Phyllis Green and Randolph Cōwen Institute for Pediatric Neuroscience, NYU Child Study Center, New York, NY 10016, USA.
Cereb Cortex. 2013 Jan;23(1):223-9. doi: 10.1093/cercor/bhs010. Epub 2012 Jan 31.
The brain's intrinsic functional architecture, revealed in correlated spontaneous activity, appears to constitute a faithful representation of its repertoire of evoked, extrinsic functional interactions. Here, using broad task contrasts to probe evoked patterns of coactivation, we demonstrate tight coupling between the brain's intrinsic and extrinsic functional architectures for default and task-positive regions, but not for subcortical and limbic regions or for primary sensory and motor cortices. While strong correspondence likely reflects persistent or recurrent patterns of evoked coactivation, weak correspondence may exist for regions whose patterns of evoked functional interactions are more adaptive and context dependent. These findings were independent of task. For tight task contrasts (e.g., incongruent vs. congruent trials), evoked patterns of coactivation were unrelated to the intrinsic functional architecture, suggesting that high-level task demands are accommodated by context-specific modulations of functional interactions. We conclude that intrinsic approaches provide only a partial understanding of the brain's functional architecture. Appreciating the full repertoire of dynamic neural responses will continue to require task-based functional magnetic resonance imaging approaches.
大脑内在的功能结构,在相关的自发活动中显现出来,似乎构成了其外在诱发功能相互作用的忠实表现。在这里,我们使用广泛的任务对比来探测诱发的共激活模式,证明了默认和任务正性区域的大脑内在和外在功能结构之间的紧密耦合,但亚皮质和边缘区域或初级感觉和运动皮质之间没有这种耦合。虽然强对应关系可能反映了诱发共激活的持续或反复模式,但对于那些诱发功能相互作用模式更具适应性和依赖于上下文的区域,可能存在弱对应关系。这些发现与任务无关。对于紧密的任务对比(例如,不一致与一致的试验),共激活的诱发模式与内在功能结构无关,这表明高级任务需求是通过功能相互作用的特定于上下文的调制来适应的。我们得出结论,内在方法仅提供了对大脑功能结构的部分理解。要全面了解动态神经反应,将继续需要基于任务的功能磁共振成像方法。