Conditions: Nicotine Addiction
Keywords: Nicotine Smoking Cigarettes Reinforcement Learning fMRI
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 54
Healthy volunteers: yes

Brief summary:
The purpose of this study is to use functional magnetic resonance imaging (fMRI) to investigate the acute and chronic effects of nicotine on motivational behavior and prediction error-related neural activation. Nonsmokers (n = 24) and smokers (n = 24) will undergo fMRI scans on two separate occasions while performing a decision-making task that will elicit prediction error signals in the mesocorticolimbic pathway of the brain. Nonsmokers will be scanned once following an acute dose of nicotine and once following placebo administration. Smokers will be scanned once following smoking as usual and once following 24-hours of smoking abstinence, in order to measure the effects of nicotine withdrawal. The study team hypothesizes that acute nicotine will increase the prediction error signal in nonsmokers compared to placebo, and that nicotine withdrawal will decrease the prediction error signal in smokers compared to the normal satiated condition. Furthermore, nonsmokers (during the placebo condition) will have greater prediction error activation than smokers (during the satiated condition). The results of this study will inform whether the initiation and maintenance of smoking behavior could be facilitated by the effects of nicotine on reinforcement learning.

Detailed description:

Arms:
arm 1: Nonsmokers will be measured following a nicotine polacrilex lozenge (2mg) on one occasion and placebo on another occasion. arm 2: Smokers will be measured in a normal satiated condition and following 24-hours of smoking abstinence

Interventions: intervention 1: Nicotine polacrilex intervention 2: Placebo intervention 3: satiety intervention 4: abstinence
Intervention descriptions: intervention 1: nonsmokers will be measured following nicotine administration intervention 2: nonsmokers will be measured following placebo administration intervention 3: smokers will be measured in a smoking satiated condition intervention 4: smokers will be measured following 24-hours of smoking abstinence

Protocol document: