Slot is a gambling machine that accepts coins or tokens and pays off prizes based on the number and arrangement of symbols lined up when the reels stop spinning. Traditionally, slot machines are mechanical devices that are activated by pulling a handle or pressing a button to spin one to three or more rotating reels marked into horizontal segments with different symbols. Modern electronic slot machines incorporate a random number generator, which determines where and how many times the reels will come to rest, as well as the size of the payoff.
Winning combinations are typically accompanied by a ringing bell and sounds to indicate the payout. Losses are often silent, though the sound of a coin hitting the glass and a clunk as the reels stop may still be heard. While the auditory feedback may make for a more exciting playing experience, it also serves as a secondary reinforcer that could in part underlie the arousal responses that make slots so addictive (Loba et al. 2001).
Although the vast majority of gamblers enjoy their gambling as harmless entertainment, a small but significant subset can suffer from serious gambling-related problems ranging from financial debt to relationships and professional difficulties to even involvement in criminal activities to support their habit (Blaszczynski, Sharpe, Walker, Shannon, & Coughlan, 2005). In order to mitigate these harms, it is important to understand what drives this allure of slots.
Previous studies of the psychological effect of music on gambling have typically examined the effects of sounds in isolation, but in slot games, music is almost always paired with images. This creates a perceptual onslaught of sounds and visual stimuli that may amplify each other, thus amplifying the effect of a winning combination (Iwamiya et al. 1994; Bullerjahn and Guldenring, 1994).
In this study, participants responded to a series of six prompts while they played a slot machine simulator on a Lenovo laptop computer. They completed a DASS-21 questionnaire, the General Enjoyment Index (GEQ), and an item that asked them to estimate how often they won on the slot machine simulator. In addition, they were asked to rate their experience with dark flow and a measure of positive affect during the slot session.
Results showed that both measures of reward reactivity (PRP and force as a function of win size) were positively correlated with ratings of dark flow. In contrast, they were uncorrelated with PGSI scores and depression scores. These findings suggest that the enjoyment attributable to dark flow is a distinct, non-problematic route to slot enjoyment. Moreover, the fact that these measures are readily available to researchers without the use of cumbersome electrodes and wires likely enhances ecological validity. As such, these measures are an important advance in our understanding of the psychological processes that underlie the allure of slots. The authors acknowledge that additional research on the effects of different aspects of slots is needed to fully explore this phenomenon. They also acknowledge that the results presented here should be interpreted with caution because the sample was relatively small and may not reflect the larger population of slot players.