People affected by post-traumatic stress disorder become susceptible to reliving trauma exposure when emotions associated with that trauma lose the factual context that places them in a rational framework, a new study by a team of Spanish and Brazilian researchers has found.
Scientists have long sought to understand just why and how this unwanted memory recurrence takes place in PTSD sufferers. In a study published in December 2014 in the journal Neurobiology of Learning and Memory, Spanish and Brazilian researchers looked at the role that emotional disconnection plays in making a person affected by PTSD susceptible to reliving trauma exposure. These researchers concluded that the disconnected processing of fearful emotions may help explain this classic PTSD symptom.
PTSD and Unwanted Reliving of Trauma
A person with PTSD has symptoms that indicate a continuing or delayed severe reaction to exposure to a highly dangerous or life-threatening situation or event. These symptoms can only be diagnosed as post-traumatic stress disorder if they exert their impact 30 days or longer after the initial trauma exposure. (People who develop diagnosable problems prior to reaching this 30-day threshold have a condition called acute stress disorder or ASD.) PTSD symptoms fall into four fairly broad categories. In addition to unwanted reliving of the source of emotional trauma, these categories are a compelling desire to avoid reminders of trauma, hyperarousal (an inability to turn off the body’s “fight-or-flight” response) and a damaging increase in negative emotional states or a negative worldview. Unwanted reliving of an emotional trauma can take the form of waking episodes called “flashbacks;” they can also take the form of nightmares. Whatever its form, such a reliving can provoke the same intense, potentially debilitating mental/psychological responses the individual felt during the originating event or situation. As a rule, an affected person can’t predict when he or she will experience flashbacks or nightmares. However, these symptoms often arise after an individual is exposed to reminders of the originating trauma. Doctors sometimes encounter great difficulty helping their PTSD patients overcome the tendency to involuntarily relive or re-experience traumatic emotional responses.
All human beings have two forms of long-term memory, known as explicit memory and implicit memory. Explicit memories contain the details of a previous experience (what happened, where things happened, etc.) and allow a person to speak about his or her memories in a somewhat objective, factual manner. Implicit memories don’t have this type of detailed content; instead, they contain the emotional responses associated with a past event or situation. Emotional disconnection or dissociation occurs when the factual content of a memory no longer links up with the psychological/emotional content of a memory. Such a disconnection is not uncommon, although its impact on mental well-being can vary broadly.
Does It Help Explain PTSD?
In the study published in the Neurobiology of Learning and Memory, researchers from three Spanish institutions and one Brazilian institution explored the potential link between emotional disconnection and PTSD with the help of 86 adults. All of these participants were exposed to situations designed to evoke a fearful response. The researchers used two testing procedures to track the connection between the explicit and implicit memories of this fear exposure. The first procedure measured the explicit ability to identify words related to the fear-inducing situations; the second procedure used a galvanic skin response test to measure implicit memory of these situations. The researchers conducted these tests half an hour after the trauma exposure; they also conducted the same tests two weeks later. After reviewing the results of the testing, the researchers concluded that the study participants exhibited a strong ability to recall their implicit, emotional responses to trauma exposure, both half an hour after this exposure and two weeks later. However, they also concluded that the participants rapidly lost their ability to accurately and explicitly recall the specific details of their traumatic experiences. The study’s authors believe their results indicate that the implicit, emotional content of a traumatic event or situation can quickly become disconnected or dissociated from the explicit, factual memory of a traumatic event or situation. They also believe that the presence of this disconnection may help explain why people affected by post-traumatic stress disorder commonly experience an involuntary reliving of their emotional trauma exposure.