Cigarette smoking and attention: processing speed or specific effects?

Rationale: It has been evidenced that nicotine acts on some dimensions of human attention. Objective: This study was carried out to test whether the positive effects of nicotine usually observed on the posterior system are specific or should rather be explained in terms of an effect of nicotine on eye movement velocity. Methods: Ten participants were submitted to four tasks assessing attention. The tasks were borrowed from Zimmermann and Fimm's Battery for the Assessment of Attention: alert, eye movements, visual search and incompatibility. The order of the different tasks was balanced among participants. A within-subjects repeated-measure design was used. Participants received a 0.9-mg or 0.1-mg nicotine cigarette. The 0.1-mg cigarette was used as control. The order of administration of doses over sessions was counterbalanced. During the testing day, volunteers smoked their own cigarette and then waited 3 h without smoking. At the end of this abstinence period, participants completed the baseline tests before smoking an experimental cigarette ad libitum. They were then tested again. Results: Participants who received nicotine appeared to respond faster in an eye movement task - a task associated with a non-elaborated attentional process. Similarly, their alert state improved. On the contrary, no effect of nicotine was observed in the incompatibility task and in the visual search task depending on elaborated attentional process. Conclusions: Data support previous observations and suggest that, first, non-elaborated information processing appeared to be more sensitive to nicotine and, second, this effect is not due to a velocity factor.