On Aug. 24, 2001, Air Transat Flight 236 ran out of fuel en route from Toronto to Lisbon with 306 passengers aboard. The right engine was leaky, and the crew had performed a delicate fuel imbalance procedure—incorrectly—from memory. Below stretched the Atlantic Ocean for hundreds of miles. As the interior lights flickered and oxygen masks dangled from the ceiling, weeping flight attendants instructed everyone to prepare for a crash landing into the sea. Then the pilot located a small military base in the Azores, and after 25 minutes of hell, the plane touched down—violently, but without badly injuring anyone—to tears and applause. (Also to flames: The wheels were on fire.)
One of the passengers on board Flight 236 was a psychologist named Margaret McKinnon, who studies behavioral neuroscience at McMaster University in Hamilton, Ontario. “At first I wasn’t sure that something terrible was happening,” she said. “But after the lights went out and the plane lost altitude so sharply, I suspected we would probably die.” As the aircraft glided over the tiny island, “I remember being surprised we’d made land, seeing houses below us, and worrying we might crash into them. Then we veered back over the ocean. I lost hope that we’d survive.”
But back on terra firma, where most of her fellow travelers saw a nightmare, McKinnon perceived an opportunity.
Two years later, she and her colleagues got 15 of the men and women from the flight to recount their experience during those 25 grueling minutes. The researchers also asked the passengers about their memories of Sept. 11, 2001 and one other, neutral day from the same period. Fifteen control subjects recalled a recent negative event from their personal lives, the terrorist attacks, and a nonemotional event. The researchers had a lot of questions: They wanted to understand more about terror’s fingerprints on the brain; the relationship between mnemonic habits and post-traumatic stress disorder; and what role clarity and vividness play in a given memory’s power to haunt.
The least surprising finding was that the plane survivors had uncommonly rich and detailed recollections of the emergency landing. Their recall was more vibrant and insistent than either their memories of Sept. 11 or the control group’s memories of negative personal emotional events. The researchers cite “the effects of arousal on mnemonic systems”: Things that terrify us lodge in our memories. It is a classic example of evolutionary psychology—our ancestors must have found it helpful to their survival, if unpleasant, to be continually aware of threats that menaced them in the past.
This is not exactly news in the field of memory research, though, and if the study didn’t yield additional insight, you’d be forgiven for thinking everyone had suffered (and described their memories of suffering) in vain. But it turned out that half of the participants subjected to agony in the air went on to develop PTSD. While most investigations of PTSD are limited by the diversity of experiences across test subjects, this one was unique in that it featured “a group collectively threatened with imminent death.” (Hooray?) Also, McKinnon’s first-person involvement and the existence of official records meant that “the moment-to-moment sequence of events was known,” the researchers write, from the showing of the in-flight movie (Chocolat) to the firefighters helping people disembark in a field of high grass.
The study, forthcoming in the journal Clinical Psychological Science, highlights a strange similarity between the accounts of passengers with and without PTSD. You might expect that men and women with a clinical diagnosis would produce more vivid and detailed reminiscences about the flight—that each recollection would become an unparalleled, supremely haunting “super-memory.” Or you might predict that the PTSD recollections would be fragmented, less accurate, or dreamlike. In fact, both the passengers with the disorder and those without generated equally vivid and accurate narrations of the emergency. A survivor with PTSD was no more or less likely to mention the flight attendant “with the shaky voice” or the pilot shouting “Brace! Brace!” or the quiet punctuated by sounds of praying.
What did vary among the accounts was the number of details that had nothing to do with Air Transat Flight 236 at all. After transcribing the memories, the researchers went back and coded statements as “internal” (“directly related to the main event … specific to time and place … conveying a sense of episodic re-experiencing”) and “external” (“factual information or extended events that did not require recollection of a specific time and place,” “tangential … autobiographical details,” editorializing, repetitions, metacognitive claims like “I can’t remember”). They found that passengers with PTSD produced far more external details than those without. This held true for the nonflight memories too: A survivor with PTSD was more likely to surround her nonemotional recollection with semantic data, repetition, and unrelated noise. The mnemonic motto for healthy participants, even those exposed to unimaginable trauma, more closely resembled “just the facts, ma’am.”
Why should this be? McKinnon and her team aren’t sure, though they note that people who score higher in neuroticism on personality tests also tend to thread their memories densely with external details. An inability to shut out less relevant information when recalling personal experiences may be related to “executive … control of mnemonic retrieval,” they write. McKinnon echoed this idea on the phone: “When someone asks you to remember your first kiss, you need to search through to find the correct memory,” she said. “You recall what the lighting was like, what you were wearing. Depending on your level of cognitive control, you might also recall a bunch of extraneous details.”
Those with a weaker command over their remembering machinery may be at risk for PTSD, which is characterized by the chaotic bursting forth of past disturbances. “What our findings show is that it is not what happened but to whom it happened that may determine subsequent onset of PTSD,” Brian Levine, a co-author of the study and a professor at the University of Toronto, told the Association for Psychological Science.
Research on people who experience horrific events has provided psychological insights in the past. Studies have explored the emotional responses of New Yorkers to Sept. 11 (unsurprisingly fraught and gloomy) and asked what emergency evacuation patterns reveal about a society’s gender roles (that women and children aren’t necessarily saved before men). The shared trauma of living through the Bangladesh Liberation War informed the responses of a generation of Pakistani men and women to memory surveys—which helped researchers refine their notion of a reminiscence bump shaped by “self-defining episodes.” People who have suffered are unfortunately necessary to any investigation of human suffering—but hopefully the knowledge McKinnon unearthed will last longer than her and others’ harrowing memories of Flight 236.