Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.
Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana.
Hum Brain Mapp. 2018 Dec;39(12):4939-4948. doi: 10.1002/hbm.24335. Epub 2018 Aug 24.
During complex tasks, patterns of functional connectivity differ from those in the resting state. However, what accounts for such differences remains unclear. Brain activity during a task reflects an unknown mixture of spontaneous and task-evoked activities. The difference in functional connectivity between a task state and the resting state may reflect not only task-evoked functional connectivity, but also changes in spontaneously emerging networks. Here, we characterized the differences in apparent functional connectivity between the resting state and when human subjects were watching a naturalistic movie. Such differences were marginally explained by the task-evoked functional connectivity involved in processing the movie content. Instead, they were mostly attributable to changes in spontaneous networks driven by ongoing activity during the task. The execution of the task reduced the correlations in ongoing activity among different cortical networks, especially between the visual and non-visual sensory or motor cortices. Our results suggest that task-evoked activity is not independent from spontaneous activity, and that engaging in a task may suppress spontaneous activity and its inter-regional correlation.
在复杂任务中，功能连接模式与静息状态下的模式不同。然而，造成这种差异的原因尚不清楚。任务期间的大脑活动反映了自发活动和任务诱发活动的未知混合物。任务状态与静息状态之间功能连接的差异不仅可能反映任务诱发的功能连接，还可能反映自发出现的网络的变化。在这里，我们描述了人类受试者观看自然电影时静息状态与观看电影时的功能连接之间的差异。这些差异仅能部分用处理电影内容所涉及的任务诱发功能连接来解释。相反，它们主要归因于任务期间持续活动驱动的自发网络的变化。任务的执行降低了不同皮质网络之间的持续活动的相关性，尤其是在视觉和非视觉感觉或运动皮质之间。我们的研究结果表明，任务诱发的活动不是独立于自发活动的，并且进行任务可能会抑制自发活动及其区域间相关性。
