The sLORETA is a functional imaging method based on certain electrophysiological and neuroanatomical constraints (Pascual-Marqui et al., 2002). The cortex has been modeled as a collection of volume elements (voxels) in the digitized Montreal Neurological Institute (MNI) coordinates corrected to the Talairach coordinates. The sLORETA algorithm solves the inverse problem by assuming related orientations and strengths of neighboring neuronal sources (represented by adjacent voxels). It has been identified as an efficient tool for functional mapping, since it is consistent with physiology and capable of correct localization (Pascual-Marqui et al., 2002). Along with comprehensive experimental validation, independent validation of the localization properties of sLORETA has been replicated by Sekihara et al. (2005), Greenblatt et al. (2005), and Wagner et al. (2004). The version of sLORETA employed here was made available at http://www.unizh.ch/keyinst/NewLORETA/LORETA01.htm
