Douw Linda, Wakeman Daniel G, Tanaka Naoaki, Liu Hesheng, Stufflebeam Steven M
Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA; Department of Anatomy and Neurosciences, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA; Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA.
Neuroscience. 2016 Dec 17;339:12-21. doi: 10.1016/j.neuroscience.2016.09.034. Epub 2016 Sep 28.
The brain is a dynamic, flexible network that continuously reconfigures. However, the neural underpinnings of how state-dependent variability of dynamic functional connectivity (vdFC) relates to cognitive flexibility are unclear. We therefore investigated flexible functional connectivity during resting-state and task-state functional magnetic resonance imaging (rs-fMRI and t-fMRI, resp.) and performed separate, out-of-scanner neuropsychological testing. We hypothesize that state-dependent vdFC between the frontoparietal network (FPN) and the default mode network (DMN) relates to cognitive flexibility. Seventeen healthy subjects performed the Stroop color word test and underwent t-fMRI (Stroop computerized version) and rs-fMRI. Time series were extracted from a cortical atlas, and a sliding window approach was used to obtain a number of correlation matrices per subject. vdFC was defined as the standard deviation of connectivity strengths over these windows. Higher task-state FPN-DMN vdFC was associated with greater out-of-scanner cognitive flexibility, while the opposite relationship was present for resting-state FPN-DMN vdFC. Moreover, greater contrast between task-state and resting-state vdFC related to better cognitive performance. In conclusion, our results suggest that not only the dynamics of connectivity between these networks is seminal for optimal functioning, but also that the contrast between dynamics across states reflects cognitive performance.
大脑是一个不断重新配置的动态、灵活的网络。然而，动态功能连接性（vdFC）的状态依赖性变异性与认知灵活性之间的神经基础尚不清楚。因此，我们在静息态和任务态功能磁共振成像（分别为rs-fMRI和t-fMRI）期间研究了灵活的功能连接性，并进行了单独的、扫描仪外的神经心理学测试。我们假设额顶叶网络（FPN）和默认模式网络（DMN）之间的状态依赖性vdFC与认知灵活性有关。17名健康受试者进行了Stroop颜色词测试，并接受了t-fMRI（Stroop计算机化版本）和rs-fMRI检查。从皮质图谱中提取时间序列，并使用滑动窗口方法为每个受试者获得多个相关矩阵。vdFC被定义为这些窗口上连接强度的标准差。更高的任务态FPN-DMN vdFC与更高的扫描仪外认知灵活性相关，而静息态FPN-DMN vdFC则呈现相反的关系。此外，任务态和静息态vdFC之间的更大差异与更好的认知表现相关。总之，我们的结果表明，不仅这些网络之间连接的动态性对最佳功能至关重要，而且跨状态动态之间的差异也反映了认知表现。
