Dong Jianxin, Jing Bin, Ma Xiangyu, Liu Han, Mo Xiao, Li Haiyun
School of Biomedical Engineering, Capital Medical University, Beijing, China.
Yanjing Medical College, Capital Medical University, Beijing, China.
Front Neurosci. 2018 Feb 2;12:34. doi: 10.3389/fnins.2018.00034. eCollection 2018.
Exploring functional information among various brain regions across time enables understanding of healthy aging process and holds great promise for age-related brain disease diagnosis. This paper proposed a method to explore fractal complexity of the resting-state functional magnetic resonance imaging (rs-fMRI) signal in the human brain across the adult lifespan using Hurst exponent (HE). We took advantage of the examined rs-fMRI data from 116 adults 19 to 85 years of age (44.3 ± 19.4 years, 49 females) from NKI/Rockland sample. Region-wise and voxel-wise analyses were performed to investigate the effects of age, gender, and their interaction on complexity. In region-wise analysis, we found that the healthy aging is accompanied by a loss of complexity in frontal and parietal lobe and increased complexity in insula, limbic, and temporal lobe. Meanwhile, differences in HE between genders were found to be significant in parietal lobe ( = 0.04, corrected). However, there was no interaction between gender and age. In voxel-wise analysis, the significant complexity decrease with aging was found in frontal and parietal lobe, and complexity increase was found in insula, limbic lobe, occipital lobe, and temporal lobe with aging. Meanwhile, differences in HE between genders were found to be significant in frontal, parietal, and limbic lobe. Furthermore, we found age and sex interaction in right parahippocampal gyrus ( = 0.04, corrected). Our findings reveal HE variations of the rs-fMRI signal across the human adult lifespan and show that HE may serve as a new parameter to assess healthy aging process.
探索不同脑区随时间变化的功能信息，有助于理解健康衰老过程，并为与年龄相关的脑部疾病诊断带来巨大希望。本文提出了一种利用赫斯特指数（HE）来探索人类大脑在成年期静息态功能磁共振成像（rs-fMRI）信号分形复杂性的方法。我们利用了来自NKI/Rockland样本的116名19至85岁成年人（44.3±19.4岁，49名女性）的rs-fMRI数据。进行了区域层面和体素层面的分析，以研究年龄、性别及其相互作用对复杂性的影响。在区域层面分析中，我们发现健康衰老伴随着额叶和顶叶复杂性的降低以及岛叶、边缘叶和颞叶复杂性的增加。同时，发现性别之间在顶叶的HE差异具有显著性（ = 0.04，校正后）。然而，性别与年龄之间没有相互作用。在体素层面分析中，发现额叶和顶叶随着衰老复杂性显著降低，而岛叶、边缘叶、枕叶和颞叶随着衰老复杂性增加。同时，发现性别之间在额叶、顶叶和边缘叶的HE差异具有显著性。此外，我们在右侧海马旁回发现了年龄和性别的相互作用（ = 0.04，校正后）。我们的研究结果揭示了rs-fMRI信号在人类成年期的HE变化，并表明HE可作为评估健康衰老过程的一个新参数。
