How was the study conducted?
Study participants were shown a picture while given an electric shock so that the sight of the picture would elicit fear. In that way, a painful memory was introduced. They were brought back a day later and reminded of the fearful incident, inducing the reconsolidation process.
Then the participants were divided into two groups. The first received “extinction treatment” for 10 minutes following reconsolidation--they were shown the same images over and over, without shocks, so they would stop associating them with pain. The second group received this same treatment, but, instead, after a six-hour delay after reconsolidation. The researchers then used an MRI scanner to measure the impact of the fear memory. Lastly, on the third day of experimentation, researchers examined the amygdala region of the participants’ brain--where fearful memories are stored-- to analyze the role it plays in erasing trauma.
What were the findings?
Following the extinction treatment, the first group showed no fear at all, while the second group still showed a significant amount of fear, confirming that timing of the treatment matters. The pain associated with the memory could only be neutralized shortly after the memory was recalled. The amygdala analysis showed that even on a third day, the first group showed no brain activity indicating fear, while the second group showed activity in the amygdala, indicating a persistent fear.
What do these findings mean?
These findings provide new hope for those at risk of developing post-traumatic stress disorder or for those who are prone to suffering from negative memories. For instance, soldiers in combat would need to be treated soon after a traumatic experience so the fresh memory can be altered.
With more time and research, these methods could be developed to the point that medication for traumatic memories is no longer necessary. This recent study is significant because it represents a first step in treating painful memories using behavioral intervention rather than medication. That would prevent risks associated with conventional drug treatments. Previous studies had focused on inhibiting cortisol, using beta-blockers, and using metyraprone to decrease cortisol (stress) levels.
T. Agren, J. Engman, A. Frick, J. Bjorkstrand, E.-M. Larsson, T. Furmark, M. Fredrikson. Science September 2012 DOI: 10.1126/science.1223006
n.p. (2012, September 22). "Emotional Memories Can Be Erased From Our Brains." Medical News Today. Retrieved from
HowStuffWorks.com Contributors. "What exactly is amnesia?" 01 August 2011. HowStuffWorks.com. <http://health.howstuffworks.com/mental-health/neurological-conditions/amnesia.htm> 26 September 2012.