Substantial research has examined cognition in aging bilinguals. However, less work has investigated the effects of aging on language itself in bilingualism. In this article I comprehensively review prior research on this topic, and interpret the evidence in light of current theories of aging and theories of bilingualism. First, aging indeed appears to affect bilinguals’ language performance, though there is considerable variability in the trajectory across adulthood (declines, age-invariance, and improvements) and in the extent to which these trajectories resemble those found in monolinguals. I argue that these age effects are likely explained by the key opposing forces of increasing experience and cognitive declines in aging. Second, consistent with some theoretical work on bilingual language processing, the grammatical processing mechanisms do not seem to change between younger and older bilingual adults, even after decades of immersion. I conclude by discussing how future research can further advance the field.

It has recently been suggested that bilingualism, rather than age of acquisition, is what underlies less than nativelike attainment in childhood L2 acquisition. Currently, however, the empirical evidence in favor of or against this interpretation remains scarce. The present study sets out to fill this gap, implementing a novel factorial design in which the variables age of acquisition and bilingualism have been fully crossed. Eighty speakers of Swedish, who were either L1 monolinguals, L1 simultaneous bilinguals, L2 sequential monolinguals (international adoptees), or L2 sequential bilinguals (childhood immigrants), were tested on phonetic, grammatical, and lexical measures. The results indicate consistent effects of age of acquisition, but only limited effects of bilingualism, on ultimate attainment. These findings thus show that age of acquisition – not bilingualism – is the primary determinant of L2 ultimate attainment.

We examined how proficiency influences the processing of emotion words in Spanish–English bilinguals (22 balanced and 20 unbalanced). All unbalanced bilinguals were more proficient in English than Spanish. Participants rated the valence of negative, neutral, and positive words in both languages while EEG was being recorded. ERP latencies and amplitudes were analyzed for two components. The language effect was significant on the late positive component (LPC) amplitude, which was larger for emotion than for neutral words for both groups in English. The unbalanced group presented larger LPC amplitudes for positive than for neutral and for neutral than for negative words in Spanish, suggesting emotion processing differences in these participants’ less proficient language. Valence effects were consistent across languages for the balanced group, but not for the unbalanced group, perhaps reflecting differences in reactivity to emotion words in the less proficient language.

The current study analyzes Spanish present tense morphology with a focus on overregularization. It examines written production from two groups of English/Spanish bilingual children in a dual immersion setting, Spanish heritage language (SHL) speakers (n = 21) and Spanish second language (SL2) learners (n = 41), comparing them to age-matched (nine to ten years old) Spanish majority language children (n = 15). Spanish majority children show full mastery of present tense regular, stem-changing and irregular morphology. SHL children seem to have acquired mastery of regular inflectional morphology, but not of stem-changing morphology. SL2 children are significantly less accurate than both majority Spanish and SHL children in terms of both regular and irregular morphology. Evidence of overregularization, but not of irregularization, is provided for both SHL and SL2 children. The analysis of overregularization errors supports a variational approach (Yang, 2016) to acquisition, storage and access of morphology.

This eye-tracking study establishes basic benchmarks of eye movements during reading in heritage language (HL) by Russian-speaking adults and adolescents of high (n = 21) and low proficiency (n = 27). Heritage speakers (HSs) read sentences in Cyrillic, and their eye movements were compared to those of Russian monolingual skilled adult readers, 8-year-old children and L2 learners. Reading patterns of HSs revealed longer mean fixation durations, lower skipping probabilities, and higher regressive saccade rates than in monolingual adults. High-proficient HSs were more similar to monolingual children, while low-proficient HSs performed on par with L2 learners. Low-proficient HSs differed from high-proficient HSs in exhibiting lower skipping probabilities, higher fixation counts, and larger frequency effects. Taken together, our findings are consistent with the weaker links account of bilingual language processing as well as the divergent attainment theory of HL.

Under the Interface Hypothesis, bilinguals’ non-nativelike referential choices may be influenced by the increased cognitive demands and less automatic processing of bilingual production. We test this hypothesis by comparing pronoun production in the L2 of nonbalanced Spanish–English bilinguals to that of English monolinguals in two cognitively challenging contexts. In Experiment 1, both monolinguals and bilinguals produced more explicit references when part of the information was unavailable to their addressee (privileged ground) than when all information was shared (common ground), evidencing audience design. In Experiment 2, verbal load led to more unspecified references than visual load and no load (an effect statistically indistinguishable between groups but numerically driven by the monolingual group). While bilinguals produced overall more pronouns than monolinguals in both experiments, there was no indication that bilinguals’ referential choice was disproportionally affected by increased cognitive demand, contrary to the predictions of the Interface Hypothesis.

This study reports a production experiment investigating the realization of objects with different verb types in controlled discourse contexts in 68 three- to seven-year-old sequential Cantonese–English bilingual children. The results show the bilingual children behaved similarly to the Cantonese monolingual peers in object omission, but exhibited protracted development and produced target-deviant forms following a Cantonese pattern in omitting objects specified in prior discourse in English. The bilingual children also showed non-target-like uses of the Cantonese post-verbal object pronoun keoi5, which were unattested in monolingual children. Our findings show evidence for bidirectional cross-linguistic influence: the direction of influence goes from the weaker to the stronger language and from the stronger to the weaker language. Vulnerability of object realization in bilingual acquisition can be better understood in terms of the interaction between cross-linguistic influence, input (e.g., quantity and structural frequencies) and other linguistic elements involved in the interface relation (e.g., verb type).

Lupyan's (2012) label-feedback hypothesis proposes that linguistic labels affect our conceptual and perceptual representations through top-down feedback. We investigated whether such representations in bilinguals are influenced by labels from both of their languages by examining the effect of Chinese word structure on picture perception in Chinese–English bilinguals. A visual-oddball task with ERP was used. Pictures of four birds were used as standards and deviants. The robin-ostrich pair shared a category cue in their Chinese names (like blackbird in English), and the pigeon-penguin pair did not. In Chinese–English bilinguals who were new to Canada, the visual mismatch negativity (vMMN) elicited by deviant stimuli was significantly larger for pairs without category cues than pairs with cues, but, in long-stay bilinguals and English monolinguals, the vMMN was similar for the two pairs. These results demonstrate that object perception is influenced by the labels in both of a bilingual's languages.

Learning to pronounce a written word implies assigning a stress pattern to that word. This task can present a challenge for speakers of languages like Italian, in which stress information must often be computed from distributional properties of the language, especially for individuals learning Italian as a second language (L2). Here, we aimed to characterize the processes underlying the development of stress assignment in native English and native Chinese speakers learning L2 Italian. Both types of bilinguals produced evidence supporting a role of vocabulary size in modulating the type of distributional information used in stress assignment, with an early bias for Italian's dominant stress pattern being gradually replaced by use of associations between orthographic sequences and stress patterns in more advanced bilinguals. We also obtained some evidence for a transfer of stress assignment habits from the bilinguals’ native language to Italian, although only in English native speakers.

A bilingual exhibits a “semantic accent” when they comprehend or use a word in one language in a way that is influenced by its translation. Semantic accents are well-captured by feature-based models: however, few studies have specifically examined the processing of features that contribute to a semantic accent. Japanese–English bilinguals and monolinguals of each language completed three feature-based tasks focusing on culture-specific semantic features. Bilinguals exhibited semantic accents in L1 and L2 in that they had stronger associations than monolinguals between the features specific to one culture and words in the other language. Within bilinguals, culture-specific features were more strongly associated with the congruent language than the incongruent language. Finally, changes in the strengths of associations between culture-specific features and words depended more on L2 cultural immersion than L2 proficiency. Semantic accents lessened in L2 and increased in L1 after many years of exposure to the L2 culture.

Previous research has demonstrated that individual differences in conflict management predict second-language (L2) reading skill. The current experiment tested the hypothesis that this relation reflects the need to manage conflict from cross-linguistic interactions (CLI). A novel model specifying the relation between L2 reading skill, CLI, and the predictors of such interactions was tested in 253 L2 English speaking adults, using structural equation modeling. In support of the hypothesis, the findings revealed that stronger CLI was related to poorer L2 reading skill. In addition, variability in non-linguistic conflict management, as measured by executive attention tasks, and relative language dominance reliably predicted CLI. Specifically, better conflict management and lower L1 dominance corresponded to fewer interactions. These results fill a crucial gap by demonstrating for the first time that the ability to manage CLI is critical to L2 reading, and that both cognitive skills and language experience contribute to variability in these interactions.

This study examined the extent to which language-switching practice enhanced L2 learners’ L2 grammatical processing by improving language selection abilities. Thirty-six English-speaking learners of French completed the same language-switching practice of L1 and L2 sentences, but received different types of pre-practice explicit information (EI) designed to address L2 learning difficulties resulting from crosslinguistic influence: one group (n = 17) received EI about English–French differences for viewpoint aspect, and a second group (n = 19) received EI about viewpoint aspect in French only. This design investigated the extent to which pre-practice linguistic knowledge moderated the effectiveness of the language-switching practice. Longitudinal analyses showed that increasing amounts of practice improved language selection abilities (increased accuracy, reduced reaction time costs), but only for learners who received EI about L1-L2 differences. These findings that language-switching was moderated by type of pre-practice EI have important implications for theories of L2 learning and instruction.

The term ‘metalinguistic’ is used to define the kind of ability whereby people for various purposes view language as an object. It is strongly associated with consciousness and touches on many aspects of literacy, multilingualism and language acquisition. Discussions in the research literature have generally been on specific aspects of metalinguistic knowledge: the time is ripe for a more fundamental reassessment focusing on how exactly metalinguistic ability is represented and processed on line, and how it fits in with other kinds of representation and processing. To this end, a particular theoretical perspective that takes into account contemporary research in cognitive science, the Modular Cognition Framework, will be applied with the aim of supporting further empirical investigations into this area of language ability and locating it within an integrated approach to cognition in general. Finally, the usefulness of metalinguistic knowledge will be briefly considered.

Numerous studies have argued that bilingualism has effects on cognitive functions. Recently, in light of increasingly mixed empirical results, this claim has been challenged. One might ponder if there is enough evidence to justify a cessation to future research on the topic or, alternatively, how the field could proceed to better understand the phantom-like appearance of bilingual effects. Herein, we attempt to frame this appearance at the crossroads of several factors such as the heterogeneity of the term ‘bilingual’, sample size effects, task effects, and the complex dynamics between an early publication bias that favours positive results and the subsequent Proteus phenomenon. We conclude that any definitive claim on the topic is premature and that research must continue, albeit in a modified way. To this effect, we offer a path forward for future multi-lab work that should provide clearer answers to whether bilingualism has neurocognitive effects, and if so, under what conditions.

Several multilingual language production models assume that language control is instigated by conflict monitoring. In turn, conflict adaptation, a control process which makes it easier to resolve interference if previously a high-interference context was detected, should also occur during multilingual production, as it is triggered by conflict monitoring. Because no evidence has been provided for conflict adaptation in the multilingual production literature, we set out to investigate this process using the n-3 effect. Our study showed that the n-3 effect can be observed during multilingual production, and thus provides evidence for conflict adaptation during multilingual production.

Listeners can adapt to errors in foreign-accented speech, but not all errors are alike. We investigated whether exposure to unsystematic tone errors in second language Mandarin impacts responses to accurately produced words. Native Mandarin speakers completed a cross-modal priming task with words produced by foreign-accented talkers who either produced consistently correct tones, or frequent tone errors. Facilitation from primes bearing correct tones was unaffected by the presence of tone errors elsewhere in the talker's speech. However, primes bearing tone errors inhibited recognition of real words and elicited stronger accentedness ratings. We consider theoretical implications for tone in foreign-accent adaptation.