Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07029, USA; School of Life Sciences and Technology, University of Electronic Science and Technology of China, Chengdu, China.
Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07029, USA; School of Life Sciences and Technology, University of Electronic Science and Technology of China, Chengdu, China.
Neuroimage. 2020 Aug 1;216:116698. doi: 10.1016/j.neuroimage.2020.116698. Epub 2020 Mar 1.
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.
脑区之间的功能交流被认为是动态的。然而，通常很难阐明观察到的动态连通性是否具有功能意义，或者仅仅是由于在不受约束的任务条件（如静息状态）下的噪声所致。在自然条件下，例如观看电影时，已经表明局部脑活动（例如在视觉皮层中）在受试者之间是一致的。基于类似的逻辑，我们建议研究自然条件下动态连通性的时间过程的受试者间相关性，以提取具有功能意义的动态连通性模式。我们分析了受试者观看短动画电影时的功能磁共振成像 (fMRI) 数据集。我们使用滑动窗口技术计算动态连通性，并量化了动态连通性的时间过程的受试者间相关性。尽管动态连通性的时间过程被认为比原始信号更嘈杂，但我们发现动态连通性的受试者间相关性与区域活动的受试者间相关性相似。最重要的是，在没有表现出区域活动高受试者间相关性的区域之间，以及在具有很少稳定功能连通性的区域之间，可能会出现高度一致的动态连通性。该分析突出了更高阶的大脑区域，例如默认模式网络，它们在观看电影期间与后部视觉区域动态交互，这可能与对电影的理解有关。
