While several studies have shown a bilingual advantage in cognitive control, others have refuted such findings, leading to debates regarding the existence of bilingual benefits. The current study conducts two experiments to investigate this issue, focusing on the effect of the age of second language immersion in young adult non-immigrant bilinguals. We use a colour-word Stroop task to assess linguistic cognitive control, and an Attention Network Test to examine non-linguistic cognitive control. Results show significant differences between Simultaneous and Early Sequential bilinguals (typically grouped together as ‘early’) in the Stroop task, but these only become apparent when both languages are mixed. Simultaneous bilinguals also show improved Executive Control efficiency, particularly in the presence of alerting and orienting cues, suggesting enhanced attentional skills for this group. We discuss these findings with respect to participant grouping and task effects, noting the importance of the language environment.

The main purpose of the work described in this paper is to examine the extent to which the L2 developmental changes predicted by Kroll and Stewart's (1994) Revised Hierarchical Model (RHM) can be understood by word association response behaviour. The RHM attempts to account for the relative “strength of the links between words and concepts in each of the bilingual's languages” (Kroll, Van Hell, Tokowicz & Green, 2010, p. 373). It proposes that bilinguals with higher L2 proficiency tend to rely less on mediation, while less proficient L2 learners tend to rely on mediation and access L2 words by translating from L1 equivalents. In this paper, I present findings from a simple word association task. More proficient learners provided a greater proportion of collocational links, suggesting that they mediate less when compared to less proficient learners. The results provide tentative support for Kroll and Stewart's model.

Our keynote article “Coactivation in bilingual grammars: A computational account of code mixing” (Goldrick, Putnam & Schwarz) aimed to provide a framework that would begin to unify psycholinguistic and formal grammatical approaches to code mixing. We situated our account within a large body of psycholinguistic and phonetic evidence suggesting that, under many conditions, multiple representational elements simultaneously occupy (to varying degrees) a single position within a linguistic structure. The presence of such blends in multilingual cognition is not compatible with many formal grammatical approaches that assume mental representations are necessarily discrete.

We explore the properties of foreigner talk through word reduction. Word reduction signals that the speaker is referring to the same entity as previously and should be preserved for foreigner talk. However, it leads to intelligibility loss, which works against foreigner talk. Pairs of speakers engaged in a task where native speakers talked either to a native or non-native listener. Natives talking to non-natives performed foreigner talk for duration and intensity. Duration and intensity were reduced for native and non-native listeners equally. These results suggest that word reduction is insensitive to communicative adjustments in the context of foreign talk.

Typically concrete words are learned better than abstract words (Kaushanskaya & Rechtzigel, 2012), and nouns are learned better than verbs (Kauschke & Stenneken, 2008). However, most studies on concreteness have not manipulated grammatical class (and vice versa), leaving the relationship between the two unclear. Therefore, in two experiments we examined the effects of grammatical class and concreteness simultaneously in foreign language vocabulary learning. In Experiment 1, English speakers learned ‘foreign language’ words (English pseudowords) mapped to concrete and abstract nouns and verbs. In Experiment 2, English speakers learned German words with the same procedure. Overall, the typical advantages for concrete words and nouns were observed. Hierarchical regression analyses provided evidence that the grammatical class effect is separable from the concreteness effect. This result challenges a strict concreteness-based source of noun/verb differences. The results also suggest that the influences of concreteness and grammatical class may vary across language measures and tasks.

Whereas most theoretical and computational models assume a continuous flow of activation from concepts to lexical items in spoken word production, one prominent model assumes that the mapping of concepts onto words happens in a discrete fashion (Bloem & La Heij, 2003). Semantic facilitation of context pictures on word translation has been taken to support the discrete-flow model. Here, we report results of computer simulations with the continuous-flow WEAVER++ model (Roelofs, 1992, 2006) demonstrating that the empirical observation taken to be in favor of discrete models is, in fact, only consistent with those models and equally compatible with more continuous models of word production by monolingual and bilingual speakers. Continuous models are specifically and independently supported by other empirical evidence on the effect of context pictures on native word production.

To assess the presence of cross-linguistic influence, this study compared the processing of Dutch sentences by English–Dutch and German–Dutch bilingual and Dutch monolingual children in a self-paced listening task. We combined insights from studies on child bilingualism and adult second language acquisition. Sentence structures showing partial overlap between languages were investigated (long passives), as well as structures with complete or no overlap (verb second and verb third sentences). We found evidence for syntactic co-activation of overlapping structures in the form of inhibition during listening. Syntactic, and possibly lexical, overlap between languages, and language dominance modulated effects. In particular, online cross-linguistic influence was visible only in the German–Dutch group. Furthermore, effects were most pronounced when structures partially overlapped and were absent in non-overlapping structures. Effects of online cross-linguistic influence became stronger the more German-dominant children were. Our results indicate that syntactic co-activation across languages affects sentence processing in bilingual children.

This study examined whether training in translation/interpretation leads to a reliance on a ‘vertical’ translation strategy in which the source language text is comprehended before the message is reformulated. Students of translation/interpreting and untrained bilinguals were given an idiom translation judgment task with literal (form and meaning) or figurative equivalents (meaning only). Dependent measures included the time taken to comprehend the first presented sentence and the accuracy and speed of judging if the second presented sentence was a translation of the first sentence. The groups did not differ in their speed of reading the first presented sentence but translation verification times differed by group and translation type: untrained bilinguals were significantly faster at verifying literal than figurative translations while trained bilinguals were equally fast for the two types. The pattern of findings is consistent with the view that training in translation fosters a processing-for-meaning-before reformulating, or vertical, translation strategy.

Although many studies have investigated the consequences of bilingualism on cognitive control, few have examined the impact of bilingualism on other cognitive domains, such as memory. Of these studies, most have focused on item memory and none have examined the role of bilingualism in source memory (i.e., the memory for contextual details from a previous encounter with a stimulus). In our study, young adult bilinguals and monolinguals completed a source memory test, whose different conditions were designed to stress working memory and inhibitory control. Bilinguals performed significantly faster than monolinguals across all conditions without compromising accuracy, and also showed an overall speed advantage on the Flanker task. We interpret these processing speed advantages within the context of current models of bilingual production.

We thank the commentators for their thoughtful critiques, which we found both insightful and stimulating to our own thinking. Our first response is that, while debates about the CPL in theoretical contexts are important, the vigor and intensity of these debates should not overshadow the fact that the main goal of our article was to highlight a finding of vital importance: Sufficient language input in early childhood matters deeply because it has long-term consequences (Lillo-Martin, 2018). Woll sums up this point both succinctly and poignantly in her report of a similar case of very late L1 exposure in adulthood who had decades of experience: “For a [deaf] child who, even in the context of early intervention, does not acquire a spoken language, the danger is that they will never have native-like mastery of any L1.” This is what truly matters. Our hope is that our keynote article and the accompanying commentaries might have a positive effect on clinical practice, educational policy, and even parental choice in this regard. In what follows, we discuss the main issues arising from the commentaries. First we note the points of agreement followed by a clarification of what we did not claim in our article. Researchers continue to debate what the shape of the AoA function looks like and its theoretical implications, which we address third. We then address the issues raised as to whether late L1 acquisition and late L2 learning differ in degree or kind, and last we discuss what we mean when we say that language acquisition during post-natal brain growth creates the capacity to learn language.

We evaluated the impact of exposure to a second language on infants’ emerging speech production skills. We compared speech produced by three groups of 12-month-old infants while they interacted with interlocutors who spoke to them in Spanish and English: monolingual English-learning infants who had previously received 5 hours of exposure to a second language (Spanish), English- and Spanish-learning simultaneous bilinguals, and monolingual English-learning infants without any exposure to Spanish. Our results showed that the monolingual English-learning infants with short-term exposure to Spanish and the bilingual infants, but not the monolingual English-learning infants without exposure to Spanish, flexibly matched the prosody of their babbling to that of a Spanish- or English-speaking interlocutor. Our findings demonstrate the nature and extent of benefits for language learning from early exposure to two languages. We discuss the implications of these findings for language organization in infants learning two languages.

Assessing language in sequential bilinguals (L2 children) for the identification of language impairment suffers from lack of appropriate standardized tools and from limited understanding of the developmental trajectories of these learners. This longitudinal study compares L2 children to children with SLI in order to better understand where these groups have overlapping performance and where they differ. An analysis of standardized test scores as well as frequency of clausal embedding and morphosyntactic errors in spontaneous speech was conducted with 22 English-speaking children (aged 6;9-12;7) acquiring French as an L2 in France and 19 monolingual French-speaking children with SLI (aged 6;5–12;11). The results revealed that L2 children used clausal embedding more often than the children with SLI, but both groups had similar rates of morphosyntactic accuracy. Facility with clausal embedding from early stages of development and continuing difficulty with morphosyntactic accuracy are argued to be characteristic of typical development in L2 children.

Mentalizing, a dynamic form of social cognition, is strengthened by language experience. Past research has found that bilingual children and adults outperform monolinguals on mentalizing tasks. However, bilingual experiences are multidimensional and diverse, and it is unclear how continuous individual differences in bilingual language experience relate to mentalizing. Here, we examine whether individual differences in bilingual language diversity, measured through language entropy, continuously pattern with mentalizing judgments among bilingual adults, and whether this relationship is constrained by first vs. second language reading. We tested sixty-one bilingual adults on a reading and inference task that compared mental state and logical inferences. We found that greater language diversity patterned with higher mentalizing judgments of mental state inferences across all readers, and that L2 readers attributed more mentalizing to logical inferences compared to L1 readers. Together, we found evidence of a positive relationship between continuous individual differences in bilingual language diversity and mentalizing.

Bilinguals’ two languages seem to be coactivated in parallel during reading, speaking, and listening. However, this coactivation in writing has been scarcely studied. This study aimed to assess orthographic coactivation during spelling-to-dictation. We took advantage of the presence of polyvalent graphemes in Spanish (one phonological representation with two orthographic specifications, e.g., / b /for both the graphemes v and b) to manipulate orthographic congruency. Spanish–English bilinguals were presented with cross-linguistic congruent (movement–movimiento) and incongruent words (government–gobierno) for a dictation task. The time and accuracy to initiate writing and to type the rest-of-word (lexical and sublexical processing) were recorded in both the native language (L1) and the second language (L2). Results revealed no differences between conditions in monolinguals. Bilinguals showed a congruency and language interaction with better performance for congruent stimuli, which was evident from the beginning of typing in L2. Language coactivation and lexical–sublexical interaction during bilinguals’ writing are discussed.

First-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.

The present study investigated the foreign language effect within an altruistic decision making process. Chinese–English bilinguals made altruistic decisions in their native (L1: Chinese) and second language (L2: English). The decisions were framed in two ways: either as “not to harm” (harm frame) or as “to help” the other person (help frame) at one's economic cost. Behavioral results suggest that bilinguals might behave more altruistically in the harm frame than the help frame (i.e., framing effect) in their native language but not in their foreign language. Electrophysiological results show that the modulation of the framing effect in the native versus foreign language originated in the early ERP components (N1 and N2) and did not present in the late positive potential (LPP). These findings suggest the foreign language effect most likely results from the reduced emotional reaction in a foreign compared to the native language.

In the present study, the Perceptual Assimilation Model (PAM) was tested on its applicability in child L2 lexical tone acquisition. The possible effect of L1 (Cantonese) lexical tones on L2 (Mandarin) lexical tone learning was explored. Accuracy rate and error patterns were examined with an AX discrimination task and a forced-choice identification task. Forty-nine native Cantonese-speaking students aged 8 years participated in the study. Results revealed that these children exhibited nearly perfect performance in the discrimination of Mandarin tones. However, significant tone differences were detected in the identification task. Tone 4 (T4) was identified with the lowest accuracy, and T1 with the highest. Error analysis revealed that Mandarin T2-T3 was the most confusing pair, followed by the T1-T4 pair. The inherent phonetic similarity between lexical tones in a language and the tone similarities across languages may also have contributed to perception difficulties, which could help to refine and supplement the PAM in the tonal/suprasegmental domain.

One of the best-known claims from language acquisition research is that the capacity to learn languages is constrained by maturational changes, with particular time windows (aka ‘critical’ or ‘sensitive’ periods) better suited for language learning than others. Evidence for the critical period hypothesis (CPH) comes from a number of sources demonstrating that age is a crucial predictor for language attainment and that the capacity to learn language diminishes with age. To take just one example, a recent study by Hartshorne, Tenenbaum and Pinker (2018) identified a ‘sharply-defined critical period’ for grammar learning, and a steady decline thereafter, based on a very large dataset (of 2/3 million English Speakers) that allowed them to disentangle critical-period effects from non-age factors (e.g., amount of experience) affecting grammatical performance. Other evidence for the CPH comes from research with individuals who were deprived of linguistic input during the critical period (Curtiss, 1977) and were consequently unable to acquire language properly. Moreover, neurobiological research has shown that critical periods affect the neurological substrate for language processing, specifically for grammar (Wartenburger, Heekeren, Abutalebi, Cappa, Villringer & Perani, 2003).

Like the BIA model (Dijkstra & van Heuven, 1998; van Heuven, Dijkstra & Grainger, 1998) and the BIA+ model (Dijkstra & van Heuven, 2002), the Multilink model is a symbolic, localist-connectionist, interactive model for lexical processing in the visual domain. In our view, the symbolic nature of Multilink makes it attractive and easily interpretable, even in relation to brain activity (Page, 2000, p. 501; 2017). Symbolic localist-connectionist models have a long tradition and have been applied to many different areas of cognitive research (e.g., Grainger & Jacobs, 1998). As a consequence, a lot is known about their properties and limitations (e.g., Bowers, 2009). These models can also easily be organized hierarchically in a cognitive functional way, and they have a reasonable degree of flexibility while still being falsifiable. Thus, despite the availability of other sophisticated frameworks for modeling language processes, a lot can still be gained from localist models.