EEG and fMRI Coregistration to Investigate the Cortical Oscillatory Activities During Finger Movement
- 418 Downloads
Electroencephalography combined with functional magnetic resonance imaging (EEG-fMRI) may be used to identify blood oxygenation level dependent (BOLD) signal changes associated with physiological and pathological EEG event. In this study we used EEG-fMRI to determine the possible correlation between topographical movement-related EEG changes in brain oscillatory activity recorded from EEG electrodes over the scalp and fMRI-BOLD cortical responses in motor areas during finger movement. Thirty-two channels of EEG were recorded in 9 subjects during eyes-open condition inside a 1.5 T magnetic resonance (MR) scanner using a MR-compatible EEG recording system. Off-line MRI artifact subtraction software was applied to obtain continuous EEG data during␣fMRI acquisition. For EEG data analysis we used the event-related-synchronization/desynchronization (ERS/ERD) approach to investigate where movement-related decreases in alpha and beta power are located. For image statistical analysis we used a general linear model (GLM) approach. There was a significant correlation between the positive-negative ratio of BOLD signal peaks and ERD values in the electrodes over the region of activation. We conclude that combined EEG-fMRI may be used to investigate movement-related oscillations of the human brain inside an MRI scanner and the movement-related changes in the EMG or EEG signals are useful to identify the brain activation sources responsible for BOLD-signal changes.
KeywordsEEG BOLD ERD Alpha power Beta power
Unable to display preview. Download preview PDF.
The authors wish to thank Profs. Gianna Maria Toffolo and Alessandra Bertoldo (Department of Information Engineering, University of Padova) for help and advice concerning statistical analysis. This work was supported by Crediveneto, Verona, Italy.
- Avesani M, Milanese F, Formaggio E, Gasparini A, Cerini R, Bongiovanni LG, Pozzi Mucelli R, Fiaschi A, Manganotti P (2008) Continuous EEG-fMRI in pre-surgical evaluation of a patient with symptomatic seizures: bold activation linked to interictal epileptic discharges caused by Cavernoma. Neuroradiol J 21(2):183–191Google Scholar
- Friston KJ, Holmes AP, Worsely KJ, Poline JP, Frith CD, Frackowiak RSJ (1995) Statistical parametric maps in functional imaging: a general linear approach. Hum Brain Mapp 2:173–181Google Scholar
- Ives JR, Warach S, Schmitt F, Edelman RR, Schomer DL (1993) Monitoring the patient’s EEG during echo planar MRI. Neurophysiology 87:417–420Google Scholar
- Manganotti P, Formaggio E, Milanese F, Gasparini A, Storti SF, Cerini R, Bongiovanni LG, Pozzi Mucelli R, Baraldo A, Fiaschi A, Avesani M (2008) Continuous EEG-fMRI study in patients with partial epilepsy and focal interictal slow-wave discharges on EEG. Magnet Resonan Imaging (in press)Google Scholar
- Oldfield RC (1971) The assessment and analysis of handedness: the Edinburgh inventory. Neuropsychologia 9(1):97–113Google Scholar
- Talairach J, Tournoux P (1998) Co-planar stereotaxic atlas of the human brain. Thieme: New York Google Scholar