The first exhibit of the National September 11 Memorial Museum is a multimedia display entitled, “We Remember”. Sixteen speakers surround visitors with a barrage of voices as accompanying text is projected onto a world map:

  • Someone barged in and said, “Oh my God. That plane has just crashed into the World Trade Center.”
  • I heard it on the radio.
  • I just remember turning on my TV, and it was breaking news.

Thousands of people recorded their memories of where they were and what they were doing when they heard about the terrorist attacks of 9/11. When I visited the museum, their stories echoed through the museum halls and summoned my own vivid memories of the day my 13-year-old self learned that villains were real and heroes do not always win. Psychologists use the term “flashbulb memories” to describe these powerful recollections of unexpected and especially emotional events, like 9/11 or the assassination of JFK. Flashbulb memories feel sharply accurate, as if a camera’s flashbulb has illuminated the moment and perfectly preserved it in our minds.

When flashbulb memories were first formally named and described in 1977, psychologists thought that such memories were precise and pristine in capturing a moment in time. We now know from studies of memories of emotionally charged events such as the Challenger explosion, the OJ Simpson trial verdict, and 9/11, that flashbulb memories are no more accurate than our memories of everyday events; they just feel more accurate. Over a decade after the attacks, our personal memories of 9/11 still feel acutely real and absolutely unforgettable, but in fact, we have actually already forgotten, without even realizing it.

In one study by memory researchers at Duke University, American college students were asked on September 12, 2001, to record their memories of what they were doing when they heard about the 9/11 attacks the day before. For comparison, they were also asked about their memories of a recent everyday event, like a college party or study session. The students were later asked to recall their memories of 9/11 and the everyday event after different intervals of time had elapsed. Both the flashbulb memories for 9/11 and the regular memories for the everyday event had similarly faded, with fewer correct details recalled and more incorrect details emerging as time elapsed.

The two memory types differed, however, in how real they felt. Students believed that their memories of 9/11 were more accurate than their memories of the everyday event. The flashbulb memories felt more vivid, like they were being relived firsthand, while the everyday memories felt more like an outside observer watched them. This perceived accuracy and vividness decreased over time for the everyday memories but remained strong for the 9/11 memories even 32 weeks later.

In a separate study by psychologists at New York University and Rutgers, New Yorkers were asked to recall their memories of 9/11 approximately three years later. Physical closeness to the World Trade Center on 9/11 predicted the strength of the flashbulb memory effect. Those who were in downtown NYC and an average of two miles from the World Trade Center reported more vivid, arousing memories and stronger confidence in the accuracy of those memories than those who were further away from the towers in midtown NYC. Furthermore, the amygdala, a region of the brain that processes emotions, was more active in the downtown group than the midtown group during the retrieval of these flashbulb memories. Thus, the brain intensely, emotionally experiences flashbulb memories, the researchers behind the study posited. This may explain why flashbulb memories feel so accurate: the emotions are real, even when the memories themselves have become distorted with time.

The National September 11 Memorial Museum ends with an opportunity for patrons to leave personal messages in a digital guestbook. These messages are then projected onto a giant screen for museum patrons to view. On the day of my visit, the screen lit up again and again with promises to never forget and always remember. In order to honor those promises, we must accept that we have already forgotten. Even memories that feel terribly real are imperfect, and we need honest representations and reminders, like those presented by the National September 11 Memorial Museum, to help us remember.