EEG-informed fMRI analysis during a hand grip task

In the last decade, an increasing interest has arisen in investigating the relationship between the electrophysiological and hemodynamic measurements of brain activity, such as EEG and (BOLD) fMRI. In particular, changes in BOLD have been shown to be associated with changes in the spectral profile of neuronal activity, rather than with absolute neural power. On the other hand, though, recent findings showed that different EEG rhythms are independently related to changes in the BOLD signal: therefore, it would be important to distinguish between the contributions of the different EEG rhythms to BOLD fluctuations when modeling the relationship between EEG and BOLD. Here we proposed a novel method to perform EEG-informed fMRI analysis, so that the EEG regressors take into account both the changes in the spectral profile and the rhythms distinction. We applied it to EEG-fMRI data during a bimanual motor task in healthy subjects, and compared the results with those obtained by regressing fMRI data onto a single regressor covering the entire range of frequencies, ignoring the distinction between different EEG rhythms. Our results showed that the proposed method better captures the correlations between BOLD signal and EEG rhythms modulations, identifying task-related well localized activated volumes.

[1]  F. L. D. Silva,et al.  Event-related EEG/MEG synchronization and desynchronization: basic principles , 1999, Clinical Neurophysiology.

[2]  R. Passingham,et al.  The Attentional Role of the Left Parietal Cortex: The Distinct Lateralization and Localization of Motor Attention in the Human Brain , 2001, Journal of Cognitive Neuroscience.

[3]  N. Tzourio-Mazoyer,et al.  Automated Anatomical Labeling of Activations in SPM Using a Macroscopic Anatomical Parcellation of the MNI MRI Single-Subject Brain , 2002, NeuroImage.

[4]  Karl J. Friston,et al.  Statistical parametric maps in functional imaging: A general linear approach , 1994 .

[5]  N. Logothetis,et al.  Neurophysiology of the BOLD fMRI Signal in Awake Monkeys , 2008, Current Biology.

[6]  Karl J. Friston,et al.  Hemodynamic correlates of EEG: A heuristic , 2005, NeuroImage.

[7]  G. Pfurtscheller Central beta rhythm during sensorimotor activities in man. , 1981, Electroencephalography and clinical neurophysiology.

[8]  S. Scott,et al.  The role of the rostral frontal cortex (area 10) in prospective memory: a lateral versus medial dissociation , 2003, Neuropsychologia.

[9]  William D. Penny,et al.  Estimating the transfer function from neuronal activity to BOLD using simultaneous EEG-fMRI , 2010, NeuroImage.

[10]  S. Cerutti,et al.  BOLD correlates of Alpha and Beta EEG-rhythm during a motor task , 2011, 2011 5th International IEEE/EMBS Conference on Neural Engineering.

[11]  Simon B. Eickhoff,et al.  A new SPM toolbox for combining probabilistic cytoarchitectonic maps and functional imaging data , 2005, NeuroImage.

[12]  W. Singer,et al.  Hemodynamic Signals Correlate Tightly with Synchronized Gamma Oscillations , 2005, Science.

[13]  Karl J. Friston,et al.  EEG-fMRI integration: a critical review of biophysical modeling and data analysis approaches. , 2010, Journal of integrative neuroscience.