An Airliner Near-Catastrophe Offers Unique Neuroscience

In August 2001, behavioral neuroscientist Margaret McKinnon was among 306 passengers and crew on Air Transat Flight 236, a transoceanic flight originating in Toronto and destined for Lisbon, Portugal. About halfway through the flight, the aircraft, an Airbus A330-243, abruptly ran out of fuel, the result of a maintenance error-caused fuel leak in the number two engine. The only possible safe landing was a military base in the Azores—whether the aircraft could make it that far was uncertain. Passengers were told to prepare for a water landing and soon the cabin lost all power and the aircraft depressurized. A countdown began. You couldn't be faulted for assuming the very worst: a failed water landing in a miles-deep ocean.

With minutes of glide time remaining, the Azores landing strip came into view and Air Transat 236 managed a relatively safe landing. Few physical injuries were reported.

Psychological injuries, however, were sure to be a different matter, and McKinnon came away from the experience with the seeds of an idea. She and her colleagues at Baycrest Health Sciences in Toronto soon recruited 15 fellow passengers to participate in a study on memory and post-traumatic stress disorder. Results from the first phase of the study were released in 2014 and involved interview-based memory tests—but not brain scans—from the event and also two control events from the same time period: 9/11 and a neutral event, examples of which include "road trips to visit out-of-city family or a university cam- pus." Results from the study's second phase, which included functional magnetic resonance imaging (fMRI), are out this week in the journal Clinical Psychological Science.

The first phase of the study consisted of passengers, some of which suffered from PTSD and some of which did not, offering recollections of the three 2001 events (the crash, 9/11, and the neutral event). What they found was that all of the passengers in the study were able to recall the near-crash with incredible vividness and accuracy, relative to the two other events. Interestingly, this enhanced recall ability seemed to be independent of PTSD, but those with the disorder demonstrated increased general memory capabilities from the time. That is, they recalled a lot of extra stuff external to the crash.

This is something noted in PTSD sufferers in other prior studies as well: "a pattern of overgeneral memory recollection is observed," the 2014 report explains, "i.e., primarily factual or repeated information as opposed to details specific in time and place definitive of episodic reexperiencing."

A crucial takeaway from the 2014 study is that PTSD does not appear to originate in enhanced memories of the traumatic event. "In the present [2014] study involving single-blow trauma, trauma-related memory enhancement did not differentiate those with or without a diagnosis of PTSD, suggesting that enhanced recall alone is not sufficient to account for the presence or absence of PTSD symptoms," McKinnon and her co-authors explain.

This brings us to the new study, which offers additional physiological detail in the form of brain scans. The gist of the brutally-real experiment is that passengers, only eight of them this time. were placed into fMRI tubes and then presented with video recreations of the Transat incident. Unsurprisingly, the accident-related videos elicited responses in the brain's emotional memory centers—the amygdala, hippocampus, and midline frontal and posterior regions. Perhaps more surprising is the finding that the subjects that had experienced the Transat flight showed similar brain activity when confronted with videos related to 9/11, whereas control subjects, those who had not been on the flight, showed far more neutral patterns.

So, the implication is that the Transat trauma was able to shade a period well beyond the actual event. "We speculate that people who have experienced trauma may become more sensitized to things in their environment," Daniela Palombo, a postdoc fellow at Boston University and the lead author of the new study (McKinnon is a co-author), told me. "You can imagine that for someone who just experienced a trauma like the [Air Transat] event, a subsequent experience that also involves planes crashing, such as the 9/11 tragedy, would become more salient to them or even more threatening—it may evoke more emotion and that in turn could influence how the event is remembered. There is certainly some research to support this idea."

Worth noting again is that the second portion of the study consisted only of eight passengers, which means that these results are not easily generalizable. They're more suggestive than anything, but, at the same time, the research is one of a kind. Shared traumatic events featuring cognitive neuroscientists don't come around every day. It's safe to say that the existence of the research itself is as remarkable as the actual findings, for better or for worse.

"Imagine your worst nightmare—that's what it was like," McKinnon recalled on the release of the first portion of the study in 2014. "This wasn't just a close call where your life flashes before your eyes in a split second and then everything is okay. The sickening feeling of 'I'm going to die' lasted an excruciating 30 minutes as the plane's systems shut down."