Apparently Traumatic™ is different from traumatic with no emphasis. I am not a neurologist but it's my understanding that you can sit people in fMRI (or other brain activity monitoring systems) along with other monitoring systems and watch the difference between a normal memory and a flash-back. Like the Traumatic™ will function differently in ways you can measure. I learned about it from The Body Keeps the Score but I haven't read further than that. If you have resources that aren't too technical let me know. Some of what was in that book was pretty soft science, but the Traumatic™ memory stuff was pretty hard as far as I could tell.