A ten-year follow-up of a study of memory for the attack of September 11, 2001: Flashbulb memories and memories for flashbulb events

Hirst, W., Phelps, E.A., Meksin, R., Vaidya, C.J., Johnson, M.K., Mitchell, K.J., Buckner, R.L., Budson, A.E., Gabrieli, J.D.E., Lustig, C., Mather, M., Ochsner, K.N., Schacter, D.L., Simons, J.S., Lyle, K.B., & Olsson, A. (2015). Journal of Experimental Psychology: General, 144, 604-623.

Within a week of the attack of September 11, 2001, a consortium of researchers from across the United States distributed a survey asking about the circumstances in which respondents learned of the attack (their flashbulb memories) and the facts about the attack itself (their event memories). Follow-up surveys were distributed 11, 25, and 119 months after the attack. The study, therefore, examines retention of flashbulb memories and event memories at a substantially longer retention interval than any previous study employing a test-retest methodology, allowing for the study of such memories over the long-term. There was rapid forgetting of both flashbulb and event memories within the first year, but the forgetting curves leveled off after that, not significantly changing even after a 10-year delay. Despite the initial rapid forgetting, confidence remained high throughout the 10-year period. Five putative factors affecting flashbulb memory consistency and event memory accuracy were examined: (1) attention to media (2) the amount of discussion, (3) residency, (4) personal loss and/or inconvenience, and (5) emotional intensity. After ten years, none of these factors predicted flashbulb memory consistency; media attention and ensuing conversation predicted event memory accuracy. Inconsistent flashbulb memories were more likely to be repeated rather than corrected over the ten-year period; inaccurate event memories, on the other hand, were more likely to be corrected. The findings suggests that even traumatic memories and those implicated in a community's collective identity may be inconsistent over time and these inconsistency can persist without the corrective force of external influences.