EEG and fMRI Coregistration to Investigate the Cortical Oscillatory Activities During Finger Movement

Abstract

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.

Grasping Hand Verbs: Oscillatory Beta and Alpha Correlates of Action-Word Processing

“…This asymmetric pattern of activation is in line with previous results showing left-lateralized power decrease during the reading of hand verbs [39] and covert verb generation [38]. Under the assumption that beta suppression represents neural activation [54], [55], [56], our findings also agree with those from fMRI studies showing left-lateralized neural activity during action-related language processing [11], [12], [14], [15], [16]. Consistently, inhibition of reaction times during the processing of hand action verbs was induced with TMS on the left, but not on the right hemispheric hand portion of the motor cortex [57].…”

Neural mirroring mechanisms and imitation in human infants

“…Localization studies in adults suggest that the alpharange component of the mu rhythm is mainly generated in primary somatosensory cortex [102][103][104]. Furthermore, the adult EEG mu response varies with changes in somatosensory aspects of observed actions [105][106][107], a finding that connects with other work at the intersection of somatosensory processing and social neuroscience [108], including affective aspects [109].…”

Brain–machine interfaces for rehabilitation of poststroke hemiplegia

“…It has been shown that SMR-ERD covaries with blood-oxygen-level-dependent (BOLD) signals as measured by magnetic resonance imaging (MRI) deriving from the same cortical areas (Formaggio et al, 2008(Formaggio et al, , 2010Yuan et al, 2010). Studies using transcranial magnetic stimulation (TMS) delivered to the primary motor cortex (M1) have shown that an increase of corticospinal tract excitability is associated with a SMR-ERD decrease (Hummel et al, 2002) and is accompanied with decrease of GABAergic intracortical inhibition (Takemi et al, 2013).…”