title: Hemisphere- and gender-related differences in small-world brain networks: a resting-state functional MRI study.
abstract: We employed resting-state functional MRI (R-fMRI) to investigate hemisphere- and gender-related differences in the topological organization of human brain functional networks. Brain networks were first constructed by measuring inter-regional temporal correlations of R-fMRI data within each hemisphere in 86 young, healthy, right-handed adults (38 males and 48 females) followed by a graph-theory analysis. The hemispheric networks exhibit small-world attributes (high clustering and short paths) that are compatible with previous results in the whole-brain functional networks. Furthermore, we found that compared with females, males have a higher normalized clustering coefficient in the right hemispheric network but a lower clustering coefficient in the left hemispheric network, suggesting a gender-hemisphere interaction. Moreover, we observed significant hemisphere-related differences in the regional nodal characteristics in various brain regions, such as the frontal and occipital regions (leftward asymmetry) and the temporal regions (rightward asymmetry), findings that are consistent with previous studies of brain structural and functional asymmetries. Together, our results suggest that the topological organization of human brain functional networks is associated with gender and hemispheres, and they provide insights into the understanding of functional substrates underlying individual differences in behaviors and cognition.
authors.affiliation: Department of Biomedical Engineering, School of Computer Science and Information Technology, Beijing Jiaotong University, Beijing, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Tian
authors.forename: Jinhui
authors.initials: J
authors.lastname: Wang
authors.forename: Chaogan
authors.initials: C
authors.lastname: Yan
authors.forename: Yong
authors.initials: Y
authors.lastname: He
mesh_terms: D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009415:Nerve Net; D012727:Sex Characteristics; D055815:Young Adult