From Science:
We often think of memories like Polaroid snapshots, images frozen in time. But they're more like the fluid, melting pocket watches of Salvador Dali's painting The Persistence of Memory. Now scientists have developed a method that takes advantage of memory's malleability to block specific fear memories, which could someday lead to new therapies for anxiety disorders and phobias. Each time you recall the ice cream cake and clown from your fifth birthday party, the memory is subject to change. Information about the color of the clown's polka-dotted suit, for example, becomes “unfrozen” and could change from red to blue. This process is called reconsolidation, and scientists have blocked scary memories in rats–such as the association between a specific tone and a painful shock–during reconsolidation with drugs. Unfortunately, these drugs stop protein synthesis in the brain, which would lead to terrible side effects in people.
A different approach to diminishing fear is called extinction training. In experiments with rats, scientists keep playing the ominous tone without a shock, and over time, the animals stop getting scared by the tone. Therapists use a similar method called exposure therapy to help people overcome debilitating fears, such as claustrophobia. But these methods aren't as long-lasting as the dangerous drugs. Earlier this year, scientists reported a happy compromise that worked in rats. They timed extinction training to when the rats' brains were reconsolidating the fearful tone memory, erasing that memory in the process.
More here.
