The representation of category typicality in the frontal cortex and its cross-linguistic variations

What's in a word? Cross-linguistic influences on Spanish-English and Chinese-English bilingual children's word reading development

This study investigates the cross-linguistic transfer of literacy skills in Spanish-English, Chinese-English bilingual, and English monolingual children (N = 283, 5-10 years). Research question 1 examines English literacy and asks how phonological and morpho-semantic skills contribute to word reading as a function of children's language background. Structural equation modeling revealed contrasting bilingual effects: compared to English monolinguals, Spanish-English bilinguals relied more on phonological awareness in word reading, whereas Chinese-English bilinguals relied more on lexical knowledge. Research question 2 examines relations between bilinguals' heritage language proficiency and English literacy. Results revealed direct and indirect effects of heritage language meta-linguistic skills on English word reading. The study yields implications for reading theories and instructional practices in optimizing literacy in linguistically diverse children.

Chinese-English bilinguals show linguistic-perceptual links in the brain associating short spoken phrases with corresponding real-world natural action sounds by semantic category

Higher cognitive functions such as linguistic comprehension must ultimately relate to perceptual systems in the brain, though how and why this forms remains unclear. Different brain networks that mediate perception when hearing real-world natural sounds has recently been proposed to respect a taxonomic model of acoustic-semantic categories. Using functional magnetic resonance imaging (fMRI) with Chinese/English bilingual listeners, the present study explored whether reception of short spoken phrases, in both Chinese (Mandarin) and English, describing corresponding sound-producing events would engage overlapping brain regions at a semantic category level. The results revealed a double-dissociation of cortical regions that were preferential for representing knowledge of human versus environmental action events, whether conveyed through natural sounds or the corresponding spoken phrases depicted by either language. These findings of cortical hubs exhibiting linguistic-perceptual knowledge links at a semantic category level should help to advance neurocomputational models of the neurodevelopment of language systems.

Psychological resilience negatively correlates with resting-state brain network flexibility in young healthy adults: a dynamic functional magnetic resonance imaging study

Background

Psychological resilience is an important personality trait whose decrease is associated with many common psychiatric disorders, but the neural mechanisms underlying it remain largely unclear. In this study, we aimed to explore the neural correlates of psychological resilience in healthy adults by investigating its relationship with functional brain network flexibility, a fundamental dynamic feature of brain network defined by switching frequency of its modular community structures.

Methods

Resting-state functional magnetic resonance imaging (fMRI) scans were acquired from 41 healthy adults, whose psychological resilience was quantified by the Connor-Davidson Resilience Scale (CD-RISC). Dynamic functional brain network was constructed for each subject, whose flexibility was calculated at all the global, subnetwork and region-of-interest (ROI) levels. After that, the associations between CD-RISC score and brain network flexibility were assessed at all levels by partial correlations controlling for age, sex, education and head motion. Correlation was also tested between the CD-RISC score and modularity of conventional static brain network for comparative purposes.

Results

The CD-RISC score was significant negatively correlated with the brain network flexibility at global level (r=-0.533, P=0.001), and with flexibility of the visual subnetwork at subnetwork level (r=-0.576, corrected P=0.002). Moreover, significant (corrected P<0.05) or trends for (corrected P<0.10) negative correlations were found between the CD-RISC score and flexibilities of a number of visual and default-mode areas at ROI level. Meanwhile, the modularity of static brain network did not reveal significant correlation with CD-RISC score (P>0.05).

Conclusions

Our results suggest that excessive fluctuations of the functional brain community structures during rest may be indicative of a lower psychological resilience, and the visual and default-mode systems may play crucial roles in such relationship. These findings may provide important implications for improving our understanding of the psychological resilience.