title: Smoking automaticity and tolerance moderate brain activation during explore-exploit behavior.
abstract: The adaptive trade-off between exploration and exploitation is a key component in models of reinforcement learning. Over the past decade, these models have been applied to the study of reward-seeking behavior. Drugs of addiction induce reward-seeking behavior and modify its underlying neurophysiological processes. These neurophysiological changes may underlie a behavioral shift from a flexible, exploratory mode to a focused, exploitative mode, which precedes the development of inflexible, habitual drug use. The goal of this study was to investigate the relationship between explore/exploit behavior and drug addiction by examining the neural correlates of this behavior in cigarette smokers. Participants (n=22) with a range of smoking behaviors completed a smoking dependence motives questionnaire and played a 6-armed bandit task while undergoing functional magnetic resonance imaging (fMRI). Exploratory behavior produced greater activation in the bilateral superior parietal and bilateral frontal cortices than exploitative behavior. Exploitative behavior produced greater activation in the bilateral superior and middle temporal gyri than exploratory behavior. fMRI data and orthogonalized smoking dependence motive scores were entered into multiple linear regression analyses. After controlling for nicotine tolerance, smoking automaticity positively correlated with activation in the same bilateral parietal regions preferentially activated by exploratory choices. These preliminary results link smoking dependence motives to variation in the neural processes that mediate exploratory decision making.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC 27710, USA; Duke-UNC Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, NC 27710, USA. Electronic address: merideth.addicott@duke.edu.
authors.forename: Merideth A
authors.initials: MA
authors.lastname: Addicott
authors.affiliation: Department of Neurobiology, Duke University, Durham, NC 27710, USA; Center for Cognitive Neuroscience, Duke University, Durham, NC 27710, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Pearson
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29403, USA.
authors.forename: Brett
authors.initials: B
authors.lastname: Froeliger
authors.affiliation: Department of Neurobiology, Duke University, Durham, NC 27710, USA; Center for Cognitive Neuroscience, Duke University, Durham, NC 27710, USA; Department of Evolutionary Anthropology, Duke University, Durham, NC 27710, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Platt
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC 27710, USA; Duke-UNC Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: F Joseph
authors.initials: FJ
authors.lastname: McClernon
mesh_terms: D000328:Adult; D016739:Behavior, Addictive / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D003657:Decision Making / Q000502:physiology*; D005106:Exploratory Behavior / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009042:Motivation / Q000502:physiology*; D012201:Reward; D012907:Smoking / Q000503:physiopathology*; D014029:Tobacco Use Disorder / Q000503:physiopathology*
keywords: Automaticity; Bandit task; Exploit; Explore; Neuroimaging; Smoking