A flashbulb memory is a memory that was laid down in great detail during a personally significant event, often a shocking event of national or international importance. These memories are perceived to have a "photographic" quality. The term was coined by Brown and Kulik (1977), who found highly emotional memories (e.g. hearing bad news) were often vividly recalled, even some time after the event. For example, a great many people can remember where they were when they heard of the terrorist attacks on September 11, 2001 or the assassination of U.S president John F. Kennedy or musician John Lennon.
Despite the great vividness of such memories, some research suggests that flashbulb memories are no more likely to be remembered than ordinary memories, if the ordinary memories are consistently returned to in a similar way (e.g., Weaver, 1993 and Talarico, 2003). The most pronounced difference between ordinary and flashbulb memory is that people believe flashbulb memories to be more accurately and vividly remembered. Part of the reason for this may be that people discuss such significant events frequently, and the after-the-fact discussion can modify what people believe they remember about the event. Neisser (1982) believes that flashbulb memories are enduring because they are constantly being reinforced by, for example, the media.
Some biologists believe that the hormone Cortisol, which is released in response to stressful incidents, causes the formation of flashbulb memories by the brain. Another theory proposes flashbulb memory is an artifact of synaptic plasticity tagging whereby memory of unimportant events share or 'steal' some of the strengthening synaptic tag of the important event.