Adaptive reconfiguration of fractal small-world human brain functional networks

被引:590
作者
Bassettt, Danielle S.
Meyer-Lindenberg, Andreas [1 ]
Achard, Sophie
Duke, Thomas
Bullmore, Edward T.
机构
[1] NIMH, Unit Syst Neurosci Psychiat Genes Cognit, NIH, Bethesda, MD 20892 USA
[2] NIMH, Psychosis Program, NIH, Bethesda, MD 20892 USA
[3] Univ Cambridge, Addenbrookes Hosp, Dept Psychiat, Brain Mappin Unit, Cambridge CB2 2QQ, England
[4] Univ Cambridge, Cavendish Lab, Dept Phys, Cambridge CB3 0HE, England
基金
英国医学研究理事会;
关键词
magnetoencephalography; wavelet; graph theory; connectivity; binding;
D O I
10.1073/pnas.0606005103
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Brain function depends on adaptive self-organization of large-scale neural assemblies, but little is known about quantitative network parameters governing these processes in humans. Here, we describe the topology and synchronizability of frequency-specific brain functional networks using wavelet decomposition of magnetoencephalographic time series, followed by construction and analysis of undirected graphs. Magnetoencephalographic data were acquired from 22 subjects, half of whom performed a finger-tapping task, whereas the other half were studied at rest. We found that brain functional networks were characterized by small-world properties at all six wavelet scales considered, corresponding approximately to classical delta (low and high), theta, alpha, beta, and gamma frequency bands. Global topological parameters (path length, clustering) were conserved across scales, most consistently in the frequency range 2-37 Hz, implying a scale-invariant or fractal small-world organization. Dynamical analysis showed that networks were located close to the threshold of order/disorder transition in all frequency bands. The highest-frequency gamma network had greater synchronizability, greater clustering of connections, and shorter path length than networks in the scaling regime of (lower) frequencies. Behavioral state did not strongly influence global topology or synchronizability; however, motor task performance was associated with emergence of long-range connections in both beta and gamma networks. Long-range connectivity, e.g., between frontal and parietal cortex, at high frequencies during a motor task may facilitate sensorimotor binding. Human brain functional networks demonstrate a fractal small-world architecture that supports critical dynamics and task-related spatial reconfiguration while preserving global topological parameters.
引用
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页码:19518 / 19523
页数:6
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