For instance, positive-going CSD activity related to a P3 potential is termed as P3 source while the negative-going CSD activity to an N1 component is described as N1 sink (Kayser et al., 2006). In effect, the CSD transformation functions as a high-pass spatial filter that minimizes the electrical distortions produced by the mediums between cortical surface and sensor (electrode) such as skull and scalp, thus facilitating spatial separation of temporally overlapping components (Turetsky et al., 2000). Therefore, the benefits of a CSD transform are a reference-free, spatially enhanced representation of the direction, location, and intensity of current generators that underlie the recorded scalp potentials (cf. Kayser and Tenke, 2006b), and provides topographies with more sharply localized peaks than those of the scalp potential, while eliminating volume-conducted contributions from distant regions and sources (Tenke and Kayser, 2005; Kayser et al., 2006).
