Cathrine Hultman: Autonomic responses and decision-making during gambling: Gene-environment interactions and translational perspectives

Abstract

This thesis investigated autonomic responses and decision-making during two gambling tasks in a population of young adults. The included papers specifically addressed: 1) autonomic responses and subjective perceptions of slot machine outcomes, with a focus on the effects of near-misses; 2) decision-making strategies in human and animal gambling tasks; and 3) differential autonomic responsivity during gambling and decision-making as a function of polymorphic variants of the dopamine D2 receptor (Taq1A and C957T), including potential influences of prior gambling exposure and sex.  

The four papers were based on data from an experimental study conducted at Västmanland Hospital in Västerås, Sweden. Participants (n = 270) completed two gambling tasks—a slot machine gambling task and the Iowa Gambling Task (IGT)—while their heart rate (HR) and skin conductance responses (SCR) were simultaneously recorded. Saliva samples were collected for DNA extraction. Additionally, Paper II included comparisons with adult outbred male Lister Hooded rats (N = 72) performing the rat Gambling Task (rGT).

Findings from Paper I contribute to the existing literature on the near-miss effect in gambling, demonstrating heightened autonomic responses to these structural features, along with distinct subjective perceptions of affect, motivation, and perceived chances of winning across different near-miss subtypes. Furthermore, females exhibited stronger responses to winning outcomes compared to males.

Comparisons of decision-making strategies in the IGT and rGT in Paper II revealed that human performance was characterized by exploration and learning over time, whereas rats displayed relatively stable preferences for advantageous choices throughout the task. Procedural differences in task protocols suggest that these models are suited to examining distinct aspects of decision-making.

Papers III and IV provide preliminary evidence that polymorphic variants of the D2 dopamine receptor are associated with differential autonomic sensitivity to slot machine gambling cues and rewards, as well as anticipatory responses linked to implicit guidance during decision-making under uncertainty. These relationships were further influenced by prior gambling exposure and sex, suggesting potential differential susceptibility to gambling stimuli.

In conclusion, near-misses should be considered in gambling regulation policies aimed at harm prevention. Translational inferences from both human and animal studies require careful methodological considerations and to what degree they capture similar psychological constructs that are relevant to real-world gambling behaviors. Furthermore, potential gene-environment interactions between genetic predispositions and gambling exposure in shaping emotional responses and decision-making warrant further investigation in well-powered studies.