Decision-making during gambling: an integration of cognitive and psychobiological approaches

Abstract

Gambling is a widespread form of entertainment that may afford unique insights into the interaction between cognition and emotion in human decision-making. It is also a behaviour that can become harmful, and potentially addictive, in a minority of individuals. This article considers the status of two dominant approaches to gambling behaviour. The cognitive approach has identified a number of erroneous beliefs held by gamblers, which cause them to over-estimate their chances of winning. The psychobiological approach has examined case-control differences between groups of pathological gamblers and healthy controls, and has identified dysregulation of brain areas linked to reward and emotion, including the ventromedial prefrontal cortex (vmPFC) and striatum, as well as alterations in dopamine neurotransmission. In integrating these two approaches, recent data are discussed that reveal anomalous recruitment of the brain reward system (including the vmPFC and ventral striatum) during two common cognitive distortions in gambling games: the near-miss effect and the effect of personal control. In games of chance, near-misses and the presence of control have no objective influence on the likelihood of winning. These manipulations appear to harness a reward system that evolved to learn skill-oriented behaviours, and by modulating activity in this system, these cognitive distortions may promote continued, and potentially excessive, gambling.

Figure 1.

The slot-machine task uses two-reels, with the same six icons displayed on each reel, and a horizontal ‘payline’ across the centre of the screen. On trials with a white screen background, the volunteer selects one ‘play icon’ on the left reel, using two buttons to scroll through the icons, and one button to select. On trials with a black screen background, the computer selects the play icon. Following icon selection, the right-hand reel spins for a variable duration (2.8–6 s), and decelerates to a standstill. During outcome (4 s), if the right reel stopped on the selected icon (i.e. matching icons displayed in the payline), the subject was awarded £0.50; all other outcomes won nothing. Following the outcome phase, there was an inter-trial interval of variable duration (2–7 s). In the fMRI version of the task, two ratings were taken on intermittent (1/3) trials: following selection, subjects were asked ‘How do you rate your chances of winning?’, and following outcome, subjects were asked ‘How much do you want to continue to play the game?’. Reprinted from Clark et al. (2009).

Figure 2.

Coronal sections through the brain showing (a(i)(ii)) the contrast of monetary wins minus non-win outcomes, at y = 4 (ventral striatum) and y = 34 (medial prefrontal cortex), thresholded at p < 0.05 corrected with family-wise error. (b) The contrast of near-miss outcomes minus full-miss outcomes, within regions sensitive to monetary wins, at y = 4 (ventral striatum; thresholded at t = 3.0 to better display extent of activation). (c) the interaction between near-miss outcomes (i.e. near-misses minus full-misses) and personal control (participant-chosen trials minus computer-chosen trials), within regions sensitive to monetary wins, at y = 34 (medial prefrontal cortex; thresholded at t = 3.0 to better display extent of activation). Data redrawn from Clark et al. (2009).