Historically, smokers were considered a single homogeneous group, but over the past two decades research has increasingly focused on differentiating daily and non-daily smokers. Despite fundamentally different smoking habits and motives, daily and non-daily smokers have similar cessation rates. In order to understand why both groups may experience a similar difficulty quitting smoking, this thesis explored neurocognitive mechanisms associated with addictive behaviour. In order to profile these mechanisms, a systematic review was conducted, highlighting there was a gap to address in two areas of research relating to drive and control. Study One (N = 60) and Study Two (N = 166) investigated attentional bias towards smoking cues using the visual probe task, finding there was no meaningful difference between daily and non-daily smokers in trait-level attentional bias. Study Three (N = 28) measured ERP components associated with inhibitory control (Go/NoGo task) and error processing (Eriksen Flanker task). There were no significant effects of interest, but the sample size was smaller than planned. This thesis made three contributions to the study of addictive behaviour. First, the systematic review highlighted that research investigating lighter and heavier smokers has a problematic level of heterogeneity in the definitions used to define the groups. Second, there was no meaningful difference in attentional bias between daily and non-daily smokers, supporting contemporary theories that attentional bias may be best conceptualised as a state-level construct. Finally, internal consistency estimates of the ERP measures of inhibitory control and error processing supported previous research reporting good psychometric properties. Overall, this thesis presented a focused profile of measures relating to drive and control neurocognitive mechanisms, but there were no meaningful differences between daily and non-daily smokers. If these mechanisms are important to addictive behaviour, future research will have to investigate their role using alternative designs.
|Date of Award||Dec 2020|
|Supervisor||Rebecca Jenks (Supervisor), Nigel Wilson (Supervisor) & Hayley Wright (Supervisor)|