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Psychological theories consider autonomic arousal to be a reinforcer for problem gambling. Structural characteristics such as near-misses, which are non-win events that come close to a real win, have been shown to elicit win-like responses while increasing motivation and gambling persistence. This study investigated the autonomic and subjective responses of young adults to different gambling outcomes. This study also investigated sex differences in autonomic and subjective responses to different gambling outcomes. Participants from Sweden (n = 270) performed a computerized slot machine task that produced wins, near-misses (before and after payline) and full-misses. Phasic measurements of heart rate (HR) and skin conductance responses (SCR) were recorded during gambling performance and ratings of perceived chance of winning, pleasure and motivation to play were collected following each gambling outcome. Autonomic responses differed across slot machine outcomes as indicated by HR and SCR. Compared with other gambling outcomes, near-misses elicited the largest HR accelerations, and they also elicited larger HR decelerations and SCRs relative to full-misses. Near-misses before and after payline elicited differential psychophysiological responses and subjective reports, suggesting different emotional processing of near-miss subtypes. Females showed increased SCRs and motivation following win outcomes compared with males. In conclusion, wins, near-misses and full-misses generate differential physiological and subjective responses among young adults. Autonomic responses to wins differed between male and female players, emphasizing the need to consider sex differences when investigating the role of autonomic arousal in gambling.

Decision-making requires that individuals perceive the probabilities and risks associated with different options. Experimental human and animal laboratory testing provide complimentary insights on the psychobiological underpinnings of decision-making. The Iowa gambling task (IGT) is a widely used instrument that assesses decision-making under uncertainty and risk. In the task participants are faced with a choice conflict between cards with varying monetary reinforcer/loss contingencies. The rat gambling task (rGT) is a pre-clinical version using palatable reinforcers as wins and timeouts mimicking losses. However, interspecies studies elaborating on human and rat behavior in these tasks are lacking. This study explores decision-making strategies among young adults (N = 270) performing a computerized version of the IGT, and adult outbred male Lister Hooded rats (N = 72) performing the rGT. Both group and individual data were explored by normative scoring approaches and subgroup formations based on individual choices were investigated. Overall results showed that most humans and rats learned to favor the advantageous choices, but to a widely different extent. Human performance was characterized by both exploration and learning as the task progressed, while rats showed relatively consistent pronounced preferences for the advantageous choices throughout the task. Nevertheless, humans and rats showed similar variability in individual choice preferences during end performance. Procedural differences impacting on the performance in both tasks and their potential to study different aspects of decision-making are discussed. This is a first attempt to increase the understanding of similarities and differences regarding decision-making processes in the IGT and rGT from an explorative perspective.

Monetary reward processing during gambling is associated with dopaminergic functioning. Emotional reactivity to different gambling stimuli can be indexed by autonomic nervous system (ANS) responses measured by skin conductance responses (SCR) and heart rate (HR). Genetic markers regulating neural dopaminergic activity, such as the D2 dopamine receptor, might confer differential sensitivity to gambling stimuli, which may also be modulated by previous exposure to gambling. To date, no previous studies have explored the relationship between genetic markers of the D2 dopamine receptor, real-life gambling exposure and ANS responses during gambling. Hence, this study explored associations and interactions between DRD2 C957T (rs6277) and ANKK1 Taq1A (rs1800497) genotypes, real-life gambling frequency and autonomic responses during reward anticipation and outcome delivery in a slot machine task producing wins, near-misses and full-misses. Participants (n = 270) performed a computerized slot machine task with recordings of SCRs and HR responses during gambling performance and provided saliva samples for DNA extraction. Taq1A A1 carriers showed increased SCRs and HR responses during reward anticipation and to wins. Greater responsivity during anticipation, as well as to wins and full-misses, was also observed in C957T heterozygotes. Regarding real-life gambling involvement, higher gambling frequency among Taq1A A1 carriers was associated with decreased HR responses during anticipation and to wins. Results suggest that polymorphic variants of the D2 dopamine receptor may confer differential sensitivity to different gambling stimuli which may further be modulated by real-life gambling exposures. However, further studies are needed in well powered samples of gamblers and control subjects.

Impairments in decision-making plays an important role in gambling disorder. Decision-making under uncertainty relies on an interplay between emotion and rationality, requiring changes in skin conductance responses (somatic markers), which involve changes in neurotransmitter release, such as dopamine. Functional variants of D2 receptor genotypes have been implicated in gambling disorder. Variability in dopamine D2 receptor genes and previous gambling may be associated with the biasing role of somatic markers in decision-making. This may also be modulated by sex. Hence, this study explored the relationship between polymorphic variants of DRD2/ANKK1 genotypes, previous exposure to gambling and sex on decision-making, and interactions with somatic markers. Participants (n = 270) performed the IOWA Gambling Task with recordings of anticipatory skin conductance responses and provided saliva samples for DNA extraction. Taq1A A1 and C957T C carriers with previous gambling exposure showed poorer decision-making than non-exposed individuals. In Taq1A A1 and C957T C variants, larger somatic markers were linked to improved decision-making, but this was not observed in individuals with gambling exposure who also displayed blunted somatic markers. Sensitivity to somatic markers as a function of C957T genotypes was also influenced by sex. Thus, the reduced D2 receptor expression in subgroups of gambling individuals may render them more susceptible to the adverse effects of gambling. Reduced sensitivity to emotional guidance may be prominent in subgroups carrying genotypes associated with reduced striatal D2 receptor expression. Results indicates differential susceptibility effects in a non-clinical sample, with possible implications for the predisposition and risk of developing problem gambling.