Koten Jan Willem, Manner Hans, Pernet Cyril, Schüppen Andre, Szücs Dénes, Wood Guilherme, Ioannidis John P A
Institute of Psychology, University of Graz, Graz, Austria.
Department of Economics, University of Graz, Graz, Austria.
PLoS One. 2024 Dec 13;19(12):e0299753. doi: 10.1371/journal.pone.0299753. eCollection 2024.
The level of correlation between two phenomena is limited by the accuracy at which these phenomena are measured. Despite numerous group reliability studies, the strength of the fMRI connectivity that can be detected given the within-subject time course reliability remains elusive. Moreover, it is unclear how within-subject time course reliability limits the robust detection of connectivity on the group level. We estimated connectivity from a working memory task. The grand mean connectivity of the connectome equaled r = 0.41 (95% CI 0.31-0.50) for the test run and r = 0.40 (95% CI 0.29-0.49) for the retest run. The mean connectivity decreased to r = 0.09 (95% CI 0.03-0.16) when test-retest reliability and auto-correlations of single time courses were considered, indicating that less than a quarter of connectivity is detectable. The square root of the detectable connectivity r = 0.09 suggests that only 0.81% of the connectivity is explained by working memory-related time course fluctuations. Null hypothesis significance testing (NHST)-based analysis revealed that within-subject time course reliability markedly affects the significance levels at which paths can be detected at the group level. This was in particular the case when samples were small or connectome coordinates were randomly selected. With a sample of 50 individuals, the connectome of a test session was completely reproduced in a retest session at P < 2.54e-6 despite the fact that almost no connectivity was explained by the cognitive experiment. Within-subject time course reliability can offer valuable insights on the detectable connectivity and should be assessed more frequently.
两种现象之间的相关程度受这些现象测量精度的限制。尽管有大量的组内信度研究，但在考虑个体内部时间进程信度的情况下，能检测到的功能磁共振成像（fMRI）连接强度仍不明确。此外，个体内部时间进程信度如何在组水平上限制连接性的稳健检测尚不清楚。我们从一个工作记忆任务中估计连接性。测试运行时，连接组的总体平均连接性r = 0.41（95%置信区间0.31 - 0.50），重测运行时r = 0.40（95%置信区间0.29 - 0.49）。当考虑重测信度和单个时间进程的自相关时，平均连接性降至r = 0.09（95%置信区间0.03 - 0.16），这表明可检测到的连接性不到四分之一。可检测连接性r = 0.09的平方根表明，只有0.81%的连接性可由与工作记忆相关的时间进程波动来解释。基于零假设显著性检验（NHST）的分析表明，个体内部时间进程信度显著影响在组水平上可检测到路径的显著性水平。当样本量较小或随机选择连接组坐标时，情况尤其如此。在有50名个体的样本中，尽管认知实验几乎无法解释连接性，但在重测会话中，测试会话的连接组在P < 2.54e - 6时被完全重现。个体内部时间进程信度可为可检测的连接性提供有价值的见解，应更频繁地进行评估。
