In this article, I want to focus on the potential adverse effects of trauma on memory, and, in particular, four types of memory :
I briefly explain the function of these four types of memory below :
EPISODIC MEMORY: Our episodic memory stores our unique memories of specific events.
SEMANTIC MEMORY: Our semantic memory stores concepts, facts, ideas, and meanings relating to the world in general/general knowledge.
PROCEDURAL MEMORY: Our procedural memory stores information about how to carry out ‘procedures’ that underlie motor, cognitive and visuospatial skills such as walking, swimming, and driving, that have become ‘second nature’ and can be performed automatically.
EMOTIONAL MEMORY: Emotional memory stores information relating to how we felt / the emotions we experienced at the time of a particular event.
A SIMPLE EXAMPLE THAT HELPS TO EXPLAIN THESE FOUR TYPES OF MEMORY :
If an individual was involved in a car accident, the four types of memory the person has of the event might be as follows :
EPISODIC MEMORY: The memory of who else was in the car at the time of the crash and what was playing on the radio.
SEMANTIC MEMORY: The memory of what a car is.
PROCEDURAL MEMORY: The memory of how to drive a car (assuming the person has been driving for a long time and is not new to it).
EMOTIONAL MEMORY: The fear felt the next time the person drives the car (the car triggers the fear-response associated with the crash which has been stored in memory).
How Can Trauma Adversely Affect These Four Types Of Memory?
EPISODIC MEMORY: Trauma can cause the part of the brain which forms and indexes episodic memories, known as the hippocampus) to ‘go off-line’ temporarily or may impair its normal functioning in such a way that the episodic memory of the traumatic event formed is fragmented, incohesive, and not properly processed. Because of this, fragments of memories that were formed when the traumatic event occurred may intrude on the mind in the form of flashbacks and nightmares after the traumatic event is over for as long as this incomplete processing persists (which, in the absence of therapy and in the most serious cases, may be for a life-time).
SEMANTIC MEMORY: Trauma can prevent information from different brain regions from integrating in a meaningful way thus impairing the person’s ability to form semantic memories – this, in turn, can lead to learning difficulties. Semantic memories are generated in a region of the brain known as the anterior temporal lobe.
PROCEDURAL MEMORY: Trauma can adversely affect our memory of how to carry our procedures/activities. Continuing with the ‘car accident’ example, the next time we drive a car our muscles may become tense so that our driving is less smooth than before the accident and we find, too, that we are thinking more than normal about simple procedures like changing gear and using the indicator (whereas, pre-accident, such procedures would have been undertaken ‘automatically’ / without conscious deliberation. The main regions of the brain involved in the operation of procedural memory are the prefrontal cortex, parietal cortex, and cerebellum.
EMOTIONAL MEMORY: The next time we sit behind the wheel after the accident, we may feel flooded with fear. The region of the brain involved in learning and forming fear memories is known as the amygdala.
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David Hosier BSc Hons; MSc; PGDE(FAHE).