If I were to ask you where you were when the Challenger exploded, or what you were doing when the 9/11 terrorist attacks happened, you'd tell me, with surprising detail, your memory of the event, how you found out, and maybe even what the weather was like that day.
But although those memories seem so vivid, those details probably wouldn't be very accurate, despite your insistence otherwise. These flashbulb memories, or memories of significant, surprising and consequential events, appear in photographic detail when you recall them, unlike everyday memories.
When you try to remember where the car is parked, it activates the posterior parahippocampus gyrus of your brain. But according to New York University psychologist Elizabeth A. Phelps, when you witness or experience a traumatic event, you see that stress has a significant role on brain function. Fear triggers the emotional memory system, and a different region of the brain, the amygdala (the brain's arousal center) fires up.
Flashbulb memories arise from highly emotional circumstances; overall, they're easier to recall, than something mundane like where the car is parked. And they're created and maintained through the brain's elaborate rehearsal of the memory, which means that you tell them as complete stories, rather than as fragments.
With time, all memories fade, including flashbulb memories. There's evidence that memory isn't what we think it is. Immediately following the Challenger explosion, for example, half of those surveyed couldn't accurately recall at least two major attributes of the event, although the participants were highly confident they had all the correct details.
And now, in a nationwide, long-term study of the vivid and emotional memories of the 9/11 attacks and their aftermath, Phelps and colleagues continue investigating flashbulb memories, in a project now known as the 9/11 Memory Consortium. The data collected from more than 3,000 people, living in seven U.S. cities, suggests so far that how we recall the details of significantly emotional events may not be any more reliable than any other memory, despite how vivid the emotional memory may seem to the memory holder.
Evidence suggests the facts we retain in our flashbulb memories are actually changeable and open to the power of suggestion. For instance, based on the misidentification by a single eye witness, Cornelius Dupree was imprisoned for 30 years in Texas for a rape and robbery he didn't commit. Out of a set of 130 convictions which were overturned thanks to DNA testing, 78 percent of the initial convictions got the verdict wrong, based on eyewitness testimony.
Like our everyday memories, flashbulb memories degrade with time, yet we have a difficult time accepting that our vivid, emotionally charged memories fade. What makes flashbulb memories special isn't their accuracy or consistency — it's our confidence in our memory, and our perception that those memories are accurate and consistent.