A narrow depression, groove, notch, or opening for passing something through, such as a door, window, or letter. (Also spelled “slot”; see below)

In the casino industry, slots remain the largest revenue generator for most operators. However, many players can develop serious gambling problems that lead to mounting financial debt, difficulties with relationships and professional pursuits, and even a variety of criminal activities in support of their gaming addictions (Blaszczynski, Sharpe, Walker, Shannon, & Coughlan, 2005). Consequently, it is crucial to understand what drives the allure of slot machines in order to prevent harm.

Unlike other forms of gambling, slot machines provide immediate feedback on the result of a spin. Wins and losses are accompanied by high-fidelity attention-grabbing music and animations that increase in duration as the winning amount increases, creating a positive feedback loop of arousal (Dixon et al., 2019). As such, they appear to offer a form of relief from negative emotions and thoughts that may otherwise hinder enjoyment of life.

To determine the mechanisms underlying the allure of slot machines, we conducted an experiment using three separate slot simulators housed in their own cabinet and connected to a computer with Labchart software (AD Instruments PowerLabs). A force transducer was fixed underneath each of the spin buttons on the simulators. When pressed, the spin button generated a volt signal that was recorded and saved on the computer as an event record. This event record was then used to calculate the simulated win amounts displayed on each machine.