Frequency-Resolved Connectome Hubs and Their Test-Retest Reliability in the Resting Human Brain
Lei Wang1,2,3 • Xiaodan Chen1,2,3 • Yuehua Xu1,2,3 • Miao Cao4,5 • Xuhong Liao6 • Yong He1,2,3,7
1 State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
2 Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal University, Beijing 100875, China
3 IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
4 Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200433, China
5 Key Laboratory of Computational Neuroscience and BrainInspired Intelligence (Fudan University), Ministry of Education, Shanghai 200433, China
6 School of Systems Science, Beijing Normal University, Beijing 100875, China
7 Chinese Institute for Brain Research, Beijing 102206, China
Abstract
Functional hubs with disproportionately extensive connectivities play a crucial role in global information integration in human brain networks. However, most resting-state functional magnetic resonance imaging (RfMRI) studies have identified functional hubs by examining spontaneous fluctuations of the blood oxygen level-dependent signal within a typical low-frequency band (e.g., 0.01–0.08 Hz or 0.01–0.1 Hz). Little is known about how the spatial distributions of functional hubs depend on frequency bands of interest. Here, we used repeatedly measured R-fMRI data from 53 healthy young adults and a degree centrality analysis to identify voxelwise frequencyresolved functional hubs and further examined their testretest reliability across two sessions. We showed that a wide-range frequency band (0.01–0.24 Hz) accessible with a typical sampling rate (fsample = 0.5 Hz) could be classified into three frequency bands with distinct patterns, namely, low-frequency (LF, 0.01–0.06 Hz), middle-frequency (MF, 0.06–0.16 Hz), and high-frequency (HF, 0.16–0.24 Hz) bands. The functional hubs were mainly located in the medial and lateral frontal and parietal cortices in the LF band, and in the medial prefrontal cortex, superior temporal gyrus, parahippocampal gyrus, amygdala, and several cerebellar regions in the MF and HF bands. These hub regions exhibited fair to good test-retest reliability, regardless of the frequency band. The presence of the three frequency bands was well replicated using an independent R-fMRI dataset from 45 healthy young adults. Our findings demonstrate reliable frequency-resolved functional connectivity hubs in three categories, thus providing insights into the frequency-specific connectome organization in healthy and disordered brains.
Keywords
Connectome; Hubs; Frequency; Degree centrality; Test-retest reliability
