Yan Chao-Gan, Yang Zhen, Colcombe Stanley J, Zuo Xi-Nian, Milham Michael P
CAS Key Laboratory of Behavioral Science, Institute of Psychology, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Center for Lifespan Innovation of Mind and Brain, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Child and Adolescent Psychiatry, NYU Langone Medical Center School of Medicine, New York, NY 10016, USA.
Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Center for Neuromodulation in Depression and Stress, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Child Mind Institute, New York, NY 10022, USA.
Sci Bull (Beijing). 2017 Dec 15;62(23):1572-1584. doi: 10.1016/j.scib.2017.09.015. Epub 2017 Oct 18.
Various resting-state fMRI (R-fMRI) measures have been developed to characterize intrinsic brain activity. While each of these measures has gained a growing presence in the literature, questions remain regarding the common and unique aspects these indices capture. The present work provided a comprehensive examination of inter-individual variation and intra-individual temporal variation for commonly used measures, including fractional amplitude of low frequency fluctuations, regional homogeneity, voxel-mirrored homotopic connectivity, network centrality and global signal correlation. Regardless of whether examining intra-individual or inter-individual variation, we found that these definitionally distinct R-fMRI indices tend to exhibit a relatively high degree of covariation, which doesn't exist in phase randomized surrogate data. As a measure of intrinsic brain function, concordance for R-fMRI indices was negatively correlated with age across individuals (i.e., concordance among functional indices decreased with age). To understand the functional significance of concordance, we noted that higher concordance was generally associated with higher strengths of R-fMRI indices, regardless of whether looking through the lens of inter-individual (i.e., high vs. low concordance participants) or intra-individual (i.e., high vs. low concordance states identified via temporal dynamic analyses) differences. We also noted a linear increase in functional concordance together with the R-fMRI indices through the scan, which may suggest a decrease in arousal. The current study demonstrated an enriched picture regarding the relationship among the R-fMRI indices, as well as provided new insights in examining dynamic states within and between individuals.
为了描述大脑的内在活动，人们开发了各种静息态功能磁共振成像（R-fMRI）测量方法。虽然这些测量方法在文献中越来越常见，但关于这些指标所捕捉的共同和独特方面仍存在问题。本研究对常用测量方法的个体间差异和个体内时间变化进行了全面考察，这些方法包括低频波动分数幅值、局部一致性、体素镜像同伦连接性、网络中心性和全局信号相关性。无论考察个体内还是个体间的差异，我们发现这些定义上不同的R-fMRI指标往往表现出相对较高程度的协变，而这在相位随机替代数据中并不存在。作为一种大脑内在功能的测量方法，R-fMRI指标的一致性在个体间与年龄呈负相关（即功能指标之间的一致性随年龄增长而降低）。为了理解一致性的功能意义，我们注意到，无论从个体间差异（即高一致性与低一致性参与者）还是个体内差异（即通过时间动态分析确定的高一致性与低一致性状态）的角度来看，较高的一致性通常与较高强度的R-fMRI指标相关。我们还注意到，在扫描过程中，功能一致性与R-fMRI指标一起呈线性增加，这可能表明唤醒水平降低。本研究展示了一幅关于R-fMRI指标之间关系的丰富图景，并为研究个体内部和个体之间的动态状态提供了新的见解。
