Department of Applied Mathematics, College of Mathematics, Faculty of Science, Beijing University of Technology, Beijing 100124, China.
School of Psychology, Capital Normal University, Beijing 100048, China.
Neuroscience. 2023 Sep 15;528:117-128. doi: 10.1016/j.neuroscience.2023.07.032. Epub 2023 Aug 5.
Mapping variability in cortical spontaneous activity (CSA) is an essential goal of understanding various sources of dark brain energy in human neuroscience. CSA was traditionally characterized using resting-state functional MRI (rfMRI) at 1.5T or 3T magnets while recently with 7T-rfMRI. However, the utility and interpretability of 7T-rfMRI must first be established for its variability. By leveraging rfMRI data from the Human Connectome Project (HCP), we derived CSA metrics with 3T-rfMRI and 7T-rfMRI for the same 84 healthy participants (52 females). The 7T-rfMRI produces different CSA metrics at multiple spatial-scales and their variability from the 3T-rfMRI. These differences were spatially dependent and varied according to specific cortical organization. For the amplitude metric, 7T-rfMRI enhanced its spatial contrasts in the anterior cortex but weakened it in the posterior cortex. An opposite pattern was observed for the connectivity metrics. The reliability changes of these metrics were scale dependent, indicating enhanced reliability for connectivity but weakened reliability for amplitude by 7T-rfMRI. These effects were primarily located in the high-order associate cortex, parsing the corresponding changes in individual differences with respect to 7T-rfMRI: (1) higher connectivity variability between participants and the lower connectivity variability within individual participants, and (2) lower amplitude variability between participants and higher amplitude variability within participants. Our work, for the first time, demonstrated the variability of the human CSA across space, rfMRI settings/platforms, and individuals. We discussed the statistical implications of our findings on CSA-based experimental designs and reproducible neuroscience as well as their translational value for personalized applications.
绘制皮质自发活动（CSA）的变异性是理解人类神经科学中各种暗脑能量源的重要目标。CSA 传统上使用 1.5T 或 3T 磁体的静息态功能磁共振成像（rfMRI）进行特征描述，而最近则使用 7T-rfMRI。然而，为了其变异性，必须首先确定 7T-rfMRI 的实用性和可解释性。通过利用人类连接组计划（HCP）的 rfMRI 数据，我们为 84 名相同的健康参与者（52 名女性）从 3T-rfMRI 和 7T-rfMRI 中得出 CSA 指标。7T-rfMRI 在多个空间尺度上产生不同的 CSA 指标及其与 3T-rfMRI 的变异性。这些差异具有空间依赖性，并根据特定的皮质组织而变化。对于幅度指标，7T-rfMRI 增强了前皮质的空间对比度，但削弱了后皮质的空间对比度。连接性指标则观察到相反的模式。这些指标的可靠性变化具有尺度依赖性，表明 7T-rfMRI 增强了连接性的可靠性，但削弱了幅度的可靠性。这些影响主要位于高级联合皮质，解析了 7T-rfMRI 对个体差异的相应变化：（1）参与者之间的连接性变异性更高，个体内的连接性变异性更低，（2）参与者之间的幅度变异性更低，个体内的幅度变异性更高。我们的工作首次证明了 CSA 在空间、rfMRI 设置/平台和个体之间的变异性。我们讨论了我们在 CSA 为基础的实验设计和可重复神经科学以及个性化应用的转化价值方面的发现对 CSA 的统计意义。
