I just read this article written by a professor of psychiatry called Posttraumatic Stress Disorder and Memory that talks about how PTSD is created from terror preventing the memory from being integrated into ordinary consciousness. Because of this they are left as a kind of re experiencing because of that disconnection.
Dr. van der Kolk goes on to say that the flashbacks and nightmares are the result of the dissociation or amnesia from normal waking consciousness. (Phsychiatrists use the term dissociation differently from how the NLP community uses it)
We remember our memories of the past as stories that change over time. In fact we distort our normal healthy memories a lot. With PTSD memories, though the memory stays the same.
Also, while they “remember” the event at an unconscious level, they often can not consciously remember (and therefore distort it over time like the game of Chinese Whispers)
Traumatized individuals often suffer from a combination of vivid recall for some elements of the trauma and amnesia’s for others. While the vivid intrusions of traumatic images and sensations are the most dramatic expressions of PTSD, the loss or absence of recollections for traumatic experiences is well-documented.
Which would mean to me that that the phobia technique would be difficult if you couldn’t access the memory and Time Line Therapy may be a better option. Both are submodality techniques, but time line can deal better with unconscious memories.