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Identifying neural drivers with functional MRI: an electrophysiological validation (2008)
| Venue: | PLoS Biol |
| Citations: | 32 - 1 self |
BibTeX
@ARTICLE{David08identifyingneural,
author = {Olivier David and Isabelle Guillemain and Rine Saillet and Sebastien Reyt and Colin Deransart and Christoph Segebarth and Antoine Depaulis and Plos Biology},
title = {Identifying neural drivers with functional MRI: an electrophysiological validation},
journal = {PLoS Biol},
year = {2008},
pages = {10--1371}
}
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Abstract
Whether functional magnetic resonance imaging (fMRI) allows the identification of neural drivers remains an open question of particular importance to refine physiological and neuropsychological models of the brain, and/or to understand neurophysiopathology. Here, in a rat model of absence epilepsy showing spontaneous spike-and-wave discharges originating from the first somatosensory cortex (S1BF), we performed simultaneous electroencephalographic (EEG) and fMRI measurements, and subsequent intracerebral EEG (iEEG) recordings in regions strongly activated in fMRI (S1BF, thalamus, and striatum). fMRI connectivity was determined from fMRI time series directly and from hidden state variables using a measure of Granger causality and Dynamic Causal Modelling that relates synaptic activity to fMRI. fMRI connectivity was compared to directed functional coupling estimated from iEEG using asymmetry in generalised synchronisation metrics. The neural driver of spike-and-wave discharges was estimated in S1BF from iEEG, and from fMRI only when hemodynamic effects were explicitly removed. Functional connectivity analysis applied directly on fMRI signals failed because hemodynamics varied between regions, rendering temporal precedence irrelevant. This paper provides the first experimental substantiation of the theoretical possibility to improve interregional coupling estimation from hidden neural states of fMRI. As such, it has important implications for future studies on brain connectivity using functional neuroimaging.
Keyphrases
neural driver functional mri electrophysiological validation fmri connectivity synaptic activity first somatosensory cortex functional connectivity analysis granger causality future study fmri measurement open question spontaneous spike-and-wave discharge spike-and-wave discharge hemodynamic effect temporal precedence irrelevant functional neuroimaging dynamic causal modelling brain connectivity fmri signal hidden neural state hidden state variable fmri time series particular importance neuropsychological model subsequent intracerebral eeg absence epilepsy generalised synchronisation metric first experimental substantiation functional coupling rat model whether functional magnetic resonance imaging important implication theoretical possibility
