SOURCE: Baycrest Rotman Research Institute, news release, June 23, 2015
FRIDAY, July 3, 2015 (HealthDay News) -- A study involving people who thought they were about to die in a plane crash reveals new clues to the long-term impact that traumatic events have on the brain.
In August of 2001, passengers on Air Transat flight 236 were on an overnight flight from Toronto to Lisbon, Portugal, when their plane ran out of fuel over the Atlantic Ocean.
Many on the harrowing flight thought they might die that night, but in the end the plane was able to make an emergency landing on a small island in the Azores.
Now, nearly 14 years later, a study led by Baycrest Health Sciences' Rotman Research Institute in Toronto looked at some of those passengers to try to understand how traumatic events might affect people long-term.
"Here we have a group of people who all experienced the same extremely intense trauma," lead researcher Dr. Daniela Palombo said in a Baycrest news release.
"How each of them responded to this terrifying event has been informative for helping us move a step closer toward understanding the brain processes involved in traumatic memory," said Palombo, who is a postdoctoral researcher at VA Boston Healthcare System.
She noted that some of the flight 236 passengers went on to develop post-traumatic stress disorder (PTSD), while others did not.
In the first phase of the study, passengers were tested three years later on their recollection of the harrowing flight. They were also asked about their memories of 9/11 (which occurred a month after the plane incident), as well as a neutral event.
The passengers typically recalled their near-death experience on flight 236 in great detail -- even if they did not suffer from PTSD, the researchers found.
In the second phase of the study, conducted 10 years after the first phase, eight of the passengers underwent brain scans while watching news footage of the Air Transat incident. They also watched footage of the 9/11 terrorist attacks and a neutral event. Most of these passengers did not have PTSD.
Even so, these passengers still had clear memories of the flight, according to the study published online June 23 in the journal Clinical Psychological Science.
"This traumatic incident still haunts passengers, regardless of whether they have PTSD or not," Palombo said. "They remember the event as though it happened yesterday. Other more mundane experiences tend to fade with the passage of time, but trauma leaves a lasting memory trace. We've uncovered some hints into the brain mechanisms through which this may occur."
Brains scans revealed increased activity in a network of brain regions involved in emotional memory, including the amygdala, hippocampus and midline frontal and posterior regions.
Brain responses were similar when passengers viewed images of 9/11 -- a less personal, but still horrific, event. This heightened brain activity was not seen in a control group of people as they recalled the events of 9/11.
The bottom line, according to the researchers: The scare the passengers had on the Air Transat flight may have changed the way their brains processed information, making them more sensitive to other negative life experiences.
The U.S. National Institute of Neurological Disorders and Stroke provides more information on the brain and how it works.