A slot is a position within a group, series or sequence. It can also be used to refer to a specific location on an aircraft such as the air gap between a main and auxiliary airfoil of a jet.

A popular form of gambling entertainment, a slot machine is an electro-mechanical machine that displays multiple reels and pays out credits when certain combinations are spun. They are found in casinos and online gaming platforms, as well as physical locations like bars and arcades. In order to play a slot machine, a player must insert cash or paper tickets into the machine’s coin slots and then press a button to spin the reels. The goal is to match symbols on the reels to complete winning combinations and trigger bonus features such as free spins, re-spins, or extra coins.

In a casino, the majority of profits are generated by slot machines. As a result, many managers are reluctant to increase the house edge of their slot machines too much, fearing that players will walk away from the game. However, increasing the price of a slot machine can also be perceived as hidden pricing by players.

To determine how to improve the user experience, we studied two measures of reward reactivity using a prototype mobile app that allows users to play simulated slot machines. Unlike other psychophysiological measures involving cumbersome electrodes and wires (that likely reduce ecological validity and may inhibit flow during play), our app uses simple mobile sensors to capture fMRI activity while participants are playing a slot machine. The app also provides feedback on arousal and two other psychological variables, including a measure of flow while mind-wandering.