Due to the elusive nature of involuntary recurrent memories, very little is known about the subjective experience of flashbacks. However, theorists agree that this phenomenon is in part due to the manner in which memories of specific events are initially encoded (or entered) into memory, the way in which the memory is organized, and also the way in which the individual later recalls the event. This view holds that traumatic memories are bound by the same parameters as all other every-day memories. Both viewpoints agree that involuntary recurrent memories result from rare events that would not normally occur. These rare events elicit strong emotional reactions from the individual, since they violate normal expectations. What is currently an issue of controversy is the nature of the defining criteria that make up an involuntary memory. Up until recently, researchers believed that involuntary memories were a result of traumatic incidents that the individual experienced at a specific time and place, while losing all the temporal and spatial features of the event during an involuntary
recollection episode. In other words, people who suffer from flashbacks lose all sense of time and place, and they feel as if they are re-experiencing the event instead of just recalling a memory. This is consistent with the special mechanism viewpoint in that the involuntary memory is based on a different memory mechanism compared to the voluntary counterpart. Furthermore, the initial emotions experienced at the time of encoding are also re-experienced during a flashback episode, which can be especially
distressing when the memory is of a traumatic event. It has also been demonstrated that the nature of the flashbacks experienced by an individual are static in that they retain an identical form upon each intrusion. This occurs even when the individual has learned new information that directly contradicts the information retained in the intrusive memory. These stimuli then become warning signals that, if encountered again, serve to trigger a flashback. This has been termed the warning signal hypothesis. For example, a person may experience a flashback while seeing sun spots on their lawn. This happens because they associate the spots with the headlights of the vehicle that they saw before being involved in a car accident. According to Ehlers and Clark, traumatic memories are more apt to induce flashbacks because of faulty encoding that cause the individual to fail in taking contextual information into account, as well as time and place information that would usually be associated with everyday memories. These individuals become
sensitized to stimuli that they associate with the traumatic event, which then serve as triggers for a flashback, even if the context surrounding the stimulus may be unrelated. These triggers may elicit an adaptive response during the time of the traumatic experience, but they soon become
maladaptive if the person continues to respond in the same way to situations in which no danger may be present. In contrast to this, theories belonging to the basic mechanism viewpoint hold that there are no separate mechanisms that account for voluntary and involuntary memories. The recall of memories for stressful events do not differ under involuntary and voluntary recall. Instead, it is the retrieval mechanism that is different for each type of recall. In involuntary recall, the external trigger creates an uncontrolled spreading of activation in memory, whereas in voluntary recall, this activation is strictly controlled and is goal-oriented. In addition, the basic mechanism’s involuntary recall for negative events, are also associated with memories of positive events. Studies have shown that out of the participants who suffer from flashbacks, about 5 percent of them experience positive non-traumatic flashbacks. They experience the same intensity level and has the same retrieval mechanism as the people who experienced negative and/or traumatic flashbacks, which includes the vividness and the emotion related to the involuntary memory. The only difference is whether the emotion evoked is positive or negative. == Cognition ==