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Chris Bull | Dorothy Leones | Alex Tamas | Sam Towarnicki
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Contents

1. Introduction
2. Neuroscientific Context
2.1. What is Memory
2.2. The Amygdala
2.3. Consolidation and Reconsolidation
2.4. What is Post Traumatic Stress Disorder?
2.5. Current Research on Treating PTSD
3. Analysis
3.1. Target Audience
3.2. Intention of the Article
3.3. Pitch and Manner
3.4. Simplifications Made in the Video
3.5. Quality of Information
3.6. Accordance to Current Scientific Research
4. Appendix (Research Strategy)
5. References




1. Introduction


This short video is a research data presentation that showcases a number of neuroscientists who are researching the effect of Post-Traumatic Stress Disorder (PTSD) and its affect on memory reconsolidation. The video is from the National Institute of Mental Health (NIMH) which is a scientific community focusing on neuroscience with the aim to improve our understanding of mental disorders and develop better methods of treatment.


The research into the link between fear and memory began in 1999 with a study by Dr. Joseph LeDoux. His studies found that memories of traumatic experience could be blocked at consolidation by injecting protein synthesis inhibitors which stopped the growth of cells in the amygdala. Following on from this, Graham Nader suggested that memory reconsolidation could be used instead. This would mean giving the protein synthesis inhibitor after retrieval of previously consolidated memory rather than before the consolidation process.


This video emphasises the need for memory in our everyday lives and its delicate nature, particularly after times of distress. It also suggests exposure training as a drug-free method to treat PTSD as ethical issues may arise with the alteration of memories. Some oppose this method, for they perceive memories to be the makeup of our being and sense of self, thus an ethical method that does not endanger our sense of self may be far more difficult to find.


This article is of significant interest as traumatic events happen all the time and many people suffer both during and for a long time after such episodes. PTSD can also inhibit personal productivity and daily functions such as leaving the house. It is important to find a way to help people combat PTSD and this research is an important step in the process towards finding that solution. A safe and effective solution is still to be found.


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2. Neuroscientific Context


2.1. What is Memory

Though the meaning of the word memory is hard to define, the subdivisions of memory in the Human Brain are easy to identify and categorise. Memory consists of working memory and long term memory, which is further split into implicit memory and explicit memory. Implicit memory consists of procedural memory, conditioning and priming whilst explicit memory contains semantic memory, episodic memory and autobiographical memory.


The memory facet addressed in this excerpt is Fear conditioning, a form of emotional learning. Though the behavioural effects exhibited in fear conditioning can be predicted through Pavlovian and Instrumental conditioning models, the physiological processes involved in emotional learning are distinct from those of other types of conditioning.


The process of fear conditioning is due to Long Term Potentiation within neurons of the Hypocampus and the Amygdala, and to a lesser extent the other parts of the limbic system.
external image amygdala.jpg


2.2. The Amygdala



The Amygdala is a group of nuclei located within the medial temporal lobes colloquially known as the fear centre of the brain or “fear hub”, as it is described in the excerpt.


The Limbic system is a collection of structures within an unconscious, relatively primitive area of the brain. The Structures of the Limbic System form a pathway, which dictates the emotional state and emotional reaction of the brain to emotional stimuli. The Amygdala is perhaps the most important structure in the Limbic system as it initiates an unconscious fear response to fearful stimuli. The conscious pre-frontal cortex regulates the fear response of the Amygdala based upon a persons’ appraisal of the dangers of a stimulus.


2.3. Consolidation & Reconsolidation

FMRI of the Amygdala with fearful stimulation.
FMRI of the Amygdala with fearful stimulation.

In order for a fear conditioned memory to develop, the stimulus response association must be consolidated from working memory into long term memory. Consolidation occurs in the basolateral complexes of the Amygdala. New associative memories of fearful are believed to be formed due to protein synthesis within the nuclei, promoting cellular growth and Long Term Potentiation. Consolidation of memory occurs within a critical time period for associations to be formed.


After a fear conditioned association has been consolidated, the memory can been brought back from long term memory into working memory, due to either another presentation of the fearful stimulus or simply thinking about the stimulus. Once this happens, the memory must be restored as a new memory, using the exact same processes. Hence why Dr. LeDoux states that “your memory is only as good as your last memory.” This is called Reconsolidation.


Dr LeDoux’s Studies have shown that protein synthesis inhibitors administered during the critical period, inhibiting protein synthesis processes during or shortly after training disrupts memory consolidation and results in a greatly weakened associative memory. Studies have demonstrated that protein synthesis inhibitors disrupt the formation of Long Term Potentiation, which would predict this outcome.


This Finding is most interesting as it also applies not just to disrupting new fear associations from forming but also to eliminate existing conditioned associations. Because every time fear associative information is retrieved from the long term memory, this information must be once again stored as a new memory. Providing protein synthesis is inhibited within the nuclei of the amygdala during the critical consolidation period, and then formation of the association memory will be stopped or weakened.


Representation of fearful stimuli are not usually necessary for reconsolidation to occur, just thinking about the stimulus will cause associative information to be reconsolidated.


2.4. What is Post Traumatic Stress Disorder?

Post Traumatic Stress Disorder (PTSD) is an anxiety disorder. PTSD is mainly brought about after an individual experiences a traumatic event that causes a threat to a persons safety or life, such as a close call with death or experiences from war, assault or torture. The main effects of the disorder are: the patient must constantly be re-experiencing the event over in their mind, either via intrusive thoughts or during dreams; the patient has increased arousal (over-stimulation, over-alertness); and also avoidance of reminders of the traumatic event. Suffers of PTSD may have a reduced quality of life due to the emotionally crippling nature of the disorder. There are no tests that can be carried out to diagnose a patient with PTSD, only the symptoms can be used to diagnose. A similar disorder to PTSD is Acute Stress Disorder which lasts only a short time (hours to days) where as PTSD displays symptoms for over a month. Although up to 50-60% of adults experience a traumatic event during their lifetime only 5-10% actually develop PTSD. From Ozer, Best, Lipsey & Weiss (2003), the risk factors for developing PTSD are:


  • Prior Trauma
  • Family history of psychological problems
  • Threats (both real and perceived) to the patients life
  • Feelings of detachment during the trauma



Many of the patients who suffer from PTSD have a smaller hippocampal volume than the average person. This was seen to be a side effect prolonged glucocorticol release due the traumatic event, this would in-turn damage the hippocampus and the lead to PTSD. However a reduced hippocampal volume is now seen as one of the main risk factors for PTSD, not a side effect.


2.5. Current Research on Treating PTSD

Current treatment for PTSD is limited as there are no drugs that can specifically stop PTSD. The drugs available to help suffers of PTSD include antidepressants (Selective Seratonin Re-uptake Inhibitors, SSRI) but although they alleviate the secondary effects of PTSD, they do not treat the cause of the disorder. However SSRI's prevent the reuptake of the neurotransmitter serotonin within the synapse, increasing the available levels of serotonin in the synapse to bind to post-synaptic terminals. The American Psychiatric Association describe these treatments as being helpful at treating the symptoms of PTSD and found that individuals who had undertaken a year of SSRI treatment were far less likely to relapse (Asnis, Kohn, Henderson & Brown, 2004). The main treatment of PTSD is through treatment such as desensitisation therapy and support groups. There is also a treatment called eye movement desensitisation and reprocessing (EMDR).


  • Desensitisation therapy is a treatment that is effective in treating PTSD. The patient is asked to relive the experience and to talk about their feelings of the trauma and to express them in a healthy manner. The aim of this therapy is to over time make the experience less stressful to the patient.
  • There are many support groups, such as Anxiety Support Australia, where a patient can meet other people suffering from PTSD and have someone to support them.
  • EMDR is a treatment designed to relax the patient through physical and mental stimulation whilst the patient thinks about their personal traumatic event.. The patient is asked to do a certain mental exercise, whilst focusing on a physical object such as the therapists finger or other stimuli. Suffers of PTSD not only re-live their traumatic experience they also fixate on it. The aim of this treatment is to break this fixation by 'overloading' the brain of the patient. Whilst in this state the patient is able process the traumatic memories and desensitise themselves to the trauma.


One of the main problems with treating PTSD is that the cause of the disorder (i.e. the traumatic event), is different for all sufferers and as such what may help treat war veterans may not help rape victims. Therefore, the treatment of PTSD varies in its process and effectiveness.


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3. Analysis


3.1. Target Audience

The short video 'Fear: Replacing Memories' was produced by The National Institute of Mental Health (NIMH) which is part of the National Institutes of Health (NIH), a component of the U.S. Department of Health and Human Services. It is part of a video series called “Speaking of Science” which presents conversations with innovative researches that work in a broad range of disciplines for the prevention, recovery and cure for mental illness.


The video can be accessed through the NIMH website (www.nimh.nih.gov) and through YouTube (www.youtube.com). Therefore the video has the potential to reach a wide global audience. The video’s view count of just over six thousand YouTube is evidence of its wide appeal. However, it is difficult to identify the number of times the video is viewed on the NIMH website.


The video seems to be aimed at those interested in the topic of post-traumatic stress disorder or anxiety disorders. It also caters to an audience interested in general mental health issues since it is part of a series of videos in this area of research. The target audience can include General Practitioners, community public health and health promotion specialists, primary care workers, mental health workers community and self-help groups. However, it is possible that a wider audience could be targeted. Technical jargon was kept to a minimum, and concepts were explained using plain language with appropriate visual aids.


3.2. Intention of the article

The purpose of this media item is to present the research that explores the concept of manipulating memories and replacing memories of fearful events. Dr. LeDoux’s research is presented using images and short clips relating to the topic of research. Short clips such as scenes of warfare and natural disasters provide examples which evoke an emotional response with the viewer.


3.3. Pitch and manner

The video touches on serious and ethical issues, but is presented in a conversational tone and manner. Dr. LeDoux acknowledges ethical questions in regards to the science of altering memories. He affirms his own viewpoint by stating we alter our memories through everyday activities. He concludes by saying “Once we put it into that context the idea that you might use memory manipulation to help people maybe doesn’t seem so malevolent”. This statement portrays himself as self-assured and reasonable. However, he does not provide any details or explore the view against altering memories.


3.4. Simplifications Made in the Video

Dr. LeDoux employs a composed and relaxed manner while he presents his research information. He does not engage in very scientific language, or technical jargon that would not be understood by a general audience. The language used by Dr. LeDoux is accessible through his use of descriptive words and analogies. This is evident in his explanation on the process of reconsolidation “ability to block the consolidation of fear memories by injecting protein synthesis inhibitors to stop growth of certain cells in the amygdala, the brain’s fear hub”.


3.5. Quality of Information

One major claim by Dr. LeDoux is the explanation of the process of reconsolidation. Dr. LeDoux explains the use of a protein synthesis inhibitor injected into the rat after the rat has retrieved the memory. He then reveals that when you test the animal the next day, the memory is no longer there. He provides only some evidence of the research by explaining the results from the protein inhibitor tested. The mechanisms behind the protein synthesis inhibitors are not revealed within the video and may cause viewers to question the quality of the information presents. However, such technical information may have been intentionally excluded to simplify the video. Furthermore, credibility of the information is added because the video encourages the audience to go to the website to find out more information.


Dr. LeDoux makes reference to an example about a person who goes to trial to testify for a crime. He uses this example to further explain his research but this only confuses the audience and establishes uncertainties about the research quality. Whilst there may be a decent amount of explanation of the research, there is only a small amount of clinical evidence to support the effectiveness of the protein synthesis inhibitor. Further, this evidence comes across as anecdotal since Dr. LeDoux is recounting the experiment. This may discourage viewers from trusting the results and its credibility.


3.6. Accordance to Current Scientific Research

There is little established scientific information in this video which makes it difficult to conclude whether Dr. LeDoux is in accordance with what is currently known in the scientific community. He claims that adding Protein synthesis inhibitors will stop growth of certain cells in the amygdala, yet he does not state which cells. He provides little scientific evidence to show that process of reconciliation is effective as he bluntly explains the results of the Protein synthesis inhibitors on the rats.


Ultimately, in relation to neuroscientific, physiological, or psychological explanations, the media item lacks some substance. However, Dr. LeDoux does attempt to explain how a memory is formed and how the memory can be rewritten by weakening the memory through the use of a drug.


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4. Appendix (Search Strategy)


Choosing the topic was a matter of trying out different videos on Youtube and finding what seemed to appeal to us most. We looked into a number of different topics such as the neuroscience of attraction, happiness, internet addiction and hypnosis. When searching information on the neuroscience of memory, we came across our video on the effects of PTSD on memory and immediately found it the most appealing.

We analysed how we could answer the topic questions based on the information given on the video and found it was a 'good fit' leaving us plenty of room to explore the topic. Also, we believed that undergoing further investigation on the topic of PTSD and memory would be a rewarding one as we all have memories and we all experience some fear in our lives.

This video was also chosen due to its academic integrity as it is presented by the National Institute of Mental Health (NIMH) and includes a presentation by Dr. Jospeh LeDoux, a professor of science at New York University and principal director at the Centre for the Neuroscience of Fear and Anxiety.


Other sources of information were found by typing in 'amygdala, fear, memory' firstly into Google to find a few recent articles from numerous sources, then finding the full pdf of the paper by logging into Sirius and locating the specified journal. Sources were also found through the 'amygdala, fear, memory' search in PubMed. Selection for articles was based on relevance to our specific topic with a particular focus on PTSD rather than simply 'fear' itself. The titles and abstracts of the articles were used to justify their relevance.


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5. References


Target Audience
The short video ‘Fear: Replacing Memories’ comes from The National Institute of Mental Health (NIMH) which is part of the National Institutes of Health (NIH), a component of the U.S. Department of Health and Human Services. It is part of a video series called “Speaking of Science” which presents a series of conversations amongst innovative researches that work in a broad range of disciplines to build a pathway for the prevention, recovery and cure for mental illness. The video can be accessed through the NIMH website and furthermore it is broadcasted world-wide on Youtube. This allows the capability of the video to be viewed by a very wide global audience. This is evident in the view count of the video reaching to about just over six thousand viewers on the Youtube website.
The target market for the media item seem to be generally aimed at those interested in the topic of post-traumatic stress disorder, other anxiety disorders or general mental health issues. This target market can include General Practicioners, community public health and health promotion specialists, primary care workers, mental health workers community and self help groups. However, being exclusively featured only on the internet can limit their viewers rather than being exposed to a wider audience using other media means.
Anxiety Treatment Australia Retrieved September 13, 2011 from http://www.anxietyaustralia.com.au/workshops.shtml

Asnis, G.M., Kohn, S.R., Henderson, M., Brown, N.L. (2004). SSRIs versus non-SSRIs in post-traumatic stress disorder: An update with recommendations. Drugs, 64 (4), 383 - 404.

Best, B. (n.d.). Chapter 9 - The amygdala and the emotions. Retrieved September 12, 2011, from http://www.benbest.com/science/anatmind/anatmd9.html

Bisson, J., Andrew, M. (2007). Psychological treatment of post-traumatic stress disorder (PTSD). Cochrane Database Systematic Reviews, 18 (3).

Coryell, M.W., Ziemann, A.E., Westmoreland, P.J., Haenfler, J.M., Kurjakvoic, Z., Zha, X, Price, M., Schnizler, M.K., Wemmie, J.A. (2007). Targeting ASIC1a reduces innate fear and alters neuronal activity in the fear circuit. Biological Psychiatry, 62 (10), 1140 - 1148.

LeDoux, J. (2007). The amygdala. Current Biology, 17 (20), 868 - 874.

LeDoux, J., Yehuda, R. (2007). Response variation following trauma: A translational neuroscience approach to understanding PTSD. Neuron, 56 (1), 19 - 32.

Lee, E.J., Son, G.H., Chung, S., Lee, S., Kim, J., Choi, S., Kim, K. (2011). Impairment of fear memory consolidation in maternally stressed male mouse offspring: Evidence for nongenomic glucocorticoid action in the amygdala. The Journal of Neuroscience, 31 (19), 7131 - 7140.

Monsey, M.S., Ota, K.T., Akingbade, I.F., Hong, E.S., Schafe, G.E. (2011). Epigenetic alterations are critical for fear memory consolidation and synaptic plasticity in the lateral amygdala. Epigenetics and Fear Learning, 6 (5), e19958.

Nader, K., Schafe, G.E., LeDoux, J.E. (2000). Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval. Nature, 406, 722 - 726.

National Institute of Health. (n.d.). Post-Traumatic Stress Disorder (PTSD). Retrieved September 12, 2011, from http://report.nih.gov/NIHfactsheets/ViewFactSheet.aspx?csid=58&key=P#P

NIMH. (2010). Fear: Replacing Memories. Retrieved August 11, 2011, from http://www.nimh.nih.gov/media/video/ledoux.shtml?WT.mc_id=rss

Ozer, E.J., Best, S.R., Lipsey, T.L., Weiss, D.S. (2003) Predictors of post traumatic stress disorder and symptoms in adults: A meta-analysis. Psychological Bulletin, 129 (1), 52 - 73.

Phelps, E.A. (2004). Human emotion and memory: Interactions of the amygdala and hippocampal complex. Current Optinions in Neurobiology 14, 198 - 202.

Science Daily. (2006). Researchers prove a single memory is processed in three separate parts of the brain. Retrieved September 12, 2011, from http://www.sciencedaily.com/releases/2006/02/060202182107.htm

Stein, D.J., Ipser, J.C., Seedat, S. (2006). Pharmacotherapy for post traumatic stress disorder (PTSD). Cochrane Database Systematic Reviews, 1.

Wilensky, A. E., Schafe, G.E., LeDoux, J.E. (2000). The amygdala modulates memory consolidation of fear-motivated inhibitory avoidance learning but not for classical fear conditioning. The Journal of Neuroscience, 20 (18), 7059 - 7066.



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Intention of the article

The purpose of this media item is to present the research that showcases the exploration on the hypothesis on whether it is possible to replace memories of fearful events by manipulation. Dr.LeDoux presents his research information through the aid of images and short clips relating to the topic of research. An example of this is short clips illustrating the horrific and traumatizing scenes of the warfare. This assists the audience to clearly understand the intention of the video.
Pitch and manner

Ethical questions in regards to the science of altering memories are acknowledged by Dr. LeDoux.
He affirms his underlying bias viewpoint as he supports his own views stating that we have to realise that manipulating a memory is a substantial part of our lives. He concludes by saying “Once we put it into that context the idea that you might use memory manipulation to help people maybe doesn’t seem so malevolent”. This statement portrays his self-assured and forward manner within the piece.


Simplifications made in the video

Dr. LeDoux employs a composed and relaxed manner while he presents his research information. He does not engage in very scientific language, nor does he utilise any jargon words that would not be comprehended by the general populace. The language used by Dr. LeDoux is highly accessible which is evident in his explaination on the process of reconsolidation “ability to block the consolidation of fear memories by injecting Protein synthesis inhibitors to stop growth of certain cells in the amygdala, the brain’s fear hub”. This demonstrates that the research is explained to the viewers in a manner that an uneducated person is likely to understand.
Quality of the information in the video

One major claim by Dr. LeDoux is the explaination of the process of reconcildation. Dr.LeDoux explains the use of a protein synthesis inhibitor injected into the rat after the rat has retrieved the memory. He then reveals that when you test the animal the next day, the memory is no longer there. This highlights that he provides minor evidence to the research by bluntly explaining the results from the protein inhibitor tested. The mechanisms behind the protein sysnthesis inhibitors is not revealed within the video and may cause viewers to question the quality of the information presents.
Dr.LeDoux makes reference to an example about a person who goes to trial to tesify for a crime. He uses this example to further explain his research but this only confuses the audience and ultimately establishes uncertainties about the research quality. Whilst there may be a decent amount of explanation of the research, the minor amount of clinical evidence to support the effectiveness of the protein synthesis inhibitor seems to be a discouraging feature for viewers in being able to trust the results and its credibility.

Accordance to current scientific research

There is little established scientific information in this video and the mechanisms behind Protein synthesis inhibitors are still unknown. This makes it difficult to conclude whether Dr.LeDoux is in accordance with what is currently known in the scientific community.
However, he claims that adding Protein synthesis inhibitors will stop growth of certain cells in the amygdala, yet he does not state which cells. He provides little scientific evidence to show that process of reconciliation is effective as he bluntly explains the results of the Protein synthesis inhibitors on the rats.

Ultimately, in relation to neuroscientific, physiological, or psychological explanations, the media item is quite hollow. Yet, Dr, LeDoux does attempt to explain how a memory is formed and how the memory can be rewritten by weakening the memory through the use of a drug.