Theory-of-mind (ToM) plays a critical role in early language acquisition. However, whether ToM continues to support word learning in adults is unknown. This study tests whether engaging nonverbal ToM assists novel word encoding and retention. We examined young adults word learning in direct-mapping and pragmatically-inferred contexts. Each word learning block for each context was proceeded by a brief, non-verbal animation that either primed the ToM system or did not engage ToM. We found that initial pragmatically-inferred meaning mapping was assisted specifically by priming ToM prior to word learning. Long-term word retention was strengthened for both pragmatically-inferred and directly-mapped words,when learning was preceded by a ToM video. These results demonstrate that ToM causally interacts with word learning processes and facilitates both encoding and retention. Our findings strengthen previous arguments that ToM plays a critical role in language development and broaden this to encompass lifelong vocabulary learning.

Language learning is a sophisticated process as learners need to detect and extract rich regularities embedded in the continuous speech inputs. Children, compared to adults, appear to learn languages more effortlessly. Nevertheless, early studies in implicit statistical learning revealed little developmental differences between children and adults. Recent work has found the speed of statistical learning in adults is associated with their neural sensitivity to probabilistic information in speech. It is not well understood, however, whether children share similar or different underlying neural processes for probabilistic information compared to adults. Specifically, are children similar to faster or slower adult statistical learners, or neither of them? In the current study, children aged between 5 and 12 completed a passive auditory oddball task, where they listened to syllables at different local and global frequency of occurrence. We used two neurophysiological measures, auditory mismatch responses (MMR) and late discriminative negativity (LDN) to compare children's sensitivity to distributional probabilities in speech with adults. We found that children were more sensitive to probabilistic information in speech inputs at both the local and the global level than both faster and slower adult statistical learners. Moreover, unlike adults who integrate probabilistic information across global and local hierarchies, children seem to process different levels of probabilistic information in parallel.

While the impact of social cognition on novel word learning has been extensively studied in monolingual populations, limited research has investigated its role in multilingual children with and without autism spectrum disorder. This study examined the role of multilingualism on the acquisition of novel English words under directly addressed and overhearing conditions. Participants included four groups of children with different language status (multilingual and monolingual and diagnostic status (typically developing and autistic). The results revealed that the learning preferences vary across participant groups depending on their language and diagnostic statuses. Additionally, dynamic patterns of novel word learning were unveiled, demonstrating the influence of English vocabulary proficiency on multilingual children's learning process. The findings highlighted the complex role of multilingualism on driving the formation of learning preference for typical developing and autistic children.