Trauma, Memory and the Brain

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Trauma changes our brains on a fundamental level, the psychologically traumatised brain causes inscrutable eccentricities which can (and do) cause it to overreact – or misreact – to stimulus and the realities of life. These neurological “misreactions” become established in part due to the effect that trauma has on the release of certain stress-responsive hormones, such as norepinephrine, along with the effect upon various areas of the brain involved in memory – particularly the amygdale and the hippocampus.

The amygdale is the part of the brain responsible for communicating the emotional importance and evaluation, via the thalamus, of sensory information to the hippocampus. In accordance with the amygdales evaluation the hippocampus will activate to a greater or lesser degree, and functions to organise this information and integrate it with previous similar sensory events. Under a normal range of situations and conditions this system works well and effectively to consolidate memories according to their emotional priority and content. However, at the extreme upper end of this hormonal activation, as with traumatic situations, a breakdown occurs. Overwhelming emotional significance registered by the amygdale actually leads to a decrease in hippocampal activation, this results in some of the traumatic input not being organised properly, not being stored as a unified whole, and not being integrated with other memories. This results in isolated sensory images and bodily sensations that are not localised in time or even in situation, nor integrated with other events. In effect these fragments of memory float about in the mind, ready to reappear at any moment.

To make matters even more complex, trauma may temporarily such down Brocas area, the region of the brain which translates experience into language, the means that we more often use to relate our experience and feelings to others and even to ourselves.

Regular memories are formed and are subject to meaningful modification, they can be retrieved when needed and can be conveyed to others through language and expression. In contrast, traumatic memories include chaotic fragments, which are sealed off from modification or modulation. Such memory fragments are wordless, placeless, and eternal. Long after the trauma has receded into the past the brains record of them may remain a fractured mass of isolated and confused emotion, images and sensations which can ring through the person like an alarm at any moment.

These sensations and feelings may not be labelled as part as belonging to memories from long ago, in fact they may not be labelled at all, as they may have been formed without language. They merely are, they come forward to take over the body giving no explanation, no narrative, no place or time, they are free-form and ineffable.

The traumatised brain has, effectively, a broken warning device in its limbic system. A bit like an old fuse box where the fuses tend to melt for no reason, reacting to an emergency when there is none.

What is dissociative fugue?

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The key feature of dissociative fugue is “sudden, unexpected travel away from home or one’s customary place of daily activities, with inability to recall some or all of one’s past,”. The travels associated with the condition can last for a few hours or as long as several months. Some individuals have traveled thousands of miles from home while in a state of dissociative fugue. (The word fugue stems from the Latin word for flight— fugere). At first, a person experiencing the condition may appear completely normal. With time, however, confusion appears. This confusion may result from the realisation that the person can not remember the past. Victims may suddenly realise that they do not belong where they find themselves.

During an episode of dissociative fugue, a person may take on a new identity, complete with a new name and even establish a new home and ties to their his/her community. More often, however, the victim realises something is wrong not long after fleeing – in a matter of hours or days. In such cases, the victim may phone home for help, or come to the attention of police after becoming distressed at finding himself/herself unexplainably in unfamiliar surroundings.

Dissociative fugue is distinct from Dissociative Identity disorder (DID). In cases of DID, which previously was called Multiple Personality Disorder (MPD), a person loses memory of events that take place when one of several distinct identities takes control of the person. If a person with dissociative fugue assumes a new identity, it does not co-exist with other identities, as is typical of DID. Repeated instances of apparent dissociative fugue are more likely a symptom of DID, not true dissociative fugue.

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