Morphological awareness and its role in early word reading in English monolinguals, Spanish-English, and Chinese-English simultaneous bilinguals

Do French speakers have an advantage in learning English vocabulary thanks to familiar suffixes?

Previous research has shown that languages from nearby families are easier to learn as second languages (L2) than languages from more distant families, attributing this difference to the presence of shared elements between the native language (L1) and L2. Building on this idea, we hypothesised that suffixes present in L1 might facilitate complex word acquisition in L2. To test this hypothesis, we recruited 76 late French-English bilinguals and tasked them with learning a set of 80 English-derived words containing suffixes that also exist in French (e.g., -able) or are unique to English (e.g., -ness). Consolidation of the learned words was assessed 1 week after the last learning session. The results showed a significant learning effect across the learning trials and consolidation, suggesting that the bilingual participants were able to acquire the derived words. However, contrary to our hypothesis, suffixes also existing in French did not give a significant advantage over English-unique suffixes. Further analysis revealed that this was due to variations in the consistency of familiar suffixes from L1. While some translation pairs shared the same suffix (e.g., amazement-étonnement), others had different suffixes (e.g., slippage-glissement). The type of translation pair with inconsistent suffix overlap (slippage-glissement) carried learning costs, preventing the bilingual participants from benefitting from the presence of familiar suffixes in L2 words. These findings suggest that shared information can be used effectively for L2 learning only if the mapping between L1 and L2 is consistent.

Brain bases of morphological awareness and longitudinal word reading outcomes

Children's spoken language skills are essential to the development of the "reading brain," or the neurocognitive systems that underlie successful literacy. Morphological awareness, or sensitivity to the smallest units of meaning, is a language skill that facilitates fluent recognition of meaning in print. Yet despite the growing evidence that morphology is integral to literacy success, associations among morphological awareness, literacy acquisition, and brain development remain largely unexplored. To address this gap, we conducted a longitudinal investigation with 75 elementary school children (5-11 years of age) who completed an auditory morphological awareness neuroimaging task at Time 1 as well as literacy assessments at both Time 1 and Time 2 (1.5 years later). Findings reveal longitudinal brain-behavior associations between morphological processing at Time 1 and reading outcomes at Time 2. First, activation in superior temporal brain regions involved in word segmentation was associated with both future reading skill and steeper reading gains over time. Second, a wider array of brain regions across the language network were associated with polymorphemic word reading as compared with broader word reading skill (reading both simple and complex words). Together, these findings reinforce the importance of word segmentation skills in learning to read and highlight the importance of considering complex word reading skills in building comprehensive neurocognitive models of literacy. This study fills a gap in our knowledge of how processing meaningful units in speech may help to explain differences in children's reading development over time and informs ongoing theoretical questions about the role of morphology in learning to read.

Shared and distinct neural correlates of first and second language morphological processing in bilingual brain

While morphology constitutes a crucial component of the human language system, the neural bases of morphological processing in the human brain remains to be elucidated. The current study aims at exploring the extent to which the second language (L2) morphological processing would resemble or differ from that of their first language (L1) in adult Chinese-English bilinguals. Bilingual participants were asked to complete a morphological priming lexical decision task drawing on derivational morphology, which is present for both Chinese and English, when their electrophysiological and optical responses were recorded concurrently. Functional near-infrared spectroscopy (fNIRS) revealed a neural dissociation between morphological and semantic priming effects in the left fronto-temporal network, while L1 Chinese engaged enhanced activation in the left prefrontal cortex for morphological parsing relative to L2 English. In the early stage of lexical processing, cross-language morphological processing manifested a difference in degree, not in kind, as revealed by the early left anterior negativity (ELAN) effect. In addition, L1 and L2 shared both early and late structural parsing processes (P250 and 300 ~ 500 ms negativity, respectively). Therefore, the current results support a unified competition model for bilingual development, where bilinguals would primarily employ L1 neural resources for L2 morphological representation and processing.

Sources of Heterogeneity in Functional Connectivity During English Word Processing in Bilingual and Monolingual Children

Diversity and variation in language experiences, such as bilingualism, contribute to heterogeneity in children's neural organization for language and brain development. To uncover sources of such heterogeneity in children's neural language networks, the present study examined the effects of bilingual proficiency on children's neural organization for language function. To do so, we took an innovative person-specific analytical approach to investigate young Chinese-English and Spanish-English bilingual learners of structurally distinct languages. Bilingual and English monolingual children (N = 152, M(SD)age = 7.71(1.32)) completed an English word recognition task during functional near-infrared spectroscopy neuroimaging, along with language and literacy tasks in each of their languages. Two key findings emerged. First, bilinguals' heritage language proficiency (Chinese or Spanish) made a unique contribution to children's language network density. Second, the findings reveal common and unique patterns in children's patterns of task-related functional connectivity. Common across all participants were short-distance neural connections within left hemisphere regions associated with semantic processes (within middle temporal and frontal regions). Unique to more proficient language users were additional long-distance connections between frontal, temporal, and bilateral regions within the broader language network. The study informs neurodevelopmental theories of language by revealing the effects of heterogeneity in language proficiency and experiences on the structure and quality of emerging language neural networks in linguistically diverse learners.