Abstract
Event-related potentials (ERP) are transient brain responses to cognitive stimuli, and they consist of several stationary events whose temporal frequency content can be characterized in terms of oscillations or rhythms. Precise localization of electrical events in the brain, based on the ERP data recorded from the scalp, has been one of the main challenges of functional brain imaging. Several currentDensity estimation techniques for identifying the electrical sources generating the brain potentials are developed for the so-called neuroelectromagnetic inverse problem in the last three decades (Baillet, Mosher, & Leahy, 2001; Koles, 1998; Michela, Murraya, Lantza, Gonzaleza, Spinellib, & Grave de Peraltaa, 2004; Scherg & von Cramon, 1986).
Key Terms in this Chapter
Multiresolution Decomposition (MRA): MRA is the design method of most of the practically relevant discrete wavelet transforms (DWT), and the justification for the algorithm of the fast wavelet transform (FWT).
Forward Problem of EEG: The procedure that calculates the electrical potential over the scalp.
Boundary Element Method (BEM): BEM is a numerical computational method of solving linear partial differential equations, which have been formulated as integral equations.
Event-Related Potential (ERP): ERP is any measured brain response that is directly the result of a thought or perception.
Subtopography: Simple scalp topography originated from decomposition of main scalp map.
Inverse Problem of EEG: The procedure which estimates the activity of the brain from given electrical potential data.
Spatial Frequency: The spatial frequency is a measure of how often the structure repeats per unit of distance.