Functional near-infrared spectroscopy evidence for the development of topological asymmetry between hemispheric brain networks from childhood to adulthood.

Lin Cai,Qi Dong,Mengjing Wang,Haijing Niu

doi:10.1117/1.nph.6.2.025005

Abstract

Cerebral asymmetry is considered an important marker of the successful development of the human brain. Recent studies have demonstrated topological asymmetries between structurally hemispheric networks in the human brain. However, it remains largely unknown whether and how the functionally topological asymmetries evolve from childhood to adulthood, a critical period that constitutes the primary peak of human brain and cognitive development. Here, we adopted resting-state functional near-infrared spectroscopy imaging data to construct hemispheric functional networks and then applied graph theory analysis to quantify the topological characteristics of the hemispheric networks. We found that the adult group exhibited consistent leftward hemispheric asymmetries in both global and local network efficiency, and the degree of leftward asymmetry in local network efficiency was significantly increased with development from childhood to adulthood. At the nodal level, the degree of leftward asymmetry in nodal efficiency, mainly involving the frontal, parietal-occipital junction, and occipital regions, increased with development. These developmental patterns of topological asymmetries suggest that the protracted maturation of functional segregation in the left hemisphere could underlie language development from childhood to adulthood and provide insight into the development of human brain functional networks.

Highlights

IntroductionHemispheric asymmetries are fundamental organizational principles of the human brain that are presumed to contribute to fast, efficient information processing, and the specific functions of language and reasoning in humans.[1,2,3] Evidence shows that the asymmetries between two brain hemispheres might be altered in states of psychiatric or neurological disease, such as autism spectrum disorder[4,5] and attention-deficit hyperactivity disorder.[6,7] healthy individuals exhibit dynamic changes in brain asymmetries throughout the lifespan.[8,9,10,11,12] These findings provide valuable information for understanding underlying pathological mechanisms and lateralized cognitive processes, such as language and motor control.Recently, neuroimaging techniques have been widely applied to human brain network studies
We found leftward asymmetry in hemispheric network efficiency and noted that the degree of leftward hemispheric asymmetry in network local efficiency significantly increased with development
With a functional optical imaging technique, we found that the hemispheric brain showed leftward asymmetries in hemispheric network efficiency, which indicates that the left hemisphere in children and adults exhibited more efficient functional segregation and integration than the right hemisphere to adapt to left-lateralized functional needs

Summary

Introduction

Hemispheric asymmetries are fundamental organizational principles of the human brain that are presumed to contribute to fast, efficient information processing, and the specific functions of language and reasoning in humans.[1,2,3] Evidence shows that the asymmetries between two brain hemispheres might be altered in states of psychiatric or neurological disease, such as autism spectrum disorder[4,5] and attention-deficit hyperactivity disorder.[6,7] healthy individuals exhibit dynamic changes in brain asymmetries throughout the lifespan.[8,9,10,11,12] These findings provide valuable information for understanding underlying pathological mechanisms and lateralized cognitive processes, such as language and motor control.Recently, neuroimaging techniques have been widely applied to human brain network studies. By constructing brain networks within a hemisphere, many studies have demonstrated significant topological asymmetry between hemispheric networks across different age spectra, such as in neonates,[13] adults,[14] and elderly participants.[15] from a developmental perspective, Zhong et al examined the change in structurally topological asymmetry of the hemispheric brain network from adolescence to young adulthood.[16] The authors found that both adolescents and adults showed rightward asymmetry in network efficiency, and the asymmetry significantly decreased over

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