Age Of L2 Acquisition Research Articles

The relationship between executive function, age of L2 acquisition and speech disfluencies in bilinguals

Disfluencies signal errors in speech processes. Research in typically fluent monolinguals indicates a correlation between disfluencies and specific executive function (EF), including cognitive flexibility, inhibitory control, working memory (WM), and attention. However, these relationships have not been systematically explored in bilinguals. This study investigates the relationship between these EF components, age of language acquisition and disfluencies in bilinguals. Two types of disfluencies were examined: stalling, where articulation is delayed until the speech plan is ready, and advancing, that is, the articulation of incomplete speech plans. A total of 120 English speech samples based on simulated job interviews from 20 typically fluent adult Spanish-English bilinguals were transcribed and coded for disfluencies. The Wechsler Adult Intelligence Scale Digit span was used to measure cognitive flexibility/inhibitory control, and the Delis-Kaplan Executive Function Color-Word Interference Test was used to assess WM/attention. Findings indicate correlations between stalling disfluencies and cognitive flexibility/inhibitory control, advancing disfluencies and WM/attention, and age of acquisition and both stalling and advancing disfluencies.

The different effects of a sensorimotor grounding on AoA between bilingual concepts.

Psycholinguistic studies have argued for the age of acquisition (AoA) of words as a marker of concept learning, showing that the semantic features of concepts themselves influence the age at which their labels are learned. However, empirical evidence suggests that semantic features such as imageability and linguistic phenomena such as frequency do not adequately predict AoA. The present study takes the developmental approach of embodied cognition and investigates the effects of sensorimotor experiences on the ease of acquisition of the concept acquired in bilinguals. Specifically, we investigated (1) whether the sensorimotor experience can explain AoA beyond frequency; (2) and whether these patterns are consistent across L1 Chinese and L2 English. We conducted sensorimotor rating measures in both Chinese and English on 207 items in which Chinese-English bilingual adults were requested to evaluate the extent to which they experienced concepts by employing six perceptual senses and five effectors for actions located in various regions of the body. Meanwhile, data on AoA and frequency were collected. The present study showed the sensorimotor experience was closely linked with AoAs in both languages. However, the correlation analysis revealed a trend of higher correlations between AoAs for the same concepts and L1 Chinese, relative to L2 English for the present Chinese-English bilinguals. Importantly, the hierarchical regression analysis demonstrated that after controlling for frequency, sensorimotor experience explained additional variance in L1 AoA. However, L2 sensorimotor experience did not explain the variance in L2 AoA. Sensorimotor experience explained more share of variance in L1 AoA but frequency accounted for more variance in L2 AoA. The findings suggest that concept acquisition should consider the grounding in appropriate sensorimotor experience beyond linguistic phenomena like frequency.

Spelling-sound consistency influences second-language age of acquisition effect: evidence for the arbitrary mapping hypothesis

ABSTRACT The age at which people acquire a word influences word recognition, known as the age of acquisition (AoA) effect. In the first language (L1), AoA effects are widely found in various languages and experimental tasks. Arbitrary Mapping Hypothesis proposes that AoA effects reflect the loss of network plasticity during the learning of mappings between input and output representations. It predicts that the AoA effect appears (or is larger) when the input-output mapping is arbitrary/inconsistent, relative to consistent input-output mapping. The present study examined how these predictions generalised to the second language (L2). We explored whether the L2 AoA effect was modulated by spelling-sound consistency in Chinese-English bilinguals, adopting a delayed word naming task. The results showed that the mapping consistency modulated the L2 AoA effect on the N170, P200 and N400 components. L2 AoA effect was insignificant in the consistent condition but was significant in the inconsistent condition: late-acquired words elicited larger N170, smaller P200, and larger N400 compared to early-acquired words. These findings suggest that L2 AoA effects occur in the spelling-sound connections, providing direct evidence for the Arbitrary Mapping Hypothesis.

Cognitive restructuring: Psychophysical measurement of time perception in bilinguals

AbstractThis paper explores the link between the metaphoric structure TIME IS SPACE and time perception in bilinguals. While there appear to be fundamental commonalities in the way humans perceive and experience time regardless of language background, language-specific spatiotemporal metaphors can give rise to differences between populations, under certain conditions. Little is known, however, about how bilinguals experience time, and the specific factors that may modulate bilingual temporal processing. Here, we address this gap by examining L1 Spanish – L2 Swedish bilinguals in a psychophysical task. Results show that duration estimation of dynamic spatial configurations analogous to L2-specific temporal metaphors is modulated by L2 proficiency. In contrast, duration estimation of spatial configurations analogous to the L1 metaphorical expressions appears to be modulated by the age of L2 acquisition. These findings are discussed in terms of associative learning and cognitive restructuring in the bilingual mind.

The age of acquisition effect in processing second language words and its relationship with the age of acquisition of the first language

AbstractThe present study investigated the age of acquisition (AoA) effect in processing second language (L2) words and how it is related to the AoA of the corresponding first language (L1) words. We adopted a lexical decision task in three experiments. The filler words were orthographically illegal in Experiment 1 to elicit more word form processing, while Experiment 2 used legal fillers to shift the bias toward semantic processing. In Experiment 3, we used a larger amount of stimuli containing more longer words with legal fillers. Our results showed that L2 AoA has a weak effect at the orthographical processing level and a stable effect at the semantic processing level. The L1 AoA modulates the L2 AoA effect at the semantic processing level, which is more likely to appear in long words. These results suggest that it is important to take bilingual representation and activation into consideration to explain the L2 AoA effect.

Subjective age of acquisition norms for 1604 English words by Spanish L2 speakers of English and their relationship with lexico-semantic, affective, sociolinguistic and proficiency variables

Psycholinguistic studies have shown that there are many variables implicated in language comprehension and production. At the lexical level, subjective age of acquisition (AoA), the estimate of the age at which a word is acquired, is key for stimuli selection in psycholinguistic studies. AoA databases in English are often used when testing a variety of phenomena in second language (L2) speakers of English. However, these have limitations, as the norms are not provided by the target population (L2 speakers of English) but by native English speakers. In this study, we asked native Spanish L2 speakers of English to provide subjective AoA ratings for 1604 English words, and investigated whether factors related to 14 lexico-semantic and affective variables, both in Spanish and English, and to the speakers’ profile (i.e., sociolinguistic variables and L2 proficiency), were related to the L2 AoA ratings. We used boosted regression trees, an advanced form of regression analysis based on machine learning and boosting algorithms, to analyse the data. Our results showed that the model accounted for a relevant proportion of deviance (58.56%), with the English AoA provided by native English speakers being the strongest predictor for L2 AoA. Additionally, L2 AoA correlated with L2 reaction times. Our database is a useful tool for the research community running psycholinguistic studies in L2 speakers of English. It adds knowledge about which factors—linked to the characteristics of both the linguistic stimuli and the speakers—affect L2 subjective AoA. The database and the data can be downloaded from: https://osf.io/gr8xd/?view_only=73b01dccbedb4d7897c8d104d3d68c46.

The role of socioemotional wellbeing difficulties and adversity in the L2 acquisition of first-generation refugee children

AbstractFirst-generation refugee children often experience pre- and post-migration adversity and display high levels of mental health/wellbeing difficulties, but to date, research has not examined the impact of such factors on refugee children's L2 acquisition. Accordingly, this study examined the influence of externalizing and internalizing problem behaviours (wellbeing), time in refugee camps and low socioeconomic status (SES) (adversity) on the English-L2 abilities of 117 Syrian refugee children (7–14 years) in their third year of residency in Canada. Wellbeing difficulties and adversity factors accounted for variance on L2 vocabulary, morphosyntax, listening comprehension and narrative production tasks, beyond the variance accounted for by age of L2 acquisition and length of L2 exposure. Specifically, externalizing problem behaviours, time in refugee camp, maternal education and maternal employment predicted variance in L2 abilities. It is concluded that refugee children could have influences on their L2 acquisition that are different from those of bilinguals with other backgrounds.

Age of Acquisition Modulates Alpha Power During Bilingual Speech Comprehension in Noise.

Research on bilingualism has grown exponentially in recent years. However, the comprehension of speech in noise, given the ubiquity of both bilingualism and noisy environments, has seen only limited focus. Electroencephalogram (EEG) studies in monolinguals show an increase in alpha power when listening to speech in noise, which, in the theoretical context where alpha power indexes attentional control, is thought to reflect an increase in attentional demands. In the current study, English/French bilinguals with similar second language (L2) proficiency and who varied in terms of age of L2 acquisition (AoA) from 0 (simultaneous bilinguals) to 15 years completed a speech perception in noise task. Participants were required to identify the final word of high and low semantically constrained auditory sentences such as “Stir your coffee with a spoon” vs. “Bob could have known about the spoon” in both of their languages and in both noise (multi-talker babble) and quiet during electrophysiological recording. We examined the effects of language, AoA, semantic constraint, and listening condition on participants’ induced alpha power during speech comprehension. Our results show an increase in alpha power when participants were listening in their L2, suggesting that listening in an L2 requires additional attentional control compared to the first language, particularly early in processing during word identification. Additionally, despite similar proficiency across participants, our results suggest that under difficult processing demands, AoA modulates the amount of attention required to process the second language.

Processing Aspectual Agreement in a Language with Limited Morphological Inflection by Second Language Learners: An ERP Study of Mandarin Chinese.

Previous studies on the neural cognitive mechanisms of aspectual processing in second language (L2) learners have focused on Indo-European languages with rich inflectional morphology. These languages have aspects which are equipped with inflected verb forms combined with auxiliary or modal verbs. Meanwhile, little attention has been paid to Mandarin Chinese, which has limited morphological inflection, and its aspect is equipped with aspectual particles (e.g., le, zhe, guo). The present study explores the neurocognitive mechanism of Mandarin Chinese aspect processing among two groups of late Mandarin Chinese proficient learners with Thai (with Mandarin Chinese-like aspect markers) and Indonesian (lack of Mandarin Chinese-like aspect markers) as their first language (L1). We measured event-related potentials (ERPs) time locked to the aspect marker le in two different conditions (the aspect violation sentences and the correct sentences). A triphasic ELAN-LAN-P600 effect was produced by the Mandarin Chinese native speakers. However, there was no ELAN and LAN in Indonesian native speakers and Thai native speakers, except a 300–500 ms negativity widely distributed in the right hemisphere and P600-like effect. This suggests that both groups of Mandarin Chinese learners cannot reach the same level as Mandarin Chinese native speakers to process Mandarin Chinese aspect information, probably due to the complex feature of Mandarin Chinese aspect maker, the participants’ L2 proficiency and age of L2 acquisition.

Add Bilingualism to the Mix: L2 Proficiency Modulates the Effect of Cognitive Reserve Proxies on Executive Performance in Healthy Aging.

We investigated the contribution of bilingual experience to the development of cognitive reserve (CR) when compared with other, traditionally more researched, CR proxies, in a sample of cognitively healthy senior (60 +) bilingual speakers. Participants performed in an online study where, in addition to a wide inventory of factors known to promote CR, we assessed several factors related to their second language (L2) use. In addition, participants’ inhibitory executive control was measured via the Flanker Task. We used Structural Equation Modeling to derive a latent composite measure of CR informed by traditional CR proxies (i.e., occupational complexity, marital status, current and retrospective socio-economic status, physical exercise, perceived positive support, maximal educational attainment, frequency of leisure activities and extent of social network). We examined whether bilingualism may act as a mediator of the effects of such proxies on cognitive performance therefore assessing the unique contribution of dual language use to CR. First, our analyses revealed facilitatory effects of both L2 age of acquisition and L2 proficiency on the executive performance. Second, our analyses confirmed the moderating role of bilingual experience on the relationship between other factors known to promote CR and cognitive integrity, revealing a strong contribution by bilingualism to CR development. Our findings provide further support to the notion that bilingualism plays an important role in mitigating cognitive decline and promoting successful aging.

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.

Exploring attention in the bilingualism continuum: A resting-state functional connectivity study

This study explores the effects of bilingualism on the subcomponents of attention using resting state functional connectivity analysis (rsFC). Unlike previous studies, measures of bilingualism - L2 Age of Acquisition (AOA), L2 exposure, and L2 proficiency - were examined along a continuum to study attentional mechanisms using rsFC instead of dichotomizing them. 20 seed regions were pre-selected for the three subcomponents of attention. The results showed a positive association between behavioral performance and rsFC for the seeds in alerting and orienting network; this was not true for the seeds in the executive control network. Secondly, rsFC for attention networks varied with different levels of bilingualism. The objective measures of bilingualism modulate all three attention networks. While the subjective measures such as L2 AOA modulates specific attention network. Thus, language performance in contrast to self-reported information, as a measure of bilingualism, has a greater potential to tap into the role of bilingualism in attentional processes.

Language dominance affects auditory translation priming in heritage speakers

Late L2 learners show translation priming from the first language to the second (L1–L2), while L2–L1 effects are inconsistent (Altarriba & Basnight-Brown, 2007). Typically, late L2 learners are both less dominant in the L2 and have a later L2 age of acquisition, making the relative contribution of language dominance and age of acquisition in L2–L1 priming unclear. We test Cantonese heritage and native speakers in an auditory translation priming paradigm. As heritage speakers first learn Cantonese (L1) but later become more proficient in English (L2), this profile potentially allows for the dissociation of dominance and age of acquisition in translation priming. If age of acquisition is the primary factor, more priming is expected to occur in the L1–L2 (Cantonese-English) direction; however, if dominance plays a stronger role, priming is expected to occur in the L2–L1 (English-Cantonese) direction. Preliminary results indicate that native speakers show L1–L2 but not L2–L1 priming, consistent with previous findings, while heritage speakers show priming in both directions, but stronger L2–L1 priming. The inter-condition difference is greater for native speakers. In short, age of acquisition plays a role in bilingual language processing (Silverburg & Samuel, 2004) and potentially drives auditory translation priming effects more strongly than language dominance.

Individual differences in representational similarity of first and second languages in the bilingual brain.

Current theories of bilingualism disagree on the extent to which separate brain regions are used to maintain or process one's first and second language. The present study took a novel multivariate approach to address this question. We examined whether bilinguals maintain distinct neural representations of two languages; specifically, we tested whether brain areas that are involved in processing word meaning in either language are reliably representing each language differently, and whether language representation is influenced by individual differences in proficiency level and age of acquisition (AoA) of L2. Thirty‐one English–Mandarin bilingual adults performed a picture–word matching task in both languages. We then used representational similarity analysis to examine which brain regions reliably showed different patterns of activity for each language. We found that both proficiency and AoA predicted dissimilarity between language representations in several brain areas within the language network as well as several regions of the ventral visual pathway, demonstrating that top‐down language knowledge and individual language experience shapes concept representation in this processing stream. The results support the model of an integrated language system in bilinguals, along with a novel description of how representations for each language change with proficiency level and L2 AoA.

The bilingual structural connectome: Dual-language experiential factors modulate distinct cerebral networks

Bilingualism is a natural laboratory for studying whether the brain’s structural connectome is influenced by different aspects of language experience. However, evidence on how distinct components of bilingual experience may contribute to structural brain adaptations is mixed. The lack of consistency, however, may depend, at least in part, on methodological choices in data acquisition and processing. Herein, we adopted the Network Neuroscience framework to investigate how individual differences in second language (L2) exposure, proficiency, and age of acquisition (AoA) – measured as continuous between-subject variables – relate to whole-brain structural organization. We observed that L2 exposure modulated the connectivity of two networks of regions subserving language comprehension and production. L2 proficiency was associated with enhanced connectivity within a rostro-caudal network, which supports language selection and word learning. Moreover, L2 AoA and exposure affected inter-hemispheric communication between control-related regions. These findings expand mechanistic knowledge about particular environmental factors associated with specific variation in brain structure.

Subcortical lesions impact confrontation naming in bilinguals with later age of acquisition: An exploratory study

The bilingual experience is believed to impact brain development and, possibly, cognitive performance. Subcortical structures, including the striatum and white matter, are believed related to confrontation naming performance among bilingual individuals with later age of acquisition (AoA) and lower proficiency of a second language (L2). However, these findings are primarily derived from healthy adult samples, although there is clinical significance for the interpretation of naming performance. The present study examined whether striatal and white matter lesions were associated with naming tasks in clinic-referred bilingual veterans (n = 29) and whether L2 AoA moderated this relationship. Clinically rated lesions, without regard for AoA, were not consistently correlated with naming performance. Moderation models (lesion × AoA) were significant across naming tasks (i.e., naming scores were negatively correlated with striatal lesions with increasing AoA). Effect sizes were higher among striatal models as compared to white matter models. Results extend prior neuroimaging findings with healthy bilinguals that AoA moderates the relationship between subcortical lesions and naming performance in bilingual patients, and suggests that clinicians should consider specifics of bilingual experience when interpreting test scores.

Bilinguals benefit from semantic context while perceiving speech in noise in both of their languages: Electrophysiological evidence from the N400 ERP

AbstractAlthough bilinguals benefit from semantic context while perceiving speech-in-noise in their native language (L1), the extent to which bilinguals benefit from semantic context in their second language (L2) is unclear. Here, 57 highly proficient English–French/French–English bilinguals, who varied in L2 age of acquisition, performed a speech-perception-in-noise task in both languages while event-related brain potentials were recorded. Participants listened to and repeated the final word of sentences high or low in semantic constraint, in quiet and with a multi-talker babble mask. Overall, our findings indicate that bilinguals do benefit from semantic context while perceiving speech-in-noise in both their languages. Simultaneous bilinguals showed evidence of processing semantic context similarly to monolinguals. Early sequential bilinguals recruited additional neural resources, suggesting more effective use of semantic context in L2, compared to late bilinguals. Semantic context use was not associated with bilingual language experience or working memory.

Perceptual discrimination measure of non-native phoneme perception in early and late Spanish-English and Japanese-English bilinguals

This study examined speech discrimination of English vowels /ɑ/ (as in “hot”), /ʌ/ (as in “hut”), and /æ/ (as in “hat”) by non-native English speakers, using an AXB discrimination task. Previous research shows that a person’s first language (L1) changes how speech is perceived in a second learned language (L2). Spanish and Japanese were chosen for this study because both languages share the same five spectrally different vowels, but Japanese additionally distinguishes between short and long versions of those five vowels. L2 proficiency and/or amount of L2 input were used as additional predictor variables. The target populations were early and late Spanish-English bilinguals and early and late Japanese-English bilinguals, which were compared to a control group of monolingual American English speakers. We are currently collecting data and based on previous studies (Shafer et al., under review), we predict: (1) monolinguals and early-bilinguals will show better performance than late-bilinguals; (2) discrimination of /ʌ/ vs. /æ/ contrast will be easier than other contrasts, /ʌ/ vs. /ɑ/ and /ɑ/ vs. /æ/. Our findings will address how L1 spectral-temporal cues and L2 age of acquisition affect L2 speech perception.

A Database of Chinese-English Bilingual Speakers: Ratings of the Age of Acquisition and Familiarity.

Recently, considerable attention has been given to the effect of the age of acquisition (AoA) on learning a second language (L2); however, the scarcity of L2 AoA ratings has limited advancements in this field. We presented the ratings of L2 AoA in late, unbalanced Chinese-English bilingual speakers and collected the familiarity of the L2 and the corresponding Chinese translations of English words. In addition, to promote the cross-language comparison and motivate the AoA research on Chinese two-character words, data on AoA, familiarity, and concreteness of the first language (L1) were also collected from Chinese native speakers. We first reported the reliability of each rated variable. Then, we described the validity by the following three steps: the distributions of each rated variable were described, the correlations between these variables were calculated, and regression analyses were run. The results showed that AoA, familiarity, and concreteness were all significant predictors of lexical decision times. The word database can be used by researchers who are interested in AoA, familiarity, and concreteness in both the L1 and L2 of late, unbalanced Chinese-English bilingual speakers. The full database is freely available for research purposes.

Subcortical Lesions Impact Confrontation Naming in Bilinguals with Later Age of Acquisition

Abstract Objective Multilinguals show greater subcortical activation during language tasks than monolinguals. Among multilinguals, prior studies found later age of acquisition (AoA) of a second language in association with more diffuse, non-traditional language representation. While such findings have clear clinical implications, little research has examined relationships among linguistic history, neuroanatomical integrity, and language skills in a clinical population. This study examined relationships between subcortical lesions and confrontation naming in strong bilinguals who acquired English (L2) later in life compared to those with earlier AoA. Participants and Method Forty-two bilinguals with Spanish as a first language (English L2) were selected from a database of veterans referred for clinical neuropsychological evaluation (M Age = 64 years; M Education = 12 years; 93% men). They reported strong bilingualism after L2 acquisition (M AoA = 10 years), with current English preference. Twenty-nine had neuroimaging, which was coded on a 4-point ordinal scale for lesion burden in white matter and striatum. Moderation models were tested for interaction between AoA and subcortical lesions in bilinguals using different L2 naming outcomes, controlling for age, education, occupation, and English fluency (i.e., Test of Premorbid Functioning). Results Moderation showed significant interaction of AoA with striatal lesion burden for scores on all naming tests, with a similar but less robust relationship between white matter lesions and naming outcomes. Graphical analysis revealed subcortical lesions had a negative impact on naming scores in those with later L2 AoA. Conclusions Results suggest “atypical” subcortical involvement in naming is more likely for bilinguals who acquired L2 later. While clinicians typically associate impaired naming with temporal lobe dysfunction, findings suggest subcortical dysfunction should be considered among bilinguals with later L2 AoA.