The objective of this project is to develop and explore the utility of techniques designed to better characterize the effects of nicotine on attention and affect in smokers and never-smokers, and to relate these effects to psychological vulnerability factors associated with smoking. As a group, smokers are vulnerable to both attentional and emotional problems and disorders, including attention-deficit, depression, and other negative-affect-related traits and disorders. The project will extend previous attentional paradigms and validate cognitive-behavioral and electrocortical paradigms designed to assess attentional and affective processes. Specifically, the project will characterize effects of nicotine and nicotine deprivation on attentional tasks designed to reflect different attentional systems. Some of these tasks will assess the ability to focus attention on a central task in the face of peripheral distractors. Other tasks will assess the effects of nicotine on the ability to allocate attention to laterally positioned stimuli. Distractors will include systematic collections of stimuli that differ cognitively, affectively, and in smoking- related potential. Project studies will assess the effects of transdermal-patch administered nicotine on attentional and affective dysfunction by measuring 1) distractability and attentional performance, 2) affective state, and 3) electrocortical topographic responses to attended stimuli and distractors. The impact of nicotine on lateralized attentional systems will be assessed by presenting distractor stimuli to a central visual field as well as to alternate hemispheres by means of visual half-field presentations. We hypothesize that nicotine will enhance attentional performance and minimize negative affect, especially in individuals more vulnerable to attentional dysfunction and negative affect/mood states. The second phase of the research will assess and compare the above attentional effects of nicotine in nonsmokers and smokers. This knowledge will be useful in developing rationally-based treatment strategies aimed at increasing smoking abstinence. During both phases, we will also genotype two specific dopamine receptors (DRD2 and DRD4). These receptors have been associated with smoking, attention deficit disorder, drug abuse, and impulsive sensation seeking. Ascertained receptor differences in genotype will be related to the effects of nicotine on mood and attentional performance, given the various types of distractors aforementioned.
