Response inhibition and sustained and attention in heavy smokers versus non-smokers

Background: Repeated nicotine administration induces neuro-adaptations associated with abnormal dopaminergic activity. These neuronal changes may contribute to impaired inhibitory control and attention deficit. However, it remains unclear whether smokers perform worse than non-smokers on tests that involve attention and control of impulsivity. The present study examined response inhibition and sustained attention capacities in a large sample of smokers and non-smokers. Methods: Continuous Performance Test (CPT) and Go/ NoGo computerized tasks were used as a measure of response-inhibition ability and sustained attention. Threeway repeated measures analysis of covariance was used with response time, variability of response time, number of commission errors (inappropriate responses to stimuli) and number of omission errors (missed stimuli) as dependent measures. Main effects were: group (smokers and controls), condition (CPT and Go/NoGo), and block (in each condition); gender, education, and age were used as covariates. Results and Conclusions: Smokers, as compared to the control group, made more errors of commission in the Go/ NoGo task, reflecting impaired inhibition ability. However, we found no significant differences between the groups in our measure of sustained attention. Impaired response inhibition was found to co-occur with heavy smoking and therefore may be a potential target for the development of more effective cessation programs.