To date, no neuroimaging studies comparing SAs and HCs on delayed memory have been published, nor have any addiction models included hypotheses toward memory deficits in addicted individuals, making it difficult to interpret these results in light of the current models of drug addiction. Cognitive flexibility, attention, and planning In a switching

Inhibitors,research,lifescience,medical task, cocaine users showed decreased activation in the left cingulate gyrus, medial and right middle frontal gyrus, left thalamus, lentiform nucleus (globus pallidus/putamen), and right precuneus compared with HCs (Kubler et al. 2005). However, activation in the DLPFC and anterior frontal cortex was similar in both groups. The authors concluded Inhibitors,research,lifescience,medical that the diminished responsiveness in anterior cingulate and prefrontal areas is in concordance with the hypothesis of under-responsive action monitoring in cocaine abusers, and that cocaine users are selectively impaired for attention switching within WM, so that, for example, steering away from E7080 solubility dmso drug-related thoughts is problematic (Kubler et al. 2005). This study is of interest because it is the only study assessing both verbal and visuospatial WM switching in cocaine abusers compared with HCs, showing specific impairment in visuospatial WM in cocaine abusers. Using a PRLT, HCs showed higher activation of the ventrolateral PFC and premotor area than smokers

Inhibitors,research,lifescience,medical during reversals following monetary loss (de Ruiter et al. 2009). However, smokers (compared with HCs) showed higher activation in the right insula and frontal operculum during reversal after monetary loss. In this, Inhibitors,research,lifescience,medical cognitive flexibility in smokers was affected but planning was intact. Smokers were asked to abstain from smoking 10 h before scanning. This may have Inhibitors,research,lifescience,medical interfered with performance and/or BOLD-activation due to withdrawal effects. However, the authors argue that this is unlikely

given the intact planning in smokers. Finally, a study by Goldstein et al. (2007b), investigating practice effects (habituation) on a sustained attention task, showed a decrease in activation of the ACC, frontal areas, and cerebellum as compared with HCs, which was associated with measures of craving, frequency of CYTH4 use, and length of abstinence in cocaine users versus HCs. These findings are somewhat surprising as decreased prefrontal activation during prolonged or repeated task performance is usually considered to reflect increased neural efficiency, due to, for example, absence of novelty effects. In addition, cuneus and precuneus were more active in HCs as compared with cocaine abusers, and signal decreases in the thalamus correlated with RT decreases related to practice sessions, especially in cocaine abusers as compared with HCs (Goldstein et al. 2007b), hypothesized to reflect a changed ability to adapt to previously experienced situations as compared with HCs. de Ruiter et al.