When you do something you enjoy -- whether it's shopping, eating, or even gambling -- your brain releases a chemical called dopamine. Now, scientists think they know why some people get more dopamine in their brain than others.That release of dopamine is called a reward response. When scientists measured dopamine levels after people played a slot machine -- they found differences in the reward response.
Experts think the difference may be genetic, and also may explain why some people become addicts. - Get more L.A. breaking news, weather, traffic and sports - Have a news tip? Send your tips, video, or pictures