PT  - JOURNAL ARTICLE
AU  - Corey J. Keller
AU  - Stephan Bickel
AU  - Christopher J. Honey
AU  - David M. Groppe
AU  - Laszlo Entz
AU  - R. Cameron Craddock
AU  - Fred A. Lado
AU  - Clare Kelly
AU  - Michael Milham
AU  - Ashesh D. Mehta
TI  - Neurophysiological Investigation of Spontaneous Correlated and Anticorrelated Fluctuations of the BOLD Signal
AID  - 10.1523/JNEUROSCI.4837-12.2013
DP  - 2013 Apr 10
TA  - The Journal of Neuroscience
PG  - 6333--6342
VI  - 33
IP  - 15
4099  - http://www.jneurosci.org/content/33/15/6333.short
4100  - http://www.jneurosci.org/content/33/15/6333.full
SO  - J. Neurosci.2013 Apr 10; 33
AB  - Analyses of intrinsic fMRI BOLD signal fluctuations reliably reveal correlated and anticorrelated functional networks in the brain. Because the BOLD signal is an indirect measure of neuronal activity and anticorrelations can be introduced by preprocessing steps, such as global signal regression, the neurophysiological significance of correlated and anticorrelated BOLD fluctuations is a source of debate. Here, we address this question by examining the correspondence between the spatial organization of correlated BOLD fluctuations and correlated fluctuations in electrophysiological high γ power signals recorded directly from the cortical surface of 5 patients. We demonstrate that both positive and negative BOLD correlations have neurophysiological correlates reflected in fluctuations of spontaneous neuronal activity. Although applying global signal regression to BOLD signals results in some BOLD anticorrelations that are not apparent in the ECoG data, it enhances the neuronal-hemodynamic correspondence overall. Together, these findings provide support for the neurophysiological fidelity of BOLD correlations and anticorrelations.