A negative ERP component, designated as N4 or N400 (300–650 ms) over centroparietal scalp, and initially elicited to semantic incongruency, has been the cornerstone of semantic ERP studies (Kutas and Hillyard, 1980; Bentin, 1989). The N400 varies systematically with the processing of potentially meaningful stimuli, where the amplitude is reduced by a number of factors (Kutas and Federmeier, 2000). Increased latency for N400 response to related/incongruent semantic information has been reported in alcoholics, especially in those with comorbid antisocial personality (ASP) (Ceballos et al., 2003). Ceballos and colleagues (2005) found significantly less negative N4 amplitudes in alcohol-dependent individuals relative to non-dependent controls. Another widely used paradigm is the semantic priming paradigm, in which a word preceded by an unrelated word (unprimed) produces a larger N400 compared to a word preceded by a related word (primed) (Bentin, 1989; McCarthy and Nobre, 1993). Reduced N4 amplitude of the difference waveform between primed and unprimed words has been reported (Nixon et al., 2002). Similarly, in a recent semantic decision task there was less attenuation of N400 amplitudes to primed words when compared to
