Parallel language activation and cognitive control during spoken word recognition in bilinguals

Parallel Interactions Between Linguistic and Contextual Factors in Bilinguals

The necessity for introducing interactionist and parallelism approaches in different branches of cognitive science emerged as a reaction to classical sequential stage-based models. Functional psychological models that emphasized and explained how different components interact, dynamically producing cognitive and perceptual states, influenced multiple disciplines. Chiefly among them were experimental psycholinguistics and the many applied areas that dealt with humans' ability to process different types of information in different contexts. Understanding how bilinguals represent and process verbal and visual input, how their neural and psychological states facilitate such interactions, and how linguistic and nonlinguistic processing overlap, has now emerged as an important area of multidisciplinary research. In this article, we will review available evidence from different language-speaking groups of bilinguals in India with a focus on situational context. In the discussion, we will address models of language processing in bilinguals within a cognitive psychological approach with a focus on existent models of inhibitory control. The paper's stated goal will be to show that the parallel architecture framework can serve as a theoretical foundation for examining bilingual language processing and its interface with external factors such as social context.

Age Impacts Speech-in-Noise Recognition Differently for Nonnative and Native Listeners

PURPOSE

The purpose of this study was to explore potential differences in suprathreshold auditory function among native and nonnative speakers of English as a function of age.

METHOD

Retrospective analyses were performed on three large data sets containing suprathreshold auditory tests completed by 5,572 participants who were self-identified native and nonnative speakers of English between the ages of 18-65 years, including a binaural tone detection test, a digit identification test, and a sentence recognition test.

RESULTS

The analyses show a significant interaction between increasing age and participant group on tests involving speech-based stimuli (digit strings, sentences) but not on the binaural tone detection test. For both speech tests, differences in speech recognition emerged between groups during early adulthood, and increasing age had a more negative impact on word recognition for nonnative compared to native participants. Age-related declines in performance were 2.9 times faster for digit strings and 3.3 times faster for sentences for nonnative participants compared to native participants.

CONCLUSIONS

This set of analyses extends the existing literature by examining interactions between aging and self-identified native English speaker status in several auditory domains in a cohort of adults spanning young adulthood through middle age. The finding that older nonnative English speakers in this age cohort may have greater-than-expected deficits on speech-in-noise perception may have clinical implications on how these individuals should be diagnosed and treated for hearing difficulties.

Exploring audiovisual speech perception in monolingual and bilingual children in Uzbekistan

This study aimed to investigate the development of audiovisual speech perception in monolingual Uzbek-speaking and bilingual Uzbek-Russian-speaking children, focusing on the impact of language experience on audiovisual speech perception and the role of visual phonetic (i.e., mouth movements corresponding to phonetic/lexical information) and temporal (i.e., timing of speech signals) cues. A total of 321 children aged 4 to 10 years in Tashkent, Uzbekistan, discriminated /ba/ and /da/ syllables across three conditions: auditory-only, audiovisual phonetic (i.e., sound accompanied by mouth movements), and audiovisual temporal (i.e., sound onset/offset accompanied by mouth opening/closing). Effects of modality (audiovisual phonetic, audiovisual temporal, or audio-only cues), age, group (monolingual or bilingual), and their interactions were tested using a Bayesian regression model. Overall, older participants performed better than younger participants. Participants performed better in the audiovisual phonetic modality compared with the auditory modality. However, no significant difference between monolingual and bilingual children was observed across all modalities. This finding stands in contrast to earlier studies. We attribute the contrasting findings of our study and the existing literature to the cross-linguistic similarity of the language pairs involved. When the languages spoken by bilinguals exhibit substantial linguistic similarity, there may be an increased necessity to disambiguate speech signals, leading to a greater reliance on audiovisual cues. The limited phonological similarity between Uzbek and Russian might have minimized bilinguals' need to rely on visual speech cues, contributing to the lack of group differences in our study.

ERP and Behavioural Correlates of Prospective Memory in Bilinguals during L1 and L2 Processing

Language influences how we process information from multiple domains. Thus, working in first (L1) or second language (L2) can modulate bilinguals' performance on basic activities, such as visual search, decision-making, or reading. However, few studies have explored the role of L1 and L2 processing during an essential ability, such as Prospective Memory (PM). This type of memory allows us to set intentions to perform in the future (e.g., to attend an appointment). Thus, this is a novel study that allows us to explore the influence of bilingual language processing on certain cognitive abilities, which have not been deeply studied yet, such as the recall of future intentions. Thereby, this study aimed to explore the neural and behavioural correlates of bilinguals during L1 and L2 processing in a PM task where participants had to carry out an ongoing task while recovering a prospective intention given a PM cue. Importantly, the nature of the PM cue (focal or non-focal) varied the monitoring demands of the task. Behavioural and Event-Related Potential (ERP) results indicated greater engagement of monitoring processes in the PM task during L2 processing. Specifically, in L2, we found lower accuracy rates in the ongoing task and smaller amplitude differences between the focal and non-focal conditions in the P3b. Altogether, these findings suggest an impairment in prospective processing due to working in L2 contexts, supporting previous research on the impact of the bilingual experience over PM.

Noise Modulates Crosslinguistic Effects on Second-Language Auditory Word Recognition

PURPOSE

This study investigates whether crosslinguistic effects on auditory word recognition are modulated by the quality of the auditory signal (clear and noisy).

METHOD

In an online experiment, a group of Spanish-English bilingual listeners performed an auditory lexical decision task, in their second language, English. Words and pseudowords were either presented in the clear or were embedded in white auditory noise. Target words were varied in the degree to which they overlapped in their phonological form with their translation equivalents and were categorized according to their overlap as cognates (form and meaning) or noncognates (meaning only). In order to test for effects of crosslinguistic competition, the phonological neighborhood density of the targets' translations was also manipulated.

RESULTS

The results show that crosslinguistic effects are impacted by noise; when the translation had a high neighborhood density, performance was worse for cognates than for noncognates, especially in noise.

CONCLUSIONS

The findings suggest that noise increases lexical competition across languages, as it does within a language, and that the crosslinguistic phonological overlap for cognates compared with noncognates can further increase the pool of competitors by co-activating crosslinguistic lexical candidates. The results are discussed within the context of the bilingual word recognition literature and models of language and bilingual lexical processing.

Effects of language background on executive function: Transfer across task and modality

The relation between linguistic experience and cognitive function has been of great interest, but recent investigations of this question have produced widely disparate results, ranging from proposals for a "bilingual advantage," to a "bilingual disadvantage," to claims of no difference at all as a function of language. There are many possible sources for this lack of consensus, including the heterogeneity of bilingual populations, and the choice of different tasks and implementations across labs. We propose that another reason for this inconsistency is the task demands of transferring from linguistic experience to laboratory tasks can differ greatly as the task is modified. In this study, we show that task modality (visual, audio, and orthographic) can yield different patterns of performance between monolingual and multilingual participants. The very same task can show similarities or differences in performance, as a function of modality. In turn, this may be explained by the distance of transfer - how close (or far) the laboratory task is to the day to day lived experience of language usage. We suggest that embodiment may provide a useful framework for thinking about task transfer by helping to define the processes of linguistic production and comprehension in ways that are easily connected to task manipulations.

The Involvement of Listening Effort in Explaining Bilingual Listening Under Adverse Listening Conditions

The current review examines listening effort to uncover how it is implicated in bilingual performance under adverse listening conditions. Various measures of listening effort, including physiological, behavioral, and subjective measures, have been employed to examine listening effort in bilingual children and adults. Adverse listening conditions, stemming from environmental factors, as well as factors related to the speaker or listener, have been examined. The existing literature, although relatively limited to date, points to increased listening effort among bilinguals in their nondominant second language (L2) compared to their dominant first language (L1) and relative to monolinguals. Interestingly, increased effort is often observed even when speech intelligibility remains unaffected. These findings emphasize the importance of considering listening effort alongside speech intelligibility. Building upon the insights gained from the current review, we propose that various factors may modulate the observed effects. These include the particular measure selected to examine listening effort, the characteristics of the adverse condition, as well as factors related to the particular linguistic background of the bilingual speaker. Critically, further research is needed to better understand the impact of these factors on listening effort. The review outlines avenues for future research that would promote a comprehensive understanding of listening effort in bilingual individuals.

Visual word recognition in bilinguals: Eye-tracking evidence that L2 proficiency impacts access of L1 phonotactics

A bilingual's language system is highly interactive. When hearing a second language (L2), bilinguals access native-language (L1) words that share sounds across languages. In the present study, we examine whether input modality and L2 proficiency moderate the extent to which bilinguals activate L1 phonotactic constraints (i.e., rules for combining speech sounds) during L2 processing. Eye-movements of English monolinguals and Spanish-English bilinguals were tracked as they searched for a target English word in a visual display. On critical trials, displays included a target that conflicted with the Spanish vowel-onset rule (e.g., sp a), as well as a competitor containing the potentially-activated 'e' onset (e.g., e gg). The rule violation was processed either in the visual modality (Experiment 1) or audio-visually (Experiment 2). In both experiments, bilinguals with lower L2 proficiency made more eye movements to competitors than fillers. Findings suggest that bilinguals who have lower L2 proficiency access L1 phonotactic constraints during L2 visual word processing with and without auditory input of the constraint-conflicting structure (e.g., spa). We conclude that the interactivity between a bilingual's two languages is not limited to words that share form across languages, but also extends to sub-lexical, rule-based structures.

Speaker Accent Modulates the Effects of Orthographic and Phonological Similarity on Auditory Processing by Learners of English

The cognate effect refers to translation equivalents with similar form between languages-i.e., cognates, such as "band" (English) and "banda" (Spanish)-being processed faster than words with dissimilar forms-such as, "cloud" and "nube." Substantive literature supports this claim, but is mostly based on orthographic similarity and tested in the visual modality. In a previous study, we found an inhibitory orthographic similarity effect in the auditory modality-i.e., greater orthographic similarity led to slower response times and reduced accuracy. The aim of the present study is to explain this effect. In doing so, we explore the role of the speaker's accent in auditory word recognition and whether native accents lead to a mismatch between the participants' phonological representation and the stimulus. Participants carried out a lexical decision task and a typing task in which they spelled out the word they heard. Words were produced by two speakers: one with a native English accent (Standard American) and the other with a non-native accent matching that of the participants (native Spanish speaker from Spain). We manipulated orthographic and phonological similarity orthogonally and found that accent did have some effect on both response time and accuracy as well as modulating the effects of similarity. Overall, the non-native accent improved performance, but it did not fully explain why high orthographic similarity items show an inhibitory effect in the auditory modality. Theoretical implications and future directions are discussed.

Individual and Sociolinguistic Differences in Language Background Predict Stroop Performance

To examine how differences in language experience and sociolinguistic context impact cognitive control, 146 Spanish-English bilingual participants were tested on a non-linguistic Stroop arrows task. Dimensions of language experience included a continuum of L2 proficiency, exposure, age of L2 acquisition, and English receptive vocabulary, along with cognitive non-verbal reasoning. Sociolinguistic context varied with more exposure to Spanish for participants in Southern California (SoCal) than in the Midwest. The task involved perceptual stimulus-stimulus conflict within stimulus features (e.g., right-pointing arrow on the left side of a display). Reaction times to trials where arrow location and direction matched (congruent), mismatched (incongruent), or arrow location was centered (neutral) were used to calculate Stroop (incongruent-congruent), facilitation (neutral-congruent), and inhibition (incongruent-neutral) effects. When examining performance on a continuum of bilingual language experience, individual differences in linguistic background (i.e., L2 proficiency and exposure, receptive vocabulary) and cognitive abilities (i.e., non-verbal reasoning abilities) predicted more efficient performance on the Stroop task. Across sociolinguistic contexts, findings revealed better performance via smaller Stroop and facilitation effects in the Midwest than in SoCal, and no group difference on the inhibition effect. We conclude that research on the cognitive consequences of bilingualism must consider a continuum of language experiences and must be situated in broader naturalistic contexts that take into account the sociolinguistic environments of language use.

Person-specific connectivity mapping uncovers differences of bilingual language experience on brain bases of attention in children

Bilingualism influences children's cognition, yet bilinguals vary greatly in their dual-language experiences. To uncover sources of variation in bilingual and monolingual brain function, the present study used standard analysis and innovative person-specific connectivity models combined with a data-driven grouping algorithm. Children (ages 7-9; N = 52) completed a visuo-spatial attention task while undergoing functional near-infrared spectroscopy neuroimaging. Both bilingual and monolingual groups performed similarly, and engaged bilateral frontal and parietal regions. However, bilinguals showed greater brain activity than monolinguals in left frontal and parietal regions. Connectivity models revealed two empirically-derived subgroups. One subgroup was composed of monolinguals and bilinguals who were more English dominant, and showed left frontal-parietal connections. The other was composed of bilinguals who were balanced in their dual-language abilities and showed left frontal lobe connections. The findings inform how individual variation in early language experiences influences children's emerging cortical networks for executive function, and reveal efficacy of data-driven approaches.

Modulation of Cross-Language Activation During Bilingual Auditory Word Recognition: Effects of Language Experience but Not Competing Background Noise

Previous research has shown that as the level of background noise increases, auditory word recognition performance drops off more rapidly for bilinguals than monolinguals. This disproportionate bilingual deficit has often been attributed to a presumed increase in cross-language activation in noise, although no studies have specifically tested for such an increase. We propose two distinct mechanisms by which background noise could cause an increase in cross-language activation: a phonetically based account and an executive function-based account. We explore the evidence for the phonetically based account by comparing cognate facilitation effects for three groups of native English listeners (monolinguals, late (L2) learners of Spanish, and heritage Spanish speakers) and four noise conditions (no noise, speech-shaped noise, English two-talker babble, and Spanish two-talker babble) during an auditory lexical decision task in English. By examining word recognition in the dominant language, the role of language control mechanisms is minimized, and by examining three different types of competing noise, the role of energetic vs. informational masking can be assessed. Contrary to predictions, we find no evidence that background noise modulates cross-language activation; cognate facilitation is constant across the four noise conditions. Instead, several indices of word recognition performance are found to correlate with aspects of linguistic experience: (1) The magnitude of the cognate facilitation effect is correlated with heritage listeners' self-ratings of Spanish proficiency; (2) Overall noise deficits are marginally larger for heritage listeners with lower English vocabulary scores; (3) Heritage listeners' Spanish self-ratings predict their magnitude of informational masking; (4) For all bilinguals, the degree of masking incurred in both English and Spanish two-talker babble is correlated with self-reported daily exposure to Spanish; and (5) The degree of masking incurred by Spanish babble is correlated with Spanish vocabulary knowledge. The results enrich our understanding of auditory word recognition in heritage speakers in particular and provide evidence that informational masking is most subject to modulation due to variation in linguistic experience. It remains to be seen whether cross-language activation is modulated by noise when the target language is the less dominant one.

Attentional orienting abilities in bilinguals: Evidence from a large infant sample

A key question in studies of cognitive development is whether bilingual environments impact higher-cognitive functions. Inconclusive evidence in search of a "bilingual cognitive advantage" has sparked debates on the reliability of these findings. Few studies with infants have examined this question, but most of them include small samples. The current study presents evidence from a large sample of 6- and 10-month-old monolingual- and bilingual-exposed infants (N = 152), which includes a longitudinal subset (n = 31), who completed a cueing attentional orienting task. The results suggest bilingual infants showed significant developmental gains in latency performance during the condition that was most cognitively demanding (Incongruent). The results also revealed bilingual infants' performance was associated with their parents' dual-language switching behavior. Taken together, these results provide support that bilingual experiences (i.e., dual-language mixing) influence infants' shifting and orienting of attention.

Spoken words activate native and non-native letter-to-sound mappings: Evidence from eye tracking

Many languages use the same letters to represent different sounds (e.g., the letter P represents /p/ in English but /r/ in Russian). We report two experiments that examine how native language experience impacts the acquisition and processing of words with conflicting letter-to-sound mappings. Experiment 1 revealed that individual differences in nonverbal intelligence predicted word learning and that novel words with conflicting orthography-to-phonology mappings were harder to learn when their spelling was more typical of the native language than less typical (due to increased competition from the native language). Notably, Experiment 2 used eye tracking to reveal, for the first time, that hearing non-native spoken words activates native language orthography and both native and non-native letter-to-sound mappings. These findings evince high interactivity in the language system, illustrate the role of orthography in phonological learning and processing, and demonstrate that experience with written form changes the linguistic mind.

On the Need for Theoretically Guided Approaches to Possible Bilingual Advantages: An Evaluation of the Potential Loci in the Language and Executive Control Systems

Whether a cognitive advantage exists for bilingual individuals has been the source of heated debate in the last decade. While empirical evidence putatively in favor of or against this alleged advantage has been frequently discussed, the potential sources of enhanced cognitive control in bilinguals have only been broadly declared, with no mechanistic elaboration of where, why, and how this purported link between bilingualism and enhanced language control develops, and how this enhancement transfers to, and subsequently improves, general executive function. Here, we evaluate different potential sources for a bilingual advantage and develop the assumptions one would have to make about the language processing system to be consistent with each of these notions. Subsequently, we delineate the limitations in the generalizations from language to overall executive function, and characterize where these advantages could be identified if there were to be any. Ultimately, we conclude that in order to make significant progress in this area, it is necessary to look for advantages in theoretically motivated areas, and that in the absence of clear theories as to the source, transfer, and target processes that could lead to potential advantages, an inconsistent body of results will follow, making the whole pursuit of a bilingual advantage moot.

Cross-linguistic interference in late language learners: An ERP study

This study investigated cross-linguistic interference in German low-proficient late learners of Spanish. We examined the modulating influence of gender congruency and cognate status using a syntactic violation paradigm. Behavioural results demonstrated that participants were more sensitive to similarities at the syntactic level (gender congruency) than to phonological and orthographic overlap (cognate status). Electrophysiological data showed that they were sensitive to syntactic violations (P600 effect) already in early acquisition stages. However, P600 effect sizes were not modulated by gender congruency or cognate status. Therefore, our late learners of Spanish did not seem to be susceptible to influences from inherent noun properties when processing non-native noun phrases at the neural level. Our results contribute to the discussion about the neural correlates of grammatical gender processing and sensitivity to syntactic violations in early acquisition stages.

Automaticity of lexical access in deaf and hearing bilinguals: Cross-linguistic evidence from the color Stroop task across five languages

The well-known Stroop interference effect has been instrumental in revealing the highly automated nature of lexical processing as well as providing new insights to the underlying lexical organization of first and second languages within proficient bilinguals. The present cross-linguistic study had two goals: 1) to examine Stroop interference for dynamic signs and printed words in deaf ASL-English bilinguals who report no reliance on speech or audiological aids; 2) to compare Stroop interference effects in several groups of bilinguals whose two languages range from very distinct to very similar in their shared orthographic patterns: ASL-English bilinguals (very distinct), Chinese-English bilinguals (low similarity), Korean-English bilinguals (moderate similarity), and Spanish-English bilinguals (high similarity). Reaction time and accuracy were measured for the Stroop color naming and word reading tasks, for congruent and incongruent color font conditions. Results confirmed strong Stroop interference for both dynamic ASL stimuli and English printed words in deaf bilinguals, with stronger Stroop interference effects in ASL for deaf bilinguals who scored higher in a direct assessment of ASL proficiency. Comparison of the four groups of bilinguals revealed that the same-script bilinguals (Spanish-English bilinguals) exhibited significantly greater Stroop interference effects for color naming than the other three bilingual groups. The results support three conclusions. First, Stroop interference effects are found for both signed and spoken languages. Second, contrary to some claims in the literature about deaf signers who do not use speech being poor readers, deaf bilinguals' lexical processing of both signs and written words is highly automated. Third, cross-language similarity is a critical factor shaping bilinguals' experience of Stroop interference in their two languages. This study represents the first comparison of both deaf and hearing bilinguals on the Stroop task, offering a critical test of theories about bilingual lexical access and cognitive control.

Cognitive control in bilinguals: Proficiency and code-switching both matter

We examined the impact of bilingualism as a construct of both language usage and language proficiency on the effectiveness of cognitive control. In particular, we asked whether the frequency of daily dense code-switching - frequent change of language within and between sentences with the same interlocutor- and the level of L2 proficiency separately and or interactively affect cognitive control efficiency in the Simon task. Results from 134 bilinguals showed that frequently code-switching bilinguals had fewer errors and their accuracy rate improved over trials leading to a smaller Simon effect. For response times (RTs), however, L2 proficiency modulated the Simon effect, and interacted with code-switching frequency in intricate ways in modulating overall RTs over trials. Crucially, highly proficient frequently code-switching bilinguals were better at conflict adaptation. These results show that bilinguals differ among themselves, and that researchers need to take both proficiency and language use into account to test the impact of bilingual experience on cognitive control. Bilingualism should be regarded as a continuum, with many different factors contributing to the language experience and affecting cognitive functioning.

Meta-Analysis Reveals a Bilingual Advantage That Is Dependent on Task and Age

Debate continues on whether a bilingual advantage exists with respect to executive functioning. This report synthesized the results of 170 studies to test whether the bilingual advantage is dependent on the task used to assess executive functioning and the age of the participants. The results of the meta-analyses indicated that the bilingual advantage was both task- and age-specific. Bilinguals were significantly faster than monolinguals (Hedges' g values ranged from 0.23 to 0.34), and significantly more accurate than monolinguals (Hedges' g values ranged between 0.18 and 0.49) on four out of seven tasks. Also, an effect of age was found whereby the bilingual advantage was larger for studies comprising samples aged 50-years and over (Hedges' g = 0.49), compared to those undertaken with participants aged between 18 and 29 years (Hedges' g = 0.12). The extent to which the bilingual advantage might be due to publication bias was assessed using multiple methods. These were Egger's Test of Asymmetry, Duval and Tweedie's Trim and Fill, Classic Fail-Safe N, and PET-PEESE. Publication bias was only found when using Egger's Test of Asymmetry and PET-PEESE method, but not when using the other methods. This review indicates that if bilingualism does enhance executive functioning, the effects are modulated by task and age. This may arise because using multiple languages has a highly specific effect on executive functioning which is only observable in older, relative to younger, adults. The finding that publication bias was not uniformly detected across the different methods raises questions about the impact that unpublished (or undetected) studies have on meta-analyses of this literature.

Bilingual Language Experience Shapes Resting-State Brain Rhythms

An increasing body of research has investigated how bilingual language experience changes brain structure and function, including changes to task-free, or "resting-state" brain connectivity. Such findings provide important evidence about how the brain continues to be shaped by different language experiences throughout the lifespan. The neural effects of bilingual language experience can provide evidence about the additional processing demands placed on the linguistic and/or executive systems by dual-language use. While considerable research has used MRI to examine where these changes occur, such methods cannot reveal the temporal dynamics of functioning brain networks at rest. The current study used data from task-free EEGS to disentangle how the linguistic and cognitive demands of bilingual language use impact brain functioning. Data analyzed from 106 bilinguals and 91 monolinguals revealed that bilinguals had greater alpha power, and significantly greater and broader coherence in the alpha and beta frequency ranges than monolinguals. Follow-up analyses showed that higher alpha was related to language control: more second-language use, higher native-language proficiency, and earlier age of second-language acquisition. Bilateral beta power was related to native-language proficiency, whereas theta was related to native-language proficiency only in left-hemisphere electrodes. The results contribute to our understanding of how the linguistic and cognitive requirements of dual-language use shape intrinsic brain activity, and what the broader implications for information processing may be.

Inhibitory control is associated with the activation of output-driven competitors in a spoken word recognition task

Although lexical competition has been ubiquitously observed in spoken word recognition, less has been known about whether the lexical competitors interfere with the recognition of the target and how lexical interference is resolved. The present study examined whether lexical competitors overlapping in output with the target would interfere with its recognition, and tested an underestimated hypothesis that the domain-general inhibitory control contributes to the resolution of lexical interference. Specifically, in this study, a Visual World Paradigm was used to access the temporal dynamics of lexical activations when participants were moving the mouse cursor to the written word form of the spoken word they heard. By using Chinese characters, the orthographic similarity between the lexical competitor and target was manipulated independently of their phonological overlap. The results demonstrated that behavioral performance in the similar condition was poorer compared to that in the control condition, and that individuals with better inhibitory control (having smaller Stroop interference effect) exhibited weaker activation of orthographic competitors (mouse trajectories less attracted by the orthographic competitors). The implications of these findings for our understanding of lexical interference and its resolution in spoken word recognition were discussed.

Bilinguals' inhibitory control and attentional processes in a visual perceptual task

The aim was to examine theories of bilingual inhibitory control superiority in the visual domain. In an ambiguous figure task, the ability to reverse (switch) interpretations (e.g., duck-rabbit) was examined in 3-5-year-olds bilinguals and monolinguals (N = 67). Bilingualism was no performance predictor in conceptual tasks (Droodle task, false belief task, ambiguous figures production task) that did not pose inhibitory demands. Bilinguals outperformed monolinguals in the ability to reverse, suggesting superior inhibitory capacity per se. Once reversal was experienced there was no difference in the time it took to reverse or reversal frequency between bilinguals and monolinguals. Bayesian analyses confirmed statistical result patterns. Findings support the established view of bilinguals' superior domain-general inhibitory control. This might be brought to bear by attending the environment differently.

Extensive Experience with Multiple Languages May Not Buffer Age-Related Declines in Executive Function

BACKGROUND

Whether bilingualism can improve aspects of cognitive function in late adulthood is hotly debated. A few limited studies have reported that bilingualism may provide a limited buffer against age-related cognitive decline; however, others have not. The present study furthered this inquiry by analyzing the combined effects of age and language experience upon executive function in a geographically diverse online sample.

METHODS

Amazon Mechanical Turk was used to recruit a sample of younger (YA) and older adults (OA) from 24 countries. A total of 81 monolingual participants (YA = 37; OA = 44) and 82 bilingual/multilingual participants (YA = 43; OA = 39) completed task-pure executive function assessments of inhibition, memory updating, and attention switching.

RESULTS

YAs performed better than OAs on both the inhibition and updating tasks. On the attention switching task, a greater switch cost occurred when participants had less time to process a stimulus cue. Notably, no effects of language (i.e., bilingualism) were significant: no main effects or interactions with aging were found for executive function performance.

CONCLUSION

The results of the present study challenge the claim that extensive experience with multiple languages can be a reliably protective factor against some normative age-related declines in executive function.

Turning languages on and off: Switching into and out of code-blends reveals the nature of bilingual language control

When spoken language (unimodal) bilinguals switch between languages, they must simultaneously inhibit 1 language and activate the other language. Because American Sign Language (ASL)-English (bimodal) bilinguals can switch into and out of code-blends (simultaneous production of a sign and a word), we can tease apart the cost of inhibition (turning a language off) and activation (turning a language on). Results from a cued picture-naming task with 43 bimodal bilinguals revealed a significant cost to turn off a language (switching out of a code-blend), but no cost to turn on a language (switching into a code-blend). Switching from single to dual lexical retrieval (adding a language) was also not costly. These patterns held for both languages regardless of default language, that is, whether switching between speaking and code-blending (English default) or between signing and code-blending (ASL default). Overall, the results support models of bilingual language control that assume a primary role for inhibitory control and indicate that disengaging from producing a language is more difficult than engaging a new language. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Multi-Talker Speech Promotes Greater Knowledge-Based Spoken Mandarin Word Recognition in First and Second Language Listeners

Spoken word recognition involves a perceptual tradeoff between the reliance on the incoming acoustic signal and knowledge about likely sound categories and their co-occurrences as words. This study examined how adult second language (L2) learners navigate between acoustic-based and knowledge-based spoken word recognition when listening to highly variable, multi-talker truncated speech, and whether this perceptual tradeoff changes as L2 listeners gradually become more proficient in their L2 after multiple months of structured classroom learning. First language (L1) Mandarin Chinese listeners and L1 English-L2 Mandarin adult listeners took part in a gating experiment. The L2 listeners were tested twice - once at the start of their intermediate/advanced L2 language class and again 2 months later. L1 listeners were only tested once. Participants were asked to identify syllable-tone words that varied in syllable token frequency (high/low according to a spoken word corpus) and syllable-conditioned tonal probability (most probable/least probable in speech given the syllable). The stimuli were recorded by 16 different talkers and presented at eight gates ranging from onset-only (gate 1) through onset +40 ms increments (gates 2 through 7) to the full word (gate 8). Mixed-effects regression modeling was used to compare performance to our previous study which used single-talker stimuli (Wiener et al., 2019). The results indicated that multi-talker speech caused both L1 and L2 listeners to rely greater on knowledge-based processing of tone. L1 listeners were able to draw on distributional knowledge of syllable-tone probabilities in early gates and switch to predominantly acoustic-based processing when more of the signal was available. In contrast, L2 listeners, with their limited experience with talker range normalization, were less able to effectively transition from probability-based to acoustic-based processing. Moreover, for the L2 listeners, the reliance on such distributional information for spoken word recognition appeared to be conditioned by the nature of the acoustic signal. Single-talker speech did not result in the same pattern of probability-based tone processing, suggesting that knowledge-based processing of L2 speech may only occur under certain acoustic conditions, such as multi-talker speech.

Bilingual effects on lexical selection: A neurodevelopmental perspective

When a listener hears a word, multiple lexical items may come to mind; for instance, /kæn/ may activate concepts with similar phonological onsets such as candy and candle. Acquisition of two lexicons may increase such linguistic competition. Using functional Near-Infrared Spectroscopy neuroimaging, we investigate whether bilingualism impacts word processing in the child's brain. Bilingual and monolingual children (N = 52; ages 7-10) completed a lexical selection task in English, where participants adjudicated phonological competitors (e.g., car/cat vs. car/pen). Children were less accurate and responded more slowly during competing than non-competing items. In doing so, children engaged top-down fronto-parietal regions associated with cognitive control. In comparison to bilinguals, monolinguals showed greater activity in left frontal regions, a difference possibly due to bilinguals' adaptation for dual-lexicons. These differences provide insight to theories aiming to explain the role of experience on children's emerging neural networks for lexical selection and language processing.

Cognitive Control Facilitates Attentional Disengagement during Second Language Comprehension

Bilinguals learn to resolve conflict between their two languages and that skill has been hypothesized to create long-term adaptive changes in cognitive functioning. Yet, little is known about how bilinguals recruit cognitive control to enable efficient use of one of their languages, especially in the less skilled and more effortful second language (L2). Here we examined how real-time cognitive control engagement influences L2 sentence comprehension (i.e., conflict adaptation). We tested a group of English monolinguals and a group of L2 English speakers using a recently-developed cross-task adaptation paradigm. Stroop sequences were pseudo-randomly interleaved with a visual-world paradigm in which participants were asked to carry out spoken instructions that were either syntactically ambiguous or unambiguous. Consistent with previous research, eye-movement results showed that Stroop-related conflict improved the ability to engage correct-goal interpretations, and disengage incorrect-goal interpretations, during ambiguous instructions. Such cognitive-to-language modulations were similar in both groups, but only in the engagement piece. In the disengagement portion, the modulation emerged earlier in bilinguals than in monolinguals, suggesting group differences in attentional disengagement following cognitive control recruitment. Additionally, incorrect-goal eye-movements were modulated by individual differences in working memory, although differently for each group, suggesting an involvement of both language-specific and domain-general resources.

Phonological Vulnerability for School-Aged Spanish-English-Speaking Bilingual Children

This study examined accuracy on syllable-final (coda) consonants in newly-learned English-like nonwords to determine whether school-aged bilingual children may be more vulnerable to making errors on English-only codas than their monolingual, English-speaking peers, even at a stage in development when phonological accuracy in productions of familiar words is high. Bilingual Spanish-English-speaking second- graders (age 7-9) with typical development (n=40) were matched individually with monolingual peers on age, sex, and speech skills. Participants learned to name sea monsters as part of five computerized word learning tasks. Dependent t-tests revealed bilingual children were less accurate than monolingual children in producing codas unique to English; however, the groups demonstrated equivalent levels of accuracy on codas that occur in both Spanish and English. Results suggest that, even at high levels of English proficiency, bilingual Spanish-English-speaking children may demonstrate lower accuracy than their monolingual English-speaking peers on targets that pattern differently in their two languages. Differences between a bilingual's two languages can be used to reveal targets that may be more vulnerable to error, which could be a result of cross-linguistic effects or more limited practice with English phonology.

Language switching decomposed through MEG and evidence from bimodal bilinguals

A defining feature of human cognition is the ability to quickly and accurately alternate between complex behaviors. One striking example of such an ability is bilinguals' capacity to rapidly switch between languages. This switching process minimally comprises disengagement from the previous language and engagement in a new language. Previous studies have associated language switching with increased prefrontal activity. However, it is unknown how the subcomputations of language switching individually contribute to these activities, because few natural situations enable full separation of disengagement and engagement processes during switching. We recorded magnetoencephalography (MEG) from American Sign Language-English bilinguals who often sign and speak simultaneously, which allows to dissociate engagement and disengagement. MEG data showed that turning a language "off" (switching from simultaneous to single language production) led to increased activity in the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (dlPFC), while turning a language "on" (switching from one language to two simultaneously) did not. The distinct representational nature of these on and off processes was also supported by multivariate decoding analyses. Additionally, Granger causality analyses revealed that (i) compared with "turning on" a language, "turning off" required stronger connectivity between left and right dlPFC, and (ii) dlPFC activity predicted ACC activity, consistent with models in which the dlPFC is a top-down modulator of the ACC. These results suggest that the burden of language switching lies in disengagement from the previous language as opposed to engaging a new language and that, in the absence of motor constraints, producing two languages simultaneously is not necessarily more cognitively costly than producing one.

How do German bilingual schoolchildren process German prepositions? - A study on language-motor interactions

While much support is found for embodied language processing in a first language (L1), evidence for embodiment in second language (L2) processing is rather sparse. In a recent study, we found support for L2 embodiment, but also an influence of L1 on L2 processing in adult learners. In the present study, we compared bilingual schoolchildren who speak German as one of their languages with monolingual German schoolchildren. We presented the German prepositions auf (on), über (above), and unter (under) in a Stroop-like task. Upward or downward responses were made depending on the font colour, resulting in compatible and incompatible trials. We found compatibility effects for all children, but in contrast to the adult sample, there were no processing differences between the children depending on the nature of their other language, suggesting that the processing of German prepositions of bilingual children is embodied in a similar way as in monolingual German children.

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.

Neural signatures of language co-activation and control in bilingual spoken word comprehension

To examine the neural signatures of language co-activation and control during bilingual spoken word comprehension, Korean-English bilinguals and English monolinguals were asked to make overt or covert semantic relatedness judgments on auditorily-presented English word pairs. In two critical conditions, participants heard word pairs consisting of an English-Korean interlingual homophone (e.g., the sound /mu:n/ means "moon" in English and "door" in Korean) as the prime and an English word as the target. In the homophone-related condition, the target (e.g., "lock") was related to the homophone's Korean meaning, but not related to the homophone's English meaning. In the homophone-unrelated condition, the target was unrelated to either the homophone's Korean meaning or the homophone's English meaning. In overtly responded situations, ERP results revealed that the reduced N400 effect in bilinguals for homophone-related word pairs correlated positively with the amount of their daily exposure to Korean. In covertly responded situations, ERP results showed a reduced late positive component for homophone-related word pairs in the right hemisphere, and this late positive effect was related to the neural efficiency of suppressing interference in a non-linguistic task. Together, these findings suggest 1) that the degree of language co-activation in bilingual spoken word comprehension is modulated by the amount of daily exposure to the non-target language; and 2) that bilinguals who are less influenced by cross-language activation may also have greater efficiency in suppressing interference in a non-linguistic task.

Cross-linguistic phonotactic competition and cognitive control in bilinguals

The current study examines the relation between cognitive control and linguistic competition resolution at the sublexical level in bilinguals. Twenty-one Spanish-English bilinguals and 23 English monolinguals completed a non-linguistic Stroop task (indexing inhibitory control) and a linguistic priming/lexical decision task (indexing Spanish phonotactic constraint competition during English comprehension). More efficient Stroop performance (i.e., a smaller Stroop effect) in bilinguals was associated with decreased competition from Spanish phonotactic constraints during English comprehension. This relation was observed when nonword targets overlapped in phonotactic constraints and phonological form with preceding cognate primes (e.g., prime: stable (Spanish: estable)/target: esteriors). Findings suggest a link between non-linguistic cognitive control and co-activation of linguistic structures at the sublexical level in bilinguals.

Multiple Language Use Influences Oculomotor Task Performance: Neurophysiological Evidence of a Shared Substrate between Language and Motor Control

In the present electroencephalographical study, we asked to which extent executive control processes are shared by both the language and motor domain. The rationale was to examine whether executive control processes whose efficiency is reinforced by the frequent use of a second language can lead to a benefit in the control of eye movements, i.e. a non-linguistic activity. For this purpose, we administrated to 19 highly proficient late French-German bilingual participants and to a control group of 20 French monolingual participants an antisaccade task, i.e. a specific motor task involving control. In this task, an automatic saccade has to be suppressed while a voluntary eye movement in the opposite direction has to be carried out. Here, our main hypothesis is that an advantage in the antisaccade task should be observed in the bilinguals if some properties of the control processes are shared between linguistic and motor domains. ERP data revealed clear differences between bilinguals and monolinguals. Critically, we showed an increased N2 effect size in bilinguals, thought to reflect better efficiency to monitor conflict, combined with reduced effect sizes on markers reflecting inhibitory control, i.e. cue-locked positivity, the target-locked P3 and the saccade-locked presaccadic positivity (PSP). Moreover, effective connectivity analyses (dynamic causal modelling; DCM) on the neuronal source level indicated that bilinguals rely more strongly on ACC-driven control while monolinguals rely on PFC-driven control. Taken together, our combined ERP and effective connectivity findings may reflect a dynamic interplay between strengthened conflict monitoring, associated with subsequently more efficient inhibition in bilinguals. Finally, L2 proficiency and immersion experience constitute relevant factors of the language background that predict efficiency of inhibition. To conclude, the present study provided ERP and effective connectivity evidence for domain-general executive control involvement in handling multiple language use, leading to a control advantage in bilingualism.

Phonotactic Constraints Are Activated across Languages in Bilinguals

During spoken language comprehension, auditory input activates a bilingual's two languages in parallel based on phonological representations that are shared across languages. However, it is unclear whether bilinguals access phonotactic constraints from the non-target language during target language processing. For example, in Spanish, words with s+ consonant onsets cannot exist, and phonotactic constraints call for epenthesis (addition of a vowel, e.g., stable/estable). Native Spanish speakers may produce English words such as estudy ("study") with epenthesis, suggesting that these bilinguals apply Spanish phonotactic constraints when speaking English. The present study is the first to examine whether bilinguals access Spanish phonotactic constraints during English comprehension. In an English cross-modal priming lexical decision task, Spanish-English bilinguals and English monolinguals heard English cognate and non-cognate primes containing s+ consonant onsets or controls without s+ onsets, followed by a lexical decision on visual targets with the /e/ phonotactic constraint or controls without /e/. Results revealed that bilinguals were faster to respond to /es/ non-word targets preceded by s+ cognate primes and /es/ and /e/ non-word targets preceded by s+ non-cognate primes, confirming that English primes containing s+ onsets activated Spanish phonotactic constraints. These findings are discussed within current accounts of parallel activation of two languages during bilingual spoken language comprehension, which may be expanded to include activation of phonotactic constraints from the irrelevant language.

Neural signatures of second language learning and control

Experience with multiple languages has unique effects on cortical structure and information processing. Differences in gray matter density and patterns of cortical activation are observed in lifelong bilinguals compared to monolinguals as a result of their experience managing interference across languages. Monolinguals who acquire a second language later in life begin to encounter the same type of linguistic interference as bilinguals, but with a different pre-existing language architecture. The current study used functional magnetic resonance imaging to explore the beginning stages of second language acquisition and cross-linguistic interference in monolingual adults. We found that after English monolinguals learned novel Spanish vocabulary, English and Spanish auditory words led to distinct patterns of cortical activation, with greater recruitment of posterior parietal regions in response to English words and of left hippocampus in response to Spanish words. In addition, cross-linguistic interference from English influenced processing of newly-learned Spanish words, decreasing hippocampus activity. Results suggest that monolinguals may rely on different memory systems to process a newly-learned second language, and that the second language system is sensitive to native language interference.

Cognitive Consequences of Trilingualism

AIMS AND OBJECTIVES

The objectives of the present research were to examine the cognitive consequences of trilingualism and explain them relative to the cognitive consequences of bilingualism.

APPROACH

A comparison of cognitive abilities in trilinguals and bilinguals was conducted. In addition, we proposed a cognitive plasticity framework to account for cognitive differences and similarities between trilinguals and bilinguals.

DATA AND ANALYSIS

Three aspects of cognition were analyzed: (1) cognitive reserve in older adults, as measured by age of onset of Alzheimer's disease and mild cognitive impairment; (2) inhibitory control in children and younger adults, as measured by response times on behavioral Simon and flanker tasks; and (3) memory generalization in infants and toddlers, as measured by accuracy on behavioral deferred imitation tasks. Results were considered within a framework of cognitive plasticity, which took into account several factors that may affect plasticity, including the age of learning a third language and the extent to which additional cognitive resources are needed to learn the third language.

FINDINGS

A mixed pattern of results was observed. In some cases, such as cognitive reserve in older adults, trilinguals showed larger advantages than bilinguals. On other measures, for example inhibitory control in children and younger adults, trilinguals were found to exhibit the same advantages as bilinguals. In still other cases, like memory generalization in infants and toddlers, trilinguals did not demonstrate the advantages seen in bilinguals.

ORIGINALITY

This study is the first comprehensive analysis of how learning a third language affects the cognitive abilities that are modified by bilingual experience, and the first to propose a cognitive plasticity framework that can explain and predict trilingual-bilingual differences.

SIGNIFICANCE

This research shows that the cognitive consequences of trilingualism are not simply an extension of bilingualism's effects; rather, trilingualism has distinct consequences, with theoretical implications for our understanding of linguistic and cognitive processes and their plasticity, as well as applied-science implications for using second and third language learning in educational and rehabilitative contexts to foster successful cognitive development and aging.

Interference and Inhibition in Bilingual Language Comprehension: Evidence from Polish-English Interlingual Homographs

The main goal of the present study was to explore the involvement of inhibition in resolution of cross-language activation in bilingual comprehension and a possible modulatory effect of L2 proficiency. We used a semantic relatedness judgment task in L2 English that included Polish-English interlingual homographs and English translations of the Polish homographs' meanings. Based on previous studies using the same paradigm, we expected a strong homograph interference and inhibition of the homographs' Polish meanings translations. In addition, we predicted that participants with lower L2 proficiency would experience greater interference and stronger inhibitory effects. The reported results confirm a strong homograph interference effect. In addition, our results indicate that the scope of inhibition generalized from the homograph's irrelevant meaning to a whole semantic category, indicating the flexibility of the inhibitory mechanisms. Contrary to our expectations, L2 proficiency did not modulate the effects of interference and inhibition, possibly due to a relatively low variability in proficiency within our participant sample.

Processing Code-Switching in Algerian Bilinguals: Effects of Language Use and Semantic Expectancy

Using a cross-modal naming paradigm this study investigated the effect of sentence constraint and language use on the expectancy of a language switch during listening comprehension. Sixty-five Algerian bilinguals who habitually code-switch between Algerian Arabic and French (AA-FR) but not between Standard Arabic and French (SA-FR) listened to sentence fragments and named a visually presented French target NP out loud. Participants’ speech onset times were recorded. The sentence context was either highly semantically constraining toward the French NP or not. The language of the sentence context was either in Algerian Arabic or in Standard Arabic, but the target NP was always in French, thus creating two code-switching contexts: a typical and recurrent code-switching context (AA-FR) and a non-typical code-switching context (SA-FR). Results revealed a semantic constraint effect indicating that the French switches were easier to process in the high compared to the low-constraint context. In addition, the effect size of semantic constraint was significant in the more typical code-switching context (AA-FR) suggesting that language use influences the processing of switching between languages. The effect of semantic constraint was also modulated by code-switching habits and the proficiency of L2 French. Semantic constraint was reduced in bilinguals who frequently code-switch and in bilinguals with high proficiency in French. Results are discussed with regards to the bilingual interactive activation model (Dijkstra and Van Heuven, 2002) and the control process model of code-switching (Green and Wei, 2014).