Posted by Annapaola Prestia Laboratory of Epidemiology Neuroimaging and Telemedicine, IRCCS Centro San Giovanni di Dio FBF, The National Centre for Research and Care of Alzheimer’s and Mental Diseases, Brescia, Italy

The structural asymmetries of the brain have been well-documented. Functional asymmetries of the brain have been repeatedly reported in a variety of functions such as language, motor, and visuospatial processing. Despite the advances in brain asymmetry research, however, little is known about whether there are differences in the topological organization of brain networks between the hemispheres and whether those differences are related to gender. In this study authors employed resting-state functionalMRI (R-fMRI) to investigate hemisphere- and gender-related differences in the topological organization of human brain functional networks. Brain networks were 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). The main findings are as follows: 1) the hemispheric networks exhibited small-world attributes (high clustering and short paths); 2) males tended to be more locally efficient in their right hemispheric networks, but females tended to be more locally efficient in their left hemispheric networks. In conclusion this study observed that males and females have quite different asymmetric patterns in their network local efficiencies and suggest that these differences are closely related to the behavioural differences.

September 20^th, 2011