Though they are similar to memories of real events - and even more intense - the characteristics of NDE memories don't necessarily prove the existence of the events that were described (OBEs, conversations with the dead, etc.). As previously mentioned, physiological mechanisms seem to explain the different NDE elements. These mechanisms may possibly "create" a perception that the subject perceives as external and real. In a sense, the individual's brain is lying to him/her, as it does during a hallucination.
Flashbulb memories?
In 1977, Harvard University's Roger Brown and James Kulik introduced the notion of "flashbulb memories". This refers to memories that are tied to the circumstances in which we learned of a major public event: the fall of the Berlin wall, the Space Shuttle Challenger explosion, the September 11th attacks, etc.
Brown and Kulik focused their research on the assassination of President Kennedy, showing that many people remembered who they were with, where they were, and what they were doing at the moment they learned of the event. According to the two Harvard University psychologists, the emotional events that give rise to flashbulb memories trigger a "special" memory storing mechanism. It ensures that the context in which we learned of a major public event is encoded in a more detailed and precise way and remains in our memory longer.
"If we consider the particularly surprising nature of the images the NDE experiencer sees, and their emotional and personal significance, it seems reasonable to establish a link between NDE memories and flashbulb memories," says Marie Thonnard. Thus they hypothesise that memories of NDEs may actually be flashbulb memories (2) of a hallucination.
In the wake of Brown and Kulik's work, a number of studies were conducted on flashbulb memories. While it appears that these particular memories are often recorded in a more detailed and long-lasting way than others, they are nonetheless subject to errors and distortions, additions over time, and the progressive erasure of certain elements. This was demonstrated by research that measured their consistency over time: after several days, several weeks, several months, and several years. Now the ULg researchers are following a similar line of research to analyse NDE memories (3).
Until now, physiological and psychological explanations for NDEs often seemed mutually exclusive. Yet the joint research conducted by the Coma Science Group and ULg's Cognitive Psychology Unit suggests that these two dimensions should in fact be integrated.
