The effects of prolonged abstinence on the processing of smoking cues: an ERP study among smokers, ex-smokers and never-smokers.

Processing bias is an important feature of substance abuse. The issue whether processing bias is a more or less permanent feature of nicotine addiction remains to be resolved. The present study addresses the role of smoking status on smoking-related processing bias. We employed Event-Related Brain Potentials (ERPs) as measure of processing bias to investigate this issue. Further, self-report measures of nicotine craving and pleasantness ratings of smoking stimuli were obtained. Three groups, smokers, ex-smokers and never-smokers, were compared on their electrophysiological brain response to smoking-related and neutral pictures. The present study shows that both the P300 and SPW amplitudes in response to smoking-related pictures are significantly more enhanced for smokers than for ex-smokers and never-smokers at frontal and central sites, whereas the magnitude of the P300 and SPW amplitudes in response to neutral pictures does not differ between the three groups. Accordingly, it can be concluded that smokers show more bias for smoking-related pictures than ex-smokers and smokers. Because there is no significant difference between the P300 and SPW amplitudes of ex-smokers and never-smokers, it can also be concluded that ex-smokers display the same (low) level of processing bias as never-smokers. In addition, nicotine-craving ratings and pleasantness ratings of smoking stimuli were higher in smokers compared to ex-smokers. It can be concluded that the smoking-related craving, pleasantness rating, and processing bias decreases after a period of prolonged abstinence.