Dopamine levels tied to uncertainty of rewards: “Researchers, using a new combination of techniques, have discovered that dopamine levels in our brains vary the most in situations where we are unsure if we are going to be rewarded, such as when we are gambling or playing the lottery…

Dopamine has long been known to play an important role in how we experience rewards from a variety of natural sources, including food and sex, as well as from drugs such as cocaine and heroin, but pinning down the precise conditions that cause its release has been difficult…

Zald believes the primary significance of the study is the possibilities it raises for future research on measuring what causes us to experience reward from a variety of sources and what happens in our brains when we are disappointed in our quest for those rewards. The research lays a foundation for a better understanding of what happens in the brain during unpredictable reward situations such as gambling and offers promise for exploring the chemical foundation of problems such as gambling addiction.”