Simultaneous Eeg-Fmri: Integrating Spatial And Temporal Resolution

Electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI) are among the most widespread neuroimaging techniques available to noninvasively characterize certain aspects of human brain function. The temporal resolution of EEG is excellent, managing to capture neural events in the order of milliseconds. On the other hand, its spatial resolution lacks precision. Conversely, fMRI offers high spatial resolution, typically on the order of mm(3). However, it has limited temporal resolution (similar to sec), which is determined by the haemodynamic response. Therefore, simultaneous acquisition of EEG and fMRI is highly desirable. In recent years, the ability to perform combined EEG-fMRI has attracted considerable attention from the neuroscience community. In this chapter, relevant methodological aspects of EEG-fMRI will be first described, focused on the nature of neurophysiologic signals and difficulties to integrate electric and haemodynamic signals derived from both techniques. Second, state of the art strategies related to artifact correction and signal analysis will be described. Finally, a possible use of EEG-fMRI will be presented, focused on its potential application in epilepsy.