Attentional bias to smoking and other motivationally relevant cues is affected by nicotine exposure and dose expectancy.

We investigated the effects of acute nicotine dose and expected dose on attentional bias (AB) to smoking and affective cues in overnight nicotine-deprived smokers (n=51; 24 women) using a balanced placebo design, which counterbalanced given nicotine dose (Given-NIC vs. Given-DENIC) with instructed nicotine dose expectancy (Told-NIC vs. Told-DENIC). Before and after smoking a study cigarette, smokers completed a vigilance task where they pressed buttons to every third consecutive even or odd digit, while ignoring intermittent smoking, pleasant, unpleasant, and neutral picture distracters. We examined the early posterior negativity (EPN) and late positive potential (LPP) components of the event-related potentials (ERPs) to the distracters, reaction time (RT) to the target digits, and ratings of the study cigarettes. The EPN was sensitive to both given and instructed nicotine dose, while the instructed dose moderated the impact of given dose for the LPP. The RT metrics were sensitive to given but not to instructed dose. The effects of given dose on ratings following cigarette smoking (e.g. enjoyment) were moderated by the instructed dose. The ERP findings suggest that the anticipated effects of nicotine improve attention much like receiving actual nicotine.

The motivational salience of cigarette-related stimuli among former, never, and current smokers.

While smokers are known to find smoking-related stimuli motivationally salient, the extent to which former smokers do so is largely unknown. In this study, we collected event-related potential (ERP) data from former and never smokers and compared them to a sample of current smokers interested in quitting who completed the same ERP paradigm prior to smoking cessation treatment. All participants (n = 180) attended 1 laboratory session where we recorded dense-array ERPs in response to cigarette-related, pleasant, unpleasant, and neutral pictures and where we collected valence and arousal ratings of the pictures. We identified 3 spatial and temporal regions of interest, corresponding to the P1 (120-132 ms), early posterior negativity (EPN; 244-316 ms), and late positive potential (LPP; 384-800 ms) ERP components. We found that all participants produced larger P1 responses to cigarette-related pictures compared to the other picture categories. With the EPN component, we found that, similar to pleasant and unpleasant pictures, cigarette-related pictures attracted early attentional resources, regardless of smoking status. Both former and never smokers produced reduced LPP responses to cigarette-related and pleasant pictures compared to current smokers. Current smokers rated the cigarette-related pictures as being more pleasant and arousing than the former and never smokers. The LPP and picture-rating results suggest that former smokers, like never smokers, do not find cigarette-related stimuli to be as motivationally salient as current smokers.

The effects of nicotine dose expectancy and motivationally relevant distracters on vigilance.

The imminence of drug use (i.e., drug availability) has been found to be related to intensity of drug craving, but its effects on attentional bias to drug cues are unclear. This study investigated the effects of nicotine availability on attentional bias to smoking, affective, and neutral cues in a sample of adult smokers during a vigilance task. At the beginning of each of 4 laboratory sessions, overnight nicotine-deprived smokers (n = 51) were instructed that they would smoke a cigarette containing either nicotine (Told-NIC) or no nicotine (Told-DENIC) after completing the rapid visual information processing task with central emotional distracters (RVIP-CED). The RVIP-CED presented digits at a rapid pace, with participants instructed to respond with button presses to every third consecutive even or odd digit. Some digits were preceded by smoking, pleasant, unpleasant, or neutral distracter slides. During Told-NIC conditions, participants produced significantly longer reaction time (RT) latency than during Told-DENIC conditions. RT sensitivity (d'), a measure of the ability to discriminate true positives from false positives, was significantly lower during the Told-NIC than during the Told-DENIC conditions to targets following cigarette distracters. These results suggest that nicotine-deprived smokers expecting to imminently smoke a cigarette experience greater distraction, particularly to smoking-related stimuli, than when expecting to smoke a denicotinized cigarette.

Emotional reactivity to emotional and smoking cues during smoking abstinence: potentiated startle and P300 suppression.

Negative affect is thought to be an important factor in the maintenance of cigarette smoking, and thus it is important to further develop objective measures of smoking-related emotional responses. Nonsmokers, non abstinent smokers, and abstinent smokers participated in a cue reactivity task where eyeblink startle amplitude and startle probe P300 (P3) suppression were measured during the presentation of emotional pictures.During unpleasant pictures, the amplitude of both measures was smaller in non abstinent smokers than in nonsmokers or abstinent smokers. P3 suppression, but not startle amplitude, was larger in abstinent smokers than in nonsmokers. Abstinence-induced increases in cigarette craving were associated with P3 suppression during tobacco-related pictures. Results suggest that tobacco abstinence increases emotional reactivity to unpleasant stimuli, which is consistent with negative reinforcement models of tobacco addiction.