It may seem like common sense: Recalling a negative memory can put you in a bad mood, and thinking about a happy memory can put you in a good mood. But there's actually scientific evidence to back that up. Studies even show that this effect is taking place whether or not we're aware of it.
So what's the big deal? It turns out that memory recall can be used to regulate mood in people who are experiencing depression, because thinking about positive memories causes the brain to release dopamine. So when someone tells you to cheer up, it may be a simple matter of thinking happy thoughts [source: Gillihan].
Not surprisingly, memories of previous experiences influence how you respond emotionally to situations. If you once nearly drowned, you might experience fear around water. If a previous love had a wandering eye, you might feel jealousy when a current flame looks at another person. What's more, the intensity of the previous experience affects the intensity of the current emotion. For example, a soldier who has had extensive combat experience or traumatic combat experience will likely have more intense anxiety later on.
Preconceived ideas also affect your emotions. Anticipation and your expectations, which are driven by memories of previous events, affect the intensity of an emotional reaction [source: Frijda].
Want to know more about the brain and your emotions? The links on the next page will give your brain some new information to process.