Anxiety disorders like Post Traumatic Stress Disorder (PTSD) are a difficulty all-too-real in our country; the number of annual cases of PTSD among soldiers, for example, has risen sharply since September 11, since soldiers started serving in Operation Iraqi Freedom, Operation Enduring Freedom and Operation New Dawn. These disorders create huge, sometimes unscalable hurdles for suffering individuals. Now more than ever our country, especially our soldiers, could benefit from the ability to rewrite the painful memories causing their disorders. Neuroscientist Daniela Schiller is working to make this a reality, writes the MIT Technology Review.
Historically, memories have been depicted as files our brains store away in our minds. When something in our environment triggers us to retrieve that memory from our mental storerooms, we experience the memory just as it was recorded and then file it away once again. When we refile the memories we do not alter them in any way. Over the past few decades, however, this belief has been overturned to reveal more accurate information on how our brains store memories, and researchers have realized we actually alter a memory each time we recall it.
Through testing on animals and humans researchers have discovered that memories are not unchangeable but rather rewritable “files” that are modified each time we remember them and then store them away again. With this knowledge Schiller, the daughter of a Holocaust victim, aims to find a precise way to rewrite painful memories.
As a postdoc at NYU Schiller began fear experiments in humans. In the experiments, an electrode was strapped to a volunteer’s wrist in order to deliver a mild but irritating electric shock. Sensors were attached to several of the volunteer’s fingers of the other hand in order to measure the his/her psychological arousal and fear in response to elements of the experiment. The volunteers were then made to stare at a computer screen, where they were shown a blue square. The researchers followed the blue square by an electric shock and repeated the process until the volunteer associated the blue square with the impending shock and created a memory of the fear.
The following day Schiller repeated the experiment with the same volunteers, only this time she showed the blue square without sending the shock. Though at first the blue square caused the volunteers fear due to their memory of it as the element that triggered the shock, they quickly stopped associating the blue square with the shock and incorporated the new memory into their internal filing cabinets, so to speak.
Schiller and her researchers began playing with timing. They discovered that if, within 10 minutes of creating the blue square-shock association in the volunteers, the blue square was shown without following it by a shock, the volunteers were immediately able to reconsolidate the memory without fear. If the researchers waited six hours, however, to show the blue square without the shock, the volunteers still experienced fear. In this way, Schiller and her researchers discovered that they could rewrite a memory before it was stored by intervening soon after the memory was created.
In the future, Schiller aims to use this method on a larger scale to combat not just fear of small electric shocks but larger, the debilitating memories some humans house in their minds. Through continued research Schiller hopes to develop a therapeutical way for humans to re-associate the painful emotions they associate with the content of certain memories. “When you affect emotional memory, you don’t affect the content,” she said. “You still remember perfectly. You just don’t have the emotional memory.”
Schiller is not the only researcher working toward this goal. For example Yan-Xue Xue of Peking University in Beijing and colleagues reported last year that they had helped heroin addicts rewrite their association of environmental triggers with a craving for the drug. The researchers reported that the effect lasted at least half a year, the length of the study.
What will happen if, in the future, we are able to rewrite our memories? I wonder if we could end up living in a world like that portrayed in Eternal Sunshine of the Spotless Mind. I just hope we don’t use the technology to erase memories of ended relationships but rather to overcome anxiety disorders and help our soldiers, among others, live their lives PTSD-free.
How do you imagine a world where we can rewrite memories? Let us know in the comments