Flashback (psychology)
[2] Flashbacks are the "personal experiences that pop into your awareness, without any conscious, premeditated attempt to search and retrieve this memory".
For those suffering post-traumatic stress disorder (PTSD), flashbacks can significantly disrupt everyday life.
[1] Theories and research on memory date back to Hermann Ebbinghaus, who began studying nonsense syllables.
These rare events elicit strong emotional reactions from the individual, since they violate normal expectations.
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.
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.
[10] 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.
[7] Dual representation theory enhances this idea by suggesting two separate mechanisms that account for voluntary and involuntary memories.
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.
Additionally, other 2009 studies by Rasmuseen and Berntsen have shown that long term memory is also susceptible to extraneous factors such as recency effect, arousal, and rehearsal as it pertains to accessibility.
Normally, voluntary memory would be associated with contextual information, allowing correspondence between time and place to happen.
Disruptive memories are almost always associated with a familiar stimulus that quickly becomes stronger through the process of consolidation and reconsolidation.
The medial temporal lobes, the precuneus, the posterior cingulate gyrus and the prefrontal cortex are the most typically referenced with regards to involuntary memories.
[14] Brain imaging studies have shown flashbacks activating areas associated with memory retrieval.
[18] The precuneus, located in the superior parietal lobe, and the posterior cingulate gyrus, have also been implicated in memory retrieval.
The procedure involves changing the content of the intrusive memories and restructuring it so the negative connotations associated with it is erased.
Using these techniques, researchers attempt to discover the structural and functional differences in the anatomy of the brain in individuals who suffer from flashbacks compared to those who do not.
Neuroimaging studies investigating flashbacks are based on current psychological theories that are used as the foundation for the research.
[27] The dorsal stream is involved in sensory processing, and therefore these activations might underlie the vivid visual experiences associated with flashbacks.
The study also found reduced activation in regions such as the inferior temporal cortex and parahippocampus which are involved in processing allocentric relations.
[2] Flashbacks have also been observed in people suffering from bipolar disorder, depression, homesickness, near-death experiences, epileptic seizures, and substance abuse.
For example, a study on the use of the Nabilone for the treatment of nightmares in PTSD patients found that, in some cases, the use of the synthetic cannabinoid reduced daytime flashbacks.
