AUTHOR=Gao Chenyang , Shu Leijin , Li Ting 

TITLE=Studying hemispheric lateralization of 4-month-old infants from different language groups through near-infrared spectroscopy-based connectivity

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2022.1049719

DOI=10.3389/fpsyt.2022.1049719

ISSN=1664-0640

ABSTRACT=Early monolingual versus bilingual experience affects linguistic and cognitive processes during the first months of life, as well as functional activation patterns. The current study explored the influence of a bilingual environment in the first months of life on resting-state functional connectivity and reported no significant difference between language groups. To further explore the influence of a bilingual environment on brain development function, we used the resting-state functional near-infrared spectroscopy public dataset of the 4-month-old infant group in the sleep state (30 Spanish; 33 Basque; 36 bilingual). Wavelet transform coherence analysis, graph theory, and granger causality analysis were applied to the functional connectivity analysis in frontal regions. Our results showed that functional connectivity was significantly higher in the left hemisphere than in the right hemisphere in both monolingual and bilingual groups. This difference was more pronounced in the bilingual group. The graph theoretic analysis also showed that the characteristic path length was significantly higher in the left hemisphere than in the right hemisphere for the bilingual infant group. Contrary to the monolingual infant group, the left-to-right direction of information flow was found in the frontal regions of the bilingual infant group in the effective connectivity analysis. The results suggested that the left hemispheric lateralization of functional connectivity in frontal regions is more pronounced in the bilingual group compared to the monolingual group. Furthermore, effective connectivity analysis may be a useful method to investigate infants resting-state brain networks of infants.