Fluctuations of the EEG-fMRI correlation reflect intrinsic strength of functional connectivity in default mode network.
Tuija Keinänen, Seppo Rytky, Vesa Korhonen, Niko Huotari, Juha Nikkinen, Osmo Tervonen, J Matias Palva, Vesa Kiviniemi
Journal of Neuroscience Research May 14, 2018 DOI: 10.1002/jnr.24257 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational neuroimaging study using simultaneous full-band EEG and ultrafast fMRI (MREG) Peer reviewed |
|---|---|
| Population | Human participants (adults; exact sample not stated in the abstract) |
| Topics | Default mode network |
| Keywords | Nerve net Humans Magnetic resonance imaging Electroencephalography Brain mapping Adult Female Electrophysiological phenomena EEG FMRI Functional connectivity Resting-state networks Resting State MRI Infra-slow fluctuations |
| Key findings | Temporal fluctuations in the correlation between infraslow EEG scalp potentials and BOLD fMRI signals depended on resting-state network connectivity strength, not on mean signal level, activation magnitude, or motion. Correlations were strongest when intrinsic RSN connectivity was strong and close to the pial surface, and weakest when connectivity was less coherent or spatially scattered, or activation was in deeper cerebral structures. |
Abstract
Both functional magnetic resonance imaging (fMRI) and electrophysiological recordings have revealed that resting-state functional connectivity is temporally variable in human brain. Combined full-band electroencephalography-fMRI (fbEEG-fMRI) studies have shown that infraslow (<.1 Hz) fluctuations in EEG scalp potential are correlated with the blood-oxygen-level-dependent (BOLD) fMRI signals and that also this correlation appears variable over time. Here, we used simultaneous fbEEG-fMRI to test the hypothesis that correlation dynamics between BOLD and fbEEG signals could be explained by fluctuations in the activation properties of resting-state networks (RSNs) such as the extent or strength of their activation. We used ultrafast magnetic resonance encephalography (MREG) fMRI to enable temporally accurate and statistically robust short-time-window comparisons of infra-slow fbEEG and BOLD signals. We found that the temporal fluctuations in the fbEEG-BOLD correlation were dependent on RSN connectivity strength, but not on the mean signal level or magnitude of RSN activation or motion during scanning. Moreover, the EEG-fMRI correlations were strongest when the intrinsic RSN connectivity was strong and close to the pial surface. Conversely, weak fbEEG-BOLD correlations were attributable to periods of less coherent or spatially more scattered intrinsic RSN connectivity, or RSN activation in deeper cerebral structures. The results thus show that the on-average low correlations between infra-slow EEG and BOLD signals are, in fact, governed by the momentary coherence and depth of the underlying RSN activation, and may reach systematically high values with appropriate source activities. These findings further consolidate the notion of slow scalp potentials being directly coupled to hemodynamic fluctuations.
Comparable studies
Other experimental studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Functional connectivity of default mode network components: Correlation, anticorrelation, and causality Healthy subjects | 2008 | Observational study using resting-state fMRI and seed correlation analysis | |
| Patterns of Brain Activity Supporting Autobiographical Memory, Prospection, and Theory of Mind, and Their Relationship to the Default Mode Network Healthy subjects | 2009 | Experimental study using fMRI | |
| Dynamic reconfiguration of the default mode network during narrative comprehension Human subjects | 2016 | Experimental study | |
| Broadband Cortical Desynchronization Underlies the Human Psychedelic State Healthy human participants | 2013 | Experimental study | |
| The brain on art: intense aesthetic experience activates the default mode network Human observers | 2012 | Observational study with fMRI and behavioral analysis |
Citations in the library
Cited by 2
Cites 5
- A default mode of brain function Proceedings of the National Academy of Sciences January 16, 2001
- Dynamic functional connectivity of the default mode network tracks daydreaming Neuroimage June 25, 2014
- A Sliding Time-Window ICA Reveals Spatial Variability of the Default Mode Network in Time Brain Connectivity October 1, 2011
- Quasi-periodic Fluctuations in Default Mode Network Electrophysiology Journal of Neuroscience August 10, 2011
- The fMRI signal, slow cortical potential and consciousness Trends in Cognitive Sciences June 15, 2009