Reconsolidation A New Drug-Free Method of Blocking Fear Memories
A drug-free procedure has been discovered by Scientists at New York University to temporarily block the return of fearful memories in people. The technique could change the way scientists and doctors look at how the brain’s memory storage process works and could lead to new ways to treat anxiety disorders, including posttraumatic stress disorder.
Researcher Daniela Schiller, PhD, and colleagues at NYU said that in their new study, which was published in the journal Nature, that they’ve been able to reshape memories. The process involves bring back to the forefront unpleasant memories and then create an opportunity for reshaping the fears, a period called “reconsolidation.”
“Reconsolidation is a natural process that is likely occurring all the time,” Elizabeth Phelps, PhD, a professor of psychology at NYU. “Our studies suggest that simply retrieving a memory is enough to trigger the reconsolidation (i.e. re-storage) process. The trick is knowing enough about exactly how this process occurs to take advantage of it to restore fear memories as safe.”
The study was completed by researchers “training” volunteers to be fearful of a visual stimulus. For their study they used colored squares and pairing the images with mild electric shocks in a process called classical fear conditioning. They then measured moisture on the skin which is an indication of fear arousal.
After the fear memory was formed, some of the 65 participants were re-exposed to the image that produced the electric shock. This was followed by “extinction training,” in which they were exposed to colored squares but not shocked. “The term extinction is generally used to describe new learning that the previously feared event is now safe,” said Phelps. The fear response disappeared only in people who went through extinction training. Those people who received extinction training after a six-hour window remained afraid of the squares, as did those in a control group.
“Our research suggests that during the lifetime of a memory there are windows of opportunity where it becomes susceptible to be permanently changed,” Schiller says in a news release. “By understanding the dynamics of memory we might, in the long run, open new avenues for treatment of disorders that involve abnormal emotional memories.”
“Timing may have a more important role in the control of fear than previously appreciated,” Phelps says in a news release. “Our memory reflects our last retrieval of it rather than an exact account of the original event.”
Thomas R. Insel, MD, director of the National Institute of Mental Health, says the study holds “promise for being translated into improved therapies for the treatment of anxiety disorders, such as posttraumatic stress disorder.”