Slot Machines and the Pleasure That Goes With Them

A slot is a narrow depression, groove, notch, or aperture; especially one for the reception of something that fits or slides into it.

In modern multiline slot machines, a player spins a reel and, if the reel lands on a winning combination of symbols, it triggers a visual and auditory feedback, such as animations of the winning symbols and credits counting up with a jingle. These feedback cues have been shown to boost the amount of enjoyment that people get from playing slots (Dixon et al., 2019).

While previous research has typically focused on the physiological effects of music in isolation from other sensory modalities, the sounds that accompany slot machine outcomes are invariably paired with images. This combination creates a perceptual onslaught of sights and sounds that amplify the effect of each other.

We provide the first empirical evidence that these sensory feedback cues can amplify the pleasure that people get from playing slots. To test this hypothesis, we designed a study in which participants played a virtual slot machine with different payback schedules and reward amounts. We measured their enjoyment using a novel psychophysiological measure (PRPs as a function of win size) and a force measure that measures how much the player is gripping the handle. Both of these measures were correlated with positive affect ratings and were uncorrelated with depression scores.

We also found that the sound of the slot machine’s wins triggered greater arousal than did its losses. This may partly explain why so many players play these addictive games: the arousal generated by winning at the slot machine distracts players from negative thoughts that would otherwise undermine their motivation to continue gambling.