Flashbacks have at least four striking features:
1. Flashbacks are experiential, marked by a sense of reliving, accompanied by sensations and affects).
2. Flashbacks are distinctly fragmentary.
3. Flashbacks are autonomous and involuntary.
4. Flashbacks are frequently associated with dissociative amnesia.
In this post, I will focus solely on the first of these — the experiential/reliving quality of flashbacks.
Why Are Flashbacks Experiential Rather Than Cognitive?
Perhaps the best current answer to this question comes from Chris Brewin in England (Brewin, Gregory, Lipton & Burgess, 2010). Brewin is one of the leading cognitive psychologists in the world. He has been studying PTSD and its intrusive symptoms for the last 15 years or so (see also Brewin, Dalgleich & Joseph, 1996). Brewin proposes that humans have two memory systems for episodic and autobiographical memory: (1) a contextual memory system that represents an event via abstract, contextually-bound representations of the event (“C-reps”), and (2) a low-level sensation-based memory system that represents events via their sensations (“S-reps”).
Although Brewin prefers to characterize these two memory system in terms of whether the context of the event IS associated with the memory representation (C-reps) or IS NOT associated with it (S-reps), he is basically talking about the difference between verbal memory and imagistic sensation memory. In a nutshell, Brewin says that both of these memory systems are part of our normal functioning. They work together.
An extreme event (i.e., trauma), however, may produce very strong imagistic sensation memory (S-reps) and weak/disconnected or even absent verbal contextualized memory (C-reps) of the event. Brewin refers to this situation as “pathological encoding.”
Brewin’s explanation of flashbacks. If a person has:
(1) a weak/disconnected or absent verbal contextual memory of an event (C-rep), AND
(2) a strong imagistic sensation memory of the event (S-rep), THEN
(3) whenever the the imagistic sensation memory is activated, “it is vividly re-experienced in the present” (Brewin et al., 2010, p. 224). AND,
(4) if the verbal contextual memory is completely absent, it will produce “extreme reexperiencing, in which all contact with the current environment is temporarily suspended” (p. 225) [i.e., a dissociative flashback]
Brewin also considers flashbacks to be adaptive:
“Flashbacks are an adaptive process in which stored information can be re-presented and processed in greater depth once the danger is past” (p. 221)
From this point of view, PTSD develops when a person fails to process the information contained in the S-reps. Brewin is quite clear in stating that such a failure is AN ACTIVE PROCESS which prevents integration of the information and perpetuates the flashbacks:
“If flashbacks are to persist. there must be mechanisms to perpetuate this lack of integration. PTSD sufferers show marked behavioral and cognitive avoidance and find their intrusions (or certain parts of them) too unpleasant to attend to, which could plausibly account for the fact that the corresponding C-rep [verbal contextualized memory] remains incomplete.” (p. 225)
I think that Brewin’s model has a clean and simple elegance. In terms of the parsimony that is highly valued in science, Brewin’s model is quite nice. Nevertheless, I have a few reservations.
1. Brewin considers flashbacks to be adaptive. This position has always bothered me and, perhaps, I now understand better why I feel that way. Certainly, part of this idea –that flashbacks are adaptive — must be correct. Certainly, we have an innate tendency to find consistency in our minds and to resolve things that don’t fit. The part of this that bothers me is that flashbacks are NOT the same as normal intrusive thoughts (which Horowitz talked about in terms of “the completion principle” and coming to terms with major life events). Flashbacks are not cognitive; they are experiential. Flashbacks are not thoughts; they are (often) a bit like sticking your finger in an empty light bulb socket. I find it hard to consider electric mental shocks to be ADAPTIVE.
2. Brewin states that flashbacks are caused by pathological encoding of an event. By this, he means that an event can be so extreme that it produces very strong imagistic sensation memory (S-reps) and weak/disconnected verbal contextual memory (C-reps). So far, I like this description of flashbacks a lot. My apprehension is about the next step in Brewin’s reasoning. In his view, all that is needed for a flashback to occur is for the imagistic sensory memory to be activated. Boom! Flashback!
I feel a bit like Peggy Lee — “Is that all there is?” Is there no other factor involved? I feel like something is missing. I feel this even more strongly when Brewin uses this same formula to explain dissociative flashbacks. According to Brewin, if the verbal contextual memory is completely absent, then any activation of the S-rep will cause a flashback that produces a complete loss of contact with the here-and-now.
What is the something else that might be missing? In nondissociative flashbacks, I think the missing piece is affect — usually fear. Have you noticed that both flashbacks and their treatment (i.e., some form of prolonged exposure) operate according to the model of a simple phobia. I think that flashbacks are a perverse positive feedback loop among the amygdala and the decontextualized S-reps (and perhaps the insula as well). This is basically a phobic reaction to the images and sensations associated with the traumatic event. In short, I think flashbacks are driven by a ‘pulsing’ amygdala.
I also think that there is something missing in Brewin’s explanation of dissociative flashbacks — namely, a hypnotic brain. I would be willing to bet that dissociative flashbacks only occur in PTSD patients with high hypnotizability. High hypnotizability is a normal trait, but I think a flashback operates as something of an implicit ‘suggestion’ to remember/reexperience the event. If this is correct, then dissociative flashbacks are a binary phenomenon (flashback + hypnotic response). Elsewhere, I have described this binary phenomenon in terms of the flashback ‘hijacking’ a normal ability (i.e., high hypnotizability) or a normal mechanism (i.e., a hypnotic brain).
Time to end this post. It has gotten too long.
But, for the research mavens in our midst, there is a bonus round.
RESEARCH IDEAS: There are surprisingly few empirical publications on flashbacks. There are even fewer articles on the phenomenology of flashbacks.
1. If PTSD patients who report having dissociative flashbacks are compared to PTSD patients with no history of dissociative flashbacks, will these two groups differ in their hypnotizability?
2. What is the difference, if any, between the flashbacks (that are experienced in the first month after trauma) of those who go on to develop PTSD and those who do not develop PTSD?
3. What is the difference, if any, between the flashbacks of trauma survivors who develop Acute Stress Disorder (ASD) and those who do not?
4. What is the difference in the flashbacks that are experienced by PTSD patients with low dissociation scores vs. those that are experienced by PTSD patients with high dissociation scores?
5. What is the difference in the flashbacks that are experienced by PTSD patients with high hypnotizability and those that are experienced by PTSD patients with low hypnotizability?
6. What is the difference in the flashbacks of ASD patients with high hypnotizability and those of ASD patients with low hypnotizability?
7. What is the difference between the flashbacks of persons with DID and the flashbacks of persons with PTSD only (and are there two identifiable subgroups among the PTSD patients — dissociative and nondissociative)?
Note: The key issue in each of the above research questions is the phenomenology of the flashbacks. Not all flashbacks are the same. There is a great need for all kinds of phenomenological research on flashbacks.
Skepticism About Trauma and PTSD
Graduate students who are interested in such research topics are counseled to beware of skeptics in academia. Graduate students should know that there are some academics with highly jaundiced views about the reality of trauma, the reality of flashbacks, and the very existence of PTSD. These skeptics can be found in some clinical psychology programs in the US and especially in academic settings in the UK. Even Chris Brewin, a very well-respected British researcher of PTSD, found it necessary to title his recent book: Posttraumatic Stress Disorder: Malady or Myth. ‘Nuf said for now.