The functional communications between brain regions are thought to be dynamic. However, it is usually difficult to elucidate whether the observed dynamic connectivity is functionally meaningful or simply due to noise during unconstrained task conditions such as resting-state. During naturalistic conditions, such as watching a movie, it has been shown that local brain activities, e.g. in the visual cortex, are consistent across subjects. Following similar logic, we propose to study intersubject correlations of the time courses of dynamic connectivity during naturalistic conditions to extract functionally meaningful dynamic connectivity patterns. We analyzed a functional MRI (fMRI) dataset when the subjects watched a short animated movie. We calculated dynamic connectivity by using sliding window technique, and quantified the intersubject correlations of the time courses of dynamic connectivity. Although the time courses of dynamic connectivity are thought to be noisier than the original signals, we found similar level of intersubject correlations of dynamic connectivity to those of regional activity. Most importantly, highly consistent dynamic connectivity could occur between regions that did not show high intersubject correlations of regional activity, and between regions with little stable functional connectivity. The analysis highlighted higher order brain regions such as the default mode network that dynamically interacted with posterior visual regions during the movie watching, which may be associated with the understanding of the movie.

中文翻译：

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功能性 MRI 显示自然视觉期间受试者间一致的动态连接

大脑区域之间的功能通信被认为是动态的。然而，通常很难阐明观察到的动态连接是否具有功能意义，或者仅仅是由于不受约束的任务条件（例如静息状态）期间的噪声所致。在自然条件下，例如观看电影，研究表明，局部大脑活动（例如视觉皮层）在不同受试者之间是一致的。遵循类似的逻辑，我们建议研究自然条件下动态连接时间过程的主体间相关性，以提取具有功能意义的动态连接模式。当受试者观看一部动画短片时，我们分析了功能性 MRI (fMRI) 数据集。我们利用滑动窗口技术计算动态连通性，并量化动态连通性时间过程的主体间相关性。尽管动态连通性的时间进程被认为比原始信号噪声更大，但我们发现动态连通性的主体间相关性与区域活动的主体间相关性水平相似。最重要的是，高度一致的动态连接可能发生在区域活动没有表现出高主体间相关性的区域之间，以及几乎没有稳定功能连接的区域之间。该分析强调了更高阶的大脑区域，例如在观看电影期间与后视觉区域动态交互的默认模式网络，这可能与对电影的理解有关。