Post Traumatic Stress Disorder, neurobiology and Freud’s seduction theory
The rationale for the essay will be to discuss how early childhood memories can contribute to Post Traumatic Stress Disorder (PTSD) later in adult life. Negative early experiences such as child abuse can have a major impact on the development of the brain. Similar to adults with PTSD, children have trouble sleeping, can not control their memories of the trauma and are constantly on alert (Kuafman, Plotsky, Meyerhof & Charney 2000). Memory alterations connected to PTSD represent a complex interrelationship between brain and mind (Wilson & Keane 2004). The essay will therefore address a psychological and neurobiological approaches which have been typically associated with the diagnosis of PTSD. The psychological approach for discussion will be Freud’s(1896) psychodynamic model of neurosis which was one of the first paradigms to place emphasis on external stressor events (Wilson 2004). The essay will concentrate on the hippocampus, a brain area involved in memory and briefly discuss the amygdala. Saplosky (1996) neurobiological study in relation to stress, glucorcotoids and hippocampus, a brain area involved in memory functioning. These brain areas will be discussed in relation to disturbing memories and deficits in memory functioning (Silver, McAllister & Yodofsky 2011).
Firstly it will be necessary to discuss what the term “memory” means. A simple definition of memory would be a persons power to remember things or the faculty by which the mind stores and remembers information (Oxford 1964). A psychological definition is more complex and although memory is seen as a single term it refers to a multitude of human capacities (Medin & Pashler 2002). There are three major processes involved in memory: encoding, storage and retrieval each operation represents a stage in memory processing (Sternberg 2009). Encoding is the process by which a memory is formed where information is changed into a useable form and stored in memory for later use (Nevid 2009). The information can be encoded in different ways; acoustically, iconic and semantically. Stored memories are quite often in the unconscious, implicit part of the mind and the retrieval process allows us to bring most memories back into the conscious mind (Sternberg 2009).
William James (1890) was one of the first to suggest memory was not a single system but rather comprises of a short and long term memory. James (1890) distinguished between primary memory as being conscious of what has just happened and secondary memory as the knowledge of events that have left our consciousness (Thorn & Page 2009). Hebb (1949) later supported James (1890) and suggested there was a neuro-physiological distinction between primary and secondary memory. Hebb (1949) proposed primary memory reflects temporarily reverberating electrical activity where as secondary memory results from permanent synaptic change (Bernstain, Penner, Clarke-Stewert & Roy 2008). Waugh and Norman (1965) elaborated on James (1890) theory and proposed the multi-store model of memory. The multi-store model proposed verbal stimuli was perceived in the primary memory which had a very limited capacity. As new stimuli were considered and as the capacity of the primary memory was reached the stimuli were displaced and forgotten (Baine 1986). However when stimuli was rehearsed it was either retained in short term storage in the primary memory or it was transferred to long term storage in the secondary memory. The more often information was rehearsed in primary memory the more likely it would be transferred to secondary memory (Baine 1986).
Waugh and Norman (1965) model was extended by Atkinson and Shiffron (1968) they suggested that for information to become a memory it had to flow through a system. The system starts with the sensory memory or immediate memory...