Behavioural and electrophysiological (ERP) determinants of decision-making in individuals with a smoking habit

Individuals with a smoking habit or with other addictions display deficits in decision-making, which are suggested to contribute to the perpetuation of their compulsive behaviour. In individuals with a smoking habit (ISH), performance in the Iowa Gambling Task (IGT), which operationalises real-life decision making under uncertainty, is worsened by both exposure to craving-inducing cigarette-related cues and abstinence. However, the behavioural and neurophysiological nature of “baseline” decision-making in ISH, the impairment of which may reflect a general insight deficit, related to an increased reliance on implicit motivational mechanisms, such as incentive habits, in controlling behaviour, has not been fully elucidated. Here, we sought to characterise the behavioural and electrophysiological (Event-Related Potentials, ERPs) determinants of “baseline” decision-making, as assessed in the IGT, in twenty ISH compared to twenty control participants. Neurophysiological processes related to option evaluation, response selection and feedback integration were assessed as the pre-outcome N500 (480 – 520 ms), the DNP and the post-outcome FRN & fP300 (450 – 700 ms) ERPs across five blocks of 60 trials during which the selection of advantageous decks, an index of decision making in the IGT, was recorded. While ISH did not perform significantly less well than controls overall under these baseline conditions, they displayed only half the improvement in decision making shown by controls over the session, and they engaged different neurophysiological processes. While the N500 amplitude was more negative for non-risky than for risky choices across groups, it was slightly smaller in ISH than in controls. Similarly, while the amplitude of the FRP was greater for negative than for positive outcomes across groups, in ISH, this contrast was inversely proportional to the severity of the smoking habit, as assessed with the Fagerström test. These findings together identify biobehavioural determinants of decision making in individuals with a smoking habit that may represent an endophenotype of the impaired insight that characterises individuals with a substance use disorder.