Slot Machines – Do Near Misses Induce Reinforcement in Gambling Responses?

A slot is an opening in a machine or container, for example a hole that you put coins in to make the machine work. It can also be a position, time or other opportunity.

In a slot machine, symbols are displayed on multiple columns (known as reels). When the spin button is pressed, the slots rotate and, if enough of the same symbols line up, the player wins credits based on the amount they have bet previously. In addition to the classical card symbols like A, K, Q and J, slots often feature themed icons that match the game’s theme.

Several experiments have shown that near misses in a classic slot machine induce an unconditioned reinforcer in gambling responses, i.e., they increase the frequency of gambling responses in a way that can be predicted from the pattern of near-misses presented in previous trials. However, these studies have a few problems that prevent them from being interpreted as support for the hypothesis that near-miss stimuli provide conditioned reinforcement.

For example, a recent experiment by Ghezzi et al. attempted to replicate the results of Strickland and Grote using a different experimental design that included simulated slot machines, but their findings were not consistent with the original study. In addition, these new experiments showed that extinction does not reduce the number of trials in which participants chose to continue playing a slot machine, even when there are more near-misses than far misses.