This review provides an update on what we know about differences in prediction in a first and second language after several years of extensive research. It shows when L1/L2 differences are most likely to occur and provides an explanation as to why they occur. For example, L2 speakers may capitalize more on semantic information for prediction than L1 speakers, or possibly they do not make predictions due to differences in the weighting of cues. A different weighting of cues can be the result of prior experience from the L1 and/or the prior experience in an experiment which affects L1 and L2 processing to a different extent. Overall, prediction in L2 processing often emerges later and/or is weaker than in L1 processing. Because L2 processing is generally slower, L1/L2 differences are likely to occur at certain levels of prediction, most notably at the form level, in line with a prediction-by-production mechanism.

Words’ morphemic structure and their orthographic representations vary across languages. How do bilingual experiences with structurally distinct languages influence children's morphological processes for word reading? Focusing on English literacy in monolinguals and bilinguals (N = 350, ages 5–9), we first revealed unique contributions of derivational (friend-li-est) and compound (girl-friend) morphology to early word reading. We then examined mechanisms of bilingual transfer in matched samples of Spanish–English and Chinese–English dual first language learners. Results revealed a principled cross-linguistic interaction between language group (Spanish vs. Chinese bilinguals) and type of morphological awareness. Specifically, bilinguals’ proficiency with the type of morphology that was less characteristic of their home language explained greater variance in their English literacy. These findings showcase the powerful effects of bilingualism on word reading processes in children who have similar reading proficiency but different language experiences, thereby advancing theoretical perspectives on literacy across diverse learners.

Are bilingual speakers’ representations of pronominal expressions completely independent in the two languages, or is there sharing of discourse-level representations cross-linguistically? In the present study, we address this question by using a sentence comprehension task that implements the cross-linguistic priming technique at the discourse-level.

In two experiments conducted with Spanish–English bilinguals, we prime dis-preferred interpretations for ambiguous pronouns in the second language (English) by using first language (Spanish) pronoun interpretation primes. In experiment 1, Spanish null pronouns prime second-mentioned/object interpretations in English, showing an effect of priming. In experiment 2, Spanish explicit pronouns prime second-mentioned/object interpretations in English, indicating that an effect of priming approaches significance.

The results demonstrate that bilinguals’ inferences about probability distributions and coherence relations are susceptible to cross-linguistic influence. The strength of the priming effect is discussed within models of cross-language abstract representations.

A growing body of research suggests that bilingualism may afford benefits to certain aspects of cognitive functioning. Inconsistent findings may arise because of methodological differences within and across studies. One limitation is that studies often compare linguistically similar languages. The present study recorded brain activity (event-related potentials; ERPs) while English monolinguals, English–French bilinguals, and Arabic–English bilinguals completed an n-back task and a delayed matching-to-sample task. Group ERP differences were observed in the absence of behavioral differences. In the delayed matching-to-sample task, monolinguals exhibited smaller N2 amplitude compared to both bilingual groups, and smaller P3b amplitude compared to English–French bilinguals. In the n-back, English–French bilinguals displayed larger P3b amplitudes than monolinguals and Arabic–English bilinguals. P3b amplitude did not differ between Arabic–English bilinguals and monolinguals in either task. These results suggest that conflicting findings across studies may be due in part to the linguistic distance between the languages under study.

Whereas growing evidence supports the advantages of bilingualism for brain structure and function, no study has shown multilingual-related neuroplasticity in response to speech stimuli at the subcortical level. To investigate the impact of multilingualism on subcortical auditory processing, the speech auditory evoked response (speech-ABR) was recorded on 35 young adults. The multilingual group completed the language experience and proficiency questionnaire (LEAP-Q). The results were that multilingual participants demonstrated evidence of enhanced neural timing processing, including a shorter wave D latency and the V-A duration, and a sharper V-A slope compared to the monolinguals in silence. In the noise condition, the speech-ABR measures degraded in most components, and no significant difference was observed between the two groups. The association between the total proficiency score and several subcortical responses was significant. This shows subcortical evidence of stronger neural synchronization in multilinguals relative to monolinguals, correlated with the self-report of multilingual experience.

This study investigates child heritage speakers’ Spanish direct objects. A task designed to elicit direct objects was completed in Spanish and English by 40 child heritage speakers of Spanish in the U.S., and in Spanish by 24 monolingual children in Mexico. Both participant groups varied their direct object forms, following the same ranking: clitics>lexical NPs>omission>doubling. Animate referents promoted clitics; inanimate referents promoted lexical NPs. Among the heritage speakers, more Spanish experience and Spanish lexical proficiency predicted more clitic use (less omission and lexical NP use). We also argue that the child heritage speakers’ production of strong pronouns, more lexical NPs, and masculine clitic lo with inanimate feminine referents suggest English influence. The study underscores the importance of examining structured variation, which revealed both similarities and differences between heritage and monolingual speakers.

Second language learners’ reading is less efficient and more effortful than native reading. However, the source of their difficulty is unclear; L2 readers might struggle with reading in a different orthography, or they might have difficulty with later stages of linguistic interpretation of the input, or both. The present study explored the source of L2 reading difficulty by analyzing the distribution of fixation durations in reading. In three studies, we observed that L2 readers experience an increase in Mu, which we interpret as indicating early orthographic processing difficulty, when the L2 has a significantly different writing system than the L1 (e.g., Chinese and English) but not when the writing systems were similar (e.g., Portuguese and English). L2 readers also experienced an increase in Tau, indicating later-arising processing difficulty which likely reflects later-stage linguistic processes, when they read for comprehension. L2 readers of Chinese also experienced an additional increase in Tau.

An episodic memory experiment was conducted to examine whether “conceptual metaphors” influence how metaphorical expressions are processed and encoded into memory. Forty Chinese–English bilinguals read lists of expressions in their L1 and L2. The data revealed that after reading a series of metaphorical expressions based on the same underlying conceptual metaphor, participants falsely recognized new sentences that instantiated the same conceptual metaphor mapping more often than control sentences that did not share this mapping. This false memory effect was robust in both participants’ L1 and L2, with the only difference between languages being that participants showed more memory errors for literal sentences related to the source domain of the conceptual metaphors when reading in their second language (i.e., English). These data suggest that although bilinguals can access the appropriate conceptual metaphors in their second language, they have difficulty inhibiting literal meaning when processing metaphorical statements.

Increasing numbers of international students enter university education via English language bridging programs. Much research has overlooked the nature of second language reading development during a bridging program, focusing instead on the development of literacy skills of international students who already meet the language requirement for undergraduate admission. We report a longitudinal eye-movement study assessing English passage reading efficiency and comprehension in 405 Chinese-speaking bridging program students. Incoming IELTS reading scores were used as an index of baseline reading ability. Linear mixed-effects regression models fitted to global eye-movement measures and reading comprehension indicated that despite initial between-subjects differences, within-subject change at each ability level progressed at the same rate, following parallel growth trajectories. Therefore, there was significant overall reading progress during the bridging program, but no evidence that the gap between low and high ability readers either closed or widened over time.

To investigate how orthography and semantics interact during bilingual visual word recognition, Dutch–English bilinguals made lexical decisions in two masked priming experiments. Dutch primes and English targets were presented that were either neighbour cognates (boek – BOOK), noncognate translations (kooi – CAGE), orthographically related neighbours (neus – NEWS), or unrelated words (huid - COAT). Prime durations of 50 ms (Experiment 1) and 83 ms (Experiment 2) led to similar result patterns. Both experiments reported a large cognate facilitation effect, a smaller facilitatory noncognate translation effect, and the absence of inhibitory orthographic neighbour effects. These results indicate that cognate facilitation is in large part due to orthographic-semantic resonance. Priming results for each condition were simulated well (all r's >.50) by Multilink+, a recent computational model for word retrieval. Limitations to the role of lateral inhibition in bilingual word recognition are discussed.

Sentence reading involves constant competition between lexical candidates. Previous research with monolinguals has shown that the neighbours of a read word are inhibited, making their retrieval as a subsequent target more difficult, but the duration of this interference may depend on reading skills. In this study, we examined neighbour priming effects in sentence reading among proficient Norwegian–English bilinguals reading in their L2. We investigated the effects of the distance between prime and target (short vs. long) and the nature of the overlap between the two words (beginning or end), and related these to differences in individual cognitive skills. Our results replicated the inhibition effects found in monolinguals, albeit slightly delayed. Interference between form-related words was affected by the L2 reading skills and, crucially, by the phonological decoding abilities of the bilingual reader. We discuss the results in light of competition models of bilingual reading as well as episodic memory accounts.

Language switching is often associated with language competition and switching costs. However, the underlying mechanisms might differ depending on context (free versus cued naming) and modality (production or comprehension). In this study, we assessed how response-stimulus intervals (RSI) influence language-switching costs. Longer RSIs might provide more time for interference from the previous trial to decay and result in smaller switching costs. Mandarin–English bilinguals completed two dual-language production tasks (Experiment 1: cued and voluntary picture naming) and one comprehension task (Experiment 2: animacy judgement) with a short RSI and a long RSI condition. While switching costs were present in all tasks, they were only influenced by RSI length in the cued-production task, with smaller switching costs in the long RSI condition. In contrast, RSI did not influence voluntary-production or comprehension costs. This suggests that bilinguals might apply language control differently to switch languages depending on the type of switching and modality.

According to the “reduced emotionality hypothesis”, we are less emotionally driven when reasoning in a foreign language (FL) than in a native language (NL). We examined whether this foreign language effect (FLe) extends to the way we perceive motivational quotes (i.e., encouraging slogans conveying a profound and inspirational message): we expected FL participants to rate motivational quotes as less profound than NL participants. Strikingly, we observed the opposite: FL participants found motivational quotes more profound than NL participants, even after controlling for potential confounders (e.g., IQ, reasoning style). Both FL and NL participants gave similarly low profundity ratings to pseudo-profound bullshit sentences (i.e., meaningless sentences sounding profound), indicating that the message must be meaningful for the FLe to arise. We propose that, like space or time, language could promote psychological distance. This favours a focus on the background of a message to indicate profoundness.

Manual co-speech gestures can facilitate language comprehension, but do they influence language comprehension in simultaneous interpreters, and if so, is this influence modulated by simultaneous interpreting (SI) and/or by interpreting experience? In a picture-matching task, 24 professional interpreters and 24 professional translators were exposed to utterances accompanied by semantically matching representational gestures, semantically unrelated pragmatic gestures, or no gestures while viewing passively (interpreters and translators) or during SI (interpreters only). During passive viewing, both groups were faster with semantically related than with semantically unrelated gestures. During SI, interpreters showed the same result. The results suggest that language comprehension is sensitive to the semantic relationship between speech and gesture, and facilitated when speech and gestures are semantically linked. This sensitivity is not modulated by SI or interpreting experience. Thus, despite simultaneous interpreters’ extreme language use, multimodal language processing facilitates comprehension in SI the same way as in all other language processing.

Social factors impact sentence comprehension in a first language (L1), suggesting that semantic processing cannot be dissociated from social and moral emotions in relation to pro/antisocial individuals. Given that integrating multiple types of information and processing emotion-laden pragmatic information is costlier in a second language (L2), we investigated whether social factors would affect discourse comprehension similarly in L2. Processing the outcomes of scenarios involving pro/antisocial protagonists provoked similar neural patterns in L2 as in L1 (Rodríguez-Gómez, Martín-Loeches, Colmenares, Romero Ferreiro & Moreno, 2020), suggesting that L2 users simultaneously integrate semantic and discourse-pragmatic information during sentence comprehension.

The moral foreign-language effect (M-FLE) translates into more utilitarian choices, even when given the option of self-sacrifice. We explore the M-FLE in 85 children, who were presented with seven moral dilemmas varying in utilitarianism, aversiveness, and whether they allowed the option of self-sacrifice; 42 answered to the dilemmas in their native language (Spanish), and 43 in a foreign language (English). Participants were more utilitarian and willing to sacrifice themselves when using their foreign language. Educational and developmental implications are discussed, especially in the context of bilingual education.

Bilingual children have better Theory-of-Mind compared to monolingual children, but comparatively little research has examined whether this advantage in social cognitive ability also applies to adults. The current study investigated whether multilingual status and/or number of known languages predicts performance on a mentalizing task in a large sample of adult participants. Multilingualism was decomposed based on whether English is the first language or not. All analyses controlled for well-known predictors of mentalizing, such as gender, same-race bias, and years of English fluency. We found a U-shaped trend, such that monolinguals and multilinguals did not differ much in their mentalizing ability, but bilinguals performed worse than monolinguals. Our study builds upon past work by examining a large sample of participants, measuring a crucial aspect of adult social cognition that has previously been unexplored, controlling for several nuisance variables, and investigating whether multilingualism leads to additional benefits in mentalizing abilities beyond bilingualism.