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.

Different language control mechanisms in comprehension and production: Evidence from paragraph reading

Chinese-English bilinguals read paragraphs with language switches using a rapid serial visual presentation paradigm silently while ERPs were measured (Experiment 1) or read them aloud (Experiment 2). Each paragraph was written in either Chinese or English with several function or content words switched to the other language. In Experiment 1, language switches elicited an early, long-lasting positivity when switching from the dominant language to the nondominant language, but when switching to the dominant language, the positivity started later, and was never larger than when switching to the nondominant language. In addition, switch effects on function words were not significantly larger than those on content words in any analyses. In Experiment 2, participants produced more cross-language intrusion errors when switching to the dominant than to the nondominant language, and more errors on function than content words. These results implicate different control mechanisms in bilingual language selection across comprehension and production.

The effects of cross-linguistic similarity on phrase-level language switching: evidence from high-proficient Chinese-English bilinguals

Previous research on language switching has debated whether high-proficient bilinguals exhibit symmetrical costs and one underlying reason for which may be the potential influence of cross-linguistic characteristics. The previous conflicting findings suggest their impact on language switching needs to be further investigated. In this study, we recruited 36 high-proficient Chinese-English bilinguals and investigated the effect of cross-linguistic similarity on the switching of quantifier expressions under three switch conditions. The results showed that switch costs were significantly greater when the quantifier expression was similar between Chinese and English than when it was different. Larger switch costs were found in the alternate switch condition than those in the non-switch or random switch conditions. In addition, participants exhibited larger switch costs when switching to the first language than when switching to the second language. The results suggest that the similarity of quantifier expressions between the first language and the second language would create more competition and thus induce larger switch costs in phrase-level language switching, which may be derived from the inner word recognition system of the mental lexicon. This study further improves the relevant theories on the origin of switch costs by supporting the Language Non-Specific Selection Hypothesis.

The dynamic role of inhibitory control in language switching during number-word task performance in dominant and balanced bilinguals

Language is one of the fascinating abilities of the human species. The beauty of language becomes intriguing when we examine language processing among bilinguals. This work attempted to study the effects of language dominance among native Hindi speakers who were either Hindi dominant, English dominant, or balanced bilingual in a language switching task. The task required the participants to read aloud the number-words that were presented singly on the computer screen. The findings support the inhibitory control model's predictions as the results were indicative of asymmetrical switch cost for both the Hindi and English dominant bilinguals. In both the language dominance condition, moving back to the dominant language from a non-dominant language required more time than vice versa. The results also indicated overall reduced reaction time in the reading task performance for balanced bilinguals, further demonstrating the benefits of balanced bilingualism.

How processing emotion affects language control in bilinguals

Research has shown that several variables affect language control among bilingual speakers but the effect of affective processing remains unexplored. Chinese-English bilinguals participated in a novel prime-target language switching experiment in which they first judged the affective valence (i.e., positive or negative) of auditorily presented words and then named pictures with neutral emotional valence in either the same (non-switch trial) or different language (switch trial). Brain activity was monitored using functional magnetic resonance imaging (fMRI). The behavioral performance showed that the typical switch cost (i.e., the calculated difference between switch and non-switch trials) emerged after processing positive words but not after negative words. Brain imaging demonstrated that processing negative words immediately before non-switch picturing naming trials (but not for switch trials) increased activation in brain areas associated with domain-general cognitive control. The opposite patterns were found after processing positive words. These findings suggest that an (emotional) negative priming effect is induced by spontaneous exposure to negative words and that these priming effects may be triggered by reactive emotional processing and that they may interact with higher level cognitive functions.

Cost or advantage? Intra-sentential language switching could facilitate L2 emotional words' comprehension in auditory modality

Language switching is encountered commonly and inevitably in bilingual society and often induces costs for target language's production. However, for auditory words' comprehension at sentence level, the limited research showed divergent findings. Some research observed comprehension costs when the language of target words was switched with the code of sentential contexts kept constant; but a potential switch advantage was also showed in non-dominant targets' processing when sentential context switches occurred. Additionally, it's well documented that the words' emotional connotations play a key role in both L1 and L2 word comprehension. Therefore, we aimed to explore which switch effect would occur when bilinguals comprehended L1/L2 emotional target nouns in auditory modality at behavioral and neural level through a visual object selection task. Behaviorally, switch related costs occurred in L1 targets' comprehension, whereas advantage effects were found in L2. Moreover, greater switch advantage occurred for positive and negative targets than for neutral ones. Consistently, larger LPC (Late Positive Component) defection was elicited for L2-Switch trials relative to L2-Nonswitch trials and the differences of LPC's amplitude could predict the behavioral advantageous effects of switching in nondominant targets' comprehension, which suggest that language switching lead to deeper re-analyses for emotional words. Taken together, it's suggested that bilinguals can adaptively utilize top-down (sentential prediction) and bottom-up (words' emotional information) cues to access weaker L2 representations.

The Role of Language Switching During Cross-Talk Between Bilingual Language Control and Domain-General Conflict Monitoring

The relationship between bilingual language control and executive control is debated. The present study investigated the effect of short-term language switching in a comprehension task on executive control performance in unbalanced bilinguals. Participants were required to perform a context task and an executive control task (i.e., flanker task) in sequence. A picture-word matching task created different language contexts in Experiment 1 (i.e., L1, L2, and dual-language contexts). By modifying the color-shape switching task, we created different contexts that do not involve language processing in Experiment 2 (i.e., color, shape, and dual context). Experiment 1 showed overall faster responses (in both congruent and incongruent trials) in the flanker task after a language switching context than after single (L1 or L2) contexts. This suggests that the language switching in a comprehension task affected general monitoring performance. By contrast, the nonlinguistic contexts in Experiment 2 did not affect flanker performance. This provides further evidence for the crucial role of language processing during switching to elicit short-term adaptions on domain-general conflict monitoring. Overall, our findings add to the previous studies by showing cross-talk between bilingual language control and domain-general conflict monitoring when language switching occurs in a comprehension task.

Control mechanisms in voluntary versus mandatory language switching: Evidence from ERPs

The present study measured event-related potentials (ERP) and behavioral performance to examine whether inhibitory control is involved in voluntary language switching, and if so, to explore the differences in inhibitory control between voluntary and mandatory language switching. Unbalanced Chinese-English bilinguals completed two picture naming tasks: one involving mandatory language switches and one in which participants could voluntarily switch between the two languages. Behavioral data showed significant switch costs and a reversed language dominance effect in both switching tasks. Critically, both effects were larger in mandatory compared to voluntary switching. ERP results revealed that neural switch costs during mandatory switching was significantly different than voluntary switching in both N2 and LPC amplitudes. In contrast, a significant difference in the reversed language dominance effect between both tasks was only observed in LPC amplitude. Together, these findings suggest the involvement of inhibitory control in both mandatory and voluntary language switching, but the degree of inhibition and the time-course of control processes between both tasks appear to be distinct.

When Language Switching is Cost-Free: The Effect of Preparation Time

Previous research has shown that language switching is costly, and that these costs are likely to persist even when speakers are given ample time to prepare. The aim of this study was to determine whether there are cognitive limitations to speakers' ability to prepare for a switch, or whether a new language can be prepared in advance and any cost to switch language eliminated. To explore this, language switching costs were measured in a group of Dutch-English (L1-L2) bilinguals who named pictures in their two languages while the preparation time was manipulated. The participants were given either no time to prepare (cue to stimulus interval, CSI: 0 ms), or some time to prepare, for the target language (CSI: 250, 500, and 800 ms). The results revealed that when speakers had no time to prepare, language switching was costly. However, when preparation time was provided, switching costs disappeared. This suggests that there might be no cognitive limitations to the ability to prepare for a language switch, and that, provided enough preparation time, the effort to switch language could be eliminated. This finding might also explain why normal code-switched conversations seem effortless, as speakers typically have ample time to prepare for the language switch.

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.

Should I focus on self-language actions or should I follow others? Cross-language interference effects in voluntary and cued language switching

We examined whether and how language produced by others influences self-language processes. This study addressed this issue by looking at effects of comprehension on language switching in cued and voluntary switching contexts. During voluntary language switching, Chinese-English bilinguals were more likely to repeat the language they previously used themselves than to repeat the language produced by others. Furthermore, during both voluntary and cued language switching, bilinguals showed larger switch costs when switching between languages themselves than when switching after hearing another language. This suggests that cross-language interference may primarily stem from the self-language system rather than from language produced by others.

Continuous theta-burst stimulation modulates language-related inhibitory processes in bilinguals: evidence from event-related potentials

The dorsolateral prefrontal cortex (DLPFC) is activated when bilinguals switch between languages. Language switching can also elicit the N2 event-related potential (ERP). This ERP component appears to capture the cognitive control processes related to conflict monitoring, response selection and response inhibition. In the present study, continuous theta-burst stimulation (cTBS) was used to examine the role of the left DLPFC in bilingual language switching, using a picture-naming task. Participants in the study were 17 Afrikaans-English bilinguals. The picture-naming task consisted of non-switch and switch trials. On non-switch trials, participants named two consecutive pictures in the same language. On switch trials, participants named consecutive pictures in different languages (e.g., Afrikaans and then English). The participants completed three testing sessions. In each session, participants received either cTBS to the left DLPFC or the vertex, or sham stimulation, and then completed the picture-naming task. The results showed that following DLPFC stimulation, the N2 ERP was attenuated on switch trials compared to non-switch trials. Vertex or sham stimulation did not modulate the N2 ERP. cTBS did not affect language switching at the behavioural level. These results provide support for the role of the left DLPFC in the cognitive control processes underlying bilingual language switching. Furthermore, the study demonstrates that these processes can be modulated via non-invasive brain stimulation and the effects detected at the neural level.

Active Bilingualism in Aging: Balanced Bilingualism Usage and Less Frequent Language Switching Relate to Better Conflict Monitoring and Goal Maintenance Ability

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 (nonswitch 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.

Effects of theta burst stimulation over the dorsolateral prefrontal cortex on language switching - A behavioral and ERP study

This study investigated the role of the left dorsolateral prefrontal cortex (DLPFC) in language switching using theta burst stimulation (TBS) and electroencephalography in late bilinguals. After a sham-controlled baseline, participants received either excitatory or inhibitory TBS over the left DLPFC before conducting picture naming tasks in pure language blocks and a language switching block, as well as a nonverbal switching task. On the behavioral level, we found no effect of TBS. However, the ERP-analysis revealed an effect of Stimulation for the picture naming tasks, characterized by alterations in the left DLPFC at 20-72 ms, and in networks associated with conflict resolution and self-monitoring at 533-600 ms. As we did not find an interaction between Stimulation and Block (switching vs non-switching), prefrontal stimulation did not specifically modulate interlanguage control. The left DLPFC might rather be involved in enhancingmaintenance of task demands and self-monitoring during language production in both mono- and bilingual contexts.

Role of joint language control during cross-language communication: evidence from cross-frequency coupling

How do bilingual interlocutors inhibit interference from the non-target language to achieve brain-to-brain information exchange in a task to simulate a bilingual speaker-listener interaction. In the current study, two electroencephalogram devices were employed to record pairs of participants' performances in a joint language switching task. Twenty-eight (14 pairs) unbalanced Chinese-English bilinguals (L1 Chinese) were instructed to name pictures in the appropriate language according to the cue. The phase-amplitude coupling analysis was employed to reveal the large-scale brain network responsible for joint language control between interlocutors. We found that (1) speakers and listeners coordinately suppressed cross-language interference through cross-frequency coupling, as shown in the increased delta/theta phase-amplitude and delta/alpha phase-amplitude coupling when switching to L2 than switching to L1; (2) speakers and listeners were both able to simultaneously inhibit cross-person item-level interference which was demonstrated by stronger cross-frequency coupling in the cross person condition compared to the within person condition. These results indicate that current bilingual models (e.g., the inhibitory control model) should incorporate mechanisms that address inhibiting interference sourced in both language and person (i.e., cross-language and cross-person item-level interference) synchronously through joint language control in dynamic cross-language communication.

Cognitive control regions are recruited in bilinguals' silent reading of mixed-language paragraphs

When switching languages, bilinguals recruit a language control network that overlaps with brain regions known to support general cognitive control, but it is unclear whether these same regions are recruited in passive comprehension of language switches. Using fMRI with a blocked design, 24 Spanish-English bilinguals silently read 36 paragraphs in which the default language was Spanish or English, and that had either (1) no switches, (2) function word switches or (3) content word switches. Relative to no switches, function switches activated the right IFG, bilateral MFG, and left IPL/SMG. In contrast, switching on content words produced limited neural switching costs observed only in the left IFG. Switching into the dominant language was more costly in the right SMG than switching into the nondominant language, and neural switching costs were correlated with switching costs in the dominant language in cued picture-naming. Seemingly passive reading comprehension involves brain regions known to support cognitive control in active switching during production, possibly reflecting the operation of a modality-general switch mechanism.

Multilingual two-digit number naming: The influence of composition rules on language switching

The aim of this study was to examine language switching in a two-digit number naming task. In contrast to single digits, two-digit numbers have a composition rule (i.e., morphological configuration) that may differ between languages. For example, the Arabic number 21 is read with an inverted composition rule in German (unit before decade) and a non-inverted composition rule in English (decade before unit). In the present experiment, one group of German native speakers and one group of Spanish native speakers had to name two-digit numbers in German, English, or Spanish. The results demonstrate a language-switch cost, revealing better performance in language repetition than in language-switch trials. This switch cost was further modulated by repeating or switching the composition rule, since the language repetition benefit (i.e., the switch cost) was reduced in trials with composition-rule switches compared with trials with composition-rule repetitions. This finding indicates that the language in which the number word has to be produced and its composition rule are not switched independently but rather may be integrated into one language schema.

Neuro-dynamics of executive control in bilingual language switching: An MEG study

Bilinguals have a remarkable ability to juggle two languages. A central question in the field is concerned with the control mechanisms that enable bilinguals to switch language with ease. Theoretical models and neuroimaging evidence suggest that a range of control processes are at play during language switching, and their underlying neural mechanisms are closely related to executive function. What remains unclear is when these control processes are engaged in language switching. In this study, we used magnetoencephalography (MEG) to examine the brain activity while unbalanced Mandarin-English bilinguals performed a digit-naming task with cued language switching. Following presentation of the language cue, an asymmetrical switch effect was observed in the left inferior frontal gyrus (IFG), where switch-related increase in evoked brain activity was larger for switching into the non-dominant language. Following presentation of the naming target, evoked brain activity in the right IFG was larger when naming was required in the non-dominant language compared to the dominant language. We conclude that control processes take place in two stages during language switching, with the left IFG resolving interference following cue presentation and the right IFG inhibiting competing labels following target presentation.

Transcranial direct current stimulation influences bilingual language control mechanism: evidence from cross-frequency coupling

How to better suppress the interference from the non-target language when switching from one language to the other in bilingual production? The current study applied transcranial direct current stimulation over the right dorsolateral prefrontal cortex to modulate language control measured by cross-frequency coupling. We found that switching to L2 was more modulated by F4-F3 alpha-beta phase-amplitude compared to switching to L1 after receiving the anodal stimulation at the language task schema phase. These findings suggest that anodal stimulation affects the selection of the target language task schema by enhancing the activation of frontal areas and facilitating the coordination between the left and the right frontal hemispheres.

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

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

Prefrontal sensitivity to changes in language form and semantic content during speech production

In bilingual speakers, language switching might involve a change in language form, meaning, or both. However, the neural substrates of language control in the three switching conditions have not been specified. We examined bilingual speech production using a picture-naming paradigm that teased apart language and semantic switching. Bilingual participants named two serially presented pictures, which show the same or different object, with one or two languages. The three switching conditions showed distinct neural activation patterns within the prefrontal cortex. Moreover, neural substrates shared by all switching conditions were primarily found in fronto-parietal regions. Besides, forward switching (L1-to-L2) activated a more widespread neural network than backward switching (L2-to-L1). We discuss differential engagement of the cognitive control system as a function of switching type during bilingual speech production.

Diffusing the bilingual lexicon: Task-based and lexical components of language switch costs

Bilingual speakers show a response time (RT) cost when switching between languages. These costs could reflect the organization of language in a shared bilingual lexicon (Grainger, Midgley, & Holcomb, 2010) or a domain general cognitive processing cost (Green & Abutalebi, 2013). To test these accounts, we analysed RT distributions of bilingual (Spanish-English) performance on generalized lexical decision (GLD) tasks using Ratcliff (1978) diffusion model. Experiment 1 revealed that language switches decrease the rate of evidence accumulation (drift rate) and slow the cognitive processes that occur prior to decision-making (non-decision time). Experiment 2 showed that the anticipation of language switches did not change these effects. The results suggest that language switch costs originate from a combination of at least two loci: lexical access and a task-specific decision process.

Language experience modulates bilingual language control: The effect of proficiency, age of acquisition, and exposure on language switching

The ability to selectively access two languages characterises the bilingual everyday experience. Previous studies showed the role of second language (L2) proficiency, as a proxy for dominance, on language control. However, the role of other aspects of the bilingual experience - such as age of acquisition and daily exposure - are relatively unexplored. In this study, we used a cued language switching task to examine language switching and mixing in two groups of highly proficient bilinguals with different linguistic backgrounds, to understand how the ability to control languages is shaped by linguistic experience. Our analysis shows that the ability to switch between languages is not only modulated by L2 proficiency, but also by daily L2 exposure. Daily L2 exposure also affects language mixing. Finally, L2 age of acquisition predicts naming latencies in the L2. Together, these findings show that language dominance is characterised by multiple aspects of the bilingual experience, which modulate language control.

How bilinguals perceive speech depends on which language they think they're hearing

Bilinguals understand when the communication context calls for speaking a particular language and can switch from speaking one language to speaking the other based on such conceptual knowledge. There is disagreement regarding whether conceptually-based language selection is also possible in the listening modality. For example, can bilingual listeners perceptually adjust to changes in pronunciation across languages based on their conceptual understanding of which language they're currently hearing? We asked French- and Spanish-English bilinguals to identify nonsense monosyllables as beginning with /b/ or /p/, speech categories that French and Spanish speakers pronounce differently than English speakers. We conceptually cued each bilingual group to one of their two languages or the other by explicitly instructing them that the speech items were word onsets in that language, uttered by a native speaker thereof. Both groups adjusted their /b-p/ identification boundary as a function of this conceptual cue to the language context. These results support a bilingual model permitting conceptually-based language selection on both the speaking and listening end of a communicative exchange.

Language and cognitive control networks in bilinguals and monolinguals

Neuroimaging studies have reported overlapping neural circuits for cognitive control when engaging in tasks that involve verbal and nonverbal stimuli in young adult bilinguals. However, no study to date has examined the neural basis of verbal and nonverbal task switching in both monolinguals and bilinguals due to the inherent challenge of testing verbal task switching with monolinguals. Therefore, it is not clear whether the finding for overlapping networks is unique to bilingualism or indicative of general cognitive control. To address this question, the current study compared functional neural activation for young adults who were bilingual speakers of English and French or monolingual English speakers who had limited French learning experience ("functional monolinguals") on verbal and nonverbal task switching. Analyses showed common variance explaining general cognitive control in task switching across verbal and nonverbal domains for both groups, in line with the explanation that task switching involves general cognitive control, as well as unique brain regions recruited by monolinguals and bilinguals. Specifically, beyond the processing common to the tasks, monolinguals also recruited distinct networks for each of verbal and nonverbal switching but bilinguals used a common shared network. Thus, the domain-general aspect of switching is different for monolinguals and bilinguals.

Trilinguals' language switching: A strategic and flexible account

The goal of this study was to determine how trilinguals select the language they intend to use in a language switching context. Two accounts are examined: (a) a language-specific account, according to which language selection considers the activation level of words of the intended language only (i.e., language co-activation without language competition), and (b) a language non-specific account, where activated words from both the intended and non-intended languages compete for selection (i.e., language co-activation with language competition). Results showed that, in both groups, all three languages competed for selection and that selection was achieved by inhibiting the currently non-relevant languages. Moreover, extending findings from previous research, the study reveals that, in both Experiments 1 and 2, the amount of inhibition was influenced not only by language proficiency but also by the typological similarity between languages. Overall, the study shows that language switching performance can be accounted for by a strategic and flexible inhibitory account. In particular, the controlling system is "strategic" in the sense that it aims at preventing potential conflicting situations, such as typological closeness between languages, and it is "flexible" in that it adjusts languages' activation levels, depending on the conflict to be solved.

Inhibition Efficiency in Highly Proficient Bilinguals and Simultaneous Interpreters: Evidence from Language Switching and Stroop Tasks

The present behavioral study aimed to examine the impact of language control expertise on two domain-general control processes, i.e. active inhibition of competing representations and overcoming of inhibition. We compared how Simultaneous Interpreters (SI) and Highly Proficient Bilinguals-two groups assumed to differ in language control capacity-performed executive tasks involving specific inhibition processes. In Experiment 1 (language decision task), both active and overcoming of inhibition processes are involved, while in Experiment 2 (bilingual Stroop task) only interference suppression is supposed to be required. The results of Experiment 1 showed a language switching effect only for the highly proficient bilinguals, potentially because overcoming of inhibition requires more cognitive resources than in SI. Nevertheless, both groups performed similarly on the Stroop task in Experiment 2, which suggests that active inhibition may work similarly in both groups. These contrasting results suggest that overcoming of inhibition may be harder to master than active inhibition. Taken together, these data indicate that some executive control processes may be less sensitive to the degree of expertise in bilingual language control than others. Our findings lend support to psycholinguistic models of bilingualism postulating a higher-order mechanism regulating language activation.

Inducing asymmetrical switch costs in bilingual language comprehension by language practice

The most widely discussed observation in the language control literature is the larger cost found when switching into the first than the second language (i.e., asymmetrical switch costs), which has been determined as a marker of persisting, reactive inhibition. While this is a common effect in bilingual language production, it generally does not occur in bilingual language comprehension. In this bilingual language comprehension study, we manipulated the relative activation of languages by letting participants practice in pure language blocks prior to a mixed language block. While no effect was found of practicing second-language words, asymmetrical switch costs were observed when practicing the same (Experiments 1 and 2) or different first-language words (Experiment 3) as in the following mixed language block. These findings indicate that, similar to bilingual production, bilingual comprehension relies on persisting, reactive language control.

Context affects L1 but not L2 during bilingual word recognition: an MEG study

How do bilinguals manage the activation levels of the two languages and prevent interference from the irrelevant language? Using magnetoencephalography, we studied the effect of context on the activation levels of languages by manipulating the composition of word lists (the probability of the languages) presented auditorily to late Finnish-English bilinguals. We first determined the upper limit time-window for semantic access, and then focused on the preceding responses during which the actual word recognition processes were assumedly ongoing. Between 300 and 500 ms in the temporal cortices (in the N400 m response) we found an asymmetric language switching effect: the responses to L1 Finnish words were affected by the presentation context unlike the responses to L2 English words. This finding suggests that the stronger language is suppressed in an L2 context, supporting models that allow auditory word recognition to be affected by contextual factors and the language system to be subject to inhibitory influence.

A sentence to remember: instructed language switching in sentence production

In the current study, we set out to investigate the influence of a sentence context on language switching. The task required German-English bilinguals to produce responses based on an alternating language sequence (L1-L1-L2-L2- …) and concepts in a specific sequential order. The concept sequence was either a sentence which was syntactically correct in both languages (language-unspecific sentence), a sentence which was correct in just one language (language-specific sentence) or a sentence which was syntactically incorrect in both languages (scrambled sentence). No switch costs were observed in language-unspecific sentences. Consequently, switch costs were smaller in those sentences than in the language-specific or scrambled sentences. The language-specific and scrambled sentence did not differ with respect to switch costs. These results demonstrate an important role of sentence context for language switch costs and were interpreted in terms of language interference and preparation processes.

Neural basis of language switching in the brain: fMRI evidence from Korean-Chinese early bilinguals

Using fMRI, we conducted two types of property generation task that involved language switching, with early bilingual speakers of Korean and Chinese. The first is a more conventional task in which a single language (L1 or L2) was used within each trial, but switched randomly from trial to trial. The other consists of a novel experimental design where language switching happens within each trial, alternating in the direction of the L1/L2 translation required. Our findings support a recently introduced cognitive model, the 'hodological' view of language switching proposed by Moritz-Gasser and Duffau. The nodes of a distributed neural network that this model proposes are consistent with the informative regions that we extracted in this study, using both GLM methods and Multivariate Pattern Analyses: the supplementary motor area, caudate, supramarginal gyrus and fusiform gyrus and other cortical areas.

Involuntary switching into the native language induced by electrocortical stimulation of the superior temporal gyrus: a multimodal mapping study

We describe involuntary language switching from L2 to L1 evoked by electro-stimulation in the superior temporal gyrus in a 30-year-old right-handed Serbian (L1) speaker who was also a late Italian learner (L2). The patient underwent awake brain surgery. Stimulation of other portions of the exposed cortex did not cause language switching as did not stimulation of the left inferior frontal gyrus, where we evoked a speech arrest. Stimulation effects on language switching were selective, namely, interfered with counting behaviour but not with object naming. The coordinates of the positive site were combined with functional and fibre tracking (DTI) data. Results showed that the language switching site belonged to a significant fMRI cluster in the left superior temporal gyrus/supramarginal gyrus found activated for both L1 and L2, and for both the patient and controls, and did not overlap with the inferior fronto-occipital fasciculus (IFOF), the inferior longitudinal fasciculus (ILF) and the superior longitudinal fasciculus (SLF). This area, also known as Stp, has a role in phonological processing. Language switching phenomenon we observed can be partly explained by transient dysfunction of the feed-forward control mechanism hypothesized by the DIVA (Directions Into Velocities of Articulators) model (Golfinopoulos, E., Tourville, J. A., & Guenther, F. H. (2010). The integration of large-scale neural network modeling and functional brain imaging in speech motor control.