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This study measured the response-locked event-related potential during a flanker task with performance-based monetarily rewarding and punishing trials in 37 undergraduate students separated into high- and low-impulsive groups based on a median split on self-reported Barrett Impulsiveness Scale. The high-impulsive group had a smaller medial frontal error-related negativity (ERN) on punishment trials than the low-impulsive group. The medial prefrontal neural system of behavior monitoring, indexed by the ERN, appears less sensitive to punishment signals in normal impulsivity. This reduced punishment sensitivity in impulsivity, a personality variation associated with several mental and personality disorders including ADHD and substance abuse may be related to the tendency to select short-term rewards despite potential long-term negative consequences in these individuals.

Alcoholism is a major health problem afflicting people all over the world. Understanding the neural substrates of this addictive disorder may provide the basis for effective interventions. So-called "executive processes" play a role in cognitive functions like attention and working memory, and appear to be disrupted in alcoholism (Noel et al., 2001). Event related potentials (ERPs) provide an excellent, minimally invasive technique for exploring these neural deficits. The current study used the P300 in number sequencing task (modified version of the Petries & Milner, 1982) requiring working memory to compare a group of patients with alcoholism and frontal lobe lesions to patients with subcortical lesions and normal controls to assess the relationship of alcoholism to frontal lobe damage. The ERP paradigm was a Number Sequencing task. Electrophysiological results indicate that the frontal lesion group had significant P300 amplitude reduction and a similar trend for alcohol dependent group but not the subcortical group compared to the normal controls.