Effects of smoking context on habituation to a repeated cognitive task.

This study assessed the role of smoking-related cues on habituation of electrodermal responding and facial neuromuscular responses in male smokers. In three of the four groups, subjects smoked for the first five trials followed by the laboratory arithmetic task. On the sixth trial one group of subjects continued to smoke nicotine cigarettes, while the context was changed for subjects in the other groups by 1) omitting the pharmacological cues (smoking a non-nicotine cigarette) or 2) omitting both the pharmacological and behavioral cues (not smoking). Subjects in a non-smoking control group did not smoke before any of the six trials. During trials 1-5, smoking significantly increased the rate of habituation of electrodermal activity. On trial 6, electrodermal activity significantly increased for subjects who had a change in smoking context, whether it involved removal of pharmacological or smoking plus pharmacological cues. No differences in electrodermal activity were observed between subjects in these groups compared to non-smoking control subjects. Smoking increased zygomatic activity (predominant during smiling) during trials 1-5, consistent with an interpretation of the positively reinforcing nature of smoking. Corrugator activity (predominant during frowning or concentration) increased for subjects who had both the pharmacological and behavioral smoking cues omitted on trial 6.