Do accent and input modality modulate processing of language switches in bilingual language comprehension?

We examined how bilinguals process language switches between their first (L1) and second language (L2). Language switching costs (slower responses to language switch than nonswitch trials) appear to arise more systematically in production than in comprehension, possibly because the latter context might sometimes elicit less language coactivation (Declerck et al., 2019). This might reduce language competition and in turn the need for bilinguals to apply language control when processing language switches. Yet even in comprehension, language coactivation may vary depending on variables such as the accent of the speaker (e.g., whether the L2 words are pronounced with an L1 or L2 accent) and input modality (spoken or written). In three experiments conducted during 2021-2022, we tested how unbalanced Mandarin-English bilinguals processed language switches during comprehension and the potential influence of a speaker's accent and input modality. Overall, across settings, participants experienced significant language switching costs. In some conditions, switching costs were larger to L1-Mandarin than to L2-English, an asymmetry consistent with the participants' dominance in L1-Mandarin and the application of language control. However, manipulating accent and input modality did not influence language switches, suggesting they did not impact language coactivation sufficiently to modulate language control. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Processing of Synonyms and Homographs in Bilingual and Monolingual Speakers.

Bilinguals have long-lasting experience with cross-language double-mappings (i.e., translation equivalents and interlingual homographs (or false friends)). Considering this, we examined whether bilinguals differ from monolinguals in within-language double-mapping (i.e., synonyms and homographs) processing. Across two experiments, we compared performances from Spanish monolinguals and Spanish-Basque bilinguals on a behavioral picture-word matching task. The words were all presented in Spanish, the native language of all participants. Participants responded to synonyms and homographs (both double-mappings) or single-mappings (controls). The reaction times in both experiments showed clear and significant costs in processing within-language double-mapping stimuli, as well as intrinsic differences in processing homographs versus synonyms. However, these effects did not differ between bilinguals and monolinguals. The present findings thus suggest that the bilinguals' extensive experience with cross-linguistic double-mappings does not transfer onto within-language double-mapping processing.

Dual-tasking while using two languages: Examining the cognitive resource demands of cued and voluntary language production in bilinguals.

The way bilinguals switch languages can differ depending on the context. In cued dual-language environments, bilinguals select a language in response to environmental cues (e.g., a monolingual conversation partner). In voluntary dual-language environments, bilinguals communicating with people who speak the same languages can use their languages more freely. The control demands of these types of language-production contexts, and the costs of language switches, have been argued to differ (Adaptive Control Hypothesis). Here, we used a dual-task paradigm to examine how cued and voluntary bilingual production differ in cognitive resources used. Forty Mandarin-English bilinguals completed two language-switching paradigms as the primary task; one in response to cues and one while using two languages freely. At the same time, they also had to respond to the pitch of tones (secondary task). Response times (RTs) on the secondary task, as well as naming times on the primary task, were shorter under the voluntary- than cued-naming condition. Task workload ratings were also higher under the cued- than voluntary-naming condition. This suggests more attentional resources are needed in a cued-naming context to monitor cues and select languages accordingly. However, the costs associated with switching from one language to the other were similar in both voluntary- and cued-naming contexts. Thus, while cued-naming might be more effortful overall, cued and voluntary switching recruited similar levels of cognitive resources.

Putting language switching in context: Effects of sentence context and interlocutors on bilingual switching.

Many bilinguals switch languages in daily-life conversations. Although this usually happens within sentence context and with another speaker, most research on the cognitive mechanisms underlying the production of language switches has studied individual words. Here, we examined how context influences both switching frequency and the temporal cost associated with it. Sixty Bulgarian-English bilinguals named pictures in their language of choice without any context, in a sentence context, and in interaction with another (recorded) bilingual. Switching frequency was lower, and costs higher, when bilinguals switched languages with context than without context. This suggests switching costs were not an artifact of tasks without context. Furthermore, both switching frequency and costs correlated across the tasks. In addition, we examined the potential influence of sentence context and the conversation partner. Predictability in sentence context has previously been argued to reduce language competition, which in turn could influence switching. We therefore compared sentences with a predictable or unpredictable target word. As hypothesized, bilinguals were less likely to switch languages when a word was predictable in its sentence context, potentially because words in the other language were less active. The conversation partner's overall switching behaviour had little impact on a bilingual's general switching rate, showing relatively low global alignment. However, local alignment was observed as switching was influenced by the partner's switching in the immediately preceding utterance. Together, these findings show that while production tasks without context can reliably measure switching costs, studying effects of context is necessary to better capture a bilingual's language-switching behavior. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A comparison of language control while switching within versus between languages in younger and older adults.

Word retrieval during language production slows down with age. However, bilinguals also require language control to manage language competition, in particular when switching languages to cues. The current study examined how this bilingual language control differs between younger and older adults. It also compared bilingual control, and age-group differences, to control that might be applied when alternating between responses within one language. In Experiment 1, 40 younger and 40 older monolingual adults completed a task alternating between noun and verb responses to pictures. The task showed costs associated with language control but these did not differ between age groups. Experiment 2 was completed by 50 older and 50 younger bilingual adults. Older adults showed larger switching costs than younger adults when switching between and within languages, suggesting they experienced more difficulty with reactive control. However, while older adults showed larger mixing costs than younger adults when using two languages in the dual-language environment relative to the single-language environment, they surprisingly showed smaller mixing costs than younger adults in the noun-verb within-language naming task. These findings show that language control, and the way it differs between older and younger adults, is not the same across within- and bilingual-language competition.

Behavioral and oscillatory signatures of switch costs in highly proficient bilinguals.

Bilinguals with a high proficiency in their first (L1) and second language (L2) often show comparable reaction times when switching from their L1 to L2 and vice-versa ("symmetrical switch costs"). However, the neurophysiological signatures supporting this effect are not well understood. Here, we ran two separate experiments and assessed behavioral and MEG responses in highly proficient Spanish-Basque bilinguals while they overtly name pictures in a mixed-language context. In the behavioral experiment, bilinguals were slower when naming items in switch relative to non-switch trials, and this switch cost was comparable for both languages (symmetrical). The MEG experiment mimicked the behavioral one, with switch trials showing more desynchronization than non-switch trials across languages (symmetric neural cost) in the alpha band (8-13 Hz). Source-localization revealed the engagement of right parietal and premotor areas, which have been linked to language selection and inhibitory control; and of the left anterior temporal lobe (ATL), a cross-linguistic region housing conceptual knowledge that generalizes across languages. Our results suggest that highly proficient bilinguals implement a language-independent mechanism, supported by alpha oscillations, which is involved in cue-based language selection and facilitates conceptually-driven lexical access in the ATL, possibly by inhibiting non-target lexical items or disinhibiting target ones.

Examining the difference in error detection when listening to native and non-native speakers.

As communication with non-native speakers becomes increasingly common, it is important to understand how foreign-accented speech might influence language processing. Non-native speech can require the listener to process errors, such as grammatical violations or unexpected word choices. The present study examines how listeners process different types of errors across native and non-native speakers. Using a self-paced listening task measuring reaction times to target words, 30 participants listened to sentences that contained either no-error, a grammatical error (e.g., "Do you wanting anything?"), or a contextual formal/informal word-choice error (e.g., "Do you require anything?" in an informal context). Participants responded more slowly while processing grammatical and word-choice errors compared with control sentences, especially when listening to non-native speech. This suggests that errors spoken by non-native speakers take longer to process, both in the case of grammatical errors and when contextually inappropriate words are used.

Diving into a pool or volcano? Examining the influence of sentence context and task demands on sentence reading in younger and older adults.

Cognitive ageing is often associated with slower lexical processing, which might influence both language production and comprehension. Words are typically used in context, which can further influence word processing and potential age differences. However, it remains unclear how older adults are affected by context during reading. Older adults are reported to have in-tact semantic knowledge, which could potentially help them to process words predicted by semantic information in the preceding context. However, potential difficulties with semantic control might mean older adults have greater difficulty suppressing interfering information from mismatching contexts. In this study we examined the influence of contexts that either predicted a specific target word ("matched", e.g., "The man watched the lava erupt from the volcano") or predicted another word than the target ("mismatched", e.g., "The swimmer dived into the volcano") as compared to neutral contexts (e.g., "They went to see the volcano"). We also examined the potential role of task demands by asking participants to either just read the sentences for comprehension or to answer questions. Forty younger adults (18-35 years old) and forty older adults (65-80 years old) completed a self-paced reading task in which we measured reading times for the target words. Older adults showed slower reading times overall. Matched sentence contexts facilitated reading times in both age groups. Surprisingly, mismatched sentence contexts did not hinder reading times in either age group. Furthermore, reading times were not influenced by task demands. Together, this shows the importance of studying language in context. While interference from mismatching sentence contexts might have not been substantial enough to delay reading, reading was faster when processing expected words. This suggests older adults can indeed benefit from semantic knowledge to facilitate word processing during comprehension. This occurred even when no additional task was presented and people were purely reading for comprehension.

Perro or txakur? Bilingual language choice during production is influenced by personal preferences and external primes.

Bilinguals living in a bilingual society continuously need to choose one of their languages to communicate a message. Sometimes, the circumstances (e.g., the presence of a monolingual) dictate language choice. When surrounded by other bilinguals, however, the bilinguals themselves can often decide which language to use. While much previous research has assessed language production when language selection is predetermined, we assessed how bilinguals choose the naming language themselves. We focused on the role of personal language preferences and examined to what extent personal preferences might be affected by external, suggestive language primes. Spanish-Basque bilinguals were asked to name pictures in their language of choice. Pictures were either presented on their own or were preceded by a linguistic or non-linguistic prime. In a separate session, participants were asked which language they preferred for each picture. Language choice during voluntary picture naming was related to personal language preferences. A bilingual was more likely to name a picture in the language they preferred for that specific picture. Furthermore, bilinguals were more likely to choose the language matching the preceding linguistic or non-linguistic prime. Effects of primes and preferences were additive and the influence of language preference on choice was equally strong in the primed and no-prime tasks. In addition to modulating language choice, following preferences and primes was also associated with faster responses. Together, these findings show that initial stages of language production and language choice are not just modulated by external primes but also by a bilingual's individual preferences.

Second-language word recognition in noise: Interdependent neuromodulatory effects of semantic context and crosslinguistic interactions driven by word form similarity.

Spoken language comprehension is a fundamental component of our cognitive skills. We are quite proficient at deciphering words from the auditory input despite the fact that the speech we hear is often masked by noise such as background babble originating from talkers other than the one we are attending to. To perceive spoken language as intended, we rely on prior linguistic knowledge and context. Prior knowledge includes all sounds and words that are familiar to a listener and depends on linguistic experience. For bilinguals, the phonetic and lexical repertoire encompasses two languages, and the degree of overlap between word forms across languages affects the degree to which they influence one another during auditory word recognition. To support spoken word recognition, listeners often rely on semantic information (i.e., the words we hear are usually related in a meaningful way). Although the number of multilinguals across the globe is increasing, little is known about how crosslinguistic effects (i.e., word overlap) interact with semantic context and affect the flexible neural systems that support accurate word recognition. The current multi-echo functional magnetic resonance imaging (fMRI) study addresses this question by examining how prime-target word pair semantic relationships interact with the target word's form similarity (cognate status) to the translation equivalent in the dominant language (L1) during accurate word recognition of a non-dominant (L2) language. We tested 26 early-proficient Spanish-Basque (L1-L2) bilinguals. When L2 targets matching L1 translation-equivalent phonological word forms were preceded by unrelated semantic contexts that drive lexical competition, a flexible language control (fronto-parietal-subcortical) network was upregulated, whereas when they were preceded by related semantic contexts that reduce lexical competition, it was downregulated. We conclude that an interplay between semantic and crosslinguistic effects regulates flexible control mechanisms of speech processing to facilitate L2 word recognition, in noise.

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.

Clear Theories Are Needed to Interpret Differences: Perspectives on the Bilingual Advantage Debate.

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 article 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.

The effects of language and emotionality of stimuli on vocabulary learning.

Learning new content and vocabulary in a foreign language can be particularly difficult. Yet, there are educational programs that require people to study in a language they are not native speakers of. For this reason, it is important to understand how these learning processes work and possibly differ from native language learning, as well as to develop strategies to ease this process. The current study takes advantage of emotionality-operationally defined as positive valence and high arousal-to improve memory. In two experiments, the present paper addresses whether participants have more difficulty learning the names of objects they have never seen before in their foreign language and whether embedding them in a positive semantic context can help make learning easier. With this in mind, we had participants (with a minimum of a B2 level of English) in two experiments (43 participants in Experiment 1 and 54 in Experiment 2) read descriptions of made-up objects-either positive or neutral and either in their native or a foreign language. The effects of language varied with the difficulty of the task and measure used. In both cases, learning the words in a positive context improved learning. Importantly, the effect of emotionality was not modulated by language, suggesting that the effects of emotionality are independent of language and could potentially be a useful tool for improving foreign language vocabulary learning.

Effects of language context on executive control in unbalanced bilinguals: An ERPs study.

The influence of the language context on language control has been widely discussed in the bilingualism literature, and there is an increase in studies examining the effect of language context on domain-general executive control. However, it remains unclear how language contexts affect executive control performance. In the present study, we created single- and mixed-language comprehension contexts. Unbalanced Chinese-English bilinguals completed a modified flanker task that was interleaved with a single-language or mixed-language picture-word matching task. The effects of language comprehension context on language control were reflected by the N2 and LPC effects. Executive control processes also differed depending on the language comprehension context, with faster behavioral responses and larger N2 but smaller P3 electrophysiological components in the mixed-language context. Moreover, the LPC amplitude in the mixed-language context predicted the behavioral performance in the executive control task. These findings suggested that flexible language control during language comprehension altered executive control processes in unbalanced bilinguals.

Changes in the Sensitivity to Language-Specific Orthographic Patterns With Age.

How do bilingual readers of languages that have similar scripts identify a language switch? Recent behavioral and electroencephalographic results suggest that they rely on orthotactic cues to recognize the language of the words they read in ambiguous contexts. Previous research has shown that marked words with language-specific letter sequences (i.e., letter sequences that are illegal in one of the two languages) are recognized more easily and faster than unmarked words. The aim of this study was to investigate sensitivity to markedness throughout childhood and early adulthood by using a speeded language decision task with words and pseudowords. A large group of Spanish-Basque bilinguals of different ages (children, preteenagers, teenagers and adults) was tested. Results showed a markedness effect in the second language across all age groups that changed with age. However, sensitivity to markedness in the native language was negligible. We conclude that sensitivity to orthotactics does not follow parallel developmental trend in the first and second language.

Interactive influence of self and other language behaviors: Evidence from switching between bilingual production and comprehension.

The neural mechanisms underlying one's own language production and the comprehension of language produced by other speakers in daily communication remain elusive. Here, we assessed how self-language production and other-language comprehension interact within a language switching context using event-related functional Magnetic Resonance Imaging (er-fMRI) in 32 unbalanced Chinese-English bilinguals. We assessed within-modality language interference during language production and comprehension as well as cross-modality interference when switching from production to comprehension and vice versa. Results revealed that the overall effect of production (across switch and repeat trials) was larger in the cross-modality than within-modality condition in a series of attentional control areas, namely the left dorsolateral prefrontal cortex, anterior cingulate cortex and left precuneus. Furthermore, the left precuneus was recruited more strongly in switch trials compared to repeat trials (i.e., switching costs) in within-production conditions but not in the cross-modality condition. These findings suggest that switching from production to comprehension recruits cognitive control areas to successfully implement switches between modalities. However, cross-language interference (in the form of language switching costs) mainly stems from the self-language production system.

Examining bilingual language switching across the lifespan in cued and voluntary switching contexts.

How bilinguals control their languages and switch between them may change across the life span. Furthermore, bilingual language control may depend on the demands imposed by the context. Across 2 experiments, we examined how Spanish-Basque children, teenagers, younger, and older adults switch between languages in voluntary and cued picture-naming tasks. In the voluntary task, bilinguals could freely choose a language while the cued task required them to use a prespecified language. In the cued task, youths and older adults showed larger language mixing costs than young adults, suggesting that using 2 languages in response to cues was more effortful. Cued switching costs, especially when the switching sequence was predictable, were also greater for youths and older adults. The voluntary switching task showed limited age effects. Older adults, but not youths, showed larger switching costs than younger adults. A voluntary mixing benefit was found in all ages, implying that voluntarily using 2 languages was less effortful than using one language across the life span. Thus, while youths and older adults experience greater difficulties using multiple languages in response to external cues, they are affected less when they can freely use their languages. This shows that age effects on bilingual language control are context-dependent. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Is inhibition involved in voluntary language switching? Evidence from transcranial direct current stimulation over the right dorsolateral prefrontal cortex.

How do bilinguals freely switch languages in daily life (i.e., voluntary language switching)? Does this involve inhibition of cross-language interference, or does easier lexical access to specific words directly trigger switches to another language? To reveal the underlying mechanism of voluntary language switching, the current study applied transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (rDLPFC), an area associated with inhibitory control, to investigate whether and how inhibitory control is involved in voluntary language switching. Interestingly, during the A-tDCS and C-tDCS sessions, bilinguals showed faster naming latencies in repeat trials compared to switch trials, indicating a switch cost. Moreover, the cathodal stimulation exhibited a larger LPC in switching to L2 compared to switching to L1. In contrast, the S-tDCS (sham) session showed no switch cost, faster switch naming latencies compared to the A-tDCS and C-tDCS sessions, and little differences in LPC between switch and repeat trials. Together, these findings suggest that modulating inhibition-related brain regions interferes with voluntary language switching.

Not All Bilinguals Are the Same: A Call for More Detailed Assessments and Descriptions of Bilingual Experiences.

No two bilinguals are the same. Differences in bilingual experiences can affect language-related processes but have also been proposed to modulate executive functioning. Recently, there has been an increased interest in studying individual differences between bilinguals, for example in terms of their age of acquisition, language proficiency, use, and switching. However, and despite the importance of this individual variation, studies often do not provide detailed assessments of their bilingual participants. This review first discusses several aspects of bilingualism that have been studied in relation to executive functioning. Next, I review different questionnaires and objective measurements that have been proposed to better define bilingual experiences. In order to better understand (effects of) bilingualism within and across studies, it is crucial to carefully examine and describe not only a bilingual's proficiency and age of acquisition, but also their language use and switching as well as the different interactional contexts in which they use their languages.

Metaphors we learn by: Directed motor action improves word learning.

Can performing simple motor actions help people learn the meanings of words? Here we show that placing vocabulary flashcards in particular locations after studying them helps students learn the definitions of novel words with positive or negative emotional valence. After studying each card, participants placed it on one of two shelves (top or bottom), according to its valence. Participants who were instructed to place positive cards on the top shelf and negative cards on the bottom shelf, consistent with metaphors that link "good" with "up," remembered the words' definitions better than participants who followed the opposite spatial mapping, and better than control participants who placed all of the cards on the desktop. Saying "up" and "down" after studying the cards was ineffective, suggesting a privileged role for motor action in activating space-valence associations that partly constitute the meanings of emotionally charged words. These results provide a first demonstration that mental metaphors can be activated strategically to improve (or impair) word learning: We call this the strategic use of mental metaphor (SUMM) effect. Even when multiple factors known to enhance encoding of verbal materials into long-term memory were matched across conditions (e.g., study time, repetition, distinctiveness, depth of processing), metaphor-congruent motor actions led to better elaborated, more durable memories.