Frequency specificity of regional homogeneity in the resting-state human brain

PLoS One. 2014 Jan 23;9(1):e86818. doi: 10.1371/journal.pone.0086818. eCollection 2014.

Abstract

Resting state-fMRI studies have found that the inter-areal correlations in cortical networks concentrate within ultra-low frequencies (0.01-0.04 Hz) while long-distance connections within subcortical networks distribute over a wider frequency range (0.01-0.14 Hz). However, the frequency characteristics of regional homogeneity (ReHo) in different areas are still unclear. To examine the ReHo properties in different frequency bands, a data-driven method, Empirical Mode Decomposition (EMD), was adopted to decompose the time series of each voxel into several components with distinct frequency bands. ReHo values in each of the components were then calculated. Our results showed that ReHo in cortical areas were higher and more frequency-dependent than those in the subcortical regions. BOLD oscillations of 0.02-0.04 Hz mainly contributed to the cortical ReHo, whereas the ReHo in limbic areas involved a wider frequency range and were dominated by higher-frequency BOLD oscillations (>0.08 Hz). The frequency characteristics of ReHo are distinct between different parts of the striatum, with the frequency band of 0.04-0.1 Hz contributing the most to ReHo in caudate nucleus, and oscillations lower than 0.02 Hz contributing more to ReHo in putamen. The distinct frequency-specific ReHo properties of different brain areas may arise from the assorted cytoarchitecture or synaptic types in these areas. Our work may advance the understanding of the neural-physiological basis of local BOLD activities and the functional specificity of different brain regions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Brain / anatomy & histology*
  • Brain / physiology*
  • Brain Mapping*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging / methods*
  • Male
  • Rest / physiology*
  • Young Adult

Grants and funding

This work is supported by the National Natural Science Foundation of China (http://www.nsfc.gov.cn/Portal0/default166.htm) under Grant Nos.61131003 and 81271549. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.