Tobacco smoking is associated with attenuated error monitoring

Rationale: Addiction is associated with neurophysiological deficits in error monitoring (EM), i.e., the continuous assessment of ongoing actions and comparing the outcomes of these actions with internal goals and standards, measured by, e.g., event-related potentials (ERPs). For tobacco smoking, the largest global substance addiction, there is no firm conclusion on the relation with EM due to a paucity of studies. 

Objectives and methods: A relatively large gender-balanced sample (N = 92, of which 44 smoking participants) performed the Eriksen-flanker task while the electroencephalogram (EEG) was recorded. The error-related negativity (ERN) and the error positivity (Pe) were measured, as well as event-related oscillations (EROs) in the theta and delta frequency bands. 

Results: The results show a blunted ERN and Pe in smoking participants compared to non-smoking participants, providing evidence for attenuated error detection and salience. Reduced power in transient event-related theta and delta oscillations for smoking participants appeared to underlie the weaker ERN and Pe, respectively. There was no group difference in behavioral performance. Group differences in Pe/Pc, theta, and delta band power remained after robustness testing (i.e., 80 % reliability criterium with 18 trials in each condition). 

Conclusions: Attenuated error monitoring was found for people who smoke tobacco, manifested as a blunted ERN and Pe, which appear to be driven by reduced bursts of theta and delta power, respectively. This shows that tobacco smoking is associated with a robust deficit in EM that has been found in other substance use disorders, and it appears to increase with dependence severity.