Impulsive behavior in cocaine dependence is associated with functional brain abnormalities as revealed by functional magnetic resonance imaging (fMRI) investigations. Kaufman and colleagues (2003) used fMRI to compare cocaine users and controls during the performance of a go-no-go task. Results showed significantly lower activation of anterior cingulate and right insula in cocaine users for successful inhibitions (STOPS) on no-go trials relative to go trials. In addition, cocaine users showed significantly lower activation in the anterior cingulate as well as right medial frontal gyrus, presupplementary motor area, left insula, and left inferior frontal gyrus for failed inhibitions (ERRORS) on no-go trials relative to go trials (Kaufman et al., 2003). In another study using a go-no-go task, but this time involving variable working memory demands, cocaine users showed reduced signal within the anterior cingulate and right prefrontal cortex compared to controls for the group by working memory load interaction for successful response inhibitions relative to go trials (Hester and Garavan, 2004). Although this study did not report the contrast of no-go with go trials, which would test for specific signals in behavioral
