Everyone has those moments in life that they replay over and over again in their heads. Sometimes it is the presentation we bumbled, and sometimes it’s the awkward date we went on. Sometimes it is missing the game winning field goal. Other times it’s darker and more lasting, a traumatic event that we carry around like a scar. It isn’t the memory that haunts us, but the feelings connected to it.

Reliving traumatic events is a major symptom of Post-Traumatic Stress Disorder (PTSD). It can come in for form of recurrent memories, nightmares or flashbacks. At any given time, an estimated 8% of Americans have PTSD and it occurs in 1 out of every 5 military personnel returning from Iraq and Afghanistan. The symptoms are severe, and require serious psychological help. New studies and therapy techniques designed to help PTSD have opened up amazing new doors to our understanding of human memory.

Recent studies have found that the brain structure is actually changed through the process of accessing a memory. The view is that a memory is less like a movie, locked somewhere in the database of our minds, and more like a story that changes a little every time we tell it. A study found that blocking certain chemicals during memory recall can actually erase a memory by inhibiting the brains ability to reconstruct the memory. We are extremely close to being able to develop a drug that would allow people to selectively erase certain memories, but is that kind of forgetting even desirable?

As it turns out, new techniques are also being developed that remove the emotional response to a memory without erasing the memory entirely, all without the use of drugs. Fear memories are stored in a different part of the brain from typical memories, in the amygdala instead of the hippocampus. This makes the frightening associations permanent, but they can be layered with more pleasant associations like putting down a floor over a trap door. A New York University study, led by Elizabeth Phelps, found a technique for accomplishing this using a psychological process called reconsolidation.

In the study, two groups were shown pictures of blue and yellow squares while giving them an electrical shock, to form an association. The next day, one group was shown the squares again in the same situation only without the shocks, called extinction training. On day three, they were shown the squares again, and they still showed signs of a heightened fear response. The other group followed the same process, only on day two they were briefly shown the squares before the extinction training, and then told to go watch television for 10 minutes before coming back. The second group did not show signs of heightened fear on day three, and the results persisted when the subjects were called back a year later.

This suggests that the act of recalling a memory before trying to break a negative association makes the process more effective. When you recall a memory, you begin the process of recoding the memory in your mind. Once the reconstruction begins, you can better guide the associations and remove the negative emotions from the memory. Basically, you can see the memory in a new light. A similar process happens every night when we go to sleep.

Dreaming is a built in mechanism for coping with difficult memories. This is one reason that people suffering from PTSD often have sleep disorders. During REM sleep, the part of the brain that handles emotion is deactivated. So while dreams are occurring, the body naturally shields itself from emotional responses. This allows the mind to reactivate the traumatic and painful memories and process them objectively. One study at the University of California, Berkeley, involved two groups who were shown emotionally arousing images twice. The first group was shown the images first in the morning and then in the evening without sleep in between. The second group was shown the images at night, and then again the next morning after a night’s sleep. The group who slept between viewings had less of an emotional response to being shown the images a second time.

Recurrent nightmares in PTSD victims are a byproduct of the body attempting to cope with a traumatic event. When the body’s natural coping mechanisms are overwhelmed, sleep disorders occur. Because of this breakdown, other techniques are needed. Recalling a traumatic event when a person is still agitated actually reinforces the negative feelings of the memory. It is important to give it time and be in a safe environment when recalling trauma to deal with it. In this setting, writing about a traumatic event can be therapeutic. The process is painful, and the negative emotions and fear will resurface. However, this allows your brain to make a jumble of disjointed memories and emotions into a coherent storyline. In doing so, your brain is able to process and reconstruct the memories gaining a level of objectivity and distancing the emotions felt during the event from the new memory of the event.

Sometimes we wish we could just forget. While this may be an option in the near future, memories are an important part of who we are. Our experiences define us as a person, which is why sometimes people say of Alzheimer’s patients that, “he just isn’t himself anymore.” A better solution than forgetting is coping. By removing the negative emotional responses, one can get a perspective of objectivity and, eventually, closure.

Additional Resources

PubMed Health Post-Traumatic Stress Disorder: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001923/

U.S. Department of Veterans Affairs National Center for PTSD: http://www.ptsd.va.gov/

Psychological First Aid: http://www.ptsd.va.gov/professional/manuals/manual-pdf/pfa/PFA_V2.pdf

The New England Journal of Medicine Post-Traumatic Stress Disorder: http://www.impact.arq.org/doc/kennisbank/1000010585-1.pdf

Wired The Forgetting Pill Erases Painful Memories Forever: http://www.wired.com/magazine/2012/02/ff_forgettingpill/all/

National Geographic Why Do We Dream? To Ease Painful Memories, Study Hints: http://news.nationalgeographic.com/news/2011/11/111129-sleep-dreaming-rem-brain-emotions-science-health/

Salon Should We Erase Painful Memories? http://www.salon.com/2011/12/31/should_we_erase_painful_memories/

Psychology Today Memory: http://www.psychologytoday.com/basics/memory

Heal My PTSD Statistics: http://healmyptsd.com/education/post-traumatic-stress-disorder-statistics