I have a published article in this regard. I explore the memory process, subtypes, and the function it serves. Some techniques such as optogenics and MDMA are possible in at least altering them or altering a person recall of them, especially those w/ PTSD like the combat vets that I encounter in my volunteer work. I am a former ER medic during the Vietnam Conflict. I do not experience PTSD myself. Though I do have flashbacks to any documentaries related to Vietnam. They do not interfere w/ my overall functioning.
Rich