Visual word recognition is constrained by writing systems. The orthographic depth hypothesis (ODH) was proposed to account for phonological activation in various degrees depending on how transparent the grapheme–phoneme conversion rule is in a writing system. This current study extends the investigation of ODH in bilingualism to understand the cross-language cognitive processes in bi-script readers. In two cross-language masked priming experiments, we show asymmetrical cognate facilitation effects, which are typically reported as a result of shared phonology and/or orthography between languages, in addition to meaning equivalence. That is, with the same set of items, when the primes were Chinese and the targets English (Experiment 1), there was no cognate facilitation effect; however, when we switched the languages in prime–target pairs (Experiment 2), the cognate facilitation effects emerged. These results indicate that shared phonology across languages is not sufficient to induce cognate facilitation effects and that language-dependent processing mechanisms play a crucial role.

Past research suggests that novel word learning is facilitated by multimodal contexts, which enrich semantic representations and strengthen memory traces. We explored whether environmental sounds (e.g., a creaking door) facilitate foreign language (FL) word learning. In all, 36 Spanish-speaking natives learned 60 written Spanish–FL word pairs, each accompanied by one of three sound conditions: a congruent sound matching the word pairs’ denotation, a meaningless tone or silence. Participants then completed a semantic priming and lexical decision task where reaction times and accuracy were collected. Performance was similar for congruent sound and tone conditions and, compared to silence, showed lower accuracy in the lexical decision task and a marginal benefit in the semantic task. These findings suggest that environmental sounds can influence learning, with varying effects depending on the task. Results are discussed in terms of current language learning models.

We conducted a detailed linguistic analysis of Oral Proficiency Interviews (OPIs) from older Spanish-English bilinguals (n = 28) to determine which cognitive, linguistic, and demographic factors predict proficiency. In the dominant language, older age was associated with lower proficiency scores, but aging effects were not significant after accounting for cognitive functioning scores. In the nondominant language, bilinguals with larger vocabulary scores, fewer speech errors, and higher education levels obtained higher proficiency scores. Multiple linguistic submeasures from the OPIs were highly correlated across languages (e.g., fast speakers spoke fast in both languages), but these same measures exhibited significant language dominance effects (e.g., bilinguals spoke faster in the dominant than in the nondominant language). These results suggest it is critical to control for cognitive functioning when examining aging effects on language production, reveal powerful individual differences that affect how people talk regardless of language, and validate the use of the OPI to measure bilingual proficiency.

Learning to map novel words onto their intended referents is a complex challenge, and one that becomes even harder when acquiring multiple languages. We investigated how label mixing affected learning novel words in one versus two languages. In a cross-situational word learning study, 80 adult participants learned either one-to-one word–object mappings, or two-to-one mappings, reflecting different challenges in learning one or two languages. We manipulated whether mappings co-occurred locally, where repetitions were prevalent, or whether co-occurrences were more distributed throughout exposure. Learners acquired two-to-one mappings better when they did not occur in local co-occurrences, but there was no effect of learning conditions for one-to-one mappings. Whether participants were proficient or not in an additional language did not have an observable effect on the learning. We suggest that local co-occurrences of multiple labels, as in language mixing environments, increase the challenge of learning words, though this effect may be only short-lived.

People’s decisions may change when made in a foreign language (FL). Research testing this foreign language effect (FLE) has mostly used scenarios where uncertainty is expunged or reduced to a form of risk, whereas real-life decisions are usually characterized by uncertainty around outcome likelihood. In the current work, we aimed to investigate whether the FLE on decision-making extends to uncertain scenarios. Moreover, as it is still unclear what linguistic and psychological factors contribute to the FLE, we tested the effects of participants’ FL background, cognitive style and risk-taking attitude on decision processes under certain and uncertain conditions. Overall, we report null effects of language context (native versus foreign language) and problem condition (certain versus uncertain prospects) on participants’ choices. In addition, we found that both FL background and decision makers’ traits modulated participants’ choices in a FL, without emerging into the ‘classic’ FLE on decision-making. However, the direction of such effects was complex, and not always compatible with previous FLE theories. In light of these results, our study highlights the need to reconceptualize the FLE and its implications on decision-making.

We tested masked morphological priming effects with prefixed and suffixed words in L2 speakers of German with L1 Turkish, a language in which prefixes are virtually absent. We found weaker prefixation than suffixation priming, suggesting that cross-linguistic morphological differences between speakers’ L1 and L2 may influence L2 morphological processing. We additionally compared our findings to those of a previous study involving L1 Russian-L2 German speakers and L1 German speakers (Ciaccio & Clahsen (2020). Variability and consistency in first and second language processing: A masked morphological priming study on prefixation and suffixation. Language Learning, 70(1), 103–136). The magnitude of prefixation versus suffixation priming of our group was significantly larger than that reported for the L1 Russian-L2 German group, further corroborating the cross-linguistic hypothesis. However, we found no significant difference between our group and L1 German speakers. Therefore, we additionally consider the hypothesis of a general processing disadvantage for prefixed words as an alternative explanation. We conclude that several factors may contribute to why prefixation, in some studies, proves to be more challenging than suffixation, cross-linguistic influences being possibly just one of them.

Simultaneous interpreting (SI) is an intensive multitasking activity that requires coordination of a variety of linguistic and cognitive control mechanisms. Research has shown that interpreters perform better in tasks that require domain-general executive functions (EF), but the question remains whether such cognitive alternation is a result of interpreting experience or it reflects a selection bias that only cognitively capable people are recruited and trained to be interpreters. We examined the cognitive changes experienced by beginner-level students engaged in an intensive, two-week interpreting training programme. Our findings show that: (a) only cognitive flexibility was enhanced by training, together with improvement in SI performance; (b) the three EF subcomponents in their pre-existing forms negatively correlated with training gains; and (c) only pre-existing cognitive flexibility was positively associated with improvement in SI performance. Findings were discussed regarding the relationship between cognitive abilities and the early-stage acquisition of interpreting.

Multilinguals face greater challenges than monolinguals in speech perception tasks, such as processing noisy sentences. Factors related to multilinguals’ language experience, such as age of acquisition, proficiency, exposure and usage, influence their perceptual performance. However, how language experience variability modulates multilinguals’ listening effort remains unclear. We analyzed data from 92 multilinguals who completed a listening task with words and sentences, presented in quiet and noise across participants’ spoken languages (Arabic, Hebrew and English). Listening effort was assessed using pupillometry. The results indicated higher accuracy and reduced effort in quiet than in noise, with greater language experience predicting better accuracy and reduced effort. These effects varied by stimulus and listening condition. For single words, greater language experience most strongly reduced effort in noise; for sentences, it had a more pronounced effect in quiet, especially for high-predictability sentences. These findings emphasize the importance of considering language experience variability when evaluating multilingual effort.

Based on the simple view of reading (SVR), we investigated factors associated with reading comprehension in Second Language (L2) minority children learning a highly consistent orthography through a network analysis. Bilingual and monolingual children participated in the research. Consistent with prior findings, reading speed supported reading comprehension for L1 learners, whereas, for L2 learners, correct decoding carried greater weight than reading speed. In monolingual children, vocabulary and morphosyntactic comprehension contributed jointly and independently to reading comprehension success. However, only vocabulary facilitated reading comprehension in bilingual children, with morphosyntactic skills showing no influence. While monolinguals benefitted from a rich vocabulary and good morphosyntactic knowledge for reading speed and accuracy, in bilingual children, only L2 reading speed was affected by linguistic skills.

Previous studies show that bilingual toddlers who develop their first language (L1) alongside another language can show early stabilization in the L1. This study investigates grammatical development of L1 Cantonese in children with very early onset of English before age 3 (earlier-onset bilinguals/EB, n = 31), with matched later-onset bilinguals (LB, n = 21) as the baseline. Input characteristics and child development measures at 3;0 and 5;8 were derived from parental reports, caretaker–child toy play and narration tasks. Results show that at 3;0, when the LB children were monolingual, the EB children were below the LB group in general grammatical complexity and seven specific grammatical structures (‘early costs’). At 5;8, the EB children converged with the LB children across grammatical measures in Cantonese, while demonstrating superior performance in English (‘long-term gains’). Our findings reveal a distinctive velocity of L1 development in early additive bilinguals raised in a bilingual society.

We investigated whether executive functions (EFs) are engaged in bilingual language control in Finnish speakers with different degrees of Swedish language experience and proficiency, including early bilinguals, late high-proficiency bilinguals and low-proficiency learners of Swedish. In an online experiment, language switching was measured with a cued naming (CN) paradigm, and a Simon task was used to assess EF performance. Following the skill-learning (task specificity) hypothesis, we expected that language switching may be automatized and no longer rely on EFs in bilinguals with high language proficiency, but not for those with lower proficiency. Thus, we expected significant associations between the tasks in the lower proficiency participants only. Our results showed no CN switching–EF associations in the more experienced L2 speakers, but a significant association in lower-proficiency participants. This suggests that language switching engages EFs only in participants with lower proficiency in whom these processes are not yet automatized.

We explored the relationships between L2 utterance fluency and cognitive fluency in monologic and dialogic tasks. The study involved 136 Chinese university-level English learners. Utterance fluency was measured through speed, breakdown, and repair fluency aspects. Cognitive fluency was indicated by L2 lexical and syntactic processing efficiency measures. Stepwise regression models, including metrics of L2-specific cognitive fluency, L2 knowledge, and L1 utterance fluency as predictors, targeted L2 utterance fluency as the dependent variable. We found that L2 cognitive fluency predicted limited variance in utterance fluency, with its influence more evident in monologues. L2 lexical processing efficiency paralleled syntactic processing efficiency’s importance in the monologic task but surpassed it in dialogues. Moreover, L2 processing speed had a more significant impact on utterance fluency than processing stability across both contexts. We suggest that cognitive fluency is not the sole determinant of utterance fluency; L2 knowledge and L1 utterance fluency play non-negligible roles.

Bilingualism delays the onset of dementia symptoms and contributes to cognitive reserve. However, the neural basis of this mechanism remains elusive. The few studies that have investigated neural mechanisms of cognitive reserve and bilingualism have focused on Alzheimer’s disease. This study investigated the neural basis of cognitive reserve among persons with frontotemporal dementia (FTD) using regional brain volumes. Sixty-eight persons with FTD (42 bilinguals and 26 monolinguals) were included. After propensity score matching for age, sex, education, FTD subtype and clinical severity, there were 26 bilinguals and 26 monolinguals. The results showed that bilinguals had reduced thalamic volume compared to monolinguals despite having similar cognitive performance. The results indicate that bilinguals were able to tolerate more severe atrophy compared to monolinguals while maintaining comparable cognitive abilities. Our study therefore suggests that bilingualism contributes to cognitive reserve in persons with FTD.

The bilingual advantage hypothesis, which associates bilingualism with benefits in executive functioning (EF), has been challenged by studies demonstrating inconsistent results. Considering explicit calls to revise the hypothesis, research has turned toward understanding which specific bilingualism-related aspects might impact bilinguals’ EF. Notably, patterns of everyday language use, referred to as interactional contexts in the adaptive control hypothesis (ACH), have emerged as a prominent factor modulating the association between bilingualism and EF. This scoping review synthesizes findings from 49 studies investigating interactional contexts and bilinguals’ EF. The results indicate that the current literature is highly heterogeneous regarding the operationalization, measurement, experimental manipulations of interactional contexts, the EF tasks employed and sample characteristics. This variability limits definitive conclusions about the adaptation of bilinguals’ EF to the demands of interactional contexts. More studies with comparable research designs and clearer predictions on the associations between EF domains and bilinguals’ language-use patterns are needed.

Reading experience provides critical input for language learning. This is typically quantified via estimates of print exposure, such as the Author Recognition Test (ART), although it may be unreliable in L2. This study introduces the Author Fluency Task (AFT) as an alternative measure, comparing with ART for assessing knowledge of English discourse connectives and collocations among 60 bilingual French/English speakers, and a comparison sample of 60 L1 English speakers. Participants completed AFT, ART, and LexTALE in both languages. Analysis of L2 measures showed AFT more accurately predicted L2 vocabulary knowledge than ART, even when controlling for proficiency (LexTALE). Conversely, ART was more effective for L1 speakers, showing a striking dissociation between the measures across language groups. Additionally, data showed limited contributions from L1 proficiency and print exposure on L2 vocabulary. These findings recommend AFT as a valuable tool for quantifying the role of L2 print exposure for language learning.

It has been argued that under certain conditions bilingualism can confer adaptations to the human mind and brain. Among the possible moderators of such adaptations, language distance occupies a distinctly ambiguous role. Equally unclear is the directionality of the effect, as juggling different languages may become more or less cognitively costly depending on how (dis)similar competing alternatives are. If different language pairings entail that a different degree of cognitive effort is needed to manage bilingualism, language distance asymmetries are predicted to differentially contribute to the robustness of bilingual adaptations. In this systematic review and Bayesian analysis, we find strong evidence for a distance effect in bilingualism, but mixed evidence concerning its directionality in terms of being more pronounced in similar versus distant languages. We chart the extreme variability that exists across studies, highlighting the need for developing ecologically accepted metrics of what counts as similar in language processing.

Many bilinguals speak both languages proficiently and habitually; however, the contexts in which the languages are used can vary. The present study examined the effects of context variation on emotions, comparing a national language used everywhere to a regional language spoken only among family and friends. We found a higher sensitivity to disgust (Experiment 1), a greater enjoyment of humor (Experiment 2) and stronger emotions in response to endearments, reprimands and insults (Experiment 3) with the regional language. The regional language induced stronger emotional responses, even though it was used less frequently than the national language. The effects of the regional language varied depending on the frequency of its use. We propose that these effects on emotions reflect the different opportunities to use the language among family and friends, contexts critical for the acquisition and regulation of emotions and in which emotions are expressed quite vividly.

We examined how language affects moral judgments in a non-WEIRD population. Tanzanian participants (N = 103) evaluated utilitarian agents in moral dilemmas, either in native Chagga or foreign Swahili. Agents were rated significantly more moral and braver when evaluated in a foreign language. Bravery predicted morality more strongly in the foreign language than in the native language. Indirect sacrifices were judged more moral than direct ones, but equally brave. These findings extend the moral foreign language effect to informally acquired languages and highlight methodological implications for cross-cultural research.

Recent studies showed contradictory results with regard to the implementation of proactive language control during bilingual sentence production. To add novel evidence to this debate, the current study investigated the blocked language order effect, a measure of proactive language control that has previously only been examined in single-word production. More specifically, bilingual participants completed a network description task, using their L1 in Blocks 1 and 3 and their L2 in Block 2. Results showed increased language intrusions in Block 3 compared to Block 1. This pattern indicates that proactive language control can be implemented during bilingual sentence production.