Amnesia due to Emotional Trauma

Introduction

Memory is the ability to retain and then recover new information, and amnesia is an impairment of memory (Breedlove & Watson, 2013). Research has shown that amnesia can be caused by head trauma and damage to the hippocampus, mammillary bodies and dorsal thalamus. These regions of the brain are required to form ‘declarative memories’, those memories that can be shown to others. Henry Molaison, known to the world as patient H.M. is probably the most famous subject in the study of amnesia and inability to make new memories due to brain trauma. In 1953, , Henry's neurosurgeon removed most of the ‘anterior temporal lobes’ in his brain to cure Henry’s out of control epilepsy and seizures (Breedlove & Watson, 2013). The surgery helped with the seizures, but Henry lost the ability to make new memories. This condition is called retrograde amnesia when the loss of memory is that of more recent events compared to remote events. Nadel & Moscovitch (1997) found in their research evidence in past studies of retrograde amnesia following damage to the hippocampal complex of humans. They also conclude that the amount of loss of memory depends upon the kind of memory is being assessed.

Research has shown that head trauma and injury can cause amnesia, but there is another controversial theory. Some experts have concluded that emotional trauma can be a reason for amnesia as well. However, this theory is under question as compared to the well established theory of amnesia caused by head trauma.

In this paper, we examine research done on the theory that emotional trauma can be a cause of amnesia. We look at the neurological reasons behind this theory and the pros and cons of this issue.

Amnesia caused by emotional trauma

Emotional trauma or trauma is defined as a response to an appalling event like an accident, rape or natural disaster (American Psychological Association, APA). Behavior of denial and shock is a typical response following the event and in some cases many years after the event. Joseph (1999) after his research on past articles about amnesia argues that memory loss after ‘severe stress and emotional trauma’ are not uncommon. This is usually due to the ‘gluco steroids’ and stress associated with the hippocampus region in the brain that plays a vital role in memory storage. He says that the intensity of amnesia depends upon factors like repetition of the traumatic event, severity and the duration of the trauma.

Post Traumatic Stress Disorder (PTSD) has often been connected to amnesia as a result of emotional trauma. In past studies, there was no substantial mechanism to measure PTSD and neurogenic amnesia. However, contemporary research give an in depth view of memory and have found the basis for dual diagnosis of PTSD combined with amnesia (Layton & Wardi-Zonna, 1995).

Breuer and Freud (1893-1895/1955) affirmed that repression is a ‘cognitive inhibition’ process that the person who faced the trauma uses. This causes amnesia of the traumatic event for the time being, but memory of the event is not eradicated entirely. They argue that these memories move into the ‘unconscious’ and are released through personality disorders, states of hysteria or PTSD (Shobe & Kihlstrom, 2007). The view point of suppressed memories or repression that can cause amnesia is popular among experts helping rape victim war survivors, PTSD sufferers as result of events like 9/11.

Do I believe that amnesia can be caused by emotional trauma?

Yes, I do believe that amnesia can be caused by emotional trauma. However, this can vary depending on the kind of trauma (e.g. amnesia suffered by war survivors or by childhood abuse survivors), duration and most definitely on the coping abilities of the sufferer. Amnesia can be used as a dominant defense mechanism against the emotional trauma. Freyd (1994) made the argument that ‘psychogenic amnesia’ is a tool a child may use to maintain a relationship and attachment to a figure that may have abused them. When these abused children grow older amnesia enables them to cope with the emotional arrests they feel with their abuser who may have violated some basic ethics of human relationships.

If survivors of emotional trauma seek help and it is successful, then the scenario of psychogenic amnesia may possibly change. Coping abilities of individuals who have suffered from emotional trauma can play a role. Some survivors are able to carry on normal life with slight effects on their behavior from the emotional trauma. In this case,  the amnesia is more helpful than being harmful and does not require help. When coping abilities are not sufficient, and PTSD develops and professional help is needed, amnesia maybe treated. The memories of emotional trauma may need revival for successful treatment of behavioral and mental conditions. Amnesia caused by emotional trauma and the continuation of this psychogenic amnesia is subject to change. I understand what Freud and Breuer declared that memories of emotional trauma travel to unconscious but are never completely abolished.

Phenomenon explained in neurologic terms

Gilbertson et al (2002) study showed that in animals exposure to stress regularly causes damage to the hippocampus and effects memory. In human studies also a smaller hippocampal is seen when suffering from posttraumatic stress disorder (PTSD). Their study involved pairs of twins with one group of twins who suffered from PTSD and the other did not. They in fact, did find a negative relation between the severity of PTSD and hippocampal volume, size. Some researchers have suggested that amnesia is a ‘disconnection syndrome’ and impairment is found for that material in memory which requires conscious remembering (Warrington and Weiskrantz, 1982). Some significant researches show that amnesia occurs when there  are severe neurological effects on the mesial temporal lobes.

Doubts cast by researches on the validity of psychological amnesia, some pros and cons

Joseph, R. (1998) proposed in his study that amnesia caused by trauma is ‘secondary to abnormal neocortical and hippocampal arousal’ According to him other factors like age, sex difference and stress in daily life before and after the trauma play a role in how much memory is lost of the event. On the other hand,  some researchers believe that the best mechanism to understand the hippocampal function is to study the amnesia caused by traumatic events (Cohen et al, 1999). In the past researchers have conducted research to show how memory is lost, affected and then retrieved due to emotional trauma. Many studies have also concluded that there is still much room for more research and study on this topic. The doubts expressed are mostly based on the viewpoint that there is a thin line between amnesia and memory loss (Sweet et al, 2008). To understand the amnesia caused by emotional trauma, it is important to understand this distinction.

References

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Gilbertson, M. W., Shenton, M. E., Ciszewski, A., Kasai, K., Lasko, N. B., Orr, S. P., & Pitman, R. K. (2002). Smaller hippocampal volume predicts pathologic vulnerability to psychological trauma. Nature Neuroscience, 5, 1242–1247. Retrieved from http://www.nature.com/neuro/journal/v5/n11/abs/nn958.html

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Shobe, K. K., & Kihlstrom, J. F. (2007). Is traumatic Memory special? Retrieved from http://ist-socrates.berkeley.edu/~kihlstrm/special.htm

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