"All the hands go up," Seamon said. "And I say, 'About a third of you are wrong.' They just sit there and say, 'How could I be wrong? I know I'm right.' "
But that doesn't mean they really happened that way.
Most people correctly remember the basic gist of what happened on Sept. 11, 2001, but chances are that they're wrong about some details — even details about which they're absolutely sure.
More 9/11 Coverage
A handful of researchers curious about how memory works have seized on 9/11 as a unique opportunity to look at the mechanics of how we remember. After 9/11, countless bumper stickers urged, "Never forget." When it comes to what's important about that day, we haven't.
But Seamon and other researchers will tell you that a surprising amount of what you remember probably never happened.
The term "flashbulb memory" goes back to a 1977 study of people's recollections of John F. Kennedy's assassination in 1963. The idea goes back further. In 1899, researchers surveyed people about where they were when they learned that Abraham Lincoln was assassinated.
In both cases, the assassinations prompted such vivid accounts that researchers assumed the memories were accurate. More recent research suggests otherwise.
(To Others And Ourselves)
"When recalling events, there's a narrative form that we have. Things that fit that form tend to be remembered well," Seamon said. "We try to tell stories that are coherent and make meaningful sense to others. Because that's what we do, we tell stories to each other."
But, Seamon said, on 9/11 we received information from many different sources, with varying accuracy. Adding to the jumble of information, certain images and facts tended to be repeated in the media over the next several months. The circumstances of how we received that information morph into a streamlined account. It's a phenomenon called "source confusion."
Oddly, it's possible that the more frequently we recall an event, the less accurately we remember it. A number of studies suggest that our memories don't go back to the event itself but rather to the last time we remembered it. Each recollection adds new flaws and reinforces previous flaws. Eventually, we settle on an "official" version.
"People are sort of figuring out, 'What's the story I'm going to tell about this event? Where was I?' " Seamon said. "But after the first year, the memory stays pretty constant. It's not changing anymore. The person has figured out the story they're telling about this event."
"This is not something that's done on a conscious level. In a sense we're almost like figuring out what happened by taking in all the information, and there's selective remembering going on."
Facts Slip Our Grasp
Elizabeth Phelps had a meeting the morning of 9/11 about the construction of a new brain imaging center at New York University. She walked out of her apartment building, "and I saw some guy looking up, so I looked up and there was a big hole in the side of the World Trade Center. I said 'Was it a small plane?' and he said, 'Big plane.' "