Cognitive processes underlying dysregulated alcohol consumption

Alcohol-use disorders are partially defined by high levels of alcohol consumption that persist despite "a persistent desire to cut down or regulate substance use" (American Psychiatric Association, 2013, criteria 1-2). They are also relatively treatment resistant, as treatment outcomes are characterised by high levels of relapse, with the treatments generally contributing little benefit over a placebo (Cutler & Fishbain, 2005). This inability to regulate consumption has been attributed to an imbalance between strong stimulus-driven (or 'bottom-up') processes that drive behaviour towards consumption, and relatively weak goal-directed (or 'top down') processes that control them. The strong stimulus-driven processes have been argued to develop through a history of alcohol consumption which sensitises structures in the basal ganglia, in particular the nucleus accumbens, to alcohol cues (Robinson & Berridge, 2003). Sensitisation of these neural structures manifests as a stimulus-driven inclination to approach and consume alcohol, called an approach-alcohol action tendency. According to this perspective, people will experience the inability to regulate consumption when their approach-alcohol action tendency is too strong to be controlled by their goaldirected control processes, especially their working memory capacity (WMC; Gladwin, Figner, Crone, & Wiers, 2011; Hofmann, Schmeichel, Friese, & Baddeley, 2011). Further understanding of the nature of an approach-alcohol action tendency and the means by which it can be modified or controlled could facilitate the development of treatments for alcohol-use disorders. This was the central aim of the present thesis, which was broken into three subordinate goals. The first was to assess whether the effect of approach-alcohol action tendency on approach alcohol behaviours is not only moderated by the ability to exert goal-directed control, but also by the individual's current task goal. The second was to determine whether alcohol action tendency is a distinct mechanism, or whether there is a common mechanism underlying both alcohol action tendency and another stimulus-driven process, selective attention. The third aim is to determine whether alcohol action tendency can be modified or inhibited. These aims were assessed in four papers that comprise the present thesis. The first paper demonstrates that dysregulated drinking is related to the interaction between alcohol action tendency, working memory capacity, and an individuals current task goal. The second paper demonstrates that alcohol action tendency and selective attention independently predicted dysregulated drinking. The third paper demonstrates that alcohol action tendency can be manipulated independently from selective attention, and that the change in action tendency affects subsequent alcohol consumption. The final paper shows that action tendency can be indirectly inhibited when people attempt to maintain abstract information in an active state, called a high cognitive load. Together these studies show that the effect of approach-alcohol action tendency is directly moderated by goal-directed control when there is a current goal to oppose the action tendency (Paper 1), or indirectly moderated by goal-directed control when they have a goal to maintain abstract information in an active state (Paper 4)...