## Abstract Interregional correlations between blood oxygen level dependent (BOLD) magnetic resonance imaging (fMRI) signals in the resting state have been interpreted as measures of connectivity across the brain. Here we investigate whether such connectivity in the working memory and default mode
Test–retest reproducibility of the default-mode network in healthy individuals
✍ Scribed by Thomas Meindl; Stefan Teipel; Rachid Elmouden; Sophia Mueller; Walter Koch; Olaf Dietrich; Ute Coates; Maximilian Reiser; Christian Glaser
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 258 KB
- Volume
- 31
- Category
- Article
- ISSN
- 1065-9471
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✦ Synopsis
Abstract
Independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) time‐series reveals distinct coactivation patterns in the resting brain representing spatially coherent spontaneous fluctuations of the fMRI signal. Among these patterns, the so‐called default‐mode network (DMN) has been attributed to the ongoing mental activity of the brain during wakeful resting state. Studies suggest that many neuropsychiatric diseases disconnect brain areas belonging to the DMN. The potential use of the DMN as functional imaging marker for individuals at risk for these diseases, however, requires that the components of the DMN are reproducible over time in healthy individuals. In this study, we assessed the reproducibility of the DMN components within and between imaging sessions in 18 healthy young subjects (mean age, 27.5 years) who were scanned three times with two resting state scans during each session at 3.0T field strength. Statistical analysis of fMRI time‐series was done using ICA implemented with BrainVoyager QX. At all three sessions the essential components of the DMN could be identified in each individual. Spatial extent of DMN activity and size of overlap within and between sessions were most reproducible for the anterior and posterior cingulate gyrus. The degree of reproducibility of the DMN agrees with the degree of reproducibility found with motor paradigms. We conclude that DMN coactivation patterns are reproducible in healthy young subjects. Therefore, these data can serve as basis to further explore the effects of aging and neuropsychiatric diseases on the DMN of the brain. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
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