Tanner Jacob C, Faskowitz Joshua, Byrge Lisa, Kennedy Daniel P, Sporns Olaf, Betzel Richard F
Cognitive Science Program, Indiana University, Bloomington, IN, United States.
School of Informatics, Computing, and Engineering, Indiana University, Bloomington, IN, United States.
Imaging Neurosci (Camb). 2023 Nov 7;1. doi: 10.1162/imag_a_00026. eCollection 2023.
Recent studies have shown that functional connectivity can be decomposed into its exact frame-wise contributions, revealing short-lived, infrequent, and high-amplitude time points referred to as "events." Events contribute disproportionately to the time-averaged connectivity pattern, improve identifiability and brain-behavior associations, and differences in their expression have been linked to endogenous hormonal fluctuations and autism. Here, we explore the characteristics of events while subjects watch movies. Using two independently-acquired imaging datasets in which participants passively watched movies, we find that events synchronize across individuals and based on the level of synchronization, can be categorized into three distinct classes: those that synchronize at the boundaries between movies, those that synchronize during movies, and those that do not synchronize at all. We find that boundary events, compared to the other categories, exhibit greater amplitude, distinct co-fluctuation patterns, and temporal propagation. We show that underlying boundary events is a specific mode of co-fluctuation involving the activation of control and salience systems alongside the deactivation of visual systems. Events that synchronize during the movie, on the other hand, display a pattern of co-fluctuation that is time-locked to the movie stimulus. Finally, we found that subjects' time-varying brain networks are most similar to one another during these synchronous events.
近期研究表明，功能连接性可被分解为其精确的逐帧贡献，从而揭示出被称为“事件”的短暂、罕见且高振幅的时间点。事件对时间平均连接模式的贡献不成比例，改善了可识别性以及脑与行为的关联，并且其表达差异与内源性激素波动和自闭症有关。在此，我们在受试者观看电影时探究事件的特征。利用两个独立获取的成像数据集，其中参与者被动观看电影，我们发现事件在个体间同步，并且基于同步水平可被分为三个不同类别：在电影边界同步的事件、在电影期间同步的事件以及完全不同步的事件。我们发现，与其他类别相比，边界事件表现出更大的振幅、独特的共同波动模式以及时间传播。我们表明，边界事件的潜在机制是一种特定的共同波动模式，涉及控制和显著性系统的激活以及视觉系统的失活。另一方面，在电影期间同步的事件显示出一种与电影刺激时间锁定的共同波动模式。最后，我们发现受试者随时间变化的脑网络在这些同步事件期间彼此最为相似。
