Variable reinforcement, a behavioral psychology principle that contends that people are more likely to participate in an activity when rewards are unpredictable, is one important component. This idea is perfectly illustrated by slot machines,cat exam slots where players may go for extended periods of time without winnings before suddenly receiving a sizable payout. Engagement and Stimulation of the Sensations. Also, a lot of slot machines use sensory feedback to increase player involvement. The brain neurotransmitter dopamine, which is linked to pleasure & reward, is released during an immersive experience that is enhanced by bright lights, engrossing sound effects, and visually appealing graphics. Being self-aware is important.