Reassessing the role of language dominance in n-2 language repetition costs as a marker of inhibition in multilingual language switching.

Speaking two or more languages shows bilingual flexibility, but flexible switching requires language control and often incurs performance costs. We examined inhibitory control assessing n-2 repetition costs when switching three languages (L1 [German], L2 [English], L3 [French]). These costs denote worse performance in n-2 repetitions (e.g., L2-L3-L2) than in n-2 nonrepetitions (e.g., L1-L3-L2), indicating persisting inhibition. In two experiments (n = 28 in Experiment 1; n = 44 in Experiment 2), n-2 repetition costs were observed, but only for L2. Looking into L2 trials specifically, we found n-2 repetition costs when switching back to L2 from the still weaker L3 but not when returning from the stronger L1, suggesting that L2 is a strong competitor for L3 (requiring L2 inhibition) but less so for L1. Finding n-2 repetition costs supports an inhibitory account of language control in general, but our study shows only partial evidence for the theoretically assumed more specific relation between language dominance and language inhibition (i.e., only for dominance relations with respect to L1 and L3 when switching back to L2). Taken together, the findings thus suggest the need for further refinement of the concept of language dominance and its relation to inhibition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A Blessing in Disguise: Flanking Words Can Cancel Language Switch Costs.

Prior research has shown that a sentence context can decrease the necessity for language control relative to single word processing. In particular, measures of language control such as language switch costs are reduced or even absent in a sentence context. Yet, this evidence is mainly based on bilingual language production and is far from straightforward. To further investigate this issue in the comprehension modality, we relied on the lexical flanker task, which is known to introduce sentence-like processing. More specifically, Dutch-English bilinguals (n = 68) performed a classification task in mixed language blocks on target words that were either presented alone or flanked by unrelated words in the same language. While overall no L1 switch costs were observed, we only observed L2 switch costs in the no-flanker condition. This pattern of results indicates that the presence of flankers can reduce or even abolish switch costs, suggesting that the language control process can benefit from sentence(-like) processing compared to single word processing.

No evidence for a mixing benefit-A registered report of voluntary dialect switching.

Previous language production research with bidialectals has provided evidence for similar language control processes as during bilingual language production. In the current study, we aimed to further investigate this claim by examining bidialectals with a voluntary language switching paradigm. Research with bilinguals performing the voluntary language switching paradigm has consistently shown two effects. First, the cost of switching languages, relative to staying in the same language, is similar across the two languages. The second effect is more uniquely connected to voluntary language switching, namely a benefit when performing in mixed language blocks relative to single language blocks, which has been connected to proactive language control. While the bidialectals in this study also showed symmetrical switch costs, no mixing effect was observed. These results could be taken as evidence that bidialectal and bilingual language control are not entirely similar.

The concept of inhibition in bilingual control.

To achieve fluent language processing as a bilingual, a dominant theoretical framework assumes that the nontarget language is inhibited. This assumption is based on several empirical effects that are typically explained with inhibitory control. In the current article, we discuss four prominent effects linked to bilingual inhibition in language production (i.e., asymmetrical switch costs, n-2 language repetition costs, reversed language dominance, and the blocked language order effect). We argue that these effects require more empirical examination in order to arrive at a firmer basis for the assumption that inhibition plays a major role during bilingual language control. In particular, the empirical replicability of the phenomena themselves needs to be established more firmly, the underlying theoretical assumptions need further examination, and the alternative explanations of the empirical effects need to be scrutinized. In turn, we conclude that inhibitory control may provide a coherent framework for bilingual language production while outlining the challenges that the inhibition account still needs to face. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Executive functions in primary progressive aphasia: A meta-analysis.

Executive functions (EFs) refer to a set of cognitive processes, specifically shifting, inhibition, updating of working memory, and are involved in the cognitive control of behavior. Conflicting results have been reported regarding impairments of EFs in Primary Progressive Aphasia (PPA). We performed a multi-level meta-analysis to confirm whether deficits of EFs exist in this population, focusing on a common EFs composite, and the components shifting, inhibition and updating separately. We included 141 studies that report on 294 EFs tasks. The overall mean weighted effect size was large (d = -1,28), indicating poorer EFs in PPA as compared to age-matched cognitively healthy controls. Differences between effect sizes of the EFs components were not significant, indicating all components are affected similarly. Overall, moderator analysis revealed that PPA variant and disease duration were significant moderators of performance, while task modality and years of education were not. The non-fluent/agrammatic PPA and the logopenic PPA variants were similarly affected, but the semantic variant was affected to a lesser extent. We discuss implications for clinical and research settings, and future research.

Fast priming of grammatical decisions: repetition and transposed-word priming effects.

We used the grammatical decision task to investigate fast priming of written sentence processing. Targets were sequences of 5 words that either formed a grammatically correct sentence or were ungrammatical. Primes were sequences of 5 words and could be the same word sequence as targets, a different sequence of words with a similar syntactic structure, the same sequence with two inner words transposed or the same sequence with two inner words substituted by different words. Prime-word sequences were presented in a larger font size than targets for 200 ms and followed by the target sequence after a 100 ms delay. We found robust repetition priming in grammatical decisions, with same sequence primes leading to faster responses compared with prime sequences containing different words. We also found transposed-word priming effects, with faster responses following a transposed-word prime compared with substituted-word primes. We conclude that fast primed grammatical decisions might offer investigations of written sentence processing what fast primed lexical decisions have offered studies of visual word recognition.

Correction: Assessing the Evidence for Asymmetrical Switch Costs and Reversed Language Dominance Effects - A Meta-Analysis.

[This corrects the article DOI: 10.5334/joc.186.].

Assessing the Evidence for Asymmetrical Switch Costs and Reversed Language Dominance Effects - A Meta-Analysis.

Two seemingly counterintuitive phenomena - asymmetrical language switch costs and the reversed language dominance effect - prove to be particularly controversial in the literature on language control. Asymmetrical language switch costs refer to the larger costs for switching into the dominant language compared to switching into the less dominant language, both relative to staying in either one language. The reversed language dominance effect refers to longer reaction times when in the more dominant of the two languages in situations that require frequent language switching (i.e., mixed-language blocks). The asymmetrical language switch costs are commonly taken as an index for processes of transient, reactive inhibitory language control, whereas the reversed language dominance effect is taken as an index for sustained, proactive inhibitory language control. In the present meta-analysis, we set out to establish the empirical evidence for these two phenomena using a Bayesian linear mixed effects modelling approach. Despite the observation of both phenomena in some studies, our results suggest that overall, there is little evidence for the generality and robustness of these two effects, and this holds true even when conditions - such as language proficiency and preparation time manipulations - were included as moderators of these phenomena. We conclude that asymmetrical switch costs and the reversed language dominance effect are important for theory development, but their utility for theory testing is limited due to their lack of robustness and the absence of confirmed moderatory variables.

Is there proactive inhibitory control during bilingual and bidialectal language production?

The bilingual language control literature generally assumes that cross-language interference resolution relies on inhibition of the non-target language. A similar approach has been taken in the bidialectal language control literature. However, there is little evidence along these lines for proactive language control, which entails a control process that is implemented as an anticipation of any cross-language interference. To further investigate the possibility of proactive inhibitory control, we examined the effect of language variety preparation time, by manipulating the cue-to-stimulus interval, on parallel language activation, by manipulating cognate status. If proactive language control relies on inhibition, one would expect less parallel language activation (i.e., a smaller cognate facilitation effect) with increased proactive inhibitory control (i.e., a long cue-to-stimulus interval). This was not the case with either bilinguals or bidialectals. So, the current study does not provide evidence for proactive inhibitory control during bilingual and bidialectal language production.

Language control in bimodal bilinguals: Evidence from ERPs.

It is currently unclear to what degree language control, which minimizes non-target language interference and increases the probability of selecting target-language words, is similar for sign-speech (bimodal) bilinguals and spoken language (unimodal) bilinguals. To further investigate the nature of language control processes in bimodal bilinguals, we conducted the first event-related potential (ERP) language switching study with hearing American Sign Language (ASL)-English bilinguals. The results showed a pattern that has not been observed in any unimodal language switching study: a switch-related positivity over anterior sites and a switch-related negativity over posterior sites during ASL production in both early and late time windows. No such pattern was found during English production. We interpret these results as evidence that bimodal bilinguals uniquely engage language control at the level of output modalities.

Is it easier to use one language variety at a time, or mix them? An investigation of voluntary language switching with bidialectals.

Previous language production research with bidialectals has provided evidence for similar language control processes as during bilingual language production. In the current study, we aim to further investigate this claim by examining bidialectals with a voluntary language switching paradigm. Research with bilinguals performing the voluntary language switching paradigm has consistently shown two effects. First, the cost of switching languages, relative to staying in the same language, is similar across the two languages. The second effect is more uniquely connected to voluntary language switching, namely a benefit when performing in mixed language blocks relative to single language blocks, which has been connected to proactive language control. If a similar pattern could be observed with bidialectals in a voluntary language switching paradigm, then this would provide additional evidence in favor of similar control processes underlying bidialectal and bilingual language production.

Parallel semantic processing in the flankers task: Evidence from the N400.

The extent to which higher-order representations can be extracted from more than one word in parallel remains an unresolved issue with theoretical import. Here, we used ERPs to investigate the timing with which semantic information is extracted from parafoveal words. Participants saw animal and non-animal targets paired with response congruent or incongruent flankers in a semantic categorization task. Animal targets elicited smaller amplitude negativities when they were paired with semantically related and response congruent animal flankers (e.g., wolf coyote wolf) compared to unrelated and response incongruent flankers (e.g., sock coyote sock) in the N400 window and a post-N400 window. We interpret the N400 effect in terms of facilitated processing from the joint activation of shared semantic features (e.g., animal, furry) across target and flanker words and the later effect in terms of post-lexical decision-making. Thus, semantic information can be extracted from flankers in parallel and impacts various stages of processing.

On the Connection Between Language Control and Executive Control-An ERP Study.

Models vary in the extent to which language control processes are domain general. Those that posit that language control is at least partially domain general insist on an overlap between language control and executive control at the goal level. To further probe whether or not language control is domain general, we conducted the first event-related potential (ERP) study that directly compares language-switch costs, as an index of language control, and task-switch costs, as an index of executive control. The language switching and task switching methodologies were identical, except that the former required switching between languages (English or Spanish) whereas the latter required switching between tasks (color naming or category naming). This design allowed us to directly compare control processes at the goal level (cue-locked ERPs) and at the task performance level (picture-locked ERPs). We found no significant differences in the switch-related cue-locked and picture-locked ERP patterns across the language and task switching paradigms. These results support models of domain-general language control.

Which bilinguals reverse language dominance and why?

When naming pictures in mixed-language blocks, bilinguals sometimes exhibit reversed language dominance effects. These have been attributed to proactive inhibitory control of the dominant language, or adaptation of language-specific selection thresholds. Even though reversed dominance arguably provides the most striking evidence of inhibition, few studies have focused on when and why this effect occurs. We investigated this topic in a large data set (>400 bilinguals) using a continuous and objective measure of language dominance. We found larger reversed language dominance effects in more (vs. less) balanced bilinguals in mixed-language blocks. However, after taking into account standard language dominance effects in single-language blocks, the extent to which dominance effects changed across block types was actually significantly smaller for more balanced bilinguals, which is in line with the inhibitory control account. Interestingly, dominance reversal was not associated with increased overall speed in the mixed-language block. Thus, dominance reversal is more likely in balanced bilinguals not because they are better at applying proactive control, but because they are more likely to overshoot when the goal is to make both languages about equally accessible - and overall, unbalanced bilinguals apply more proactive control than balanced bilinguals to facilitate picture naming in mixed-language blocks.

How readers process syntactic input depends on their goals.

During reading, the recognition of words is influenced by the syntactic compatibility of surrounding words: a sentence-superiority effect. However, when the goal is to make syntactic categorization decisions about single target words, these decisions are influenced by the syntactic congruency rather than compatibility of surrounding words. Although both these premises imply that readers can extract syntactic information from multiple words in parallel, they also suggest that how the brain organizes syntactic input-and consequently how surrounding stimuli affect word recognition-depends on the reader's top-down goals. The present study provides a direct test of this conception. Participants were offered nouns and verbs amidst a grammatical context ('this horse fell') and ungrammatical context ('fell horse this'). Using a conditional task setup, we manipulated the amount of emphasis put on respectively sentences and single words. In two blocks readers were instructed to make sentence grammaticality judgments only if the middle word was respectively noun or verb; in two other blocks readers were instructed to syntactically categorize the middle word only if the sentence was respectively correct or incorrect. We established an interaction effect whereby the impact of grammatical correctness on syntactic categorization decisions was greater than the effect of grammatical correctness per se. This first sentence-superiority effect in the categorization of single words, combined with the absence of this effect in prior flanker studies, leads us to surmise that word-to-word syntactic constraints only operate if the reader is engaged in sentence processing.

What about proactive language control?

While several reviews provide an in-depth discussion on reactive language control, which is the language control process that is initiated when the non-target language disrupts the selection of target language words, few have touched on proactive language control, which is the language control process implemented as an anticipation of any non-target language interference disrupting the selection of target language words. In the current review, three prominent markers of proactive language control are discussed (i.e., the reversed language dominance effect, language-mixing costs, and the blocked language-order effect). Based on these three markers, it appears that proactive language control can be implemented to mainly restrict interference from the first language during bilingual language production, but is typically absent during bilingual language comprehension. The literature also implies that proactive language control might be partly domain general. With respect to the underlying mechanism of proactive language control, there are some indications that proactive language control relies on inhibition, but no unequivocal evidence has been provided so far.

Unified syntax in the bilingual mind.

Are syntactic representations shared across languages, and how might that inform the nature of syntactic computations? To investigate these issues, we presented French-English bilinguals with mixed-language word sequences for 200 ms and asked them to report the identity of one word at a post-cued location. The words either formed an interpretable grammatical sequence via shared syntax (e.g., ses feet sont big - where the French words ses and sont translate into his and are, respectively) or an ungrammatical sequence with the same words (e.g., sont feet ses big). Word identification was significantly greater in the grammatical sequences - a bilingual sentence superiority effect. These results not only provide support for shared syntax, but also reveal a fascinating ability of bilinguals to simultaneously connect words from their two languages through these shared syntactic representations.

A different perspective on domain-general language control using the flanker task.

Bilingual models diverge in whether they assume that language control is domain general. Most studies that investigated this claim focused on bilingual language production and relied on the comparison between language switching and task switching. In the current study, we set out to investigate whether language control is domain general in a different context (i.e., bilingual language comprehension) and with a different paradigm (i.e., the flanker task). To this end, we let French-English bilinguals perform a bilingual (flankers are words from the same or different language as the target word) and a non-linguistic (numerical magnitude with digits) flanker task. The results showed that there was no difference in the language congruency effect between participants with a high and low non-linguistic congruency effect. These results indicate that there is no substantial overlap in the mechanisms involved in comprehension-based language control and executive control.

What absent switch costs and mixing costs during bilingual language comprehension can tell us about language control.

In the current study, we set out to investigate language control, which is the process that minimizes cross-language interference, during bilingual language comprehension. According to current theories of bilingual language comprehension, language-switch costs, which are a marker for reactive language control, should be observed. However, a closer look at the literature shows that this is not always the case. Furthermore, little to no evidence for language-mixing costs, which are a marker for proactive language control, has been observed in the bilingual language comprehension literature. This is in line with current theories of bilingual language comprehension, as they do not explicitly account for proactive language control. In the current study, we further investigated these two markers of language control and found no evidence for comprehension-based language-switch costs in six experiments, even though other types of switch costs were observed with the exact same setup (i.e., task-switch costs, stimulus modality-switch costs, and production-based language-switch costs). Furthermore, only one out of three experiments showed comprehension-based language-mixing costs, providing the first tentative evidence for proactive language control during bilingual language comprehension. The implications of the absence and occurrence of these costs are discussed in terms of processing speed and parallel language activation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Common Cognitive Control Processes Underlying Performance in Task-Switching and Dual-Task Contexts.

In the present study, participants performed highly comparable task-switching and dual-task paradigms, and the paradigm-specific performance costs were analysed in the context of the commonly postulated core components of cognitive control (i.e., working memory updating, inhibition, and shifting). In the task-switching paradigm, we found switch costs (i.e., switch trials vs. repetition trials) and mixing costs (i.e., repetition trials in mixed-task blocks vs. single-task trials). In the dual-task paradigm, we observed a psychological refractory period (PRP) effect (i.e., Task 2 [T2] performance after short stimulus-onset asynchrony [SOA] vs. long SOA), dual-task costs (i.e., T2 dual-task performance with a long SOA in trials with a task repetition between Task 1 [T1] and T2 vs. single-task performance), and switch costs in T2 (i.e., dual-task performance in trials with a switch between T1 and T2 vs. dual-task performance in trials with a repetition between T1 and T2). A within-subjects comparison of the performance costs showed a correlation between mixing costs and dual-task costs, possibly indicating shared underlying cognitive control processes in terms of working memory updating. Surprisingly, there was also a correlation between switch costs and the PRP effect, presumably suggesting that cognitive control, as opposed to passive queuing of response selection processes, contributes to the PRP effect.