Traumatic incident can skew people's perceptions for years
Passengers on Air Transat flight 236 that almost crashed paid more attention to words such as 'runway' than control group
Researchers studied passengers of a flight that suffered a catastrophic fuel leak over the Atlantic in 2001. Photograph: Nicholas Burningham/Alamy
Tests on passengers who escaped death when their plane ran out of fuel over the Atlantic have shown how a single traumatic incident can skew people's perceptions for years after an event.
Researchers in Canada studied passengers who flew on Air Transat flight 236, which suffered a catastrophic fuel leak as it crossed the Atlantic from Toronto to Lisbon in 2001. After both engines failed, the pilots put the plane into a glide for more than 100 miles and touched down safely with 306 people on board at a military base in the Azores.
One of the passengers was Margaret McKinnon, a researcher at McMaster University in Ontario. Eight years after the incident, she recruited 14 others who were on the ill-fated flight to take part in a study to investigate the psychological impact of the near-disaster.
In the study, the former passengers sat in front of a computer which flashed up a series of words, each appearing for just 100 milliseconds in quick succession. At the end of each session, the person taking part had to type out a string of numbers that had appeared between two of the words, such as 222222, and then the one word in the series that appeared in a different colour to the rest.
When the passengers and a group of age-matched controls sat the test the first time, the computer flashed up a series of neutral words, such as "upholstery", "beatification" and "demographics" with common emotionally charged words interspersed, such as "disaster", "blood" and "horror". As expected, all of the participants paid more attention to the emotionally charged words, and so scored highly when asked to remember them at the end of each session.
But in a second round of tests, the scientists interleaved words that had no special meaning for the control group, but were associated with the airline incident, such as "Atlantic", "runway", "stewardess" and "Transat". When the former passengers sat the test, they scored five to 10 percentage points higher than the control group, because the words were emotive to them and they paid more attention.
The results showed that nearly a decade after the near-disaster, key words linked to the disaster were still highly emotive for the passengers, even when they appeared for only 100 milliseconds. For them, words that reminded them of the flight were as emotionally charged as the words "horror" and "disaster" were for those in the control group.
"This shows that a singular, emotionally traumatic experience can result in enduring changes in our perceptual experience," said Daniel Lee at the Society for Neuroscience meeting in San Diego
