Two blocks of trials were presented in each session. The first was considered a habituation block used to acclimate the participant to the novel effects of the startle procedure, nasal spray administration, and general laboratory surroundings. All participants received placebo spray prior to this block. The second (test) block was similar to the habituation block in terms of slide content. Smokers received either nicotine or placebo nasal spray prior to the test block of trials. Self-report of nicotine withdrawal and nicotine craving was measured prior to each laboratory session. Before beginning the laboratory portion of the experiment, smokers were administered instruments assessing self-reported levels of nicotine use, acute stress, and affect. Subjects denied the use of nicotine products other than cigarettes.
