Department of Psychology, Yale University, USA.
Department of Psychology, Yale University, USA.
Neuroimage. 2019 Mar;188:14-25. doi: 10.1016/j.neuroimage.2018.11.057. Epub 2018 Dec 3.
Dynamic functional connectivity (DFC) aims to maximize resolvable information from functional brain scans by considering temporal changes in network structure. Recent work has demonstrated that static, i.e. time-invariant resting-state and task-based FC predicts individual differences in behavior, including attention. Here, we show that DFC predicts attention performance across individuals. Sliding-window FC matrices were generated from fMRI data collected during rest and attention task performance by calculating Pearson's r between every pair of nodes of a whole-brain atlas within overlapping 10-60s time segments. Next, variance in r values across windows was taken to quantify temporal variability in the strength of each connection, resulting in a DFC connectome for each individual. In a leave-one-subject-out-cross-validation approach, partial-least-square-regression (PLSR) models were then trained to predict attention task performance from DFC matrices. Predicted and observed attention scores were significantly correlated, indicating successful out-of-sample predictions across rest and task conditions. Combining DFC and static FC features numerically improves predictions over either model alone, but the improvement was not statistically significant. Moreover, dynamic and combined models generalized to two independent data sets (participants performing the Attention Network Task and the stop-signal task). Edges with significant PLSR coefficients concentrated in visual, motor, and executive-control brain networks; moreover, most of these coefficients were negative. Thus, better attention may rely on more stable, i.e. less variable, information flow between brain regions.
动态功能连接(DFC)旨在通过考虑网络结构的时间变化来最大化从功能脑扫描中获得的可分辨信息。最近的研究表明,静态的,即不变的静息状态和基于任务的 FC 可以预测行为的个体差异,包括注意力。在这里,我们表明 DFC 可以预测个体之间的注意力表现。通过在重叠的 10-60 秒时间片段内计算全脑图谱中每个节点对之间的 Pearson r,从 fMRI 数据中生成滑动窗口 FC 矩阵,用于静息和注意任务性能。接下来,取窗口之间 r 值的方差来量化每个连接强度的时间变异性,从而为每个个体生成 DFC 连接组。然后,采用留一受试者外交叉验证方法,用偏最小二乘回归(PLSR)模型从 DFC 矩阵中预测注意力任务表现。预测和观察到的注意力评分显著相关,表明在休息和任务条件下都能成功进行样本外预测。将 DFC 和静态 FC 特征相结合可以在数值上提高预测精度,优于单独使用任何一种模型,但这种提高在统计学上并不显著。此外,动态和组合模型还可以推广到两个独立的数据集(执行注意力网络任务和停止信号任务的参与者)。具有显著 PLSR 系数的边缘集中在视觉、运动和执行控制脑网络中;此外,这些系数大多数为负。因此,更好的注意力可能依赖于大脑区域之间更稳定的,即变化较小的信息流。