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

Abstract

21 28015 Madrid, SPAIN 22 eanton@nebrija.es 23 Telephone: +34677570001 24 42 consideration different perspectives in the domain-specificity of the executive functions and 43 working memory. 44 45 46 Keywords: Bilingualism; executive functioning; working memory. 47 93 seemed noticeable only when the environment was demanding enough (see 1,24, for similar 94 conclusions; but see 18, for a discussion on the impurity of the use of global RTs as a measure of 95 monitoring). Even though these two classic perspectives argued for an advantage in concrete 96 aspects of EF (i.e., monitoring or inhibition), the mixed results prevent researchers to draw strong 97 conclusions as to which EF component was enhanced by bilingualism. Instead, it has been recently 5 98argued that a failure of bilinguals to inhibit their attention to the non-target language requires a 99 more effortful involvement of EF, causing a more general and unified EF enhancement (23). 100The bilingual advantage, however, is not only one of the most popular research topics in the 101 field of bilingualism nowadays, but also one of the most controversial ones (see 26,27, among 102 others, as an example of the growing debate regarding its existence). Some concerns have been 103 raised regarding the results and interpretation of the bilingual advantage (26,(28)(29)(30)(31). In a nutshell, 104 these authors argue that the bilingual advantage that has been shown in the previous literature is 105 actually a consequence of uncontrolled external factors, small sample sizes and task-dependent 106 effects. Actually, there are many external factors that have been shown to have a direct impact in 107EF performance, such as participants' socio-economic status (SES), immigrant status or ethnicity 108 background (32,33). Importantly, these factors tend to differ between bilingual and monolingual 109 populations in certain populations. For example, immigrants -who tend to be bilinguals -show 110 better morbidity and mortality outcomes than non-immigrants around the world (34-39) which is 111 known as "the healthy immigrant" effect. Furthermore, they also display a higher educational 112 profile or IQ level (40-42) than nonimmigrants. Even if it is debatable whether these features are a 113 cause or a consequence of being an immigrant, it seems that individuals who get to pass the 114 immigration screening of host countries display better physical and psychological conditions (43). 115If those factors are not equal between monolinguals and bilinguals at test, they might potentially 116 cause differences between groups in EF, and there would be no way of disentangling the potential 117 effects of bilingualism from those produced by the uncontrolled factors. Upon reviewing the 118 existing literature showing a bilingual advantage, one could find that the abovementioned concern 119 seems to be the rule more than the exception for the majority of the studies. We observe studies in 120 which SES was not controlled for (13,44), in which comparisons are made between monolinguals 12...

The effects of bilingualism on attentional processes in the first year of life

“…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 et al., 2014; Antón, Fernández García, Carreiras, & Duñabeitia, 2016; Barac, Moreno, & Bialystok, 2016; Carlson & Meltzoff, 2008; Duñabeitia et al., 2014; Esposito, Baker‐Ward, & Mueller, 2013; Martin‐Rhee & Bialystok, 2008; Paap et al., 2015). Instead, more recent accounts have emphasized 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‐Faidella, & Sebastián‐Gallés, 2009).…”

“…Second, bilingual advantage effects in children, young adults, and the elderly have been recently contested (e.g. Antón et al, 2019; Antón et al, 2014; Antón et al, 2016; Costa & Sebastián‐Gallés, 2014; De Bruin et al., 2015; Duñabeitia et al., 2014; Gathercole et al., 2014; Lehtonen et al., 2018; Paap et al., 2015). Such inconsistencies in findings and replication failures across bilingual populations, experimental techniques, and laboratories raise the need for direct tests of the replication validity of the earliest manifestations of the bilingual advantage.…”

On the phantom-like appearance of bilingualism effects on neurocognition: (How) should we proceed?

“…Both studies report results from Spanish-Basque typically developing children. Also, both studies fail to find evidence for bilingual effects (but see later work by Antón, Carreiras & Duñabeitia, 2019 for results that show bilinguals from the very same region outperforming monolinguals on some working memory tasks). Given their (i) power, (ii) meticulous design, and (iii) adequate control measures and careful across-group matching in terms of various indices, it comes as no surprise that Paap et al (2015) highlight the importance of these two studies and comment that “[they] are noteworthy because the bilinguals acquired both languages early, were highly proficient, and were immersed in a bilingual region” (p. 268).…”

“…Defining this right type of subjects is very much an open issue. In certain studies (e.g., Antón et al, 2014; 2019 and Duñabeitia et al, 2014), there is an effort to control for specific critical proxies for bilingual experiences to ensure some consistency, if not relative homogeneity for certain variables such as balanced and high proficiencies in an arguably comparable context, such as immersion in fully bilingual societies. At the same time, proficiency or balance may not be the most critical measures to tap into.…”

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

“…All the BFs were greater than 4.8 and the BF for the critical interference effect was BF = 5.6. In a third large study, Antón et al (2019) matched 90 bilinguals and 90 monolinguals on age, IQ, SES (socioeconomic status), and L1 knowledge from a bigger sample of 126 monolinguals and 141 bilinguals. There were no significant bilingual advantages in either interference scores or global RT across four interference tasks: flanker, Simon, colour Stroop, and numerical Stroop.…”