Analysis of Brain Activity for Motor Task Using Simultaneous EEG-fMRI

Integration of electroencephalogram (EEG) Signal and functional magnetic resonance imaging (fMRI) has opened a new avenue in Computational Neuro Cognitive Science studies as these two are complimentary methods for the analysis of brain activity. We are proposing a novel approach for the correlation between the EEG signal and fMRI to evaluate the blood oxygen level dependent (BOLD) signal changes and electrophysiological activity with high gain of spatio temporal resolution of the brain activity during a task. In this study, simultaneous EEG-fMRI was performed for hand motor task. sLORETA (Standardized low-resolution brain electromagnetic tomography) was reconstructed using segmented EEG for right-hand, left-hand movement and resting state. We estimated condition-specific effects by using statistical parametric maps (SPMs) with general linear model (GLM) approach .By correlating the sLORETA images of EEG and the fMRI images on MNI template during motor task we could demonstrate similar brain activity in both. However with the advantage of simultaneous EEG-fMRI signal acquired at same time points we had a better insight on temporo-spatial information of brain activity during a given task. This method has a huge utility value both in a clinical setting and cognitive studies for example in cryptogenic lesions on imaging with epileptic form discharges detected on EEG combined approach can explain the focal point of seizure and path of its spread to rest of the neuronal substrates on an anatomical image.