On the other hand, nicotine-induced performance enhancement is consistently observed during monotonous tasks requiring sustained attention, vigilance, and visuospatial orientation (Lawrence et al., 2002; Newhouse et al., 2004; Hahn et al., 2007). Emerging evidence suggests nicotine augments performance by suppressing DMN processes while also enhancing those associated with the TPN. For example, in minimally-abstinent smokers, nicotine enhances deactivations in regions overlapping those of the DMN during task cue presentation which is also associated with faster responding to subsequently presented targets (Fig 4AB; Hahn et al., 2007). Enhanced suppression of DMN regions may be a general mechanism by which nicotine elevates global task-based focus, as similar enhanced deactivations, occurring concurrently with augmented performance, have been observed when probing different cognitive constructs such as stimulus detection, selective/divided attention (Hahn et al., 2009), sustained attention (Beaver et al., 2011), and overt attentional shifting (Ettinger et al., 2009). Nicotine administered to non-smokers decreases DMN activity “at rest” (Fig 4C; Tanabe et al., 2011), suggesting such effects are not constrained to task-specific contexts nor limited to the amelioration of abstinence-induced effects in smokers. In contrast
