Newswise — The details of where you were and what you were doing when you learned about the terrorist attacks of Sept. 11, 2001, are stamped indelibly into your memory, vivid as a photograph. Or are they?

No, says Charles Weaver, Ph.D., professor of psychology and neuroscience at Baylor University.

Much has been made of so-called “flashbulb memory” — recollection of our surroundings and reactions during such events as 9/11, the attack on Pearl Harbor and the assassination of President John F. Kennedy. At one point, researchers believed these to be photograph-like (hence the term) memories: detailed, vivid, accurate and unchanging.

In reality, “we sort through many possible details from a variety of sources over a period of time,” Weaver said.

“Gradually, our memories take shape; we get our stories straight.” For example, “your memories of 9/11 might contain details you could not have learned until later in the week.

“Flashbulb memories are almost an illusion of memory —we believe them to be perfect, although they are subject to the same distortions as any other kind of memory,” he said. “Your memories of major events are characterized not by accuracy, but by confidence. And confidence is a very poor measure of accuracy.”

Weaver, a researcher of memory and cognition, has published studies on flashbulb memory and eyewitness memory. He also has served as a forensic expert on eyewitness identification in civil and criminal cases in more than 15 states.

After a significant event, Weaver says, our minds consolidate and compress our experiences, facts and emotions into a coherent but not necessarily precise memory.

Viewing or listening to media accounts sometimes produces memories of things that didn’t actually occur. Talking with friends and loved ones can muddy the water further, he said — just as it can with more mundane happenings.

“It’s like you’re sitting around with friends and saying, ‘Remember the time we did that?’ And someone else says, ‘No, it was at breakfast, not lunch.’

“Your memories converge — at the expense of the accuracy of both memories. That’s why police separate eyewitnesses as soon as possible after the event,” Weaver said.

While recollections of major events are generally reliable, “they’re no different than other memories when it comes to details being shaped and lost,” he said. “Your memory isn’t any more reliable than usual; you can’t trust it as infallible.”

To retain one’s personal memories of significant events, the best approach is to write them down, he said.

“That’s what I recommend when we take students abroad,” Weaver said. “Details that seem like you’ll never forget, you’ll forget in a hurry.”

ABOUT BAYLORBaylor University is a private Christian university and ranked nationally as a research institution by the Carnegie Foundation for the Advancement of Teaching. Baylor provides a vibrant campus community for approximately 15,000 students. It blends interdisciplinary research with a faculty commitment to teaching and scholarship. Chartered in 1845 by the Republic of Texas through the efforts of Baptist pioneers, Baylor is the oldest continually operating university in Texas. Located in Waco, Baylor welcomes students from all 50 states and more than 80 countries to study a broad range of degrees among its 11 nationally recognized academic divisions.