Abstract
RATIONALE: Acute nicotine abstinence is associated with disruption of executive function and reward processes; however, the neurobiological basis of these effects has not been fully elucidated. METHODS: The effects of nicotine abstinence on brain function during reward-based probabilistic decision making were preliminarily investigated by scanning adult smokers (n = 13) following 24 h of smoking abstinence and in a smoking-satiated condition. During fMRI scanning, participants completed the wheel of fortune task (Ernst et al. in Neuropsychologia 42:1585-1597, 2004), a decision-making task with probabilistic monetary outcomes. Brain activation was modeled during selection of options, anticipation of outcomes, and outcome feedback. RESULTS: During choice selection, reaction times were slower, and there was greater neural activation in the postcentral gyrus, insula, and frontal and parietal cortices in the abstinent condition compared to the satiated condition. During reward anticipation, greater activation was observed in the frontal pole, insula, and paracingulate cortex in the abstinent condition compared to the satiated condition. Greater activation was also shown in the precentral gyrus and putamen in the satiated condition compared to the abstinent condition. During the outcome phase, rewards (compared to no rewards) resulted in significant activation in the paracingulate cortex in the satiated condition compared to the abstinent condition. CONCLUSIONS: The results of this preliminary study suggest that smoking withdrawal results in greater recruitment of insular, frontal, and parietal cortical areas during probabilistic decision making.