Resting state fMRI (rsfMRI) is frequently used to study brain function, including in clinical populations. Similarity of blood-oxygen-level-dependent (BOLD) fluctuations during rsfMRI between brain regions is thought to reflect intrinsic functional connectivity (FC), potentially due to history of coactivation. To quantify similarity, studies have almost exclusively relied on Pearson correlation, which assumes linearity and can therefore underestimate FC if the hemodynamic response function differs regionally or there is BOLD signal lag between timeseries. Here we show in three cohorts of children, adolescents and adults, with and without autism spectrum disorders (ASDs), that measuring the similarity of BOLD signal fluctuations using non-linear dynamic time warping (DTW) is more robust to global signal regression (GSR), has higher test-retest reliability and is more sensitive to task-related changes in FC. Additionally, when comparing FC between individuals with ASDs and typical controls, more group differences are detected using DTW. DTW estimates are also more related to ASD symptom severity and executive function, while Pearson correlation estimates of FC are more strongly associated with respiration during rsfMRI. Together these findings suggest that non-linear methods such as DTW improve estimation of resting state FC, particularly when studying clinical populations whose hemodynamics or neurovascular coupling may be altered compared to typical controls.

中文翻译：

---

动态时间扭曲在检测自闭症谱系障碍的非典型功能连接方面优于皮尔逊相关性


静息态功能磁共振成像 (rsfMRI) 经常用于研究脑功能，包括临床人群的脑功能。 rsfMRI 期间大脑区域之间的血氧水平依赖性 (BOLD) 波动的相似性被认为反映了内在的功能连接 (FC)，可能是由于共激活的历史。为了量化相似性，研究几乎完全依赖皮尔逊相关性，皮尔逊相关性假设线性，因此如果血流动力学响应函数在区域内不同或时间序列之间存在 BOLD 信号滞后，则可能会低估 FC。在这里，我们在三组儿童、青少年和成人中展示，无论是否患有自闭症谱系障碍 (ASD)，使用非线性动态时间扭曲 (DTW) 测量 BOLD 信号波动的相似性对于全局信号回归 (GSR) 来说更加稳健。 ），具有更高的重测可靠性，并且对 FC 中与任务相关的变化更敏感。此外，当比较 ASD 个体和典型对照之间的 FC 时，使用 DTW 可以检测到更多的群体差异。 DTW 估计值也与 ASD 症状严重程度和执行功能更相关，而 FC 的 Pearson 相关估计值与 rsfMRI 期间的呼吸关系更密切。这些发现共同表明，DTW 等非线性方法可以改善静息态 FC 的估计，特别是在研究与典型对照相比其血流动力学或神经血管耦合可能发生改变的临床人群时。