Experimentally Induced Language Modes and Regular Code-Switching Habits Boost Bilinguals’ Executive Performance: Evidence From a Within-Subject Paradigm

Abstract

Bilingualism may modulate executive functions (EFs), but the mechanisms underlying this phenomenon are poorly understood. In this study, we investigated two potential sources of variability in bilinguals' EF performance: (1) interactional contexts and codeswitching, and (2) dominance profiles. Previous research on code-switching often relied on self-reports of regular code-switching habits. In this study, we investigated the effects of experimentally induced language modes (single language versus codeswitching modes) on bilinguals' EF performance. Crucially, in the bilingual conditions, we differentiated between different types of intra-sentential code-switching (Insertion, Alternation, and Dense code-switching). Moreover, we investigated the interaction of the effects of temporary language modes with bilinguals' sociolinguistic codeswitching habits. All our participants were L1-dominant German-English bilinguals (N = 29) immersed in an L2 context. We assessed the effects of dominance by correlating individual bilinguals' L1-dominance with their EF performance. In addition, we investigated whether language modes activate different EF patterns in bilinguals, as opposed to monolinguals, i.e., individuals who have no additional language to suppress. Based on models of bilingual language processing, we predicted our bilinguals to display the best EF performance in L2 single language contexts, as these require them to activate inhibitory schemata to suppress their dominant L1. Indeed, bilinguals performed better in the single language than in the code-switching conditions. The results also suggested that bilinguals activated more inhibitory control compared to monolinguals, supporting the notion that bilingual processing involves inhibition. The task conditions inducing different code-switching modes differed only in terms of the predictors explaining EF performance in the regression. We observed negative correlations between the frequency of engaging in a given type of code-switching and performance in language modes inducing non-corresponding control modes. The results suggested that Dense code-switching draws upon proactive control modes

Structural neural correlates of habitual code-switching practices in bilinguals

“…Another goal of our study was to determine whether engagement in different code-switching types (Muysken, 2013) leaves distinct structural signatures on the volumes of the caudate nucleus and thalamus. We based our predictions on the Inhibitory control continuum model and existing empirical studies, which reported that the degree of separation of both languages within a code-switch modulates the cognitive control processes involved (Hofweber et al, 2016(Hofweber et al, , 2020aTreffers-Daller, 2009). Indeed, our results suggest that differences in volumes in the regions of interest are linked to the degree of separation of both languages.…”

Language Dominance and Sociolinguistic Experience Are Related to Language Control and Domain-General Monitoring Control: An Investigation in Bilinguals Who Live in a Minority/Majority Sociolinguistic Setting

“…One possible account for the finding is that bilingual individuals with varying language dominance patterns engage in different types of code-switching in the Uyghur-Chinese bilingual community, and only those executive functions that are needed to underlie these language practices are impacted. It may be that L1-dominant bilinguals require an effortful suppression of the dominant L1 when they are exposed to the single L2 sociolinguistic context ( Hofweber et al, 2020 ), and this may lead to an improvement in domain-general inhibitory control. However, this is not a full explanation for our finding, because it is known from previous studies that their possibly exclusive language practice of insertional code-switching only recruits a medium level of inhibition, which is lower than what is needed during alternational code-switching ( Treffers-Daller, 2009 ).…”

Bilingualism: A Neurocognitive Exercise in Managing Uncertainty

“…The notion of behavioral context is central to many usage-based theories about language and bilingualism, because people perceive and produce the various languages that they know with interlocutors in their environments (such as at home or in the workplace). This rich contextualization of language has wide-ranging consequences for language fluency, processing, representation and control, and it may also carry consequences for domain general cognitive control and underlying brain mechanisms (Adler et al, 2020;Anderson et al, 2018;Beatty-Martinez et al, 2019;Green & Abutalebi, 2013;Grosjean, 2001Grosjean, , 2016Hofweber et al, 2020;Tiv, Gullifer, et al, 2020b). To give one example, the adaptive control hypothesis (Green & Abutalebi, 2013) posits that language usage within particular INTERACTIONAL CONTEXTS will have adaptive consequences for control and brain organization, where interactional contexts consist of the "recurrent pattern of conversational exchanges within a community of speakers" (Green & Abutalebi, 2013, p. 516).…”

“…Thus, researchers interested in uncertainty from a cognitive, attention, or decision-making perspective can exploit background language characteristics of participants as a sort of natural experiment. For example, the long-term role of behavioral context in cognitive adaptation can be investigated, between participants, by recruiting and contrasting participants who systematically Downloaded from http://direct.mit.edu/nol/article-pdf/doi/10.1162/nol_a_00044/1927613/nol_a_00044.pdf by guest on 13 July 2021 vary in their language background in terms of interactional context (Beatty-Martinez et al, 2019;Hofweber et al, 2020), providing a sort of naturalistic experiment. Within-participant comparisons can be made through longitudinal studies, for example, by recruiting samples of participants beginning their studies in a new (linguistic) environment and again several months later.…”

“…Within-participant comparisons can be made through longitudinal studies, for example, by recruiting samples of participants beginning their studies in a new (linguistic) environment and again several months later. Shorter term influences of behavioral context can be investigated by manipulating the interactional context of the experimental environment or interspersing cognitive tasks and language tasks that differ in language-related uncertainty (Adler et al, 2020;Hofweber et al, 2020; Y. J. Wu & Thierry, 2013).…”