How does our memory usually work without the interference from trauma?
There is 3 stages and processes which happen inside our brains to retain information.
- Encoding: This is the cognitive process where and in which the information is learned, taken in and understood. Here it is altered, encoded, to support the storage system inside out minds. There is 4 methods in which memory is encoded. 1. Visual, this is how something looks. 2. Acoustic, how something sounds, Sematic, what something means and tactile, how something feels. Even though the information usually enters of memory system in the form it is encoded, the information which is stored may be different to the way it was originally was encoded.
- Storage: Like in a computer database, storage refers to the place where to encoded information is stored and is also responsible for how this information is stored but also where, how much and for how long of a time the information is sported within your memory system. There is 2 types of memory: Short-term and Long-term. Information is first stored in the short-term memory system, and them if your storage deems that information necessary it will move the encoded information into your long term memory. Usually and primarily sematic encoded information is primarily stored in long term memory. Once the information is stored the information, the individual needs to recall or retrieve this information to gain access it.
- Retrieval: This is the process where we retrieve or recall the information in which is stored. Retrieving information from short-term and long-term memory differ, due to how the information is stored.
How does trauma affect memory and recall?
‘People often assume and expect that we will be able to recollect major events in our lives with clear and unwavering accuracy and that this determines the “truth” of what happened’ (Department of Justice Canada, 2019). However, traumatic events cause the information to be encoded differently then the usual in our day to day lives, due to this we frequently retrieve and recall the information and narration of our experiences with trauma differently to everyday life and the routine However, certain traumatising event our brain can deem “this is important, you need to remember this forever, because it could save your life at a later date” and therefore these memories are etched into a minds forever and seem impossible to forget. When we encode information from an event we focus on what our brain deems to be important and less so on those which it deems as not important or significant (Department of Justice Canada, 2019).
During normal circumstances, the amygdala neurons ‘encode fear memory traces (or fragments) while the hippocampus learns about the context of the fear. But when faced with threatening experiences, this emotionally arousing information increases amygdala activity. That activity correlates with more deeply remembered memory traces in the amygdala’ (Department of Justice Canada, 2019). Because fear and stress intensifies and heightens the acitivation of the amygdala, traumatic memories are reinforced and potent, however this also means this hippocampal function which is usually to putting the experience and events in chronological order and also into perspective, which is essential into forming explicit memories (cognitive memories), is blocked and impaired. This means these memories are not integrated into their hippocampus and the memory storage system and many victims of traumatic events experience ‘fragments’ or otherwise called implicit or limbic memory traces. Many people have experienced the feeling of “It was all a blur” after a stressful event and these are the reasons why.
Due to this, these implicit memories or fragments, means someone can remember the behavioral knowledge of their experience without consciously able to recall the events, therefore it is not a memories which one can reflect on or even think about and therefore it is difficult to understand and process, which creates difficulties in recovery from trauma. However, these memories are often fragmented in time which creates gaps in the memory but also consist deeply of information from the primary sense, (visuals, smells, sounds) especially ones which are linked primarily to the physiological fear felt during specific moments (Department of Justice Canada, 2019).
What are Intensified Traumatic and Flashbulb Memories? And what causes them?
As stated previously fear and stress can produce two very different results in memory, either in intensified memories, the ones which are etched into our minds seemingly forever, or it can result in the implicit fragmented memories which I described previously. These are both caused and due to the result of the stress hormones released and affecting the brains function of encoding and storing memories. However, studies have shown that when the adrenal glands release large amounts of adrenaline during this experiences, it helps the hippocampus to encode memories more intensely. But due to the burst of adrenaline usually occurring at the beginning of a traumatic experience, it is not uncommon for people to have extremely vivid and full memories from the beginning of the traumatic experience when the defence circuitry in the brain was originally and first triggered and when the initial burst of stress hormones were released. Due to this the burst of adrenaline is believe to enhance the storage of memories at the beginning of the traumatic event, therefore as it strengthens the memories pathways and creates what is usually referred to what is called flashbulb memories. ‘Experiences with emotional significance are more likely to be consolidated into episodic memory and made available for intentional, conscious recollection than those with little or no emotional significance. The brain encodes what it pays attention to. During a threatening event, the brain focuses on what is central to survival so it does not focus on insignificant and peripheral details, so it does not encode them’ (Department of Justice Canada, 2019).
Due to the high levels of the cortisol (the stress hormone) which are secreted alongside adrenaline, the brain and specifically as mentioned the hippocampus super-encodes these intense early moments of the experience, however if the stress-levels, fear and threat continues the brain continues to secrete high levels of cortisol therefore the hippocampus then get overwhelmed with the cortisol levels and therefore may then lead the very little and minimal encoding, and therefore this is how the you can go from one extreme to another with your memory of a traumatic event, from flashbulb memories to fragments (Department of Justice Canada, 2019).
What are fragmented memories?
An example of fragmented memory is that for instance ‘a sexual assault victim might not recall the layout of the room where the rape happened. The hippocampus might not encode time-sequencing information because its functioning is altered during a traumatic event’ (Department of Justice Canada, 2019). But also due to intense influx of hormones the brain, and specifically memory centres of the brain such as the hippocampus can be permanently damaged. The hippocampus can also disrupt he system of encoding conscious and explicit memories when the stress homes block or damage the hippocampus but also can inhibited when there is intense amygdala activation.
Due to the fact the amygdala is critical in the involvement of calculating how emotionally significant an event is, when a threat is perceived it initiates a stimulation of emotional arousal. The intention of this is to force us as an individual to pay attention, be alert and be ready to respond to the threat. However, because it is also selective, it will make us pay attention to particular things and then it will encode this. Due to the fact fear makes us pay attention to small details and normally very few details, it means one may not remember all the facts and experiences from the traumatic event such as, a woman who experienced sexual assault may remember the colour of the t-shirt her attacker was wearing but not remember key details of the event, or what her surroundings looked like.
Also, during these events one can become dissociated, and the two networks of the hippocampal and amygdala because disconnected. Leading to the emotional memories and the more explicit processing of the hippocampal not working together leading to the memories not being integrated and therefore emotions, sensation and other memories and feelings become disconnected from their context and time sequence, therefore as result leads to one being able to recall how they felt but not necessarily the details, or any words or narrative surrounding the event to therefore be recalled.
As when encoding memory inside the brain is impaired, the brain prioritised the aspects of the experience which are deem vital for survival, or what are deemed to be of very little emotional importance. This then leads frequently to a disorganised and also incomplete narrative of the experience and memory.
Due to all this, defence lawyers take advantage of all this and use it to undermine the credibility of the sexual assault and rape victims and in many cases media and critics in high profile cases use the gaps in memory to attack victims credibility also. This is a problem which lies deep and connects with the rape myths, and victim blaming culture our society has and there is little understanding surrounding this area, and one of the reasons I believe that this is an important topic to explore especially and the current societal time.