http://www.nitrc.org/forum/forum.php?forum_id=8290 <table border="0" width="100%"><tr><td align="left"/></tr></table> <p><b>Characterizing the modulation of resting-state fMRI metrics by baseline physiology.</b></p> <p>Neuroimage. 2018 Feb 13;:</p> <p>Authors: Chu PPW, Golestani AM, Kwinta JB, Khatamian YB, Chen JJ</p> <p>Abstract<br/> The blood-oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal is commonly used to assess functional connectivity across brain regions, particularly in the resting state (rs-fMRI). However, the BOLD fMRI signal is not merely a representation of neural activity, but a combination of neural activity and vascular response. These aspects of the BOLD signal are easily influenced by systemic physiology, potentially biasing BOLD-based functional connectivity measurements. In this work, we focus on the following physiological modulators of the BOLD signal: cerebral blood flow (CBF), venous blood oxygenation, and cerebrovascular reactivity (CVR). We use simulations and experiments to examine the relationship between the physiological parameters and rs-fMRI functional connectivity measurements in three resting-state networks: default mode network, somatosensory network and visual network. By using the general linear model, we demonstrate that physiological modulators significantly impact functional connectivity measurements in these regions, but in a manner that depends on the interplay between signal- and noise-driven correlations. Moreover, we find that the physiological effects vary by brain region and depend on the range of physiological conditions probed; the associations are more complex than previously reported. The results confirm that it is important to account for the effect of physiological modulators when comparing resting-state fMRI metrics. We note that such modulatory effects may be amplified by disease conditions, which will warrant future investigations.<br/> </p><p>PMID: 29452265 [PubMed - as supplied by publisher]</p> en-us Copyright 2000-2026 NITRC OSI Thu, 30 Apr 2026 15:35:40 GMT http://blogs.law.harvard.edu/tech/rss NITRC RSS generator