Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases, University Pablo de Olavide, Seville, Spain.
Neuroimage. 2012 Feb 15;59(4):3522-32. doi: 10.1016/j.neuroimage.2011.10.086. Epub 2011 Nov 7.
Graph theoretical analyses applied to neuroimaging datasets have provided valuable insights into the large-scale anatomical organization of the human neocortex. Most of these studies were performed with different cortical scales leading to cortical networks with different levels of small-world organization. The present study investigates how resolution of thickness-based cortical scales impacts on topological properties of human anatomical cortical networks. To this end, we designed a novel approach aimed at determining the best trade-off between small-world attributes of anatomical cortical networks and the number of cortical regions included in the scale. Results revealed that schemes comprising 540-599 regions (surface areas spanning between 250 and 275 mm(2)) at sparsities below 10% showed a superior balance between small-world organization and the size of the cortical scale employed. Furthermore, we found that the cortical scale representing the best trade-off (599 regions) was more resilient to targeted attacks than atlas-based schemes (Desikan-Killiany atlas, 66 regions) and, most importantly, it did not differ that much from the finest cortical scale tested in the present study (1494 regions). In summary, our study confirms that topological organization of anatomical cortical networks varies with both sparsity and resolution of cortical scale, and it further provides a novel methodological framework aimed at identifying cortical schemes that maximize small-worldness with the lowest scale resolution possible.
图论分析应用于神经影像学数据集为人类新皮质的大规模解剖结构组织提供了有价值的见解。这些研究大多是在不同的皮质尺度下进行的，导致皮质网络具有不同水平的小世界组织。本研究探讨了基于厚度的皮质尺度的分辨率如何影响人类解剖皮质网络的拓扑性质。为此，我们设计了一种新方法，旨在确定解剖皮质网络的小世界属性和包含在尺度中的皮质区域数量之间的最佳权衡。结果表明，在稀疏度低于 10%的情况下，包含 540-599 个区域（表面积在 250 到 275mm²之间）的方案在小世界组织和使用的皮质尺度大小之间表现出更好的平衡。此外，我们发现，代表最佳权衡的皮质尺度（599 个区域）比基于图谱的方案（Desikan-Killiany 图谱，66 个区域）更能抵抗有针对性的攻击，最重要的是，它与本研究中测试的最细皮质尺度（1494 个区域）并没有太大的区别。总之，我们的研究证实，解剖皮质网络的拓扑组织不仅随稀疏度而且随皮质尺度的分辨率而变化，并且进一步提供了一种新的方法学框架，旨在确定以最低的尺度分辨率最大化小世界的皮质方案。
