Ideally, such treatments can help transform the traumatic memory into one that more closely resembles ordinary sad memories. “It’s like having a block in the right place,” he said. “If I can access a memory, I know it’s a memory. I know it’s not happening to me now.”
Dr. Ruth Lanius, the director of PTSD research at the University of Western Ontario who was not involved in the study, described its findings as “seminal,” both because it establishes that traumatic memories have distinct pathways and because it indicates that key mechanisms for traumatic memory may involve less-examined areas of the brain. Much research into PTSD has focused on the amygdala, the stress detection center of the brain, and the hippocampus, she said. The posterior cingulate cortex is “really involved in the reliving of memories,” and in seeking self-relevance, which may explain why a sensory reminder may cause overwhelming fear or panic.
“A soldier, if they hear fireworks, they may run and take cover,” Dr. Lanius said. “Traumatic memories are not remembered, they are relived and re-experienced.”
Clinicians, she said, can use these findings to treat patients who “don’t feel that the trauma is over,” employing therapies that “bring on line context, so you know, ‘Oh, that happened in the past.’” She said researchers should explore therapies, like mindfulness, which are known to activate the parts of the brain known to provide context.
If biological markers for PTSD can eventually be identified, it would be “a major scientific contribution,” settling differences within the field about what experiences constitute a trauma, said Brian Marx, deputy director of the Behavioral Science Division of the National Center for PTSD, who was not involved in the study.