Flashbulb Memories

Human Memory 207,

Do Flashbulb memories differ from other forms of memory?

"Our past is preserved in a variety of memories of very different nature" (Salaman, 1970)

There are many proposed divisions and sub-divisions of human memory, such as working memory, procedural memory, semantic memory or episodic memory. Many of the systems seem to overlap, with each having varying functions related to the maintenance of what is essentially human life. For example, episodic and autobiographical memory fundamentally share the same functions. One of the many functions is what Tulving (1983) called "Mental time travel", the ability to experience past event. Autobiographical memories are thought to be structured at different levels of temporal and spatial specificity that together are used as reference for the construction of "self". This mental time travel can take place through different hierarchic levels of autobiographical organisation. The hierarchy level can be as general as "university" or as specific as remembering the topic of conversation with a certain person on a certain day (Cohen, 1998). Autobiographical memories are therefore seen as being autonoetic in that they carry information about the context in which they were experienced.

One example of an extreme form of contextual specific memory is the death of Princess Diana. Many people especially the media ask a common question such as "what were you doing when you heard the news". Many people claim to be able to remember such major moments with unusual clarity and vividness, as if the events were etched on their minds throughout their lives. The question is whether these "flashbulb memories" are functionally different to all other types of memory such as autobiographical memory.

Brown & Kulik (1977), introduced the term flashbulb memory to describe memories that are preserved in an almost indiscriminate way. They postulated that these flashbulb memories were indeed different from ordinary memories, with some defining characteristics. Although these memories are thought to be photographic in their clarity and detail, they do not preserve all features of an event. Conversely Brown & Kulik proposed that idiosyncratic event details are remembered. These details help form what has been described as a "live" memory in that the "reception field" is remembered including 'where', 'when' and 'who with' factors of an event. Brown & Kulik (1977) studied memories for important events such as the death of John F Kennedy. They found that irrelevant details were often recalled and it appeared that they had retained "a brief moment of time associated with an emotional event" (Smyth et al, 1994). Brown & Kulik suggested that flashbulb memories are formed by the activity of an ancient brain mechanism evolved to capture emotional and cognitive information relevant to the survival of an individual or group.

To summarise, flashbulb memories FMs are thought to be an unique survival mechanism distinct from other form of memory in their clarity, longevity and attention to idiosyncratic detail.

These characteristics of flashbulb memories can be mapped onto issues concerning memory. As with many memory systems, the argument over the distinctiveness of flashbulb memories involves encoding, storage and retrieval. These issues relate to many issues within Flashbulb memory such as their formation, accuracy, consistency and longevity. It appears that these processes are interrelated with each process being dependent on another.

In terms of FM formation, Brown & Kulik thought that the clarity and detail of FMs is correlated with the emotion, surprise and personal consequentiallity of the event. They also thought that surprise initiates FM formation, while personal consequentiallity determines the elaborateness of the resulting FM. As support for this they found that more blacks had FMs associated with the death of Martin Luther King compared to whites. Apparently this was due to an increased emotional personal consequentiallity felt their part of society. Therefore self referring prior knowledge of surprising important events is thought to support privileged encoding of FMs compared to other mundane memories. In support for this Livingstone (1967) proposed that when an event passes a certain biological criterion, the limbic system discharges into the reticular system, which further discharges throughout the cortical hemispheres. This firing above a certain level has been termed the "now print" mechanism. This system can be seen as being rather like the flash going off on a camera. However this view is criticised on the grounds that this "biological level" is not specifically identified.

In a further criticism Neisser (1982c) has claimed that FMs are not specially encoded and therefore not unique. Neisser proposed that FMs were Simply ordinary memories made clearer and longer lasting by frequent rehearsal after the event. This argument seems quite logical, as particularly in this global age the media and society frequently replay and retell events of extreme public attention or emotion. Flashbulb memories could therefore be seen as memories that have be actively reconstructed to such an extent that they can be clearly replayed in our minds. Flashbulb memories are seen by Neisser not as a special evolutionary mechanism, but as a method of promoting the integration of an individual within a society. In this reconstruction, personal consequentiallity is applied after an event once is importance is measured within society.

This also questions the validity and accuracy of "flashbulb memories" in that they are memories actively reconstructed and transformed over time. Neisser & Harsch (1992) measured flashbulb memories of the shuttle challenger explosion. They found that after one day 9 subjects claimed to have learned of the event from television, however 34 months later this figure had risen to 19. As a further nail in the coffin for Brown and Kulik's flashbulb memory hypothesis Christianson & Loftus (1987) found that high emotion served to narrow attention to focus to the central aspects of an event a the expense of peripheral details. This would seem to indicate that the idiosyncratic