Enhancement of neurotransmission through prefrontal and paralimbic cortico–basal ganglia–thalamic circuits may account for the most commonly reported cognitive effect of cigarette smoking, namely, improved attentional performance (Newhouse et al. 2004), and also related effects, such as improvements in reaction times (Hatsukami et al. 1989; Pritchard et al. 1992; Shiffman et al. 1995), arousal (Parrott and Kaye 1999), motivation (Powell et al. 2002), and sustained attention (Rusted et al. 2000). Prefrontal (including both dorsolateral and ventrolateral) (Duncan and Owen 2000; Rees and Lavie 2001; Smith and Jonides 1999) and ACC (Carter et al. 1999; Duncan and Owen 2000; Peterson et al. 1999; Smith and Jonides 1999) cortices are reported to activate during attentional control tasks (especially visuospatial tasks) (Pessoa et al. 2003). Cigarette smoking may enhance attentional control through direct stimulation of nAChRs within these structures or perhaps through subcortical stimulation of nAChRs in the thalamus and via DA release and/or MAO inhibition in the basal ganglia.
