A New Hypothesis
Perhaps the most disruptive aspect of post traumatic stress disorder (PTSD) and other anxiety-related disorders is the role of "weak" or incidental sensory data. Because this data is converted into a long term memory along with the stronger, more traumatic details, it can piggyback onto the trauma and act as a trigger for the negative feelings associated with it. This results in seemingly innocuous stimuli causing a stress response.
"If you are walking in a high-crime area and you take a shortcut through a dark alley and get mugged, and then you happen to see a mailbox nearby, you might get really nervous when you want to mail something later on," explains Samuel Schacher, a professor of neuroscience at Columbia University Medical Center (CUMC).
When Schacher studied this phenomenon along with other researchers at CUMC and McGill University, the team found that a long-held belief about it — that both the incidental data and significant information were processed in the same way in the brain — may be inaccurate.
Through experiments on a marine snail called an Aplysia, the researchers concluded that the incidental data and the significant data used unique proteins to form their connections to the motor neuron. Because of this, the researchers found they could block one type of protein without affecting the other, thus eliminating the connection formed by the incidental data without affecting the one formed by the significant data.
Using Schacher's mugging as an example, this would mean researchers could remove a person's fear of mailboxes while letting them retain their memory of the mugging, which might be useful in preventing them from entering a similar situation in the future or for recalling the event for criminal proceedings.
According to the National Center for PTSD, the condition affects an estimated 7 to 8 percent of Americans at some point in their lives, and the chances of women developing the condition are more than twice as high as men: 10.4 percent compared to 5 percent. By removing the memories that trigger breakdowns or flashbacks, such as the mailbox, the lives of PTSD sufferers could be improved.
The ability to selectively erase memories could be useful for a number of problems beyond PTSD, too. For example, drug addicts whose cravings are caused by apparently random stimuli could be treated to no longer respond to that stimuli.
In addition to opening up the potential for us to erase memories, a better understanding of how our minds store what we experience could also allow us to enhance our memory capabilities. This could be done through selective electrical brain stimulation, brain implants, or by memory exercises. Ultimately, the more we can learn about the various functions of our brains, including memory storage, the more potential we have to manipulate them, ushering in a new age in human evolution.