Кешірімді естеліктер құбылысы

Psychological phenomenon in which a person re experiences a memory

A flashback, or involuntary recurrent memory, is a psychological phenomenon in which an individual has a sudden, usually powerful, re experiencing of a past experience or elements of a past experience. These experiences can be frightful, happy, sad, exciting, or any number of other emotions.

Flashbacks are the "personal experiences that pop into your awareness, without any conscious, premeditated attempt to search and retrieve this memory". These experiences occasionally have little to no relation to the situation at hand. For those suffering post traumatic stress disorder (PTSD), flashbacks can significantly disrupt everyday life. Ebbinghaus classified three distinct classes of memory: sensory, short term, and long term memory. Sensory memory is made up of a brief storage of information within a specific medium (the line you see after waving a sparkler in your field of vision is created by sensory memory). 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.

Memory has typically been divided into sensory, short term, and long term processes. These sensory experiences take place just before the flashback event. They act as a conditioning stimulus for the event to appear as an involuntary memory. The presence of the primer increases the likelihood of the appearance of a flashback. Just as the sensory memory can result in this, it can also help erase the connections between the memory and the primer. Counter conditioning and rewriting the memory of the events that are related to the sensory cue may help dissociate the memory from the primer.

There have been many suspicions that disruptive memories may cause deficiencies in short term memories. For people who suffer from flashbacks, the hippocampus that is involved with the working memory has been damaged, supporting the theory that the working memory could have also been affected. Many studies were conducted to test this theory and all results concluded that intrusive memory does not affect the short term memory or the working memory.

Out of the three types of memory processes, long term memory contains the greatest amount of memory storage and is involved in most of the cognitive processes. According to Rasmuseen and Berntsen, "long term memory processes may form the core of spontaneous thought" (2009).

Episodic memory is a type of long term memory where the involuntary memories are made up of intense autobiographical memories. As a version of declarative memory, this follows the same idea that the more personal the memory is, the more likely it will be remembered. Disruptive memories are almost always associated with a familiar stimulus that quickly becomes stronger through the process of consolidation and reconsolidation. The major difference is that intrusive thoughts are harder to forget. Most mental narratives tends to have varying levels of some type of emotions involved with the memory. For flashbacks, most of the emotions associated with it are negative, though it could be positive as well. These emotions are intense and makes the memory more vivid. Decreasing the intensity of the emotion associated with an intrusive memory may reduce the memory to a calmer episodic memory.

Several brain regions have been implicated in the neurological basis of flashbacks. The medial temporal lobes, the precuneus, the posterior cingulate gyrus and the prefrontal cortex are the most typically referenced with regards to involuntary memories. The hippocampus, located within the medial temporal regions, has also been highly related to memory processes. There are numerous functions in the hippocampus that includes aspects of memory consolidation. Brain imaging studies have shown flashbacks activating areas associated with memory retrieval. The precuneus, located in the superior parietal lobe, and the posterior cingulate gyrus, have also been implicated in memory retrieval. In addition, studies have shown activity in areas of the prefrontal cortex to be involved in memory retrieval.

The psychological phenomenon has frequently been portrayed in film and television. Some of the most accurate media portrayals of flashbacks have been those related to wartime, and the association of flashbacks to PTSD caused by the traumas and stresses of war.