Narrator: This is Science Today. Not all memories have equal weight. You remember something that's important or emotional because when it happened, your body released adrenaline, which boosted your memory system. Researcher Larry Cahill of the University of California, Irvine says the discovery of the connection between adrenaline and memory opens up ways to enhance or impair memories before they become fixed.

Cahill: When you learn something, it is not in your head in the final form that it's going to be. This we know for sure, memories take time to form, so you have a little window of opportunity.

Narrator: Cahill and his fellow researchers are looking for methods to prevent the formation of traumatic memories in disaster victims soon after disaster happens.

Cahill: And we're actually trying now to set up a program where we try and prevent the formation of what's called post-traumatic stress disorder using drugs that affect the adrenaline system, that block the adrenaline system. We're in the earliest stages of doing this but we're very excited about it and we're going for it.

Narrator: It also might be possible to artificially improve memory as well. For Science Today, I'm Steve Tokar.