Covert capture and attenuation of fear memory

Covert capture and attenuation of fear memory

Scientists could be a step closer to finding a way to reduce the impact of traumatic memories, according to a study published recently in the journal Nature Neuroscience.

The findings suggest that procedures used by clinicians to indirectly reactivate traumatic memories render a window whereby those memories can be altered, or even erased completely.

In therapy, imaginal reminders are often used to safely retrieve traumatic memories of experiences. For example, the senior author said a military veteran wounded by an improvised explosive device may be asked to re-experience trauma cues - like the lights and sounds of the explosion - without the negative consequences. The idea is that the fear responses can be dampened through this exposure therapy.

"The one major challenge is when you do the extinction procedures, it doesn't erase the original trauma memory," the senior author said. "It's always there and can bubble back up, which is what causes relapse for people who re-experience fear."

With this in mind, the researchers hoped to answer whether they could isolate a memory and drive fear responses by reactivating it artificially - and potentially disrupt the original memory itself. The senior author said their findings suggest that procedures currently used by clinicians to indirectly reactivate traumatic memories create an opportunity to change or eliminate them.

To do this, the researchers used a conditioning procedure in which a cue becomes indirectly associated with a fearful event. When the cue is presented later, it indirectly reactivates a memory of the event and increases activity in the hippocampus, a brain area important for memory.

The study showed that indirectly reactivating a contextual fear memory through re-exposure to the cue can make the memory vulnerable to disruption. The senior auhtor said further research is needed to answer if scientists can produce a permanent loss of the traumatic information.