Region specific activations and altered topographic features of CSD have also been reported in other tasks and during the resting state with EEG. Ji et al. (1999) found suppressed activations over the left temporal-occipital areas in alcoholics during both matching and nonmatching conditions (around 250 ms) with prominent left hemispheric activation in controls in a visual category matching task (i.e., match/mismatch S1–S2 paradigm). Roopesh et al. (2010) investigated the N400 component in 87 alcohol dependent subjects and 57 community controls using a lexical decision task which required a button press response to indicate the presented visual stimulus was a word or non-word. It was found that control subjects, as expected, revealed a significant “priming effect” which is attenuation of the N400 response to the primed word in comparison to the unprimed word, whereas alcoholic subjects showed significantly less N400 attenuation. The CSD topography revealed a centroparietal and right hemisphere predominant source only for the control group. In alcoholics, by contrast, the posterior source was largely at the midline region and the sink shifted to the left for the primed condition,
