null results and those resulting in significant bilingual advantages tend to have small sample sizes. Some published studies reporting significant bilingual advantages arguably produce no group differences if more appropriate tests of the critical interaction or more appropriate baselines are used. Some positive findings are likely to have been caused by failures to match on demographic factors and others have yielded significant differences only with a questionable use of the analysis-of-covariance to "control" for these factors. Although direct replications are under-utilized, when they are, the results of seminal studies cannot be reproduced. Furthermore, most studies testing for bilingual advantages use measures and tasks that do not have demonstrated convergent validity and any significant differences in performance may reflect task-specific mechanism and not domain-free executive functions (EF) abilities. Brain imaging studies have made only a modest contribution to evaluating the bilingual-advantage hypothesis, principally because the neural differences do not align with the behavioral differences and also because the neural measures are often ambiguous with respect to whether greater magnitudes should cause increases or decreases in performance. The cumulative effect of confirmation biases and common research practices has either created a belief in a phenomenon that does not exist or has inflated the frequency and effect size of a genuine phenomenon that is likely to emerge only infrequently and in restricted and undetermined circumstances.
Copyright © 2015 Elsevier Ltd. All rights reserved.
We explored whether a bilingual advantage in executive control is associated with differences in cultural and ethnic background associated with the bilinguals' immigrant status, and whether dialect use in monolinguals can also incur such an advantage. Performance on the Simon task in older non-immigrant (Gaelic-English) and immigrant (Bengali, Gujarati, Hindi, Malay, Punjabi, Urdu-English) bilinguals was compared with three groups of older monolingual English speakers, who were either monodialectal users of the same English variety as the bilinguals or were bidialectal users of a local variety of Scots. Results showed no group differences in overall reaction times as well as in the Simon effect thus providing no evidence that an executive control advantage is related to differences in cultural and ethnic background as was found for immigrant compared to non-immigrant bilinguals, nor that executive control may be improved by use of dialect. We suggest the role of interactional contexts and bilingual literacy as potential explanations for inconsistent findings of a bilingual advantage in executive control.
Paap and Greenberg concluded that there is no coherent evidence for bilingual advantages in executive
processing. More optimistic researchers believe that the advantages may be restricted to certain types of
bilinguals. Recent large-scale and lifespan investigations that tested highly fluent bilinguals from
communities where the same two languages are spoken by most residents reported no bilingual
advantages in any age group or in any of the tasks used to measure executive functioning. The present
study takes a complementary approach by examining a sample that is quite homogeneous in terms of
current life experiences, but heterogeneous in terms of its exposure to second languages. The composite
database of 168 bilinguals and 216 monolinguals is used to explore for differences based on: (1) the age
of acquiring a second language (L2), (2) the relative proficiency of an L2 and (3) the number of
languages used. Across 12 different measures of executive function, derived from 4 different nonverbal
tasks, there was no consistent evidence supporting the hypotheses that either early bilingualism, highly
fluent balanced bilingualism, or trilingualism enhances inhibitory control, monitoring or switching. In
fact, when statistically significant effects did occur, they more often disconfirmed than confirmed these
hypotheses.
Objective: To test the hypothesis that foreign language and music instruction in early life are associated with lower incidence of mild cognitive impairment (MCI) and slower rate of cognitive decline in old age. Method: At enrollment in a longitudinal cohort study, 964 older persons without cognitive impairment estimated years of foreign language and music instruction by age 18. Annually thereafter they completed clinical evaluations that included cognitive testing and clinical classification of MCI. Results: There were 264 persons with no foreign language instruction, 576 with 1–4 years, and 124 with > 4 years; 346 persons with no music instruction, 360 with 1–4 years, and 258 with > 4 years. During a mean of 5.8 years of observation, 396 participants (41.1%) developed MCI. In a proportional hazards model adjusted for age, sex, and education, higher levels (> 4 years) of foreign language (hazard ratio [HR] = 0.687, 95% confidence interval [CI] [0.482, 0.961]) and music (HR = 0.708, 95% CI [0.539, 0.930]) instruction by the age of 18 were each associated with reduced risk of MCI. The association persisted after adjustment for other early life indicators of an enriched cognitive environment, and it was stronger for nonamnestic than amnestic MCI. Both foreign language and music instruction were associated with higher initial level of cognitive function, but neither instruction measure was associated with cognitive decline. Conclusions: Higher levels of foreign language and music instruction during childhood and adolescence are associated in old age with lower risk of developing MCI but not with rate of cognitive decline.
Bilinguals have been shown to outperform monolinguals in a variety of tasks that do not tap into linguistic processes. The origin of this bilingual advantage has been questioned in recent years. While some authors argue that the reason behind this apparent advantage is bilinguals' enhanced executive functioning, inhibitory skills and/or monitoring abilities, other authors suggest that the locus of these differences between bilinguals and monolinguals may lie in uncontrolled factors or incorrectly matched samples. In the current study we tested a group of 180 bilingual children and a group of 180 carefully matched monolinguals in a child-friendly version of the ANT task. Following recent evidence from similar studies with children, our results showed no bilingual advantage at all, given that the performance of the two groups in the task and the indices associated with the individual attention networks were highly similar and statistically indistinguishable.
This study explores the extent to which a bilingual advantage can be observed for three tasks in an established population of fully fluent bilinguals from childhood through adulthood. Welsh-English simultaneous and early sequential bilinguals, as well as English monolinguals, aged 3 years through older adults, were tested on three sets of cognitive and executive function tasks. Bilinguals were Welsh-dominant, balanced, or English-dominant, with only Welsh, Welsh and English, or only English at home. Card sorting, Simon, and a metalinguistic judgment task (650, 557, and 354 participants, respectively) reveal little support for a bilingual advantage, either in relation to control or globally. Primarily there is no difference in performance across groups, but there is occasionally better performance by monolinguals or persons dominant in the language being tested, and in one case-in one condition and in one age group-lower performance by the monolinguals. The lack of evidence for a bilingual advantage in these simultaneous and early sequential bilinguals suggests the need for much closer scrutiny of what type of bilingual might demonstrate the reported effects, under what conditions, and why.
In recent decades several authors have suggested that bilinguals exhibit enhanced cognitive control as compared to monolinguals and some proposals suggest that this main difference between monolinguals and bilinguals is related to bilinguals’ enhanced capacity of inhibiting irrelevant information. This has led to the proposal of the so-called bilingual advantage in inhibitory skills. However, recent studies have cast some doubt on the locus and generality of the alleged bilingual advantage in inhibitory skills. In the current study we investigated inhibitory skills in a large sample of 252 monolingual and 252 bilingual children who were carefully matched on a large number of indices. We tested their performance in a verbal Stroop task and in a nonverbal version of the same task (the number size-congruency task). Results were unequivocal and showed that bilingual and monolingual participants performed equally in these two tasks across all the indices or markers of inhibitory skills explored. Furthermore, the lack of differences between monolingual and bilingual children extended to all the age ranges tested and was not modulated by any of the independent factors investigated. In light of these results, we conclude that bilingual children do not exhibit any specific advantage in simple inhibitory tasks as compared to monolinguals.
Objective:
Clinic-based studies suggest that dementia is diagnosed at older ages in bilinguals compared with monolinguals. The current study sought to test this hypothesis in a large, prospective, community-based study of initially nondemented Hispanic immigrants living in a Spanish-speaking enclave of northern Manhattan.
Method:
Participants included 1,067 participants in the Washington/Hamilton Heights Inwood Columbia Aging Project (WHICAP) who were tested in Spanish and followed at 18-24 month intervals for up to 23 years. Spanish-English bilingualism was estimated via both self-report and an objective measure of English reading level. Multilevel models for change estimated the independent effects of bilingualism on cognitive decline in 4 domains: episodic memory, language, executive function, and speed. Over the course of the study, 282 participants developed dementia. Cox regression was used to estimate the independent effect of bilingualism on dementia conversion. Covariates included country of origin, gender, education, time spent in the United States, recruitment cohort, and age at enrollment.
Results:
Independent of the covariates, bilingualism was associated with better memory and executive function at baseline. However, bilingualism was not independently associated with rates of cognitive decline or dementia conversion. Results were similar whether bilingualism was measured via self-report or an objective test of reading level.
Conclusions:
This study does not support a protective effect of bilingualism on age-related cognitive decline or the development of dementia. In this sample of Hispanic immigrants, bilingualism is related to higher initial scores on cognitive tests and higher educational attainment and may not represent a unique source of cognitive reserve.
Statistical inference in psychology has traditionally relied heavily on p-value significance testing. This approach to drawing conclusions from data, however, has been widely criticized, and two types of remedies have been advocated. The first proposal is to supplement p values with complementary measures of evidence, such as effect sizes. The second is to replace inference with Bayesian measures of evidence, such as the Bayes factor. The authors provide a practical comparison of p values, effect sizes, and default Bayes factors as measures of statistical evidence, using 855 recently published t tests in psychology. The comparison yields two main results. First, although p values and default Bayes factors almost always agree about what hypothesis is better supported by the data, the measures often disagree about the strength of this support; for 70% of the data sets for which the p value falls between .01 and .05, the default Bayes factor indicates that the evidence is only anecdotal. Second, effect sizes can provide additional evidence to p values and default Bayes factors. The authors conclude that the Bayesian approach is comparatively prudent, preventing researchers from overestimating the evidence in favor of an effect.
© The Author(s) 2011.
Many studies have confirmed the presence of a bilingual advantage which is manifested as enhanced cognitive and attention control. However, very few studies have investigated the role of second language proficiency on the modulation of conflict-monitoring in bilinguals. We investigated this by comparing high and low proficient Hindi-English bilinguals on a modified saccadic arrow Stroop task under different monitoring conditions, and tested the predictions of the bilingual executive control advantage proposal. The task of the participants was to make an eye movement toward the color patch in the same color as the central arrow, ignoring the patch to which the arrow was pointing. High-proficient bilinguals had overall faster saccade latency on all types of trials as compared to the low proficient bilinguals. The overall saccadic latency for high proficiency bilinguals was similarly affected by the different types of monitoring conditions, whereas conflict resolution advantage was found only for high monitoring demanding condition. The results support a conflict-monitoring account in a novel oculomotor task and also suggest that language proficiency could modulate executive control in bilinguals.
Until now, research on bilingual auditory word recognition has been scarce, and although most studies agree that lexical access is language-nonselective, there is less consensus with respect to the influence of potentially constraining factors. The present study investigated the influence of three possible constraints. We tested whether language nonselectivity is restricted by (a) a sentence context in a second language (L2), (b) the semantic constraint of the sentence, and (c) the native language of the speaker. Dutch–English bilinguals completed an English auditory lexical decision task on the last word of low- and high-constraining sentences. Sentences were pronounced by a native Dutch speaker with English as the L2, or by a native English speaker with Dutch as the L2. Interlingual homophones (e.g., lief “sweet” – leaf /liːf/) were always recognized more slowly than control words. The semantic constraint of the sentence and the native accent of the speaker modulated, but did not eliminate interlingual homophone effects. These results are discussed within language-nonselective models of lexical access in bilingual auditory word recognition.
Three studies compared bilinguals to monolinguals on 15 indicators of executive processing (EP). Most of the indicators compare a neutral or congruent baseline to a condition that should require EP. For each of the measures there was no main effect of group and a highly significant main effect of condition. The critical marker for a bilingual advantage, the Group×Condition interaction, was significant for only one indicator, but in a pattern indicative of a bilingual disadvantage. Tasks include antisaccade (Study 1), Simon (Studies 1-3), flanker (Study 3), and color-shape switching (Studies 1-3). The two groups performed identically on the Raven's Advanced Matrices test (Study 3). Analyses on the combined data selecting subsets that are precisely matched on parent's educational level or that include only highly fluent bilinguals reveal exactly the same pattern of results. A problem reconfirmed by the present study is that effects assumed to be indicators of a specific executive process in one task (e.g., inhibitory control in the flanker task) frequently do not predict individual differences in that same indicator on a related task (e.g., inhibitory control in the Simon task). The absence of consistent cross-task correlations undermines the interpretation that these are valid indicators of domain-general abilities. In a final discussion the underlying rationale for hypothesizing bilingual advantages in executive processing based on the special linguistic demands placed on bilinguals is interrogated.
Recent behavioral data have shown that lifelong bilingualism can maintain youthful cognitive control abilities in aging. Here, we provide the first direct evidence of a neural basis for the bilingual cognitive control boost in aging. Two experiments were conducted, using a perceptual task-switching paradigm, including a total of 110 participants. In Experiment 1, older adult bilinguals showed better perceptual switching performance than their monolingual peers. In Experiment 2, younger and older adult monolinguals and bilinguals completed the same perceptual task-switching experiment while functional magnetic resonance imaging (fMRI) was performed. Typical age-related performance reductions and fMRI activation increases were observed. However, like younger adults, bilingual older adults outperformed their monolingual peers while displaying decreased activation in left lateral frontal cortex and cingulate cortex. Critically, this attenuation of age-related over-recruitment associated with bilingualism was directly correlated with better task-switching performance. In addition, the lower blood oxygenation level-dependent response in frontal regions accounted for 82% of the variance in the bilingual task-switching reaction time advantage. These results suggest that lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes.
(
This reprinted article originally appeared in the Journal of Experimental Psychology,
1935, Vol 18, 643–662. The following abstract of the original article appeared in PA, Vol 10:1863.) In this study pairs of conflicting stimuli, both being inherent aspects of the same symbols, were presented simultaneously (a name of one color printed in the ink of another color—a word stimulus and a color stimulus). The difference in time for reading the words printed in colors and the same words printed in black is the measure of the interference of color stimuli on reading words. The difference in the time for naming the colors in which the words are printed and the same colors printed in squares is the measure of the interference of conflicting word stimuli on naming colors. The interference of conflicting color stimuli on the time for reading 100 words (each word naming a color unlike the ink-color of its print) caused an increase of 2.3 sec or 5.6% over the normal time for reading the same words printed in black. This increase is not reliable, but the interference of conflicting word stimuli on the time for naming 100 colors (each color being the print of a word which names another color) caused an increase of 47.0 sec or 74.3% of the normal time for naming colors printed in squares.… (PsycINFO Database Record (c) 2012 APA, all rights reserved)
This study explores whether the cognitive advantage associated with bilingualism in executive functioning extends to young immigrant children challenged by poverty and, if it does, which specific processes are most affected. In the study reported here, 40 Portuguese-Luxembourgish bilingual children from low-income immigrant families in Luxembourg and 40 matched monolingual children from Portugal completed visuospatial tests of working memory, abstract reasoning, selective attention, and interference suppression. Two broad cognitive factors of executive functioning-representation (abstract reasoning and working memory) and control (selective attention and interference suppression)-emerged from principal component analysis. Whereas there were no group differences in representation, the bilinguals performed significantly better than did the monolinguals in control. These results demonstrate, first, that the bilingual advantage is neither confounded with nor limited by socioeconomic and cultural factors and, second, that separable aspects of executive functioning are differentially affected by bilingualism. The bilingual advantage lies in control but not in visuospatial representational processes.
This study investigated whether early especially efficient utilization of executive functioning in young bilinguals would transcend potential cultural benefits. To dissociate potential cultural effects from bilingualism, four-year-old U. S. Korean-English bilingual children were compared to three monolingual groups - English and Korean monolinguals in the U.S.A. and another Korean monolingual group, in Korea. Overall, bilinguals were most accurate and fastest among all groups. The bilingual advantage was stronger than that of culture in the speed of attention processing, inverse processing efficiency independent of possible speed-accuracy trade-offs, and the network of executive control for conflict resolution. A culture advantage favoring Korean monolinguals from Korea was found in accuracy but at the cost of longer response times.
The regular use of two languages by bilingual individuals has been shown to have a broad impact on language and cognitive functioning. In this monograph, we consider four aspects of this influence. In the first section, we examine differences between mono-linguals and bilinguals in children's acquisition of language and adults' linguistic processing, particularly in terms of lexical retrieval. Children learning two languages from birth follow the same milestones for language acquisition as mono-linguals do (first words, first use of grammar) but may use different strategies for language acquisition, and they generally have a smaller vocabulary in each language than do monolin-gual children learning only a single language. Adult bilinguals typically take longer to retrieve individual words than monolin-guals do, and they generate fewer words when asked to satisfy a constraint such as category membership or initial letter. In the second section, we consider the impact of bilingualism on nonverbal cognitive processing in both children and adults. The primary effect in this case is the enhancement of executive control functions in bilinguals. On tasks that require inhibition of distract-ing information, switching between tasks, or holding information in mind while performing a task, bilinguals of all ages outperform comparable monolinguals. A plausible reason is that bilinguals recruit control processes to manage their ongoing linguistic per-formance and that these control processes become enhanced for other unrelated aspects of cognitive processing. Preliminary evi-dence also suggests that the executive control advantage may even mitigate cognitive decline in older age and contribute to cognitive reserve, which in turn may postpone Alzheimer's disease. In the third section, we describe the brain networks that are responsible for language processing in bilinguals and demon-strate their involvement in nonverbal executive control for bilinguals. We begin by reviewing neuroimaging research that identifies the networks used for various nonverbal executive control tasks in the literature. These networks are used as a ref-erence point to interpret the way in which bilinguals perform both verbal and nonverbal control tasks. The results show that bilinguals manage attention to their two language systems using the same networks that are used by monolinguals performing nonverbal tasks. In the fourth section, we discuss the special circumstances that surround the referral of bilingual children (e.g., language delays) and adults (e.g., stroke) for clinical intervention. These referrals are typically based on standardized assessments that use normative data from monolingual populations, such as vocabulary size and lexical retrieval. As we have seen, however, these measures are often different for bilinguals, both for children and adults. We discuss the implications of these linguistic differences for standardized test performance and clinical approaches. We conclude by considering some questions that have important public policy implications. What are the pros and cons of French or Spanish immersion educational programs, for example? Also, if bilingualism confers advantages in certain respects, how about three languages—do the benefits increase? In the healthcare field, how can current knowledge help in the treatment of bilingual aphasia patients following stroke? Given the recent increase in bilingualism as a research topic, answers to these and other related questions should be available in the near future.
Executive functions (EFs)-a set of general-purpose control processes that regulate one's thoughts and behaviors-have become a popular research topic lately and have been studied in many subdisciplines of psychological science. This article summarizes the EF research that our group has conducted to understand the nature of individual differences in EFs and their cognitive and biological underpinnings. In the context of a new theoretical framework that we have been developing (the unity/diversity framework), we describe four general conclusions that have emerged from our research. Specifically, we argue that individual differences in EFs, as measured with simple laboratory tasks, (1) show both unity and diversity (different EFs are correlated yet separable); (2) reflect substantial genetic contributions; (3) are related to various clinically and societally important phenomena; and (4) show some developmental stability.
Cognitive reserve is invoked to explain the protective effects of education and cognitively-stimulating activities against all-cause dementia and Alzheimer's disease (AD). For non-native English speakers (n-NES), speaking English may be a cognitive activity associated with lower dementia risk. We hypothesized that n-NES have lower risk of incident dementia/AD and that educational level might modify this relationship. Participants took part in the Einstein Aging Study (Bronx, NY), a longitudinal study of aging and dementia. All (n = 1779) spoke fluent English and self-reported birthplace and whether English was their first language. n-NES additionally reported mother tongue, age of English acquisition, and current percentile-use of a non-English language. Nested Cox proportional hazards models progressively adjusted for gender, race, education, and immigrant and marital status estimated hazard ratios (HR) for incident dementia/AD as a function of n-NES status. 390 (22%) participants were n-NES. 126 incident dementia cases occurred during 4174 person-years of follow-up (median 1.44; range 0–16); 101 individuals met criteria for probable/possible AD. There was no statistically-significant association between n-NES status and incident dementia in the fully-adjusted model (HR 1.26; 95% CI 0.76–2.09; p = 0.36). Results were similar for AD. Stratification of education into three groups revealed increased risk of dementia for n-NES with ≥ 16 years of education (HR 3.97; 95% CI 1.62–9.75; p = 0.003). We conclude that n-NES status does not appear to have an independent protective effect against incident dementia/AD, and that n-NES status may contribute to risk of dementia in an education-dependent manner.
Previous research has found an advantage for bilinguals relative to monolinguals on tasks of attentional control. This advantage has been found to be larger in older adults than in young adults, suggesting that bilingualism provides a buffer against age-related declines in executive functioning. Using a computerized Stroop task in a nonimmigrant sample of young and older monolinguals and bilinguals, the current investigation tried to replicate previous findings of a bilingual advantage. A bilingual advantage would have been demonstrated by smaller Stroop interference (i.e., smaller increases in response time for incongruent than for neutral trials) for bilinguals than for monolinguals. The results showed that bilingual young adults showed a general speed advantage relative to their monolingual counterparts, but this was not associated with smaller Stroop interference. Older adults showed no effect of bilingualism. Thus, the present investigation does not find evidence of a bilingual advantage in young or older adults and suggests limits to the robustness and/or specificity of previous findings.
It has been proposed that the unique need for early bilinguals to manage multiple languages while their executive control mechanisms are developing might result in long-term cognitive advantages on inhibitory control processes that generalize beyond the language domain. We review the empirical data from the literature on nonlinguistic interference tasks to assess the validity of this proposed bilingual inhibitory control advantage. Our review of these findings reveals that the bilingual advantage on conflict resolution, which by hypothesis is mediated by inhibitory control, is sporadic at best, and in some cases conspicuously absent. A robust finding from this review is that bilinguals typically outperform monolinguals on both compatible and incompatible trials, often by similar magnitudes. Together, these findings suggest that bilinguals do enjoy a more widespread cognitive advantage (a bilingual executive processing advantage) that is likely observable on a variety of cognitive assessment tools but that, somewhat ironically, is most often not apparent on traditional assays of nonlinguistic inhibitory control processes.
The role of response effects (tendencies to respond to factors other than item content) in the self-assessment of second language ability was investigated through a split-ballot procedure using positively- and negatively-worded ques tions and graded (i.e. level-specific questions). Results indicate that both an acquiescence effect (a tendency to respond positively regardless of item con tent) and overestimation were present. Although both effects were present at all levels of subjects, they were most evident for less experienced learners. Discussion focuses on explanation of these effects and implications for both test construction and pedagogy.
Understanding how and when cognitive change occurs over the life span is a prerequisite for understanding normal and abnormal development and aging. Most studies of cognitive change are constrained, however, in their ability to detect subtle, but theoretically informative life-span changes, as they rely on either comparing broad age groups or sparse sampling across the age range. Here, we present convergent evidence from 48,537 online participants and a comprehensive analysis of normative data from standardized IQ and memory tests. Our results reveal considerable heterogeneity in when cognitive abilities peak: Some abilities peak and begin to decline around high school graduation; some abilities plateau in early adulthood, beginning to decline in subjects' 30s; and still others do not peak until subjects reach their 40s or later. These findings motivate a nuanced theory of maturation and age-related decline, in which multiple, dissociable factors differentially affect different domains of cognition.
© The Author(s) 2015.
Bilingualism has been reported to delay the age of retrospective report of first symptom in dementia. This study determined if the age of clinically diagnosed Alzheimer's disease and vascular dementia occurred later for bilingual than monolingual, immigrant and U.S. born, Hispanic Americans. It involved a secondary analysis of the subset of 81 bi/monolingual dementia cases identified at yearly follow-up (1998 through 2008) using neuropsychological test results and objective diagnostic criteria from the Sacramento Area Latino Study on Aging that involved a random sampling of community dwelling Hispanic Americans (N = 1789). Age of dementia diagnosis was analyzed in a 2 × 2 (bi/monolingualism × immigrant/U.S. born) ANOVA that space revealed both main effects and the interaction were non-significant. Mean age of dementia diagnosis was descriptively (but not significantly) higher in the monolingual (M = 81.10 years) than the bilingual (M = 79.31) group. Overall, bilingual dementia cases were significantly better educated than monolinguals, but U.S. born bilinguals and monolinguals did not differ significantly in education. Delays in dementia symptomatology pertaining to bilingualism are less likely to be found in studies: (a) that use age of clinical diagnosis vs. retrospective report of first dementia symptom as the dependent variable; and (b) involve clinical cases derived from community samples rather than referrals to specialist memory clinics.
Copyright © 2014 Elsevier Ltd. All rights reserved.
Although self-assessment has been prevalent for a number of years in such fields as psychology, sociology, business, and so on, its use in second language teaching/learning has remained rather rare. Whether this situation stems from skepticism about students' capacity to provide meaningful information about their ability to use the language or from an inappropriate use of self-assessment is difficult to assess. This article reports a sequence of experiments leading to the use of self-assessment as a placement test. These experiments dealt with such questions as, Do students have the ability to meaningfully evaluate their own performance? Does the type of instrument used effect that ability? Can students be satisfactorily placed by self-assessment results alone? The conclusion is that at least under the conditions described, self-assessment must be considered a very valuable tool as a placement instrument.
The ability to speak two languages often marvels monolinguals, although bilinguals report no difficulties in achieving this feat. Here, we examine how learning and using two languages affect language acquisition and processing as well as various aspects of cognition. We do so by addressing three main questions. First, how do infants who are exposed to two languages acquire them without apparent difficulty? Second, how does language processing differ between monolingual and bilingual adults? Last, what are the collateral effects of bilingualism on the executive control system across the lifespan? Research in all three areas has not only provided some fascinating insights into bilingualism but also revealed new issues related to brain plasticity and language learning.
The aim of this study was to determine whether bilingualism is associated with dementia in cross-sectional or prospective analyses of older adults.
In 1991, 1616 community-living older adults were assessed and were followed 5 years later. Measures included age, sex, education, subjective memory loss (SML), and the modified Mini-mental State Examination (3MS). Dementia was determined by clinical examination in those who scored below the cut point on the 3MS. Language status was categorized based upon self-report into 3 groups: English as a first language (monolingual English, bilingual English) and English as a Second Language (ESL).
The ESL category had lower education, lower 3MS scores, more SML, and were more likely to be diagnosed with cognitive impairment, no dementia at both time 1 and time 2 compared with those speaking English as a first language. There was no association between being bilingual (ESL and bilingual English vs. monolingual) and having dementia at time 1 in bivariate or multivariate analyses. In those who were cognitively intact at time 1, there was no association between being bilingual and having dementia at time 2 in bivariate or multivariate analyses.
We did not find any association between speaking >1 language and dementia.
Contemporary research on bilingualism has been framed by two major discoveries. In the realm of language processing, studies of comprehension and production show that bilinguals activate information about both languages when using one language alone. Parallel activation of the two languages has been demonstrated for highly proficient bilinguals as well as second language learners and appears to be present even when distinct properties of the languages themselves might be sufficient to bias attention towards the language in use. In the realm of cognitive processing, studies of executive function have demonstrated a bilingual advantage, with bilinguals outperforming their monolingual counterparts on tasks that require ignoring irrelevant information, task switching, and resolving conflict. Our claim is that these outcomes are related and have the overall effect of changing the way that both cognitive and linguistic processing are carried out for bilinguals. In this article we consider each of these domains of bilingual performance and consider the kinds of evidence needed to support this view. We argue that the tendency to consider bilingualism as a unitary phenomenon explained in terms of simple component processes has created a set of apparent controversies that masks the richness of the central finding in this work: the adult mind and brain are open to experience in ways that create profound consequences for both language and cognition.
The purpose of the study was to determine the association between bilingualism and age at onset of dementia and its subtypes, taking into account potential confounding factors.
Case records of 648 patients with dementia (391 of them bilingual) diagnosed in a specialist clinic were reviewed. The age at onset of first symptoms was compared between monolingual and bilingual groups. The influence of number of languages spoken, education, occupation, and other potentially interacting variables was examined.
Overall, bilingual patients developed dementia 4.5 years later than the monolingual ones. A significant difference in age at onset was found across Alzheimer disease dementia as well as frontotemporal dementia and vascular dementia, and was also observed in illiterate patients. There was no additional benefit to speaking more than 2 languages. The bilingual effect on age at dementia onset was shown independently of other potential confounding factors such as education, sex, occupation, and urban vs rural dwelling of subjects.
This is the largest study so far documenting a delayed onset of dementia in bilingual patients and the first one to show it separately in different dementia subtypes. It is the first study reporting a bilingual advantage in those who are illiterate, suggesting that education is not a sufficient explanation for the observed difference. The findings are interpreted in the context of the bilingual advantages in attention and executive functions.
Abstract
Here we examined the role of bilingualism on cognitive inhibition using the Stroop task. Our hypothesis was that the frequency of use of a second language (L2) in the daily life of successive bilingual individuals impacts the efficiency of their inhibitory control mechanism.
Thirty-three highly proficient successive French-German bilinguals, living either in a French or in a German linguistic environment, performed a Stroop task on both French and German words. Moreover, 31 French monolingual individuals were also tested with French words. We showed that the bilingual advantage (1) was reinforced by the use of a third language, and (2) was modulated by the duration of immersion in a second language environment. This suggests that top-down inhibitory control is most involved at the beginning of immersion. Taken together, the present findings lend support to the psycholinguistic models of bilingual language processing that postulate top-down active inhibition is involved in language control.
Previous research has shown that bilingual children perform better than comparable monolinguals on tasks requiring control of attention to inhibit misleading information. The present paper reports a series of studies that traces this processing difference into adulthood and eventually aging. The task used in all groups, from children to older adults, is the Simon task, a measure of stimulus-response incompatibility. The results showed that bilinguals performed better than monolinguals in early childhood, adulthood, and later adulthood. There was no difference in performance between monolinguals and bilinguals who were young adults, specifically university undergraduates. Our interpretation is that performance is at its peak efficiency for that group and bilingualism offers no further boost. The results are discussed in terms of the effect of bilingualism on control of attention and inhibition through the lifespan.
The main objective of this article is to provide new evidence regarding the impact of bilingualism on the attentional system. We approach this goal by assessing the effects of bilingualism on the executive and orienting networks of attention. In Experiment 1, we compared young bilingual and monolingual adults in a numerical version of the Stroop task, which allowed the assessment of the executive control network. We observed more efficient performance in the former group, which showed both reduced Stroop Interference and larger Stroop Facilitation Effects relative to the latter. Conversely, Experiment 2, conducted with a visual cueing task in order to assess the orienting network, revealed similar Cueing Facilitation and Inhibition (Inhibition of Return – IOR) Effects for both groups of speakers. The implications of the results of these two experiments for the origin and boundaries of the bilingual impact on the attentional system are discussed.
Previous research has shown that bilingual children excel in tasks requiring inhibitory control to ignore a misleading perceptual cue. The present series of studies extends this finding by identifying the degree and type of inhibitory control for which bilingual children demonstrate this advantage. Study 1 replicated the earlier research by showing that bilingual children perform the Simon task more rapidly than monolinguals, but only on conditions in which the demands for inhibitory control were high. The next two studies compared performance on tasks that required inhibition of attention to a specific cue, like the Simon task, and inhibition of a habitual response, like the day-night Stroop task. In both studies, bilingual children maintained their advantage on tasks that require control of attention but showed no advantage on tasks that required inhibition of response. These results confine the bilingual advantage found previously to complex tasks requiring control over attention to competing cues (interference suppression) and not to tasks requiring control over competing responses (response inhibition).
During a 1-sec tachistoscopic exposure, Ss responded with a right or left leverpress to a single target letter from the sets
H and K or S and C. The target always appeared directly above the fixation cross. Experimentally varied were the types of
noise letters (response compatible or incompatible) flanking the target and the spacing between the letters in the display.
In all noise conditions, reaction time (RT) decreased as between-letter spacing increased. However, noise letters of the opposite
response set were found to impair RT significantly more than same response set noise, while mixed noise letters belonging
to neither set but having set-related features produced intermediate impairment. Differences between two target-alone control
conditions, one presented intermixed with noise-condition trials and one presented separately in blocks, gave evidence of
a preparatory set on the part of Ss to inhibit responses to the noise letters. It was concluded that S cannot prevent processing
of noise letters occurring within about 1 deg of the target due to the nature of processing channel capacity and must inhibit
his response until he is able to discriminate exactly which letter is in the target position. This discrimination is more
difficult and time consuming at closer spacings, and inhibition is more difficult when noise letters indicate the opposite
response from the targe
Building on earlier evidence showing a beneficial effect of bilingualism on children's cognitive development, we review recent studies using both behavioral and neuroimaging methods to examine the effects of bilingualism on cognition in adulthood and explore possible mechanisms for these effects. This research shows that bilingualism has a somewhat muted effect in adulthood but a larger role in older age, protecting against cognitive decline, a concept known as 'cognitive reserve'. We discuss recent evidence that bilingualism is associated with a delay in the onset of symptoms of dementia. Cognitive reserve is a crucial research area in the context of an aging population; the possibility that bilingualism contributes to cognitive reserve is therefore of growing importance as populations become increasingly diverse.
The current study investigated the relationship between bilingual language proficiency and onset of probable Alzheimer's disease (AD) in 44 Spanish-English bilinguals at the UCSD Alzheimer's Disease Research Center. Degree of bilingualism along a continuum was measured using Boston Naming Test (BNT) scores in each language. Higher degrees of bilingualism were associated with increasingly later age-of-diagnosis (and age of onset of symptoms), but this effect was driven by participants with low education level (a significant interaction between years of education and bilingualism) most of whom (73%) were also Spanish-dominant. Additionally, only objective measures (i.e., BNT scores), not self-reported degree of bilingualism, predicted age-of-diagnosis even though objective and self-reported measures were significantly correlated. These findings establish a specific connection between knowledge of two languages and delay of AD onset, and demonstrate that bilingual effects can be obscured by interactions between education and bilingualism, and by failure to obtain objective measures of bilingualism. More generally, these data support analogies between the effects of bilingualism and "cognitive reserve" and suggest an upper limit on the extent to which reserve can function to delay dementia.
When comparing digits of different physical sizes, numerical and physical size interact. For example, in a numerical comparison task, people are faster to compare two digits when their numerical size (the relevant dimension) and physical size (the irrelevant dimension) are congruent than when they are incongruent. Two main accounts have been put forward to explain this size congruity effect. According to the shared representation account, both numerical and physical size are mapped onto a shared analog magnitude representation. In contrast, the shared decisions account assumes that numerical size and physical size are initially processed separately, but interact at the decision level. We implement the shared decisions account in a computational model with a dual route framework and show that this model can simulate the modulation of the size congruity effect by numerical and physical distance. Using other tasks than comparison, we show that the model can simulate novel findings that cannot be explained by the shared representation account.