could also be differentiated using the CSD method, namely CSD measure could elicit differences in activation patterns between schizophrenic subjects with and without hallucinations (Kayser et al., 2012). Additionally, CSD has been found useful to understand neuroelectric activations in patients with brain lesions (Harmony et al., 1993; Fernandez-Bouzas et al., 1995, 1997) and epilepsy (Rodin, 1999; Ulbert et al., 2004; Fabo et al., 2008). Specifically, Harmony et al. (1993) interpreted the finding that significant correlations of the volume and the density of the brain edema were with only theta and alpha power (representing local activity) of the CSD measure but additionally included delta power (representing long-range activity) of the voltage measure could be due to the fact that the Laplacian acts as a spatial filter emphasizing local sources over distant sources, while the non-transformed EEG potential tends to produce a more extensive and diffuse picture of neuroelectric abnormality and hence lacks the information about its source activation. Follow-up studies from the same researchers also compared both measures and further confirmed the superiority of CSD measure in localizing brain lesions than the traditional voltage measure (Fernandez-Bouzas et al., 1995, 1997). However, it should also be mentioned that even though the CSD
