Abstract
Experimental studies on smoking and response-inhibition capacity have revealed inconsistent findings, which might be due to differences in sensitivity of the behavioral paradigms used. Here we aimed to replicate the impaired response inhibition in male smokers that was found in a previous study using a two-choice oddball task. This task enables the use of response times as index of inhibition capacity and equalizes the response requirement for the different trial types. In addition, we measured event-related brain potentials to explore the nature of the cognitive processes underlying the behavioral difference. Smokers (n = 19) and non-smokers (n = 19) were asked to make a different response to frequent standard stimuli (cigarette-unrelated pictures) than to infrequent deviant stimuli (cigarette-related pictures). Compared to non-smokers, smokers took a longer time to respond to deviant but not standard stimuli. In addition, smokers, but not non-smokers, displayed a smaller N2 amplitude to deviant than standard stimuli, and only the non-smokers showed larger P3 amplitudes to deviant compared to standard stimuli. Moreover, the response time (RT) measure was differentially correlated with N2 and P3 amplitudes in smokers and non-smokers. The joint results support the notion of deviant cognitive processes in smokers compared to non-smokers that are either directly or indirectly related to response-inhibition capacity.
