Brain electrophysiological measures, such as electroencephalogram (EEG) and event-related potentials/oscillations (ERP/ERO), remain the most valuable method to study the sensory, motor, and cognitive phenomena as they unfold, due to their excellent time resolution at the scale of milliseconds [12]. Although fMRI has higher spatial resolution than EEG, it is nevertheless an indirect measure of neural activity based on the brain’s metabolic activity and has poor temporal resolution owing to the biophysics of the hemodynamic response [38]. On the other hand, EEG records direct neural activity resulting from the excitatory and inhibitory signals of synchronously firing neurons [39]. While it is recognized that the plethora of neural processes that operate in a domain of tens of milliseconds will remain beyond the capabilities of the fMRI techniques [38], fast ongoing neurocognitive processes and their brain network dynamics can be investigated with EEG based measures.
