OBJECTIVE: Resting-state networks (RSNs), including the default mode network 
(DMN), have been considered as markers of brain status such as consciousness, 
developmental change, and treatment effects. The consistency of functional 
connectivity among RSNs has not been fully explored, especially among 
resting-state-related independent components (RSICs).
MATERIALS AND METHODS: This resting-state fMRI study addressed the consistency 
of functional connectivity among RSICs as well as their spatial consistency 
between 'at day 1' and 'after 4 weeks' in 13 healthy volunteers.
RESULTS: We found that most RSICs, especially the DMN, are reproducible across 
time, whereas some RSICs were variable in either their spatial characteristics 
or their functional connectivity. Relatively low spatial consistency was found 
in the basal ganglia, a parietal region of left frontoparietal network, and the 
supplementary motor area. The functional connectivity between two independent 
components, the bilateral angular/supramarginal gyri/intraparietal lobule and 
bilateral middle temporal/occipital gyri, was decreased across time regardless 
of the correlation analysis method employed, (Pearson's or partial correlation).
CONCLUSION: RSICs showing variable consistency are different between spatial 
characteristics and functional connectivity. To understand the brain as a 
dynamic network, we recommend further investigation of both changes in the 
activation of specific regions and the modulation of functional connectivity in 
the brain network.