Because I have recently been most troubled by my hyperarousal, and because I have noted a similar symptom in Autism and ADHD children and adults, I have long hypothesized that a similar neurological disorder is at work. After researching the potential similarity between Autism and PTSD and hypersensititity to stimulation, I did finally find that researach is demonstrating similar brain/trauma responses in lab animals and is being studied as the possible etiology (cause) of the problems in the nervous systems and brains of people with PTSD and Autism, although etiology is not being targeted as much as I would like as this is all newly emerging. The etiology of PTSD and corresponding FLASHBACKS as a major difference in trauma survivors who go on to have PTSD is studied in Right/Left brain traumatic memory storage is discussed on a link to the main site I found here: http://pn.psychiatryonline.org/content/39/6/61.1.full. To summarize: those who have PTSD do not store the trauma memory verbally on the left/frontal side of the brain. They dissociate more during the truama, and thereby store the information on the right/rear area. This is pre-verbal memory, where non-verbal experience is stored, and such memories in that region are primary visual, and other senses, without verbal components. Thus, Flashbacks are not easily narrated, as the memories lack narration. Those who experience their traumatic memories as mostly narrative are less prone to develop PTSD than those who experience them as experiential/sensory and store them on the right. The fear/reptillian brain and poly-vagal study by "Stephen W. Porges, Professor and Director of the Brain-Body Center in the College of Medicine at the University of Illinois at Chicago, explains that the vagus nerve—the primary nerve for the parasympathetic nervous system—has two major branches: an ancient unmyelinated branch that we share with reptiles and a more recently evolved myelinated branch unique to mammals that "is linked to the cranial nerves that control facial expression and vocalization." Porges's polyvagal theory proposes an automatic-response hierarchy emphasizing that when mammals detect they are in a safe environment, their bodies automatically activate the more recently developed myelinated branch of the vagus nerve that promotes "calm states, to self-soothe and to engage." What Porges calls the social engagement system determines the quality of interpersonal exchanges..." (source: http://mybrainnotes.com/brain-fear-autism.html) Thus, if we can narrate and begin to activate the left brain deliberately, can we by pass the right side more?