The near-miss effect in online slot machine gambling: A series of conceptual replications.

OBJECTIVE: Near-misses are a structural characteristic of gambling products that can be engineered within modern digital games. Over a series of preregistered experiments using an online slot machine simulation, we investigated the impact of near-miss outcomes on subjective ratings (motivation, valence) and two behavioral measures (speed of gambling, bet size). METHOD: Participants were recruited using Prolific and gambled on an online three-reel slot machine simulator that delivered a one in three rate of X-X-O near-misses. Study 1 measured trial-by-trial subjective ratings of valence and motivation (Study 1a, n = 169; Study 1b, n = 148). Study 2 (n = 170) measured spin initiation latencies as a function of the previous trial outcome. Study 3 (n = 172) measured bet size as a function of the previous trial outcome. RESULTS: In Study 1a, near-misses increased the motivation to continue gambling relative to full-misses, supporting Hypothesis 1. On valence ratings, near-misses were rated significantly more positively than full-misses, in the opposite direction to Hypothesis 2; this effect was confirmed in a close replication (Study 1b). In Study 2, participants gambled faster following near-misses relative to full-misses, supporting Hypothesis 3. In Study 3, participants significantly increased their bet size following near-misses relative to full-misses, supporting Hypothesis 4. CONCLUSION: Across all dependent variables, near-miss outcomes yielded statistically significant differences from objectively equivalent full-miss outcomes, corroborating the "near-miss effect" across both subjective and behavioral measures, and in the environment of online gambling. The unexpected findings on valence ratings are considered in terms of boundary conditions for the near-miss effect, and competing theoretical accounts based on frustration/regret, goal generalization, and skill acquisition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Post-reinforcement pauses during slot machine gambling are moderated by immersion.

The post-reinforcement pause (PRP) is an operant effect in which response latencies increase on trials following the receipt and consumption of reward. Human studies demonstrate analogous effects in electronic gambling machines that utilise random ratio reinforcement schedules. We sought to identify moderators of the human PRP effect, hypothesising that the magnitude of gamblers' PRPs is moderated by the type of reinforcing outcome (genuine wins vs. losses-disguised-as-wins [LDWs] vs. free-spin bonus features) and individuals' level of gambling immersion, a cognitive state linked to problem gambling. Experienced slot machine users (N = 53) played a real slot machine for 20 min. The dependent variable was defined as the time delay in the initiation of each bet ("Spin Initiation Latency"; SIL). Using 80% of trials, a linear model was fit regressing SIL on the independent variables (outcome type, immersion, and outcome-by-immersion interaction), and a larger group of covariates (participant ID, trial number, winnings, etc.) selected using double-robust LASSO-regularised regression. The previously unseen 20% of cases were used to validate the model. Positively reinforcing outcome types (wins, LDWs, bonus spins) showed significantly larger SILs than losses, indicating a PRP effect. Immersion did not predict response latencies, but win-by-immersion and LDW-by-immersion interactions indicated that pauses were greater among more immersed participants. The small number of free-spin bonus features showed similar trends that were not statistically significant. These results indicate that gamblers immersed in play remained sensitive to in-game reinforcement (contrary to a prevailing account), and provide guidance for researchers bridging laboratory research and real-world behaviour.

Do pupillary responses during authentic slot machine use reflect arousal or screen luminance fluctuations? A proof-of-concept study.

Modern slot machines are among the more harmful forms of gambling. Psychophysiological measures may provide a window into mental processes that underpin these harms. Here we investigated pupil dilation derived from eye tracking as a means of capturing changes in sympathetic nervous system arousal following outcomes on a real slot machine. We hypothesized that positively reinforcing slot machine outcomes would be associated with increases in arousal, reflected in larger pupil diameter. We further examined the contribution of game luminance fluctuations on pupil diameter. In Experiment 1A, experienced slot machine gamblers (N = 53) played a commercially-available slot machine in a laboratory for 20 minutes while wearing mobile eye tracking glasses. Analyses differentiated loss outcomes, wins, losses-disguised-as-wins, and (free-spin) bonus features. Bonus features were associated with rapid increases in pupil diameter following the onset of outcome-related audiovisual feedback, relative to losses. In Experiment 1B, luminance data were extracted from captured screen videos (derived from Experiment 1A) to characterize on-screen luminance changes that could modulate pupil diameter. Bonus features and wins were associated with pronounced and complex fluctuations in screen luminance (≈50 L and ≈25L, respectively). However, the pupil dilation that was observed to bonus features in Experiment 1A coincided temporally with only negligible changes in screen luminance, providing partial evidence that the pupil dilation to bonus features may be due to arousal. In Experiment 2, 12 participants viewed pairs of stimuli (scrambled slot machine images) at luminance difference thresholds of ≈25L, ≈50L, and ≈100L. Scrambled images presented at luminance differences of ≈25L and greater were sufficient to cause pupillary responses. Overall, pupillometry may detect event-related changes in sympathetic nervous system arousal following gambling outcomes, but researchers must pay careful attention to substantial in-game luminance changes that may confound arousal-based interpretations.

Investigating Flow State and Cardiac Pre-ejection Period During Electronic Gaming Machine Use.

Flow activities (e.g. sports and gaming) have been associated with positive affect and prolonged engagement. In the gambling field, modern electronic gaming machines (EGMs, including modern slot machines) have drawn concern as a potentially flow-inducing activity that may be associated with gambling-related harms. Current research has heavily relied on self-reported flow, and further insights may be afforded by physiological methods. We present data from three separate experiments in which self-reported gambling flow and cardiac pre-ejection period (PEP; a measure of sympathetic nervous system arousal) were examined. Male undergraduate participants gambled on a genuine EGM in a laboratory setting for a period of at least 15 min, and completed the Flow subscale of the game experience questionnaire (GEQ). Aggregated data were analyzed using multilevel regression. Although EGM gambling was not associated with significant changes in PEP across participants, we found that self-reported flow states were associated with significant decreases in PEP during the first five minutes of EGM use. Thus, participants who experienced flow showed a greater sympathetic nervous system response to the onset of gambling. Though these effects were consistent in experiments 1 and 2, in experiment 3 the effect was inverted during the same time window. We conclude that flow during EGM gambling appears to be associated with early changes in sympathetic nervous system activity, but stress that more research is needed to characterize boundary conditions and moderating factors.

Zoned in or zoned out? Investigating immersion in slot machine gambling using mobile eye-tracking.

BACKGROUND AND AIMS: Immersion during slot machine gambling has been linked to disordered gambling. Current conceptualizations of immersion (namely dissociation, flow and the machine zone) make contrasting predictions as to whether gamblers are captivated by the game per se ('zoned in') or motivated by the escape that immersion provides ('zoned out'). We examined whether selected eye-movement metrics can distinguish between these predictions. DESIGN AND SETTING: Pre-registered, correlational analysis in a laboratory setting. Participants gambled on a genuine slot machine for 20 minutes while wearing eye-tracking glasses. PARTICIPANTS: Fifty-three adult slot machine gamblers who were not high-risk problem gamblers. MEASUREMENTS: We examined self-reported immersion during the gambling session and eye movements at different areas of the slot machine screen (the reels, the credit window, etc.). We further explored these variables' relationships with saccade count and amplitude. FINDINGS: The ratio of dwell time on the game's credit window relative to the game's reels was positively associated with immersion (t(51)  = 1.68, P = 0.049 one-tailed, R2  = 0.05). Follow-up analyses described event-related changes in these patterns following different spin outcomes. CONCLUSIONS: Immersion while gambling on a slot machine appears to be associated with active scanning of the game and a focus on the game's credit window. These results are more consistent with a 'zoned in' account of immersion aligned with flow theory than a 'zoned out' account based on escape.

Slot machine gambling and testosterone: Evidence for a "winner-loser" effect?

The "winner-loser effect" refers to a phenomenon in testosterone research where the outcome of a social competition induces increases (wins) and/or decreases (losses) in testosterone levels. Here, we sought to test to what extent changes in testosterone occur in response to gambling behavior. More specifically, we hypothesized that the winner-loser effect would extend to slot machine gambling as a solitary (noncompetitive) gambling activity in players who "anthropomorphized" the slot machine, thus treating the machine as a human opponent. Male participants (n = 113) were recruited into a quasi-experimental design involving 15 min of authentic slot machine gambling, incentivized by a $10 cash bonus for participants who finished in profit. In addition to salivary measures of testosterone, salivary cortisol and self-reported anthropomorphization of the slot machine were tested as potential moderators. Contrary to predictions, winning and losing slot machine sessions did not exert significant differential effects on testosterone, and this pattern was not moderated by cortisol levels or slot machine anthropomorphization. Exploratory analyses tested relationships between subjective gambling experiences in the sessions and testosterone change. Higher positive affect and flow predicted greater testosterone declines from pre- to postgambling. The testosterone results add to a growing literature on the boundary conditions of the winner-loser effect and inform future studies on testosterone reactivity in relation to gambling and disordered gambling. The tendency to anthropomorphize slot machines is a neglected cognitive distortion in gambling that merits further study. (PsycINFO Database Record (c) 2018 APA, all rights reserved).