Reward responsivity and inhibitory control in smokers
Neurobiological models of addiction suggest that abnormalities in brain reward pathways may distort inhibitory control processes and behavioural responses to non-drug incentives. This talk will outline a series of studies with smokers exploring: abstinence-related impairments; their ‘recovery’ over protracted abstinence; predictive utility for smoking relapse; and an intervention attempt.
In the initial study, one hundred and forty five smokers tested under nicotine and abstinence conditions showed impaired inhibitory control and dampened responsiveness to reward during abstinence. We then explored whether these impairments recovered over 3 months of smoking cessation in the same participants. Whilst reward responsivity showed significant improvement, there was no improvement in inhibitory control. Furthermore, weakened inhibitory control predicted relapse to smoking.
In a more recent study, we explored whether engaging in a response inhibition task emphasizing restrained responding will reduce cigarette craving and smoking-related behaviour in abstinent smokers. Although the restraint manipulation did result in fewer inhibition errors, this had no effect on craving or the number of puffs taken on an electronic cigarette in a subsequent taste-preference task.
In conclusion, abstinence from smoking is associated with reward responsivity and response inhibition deficits. The latter does not appear to improve with protracted abstinence and those smokers with weaker inhibitory control relapse sooner. Our initial intervention to try to promote response inhibition in order to reduce craving and smoking behaviour has been unsuccessful. Work is continuing to explore whether, and in what form, response inhibition training can impact on smoking behaviour.