Today’s post is really Trying To Forge a Deeper Understanding of Flashbacks: Part III. My choice of the above title, however, nicely encapsulates today’s topic and avoids the mind-dulling repetitiveness (“O, the wretched monotony!”) of continuing to use the same title.

A few days ago, I said that 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.

I addressed only reliving last time. Today, (unfortunately?) more of the same — but from a very different perspective.

Memory Researchers Say, ‘There Is Nothing Special About Flashbacks’

To oversimplify, there are two kinds of academic challenges to the clinical concept of flashbacks. First, there are those who appear to hold an ideological grudge against the concept of flashbacks. These grudge-bearing ideologues often selectively ‘cherry pick’ scientific findings, cheerfully omit or distort scientific findings, and may use thinly veiled ad hominem arguments. I refer to this contingent as skeptics. Their views are not the topic of today’s post.

Second, there are researchers who believe that well-accepted findings about memory are quite capable of explaining flashbacks. Their logic and empirical studies are eminently reasonable, straightforward, and are usually well done. I refer to them as memory researchers. Today, I will begin to discuss a program of research by Dorthe Berntsen at Aarhus University in Denmark.

Most memory research is about voluntary memory — memories that we search for and deliberately retrieve. Berntsen’s research is about involuntary memories — memories that just “happen.” These memories come from ‘out of the blue.’ They are spontaneous and unbidden.

I have just finished reading Berntsen’s book Involuntary Autobiographic Memories (2009):

“Often memories of past events come to mind in a manner that is completely unexpected and involuntary. They come with no preceding decision to remember, with no plans and no commitment. They may suddenly pop up in response to stimuli in our environment or aspects of our current thought.” (Berntsen, 2009, p. 1)

Sound familiar?  Hmmm. You can readily see why this scholar and researcher of involuntary memory would ask, ‘Are the flashbacks that clinicians talk about any different from this?’

Momentary aside: Many of you will immediately recognize that Berntsen’s question reflects the eternal tension between clinicians and nonclinical academics. Clinicians describe dramatic clinical phenomena and propose theories and mechanisms to explain them. Nonclinical academics then say, “Yes, but… [a] ‘How is this different from what we already understand very well to be a natural phenomenon of X,’ or, somewhat more harshly, [b] ‘You are really talking about X and you clearly have not kept up with the excellent, well-replicated research about X,.’ or contemptuously, [c] ‘You guys have no idea what you are talking about (but we true academics do) and we pity the havoc that you are wreaking upon your clients!” Thus it has always been. And, one assumes, always will be.

I find Berntsen to be enlightening and enriching because she belongs to the first of these three groups of academics.

Berntsen cites Hermann Ebbinghaus (1885), the revered psychologist who pioneered and inspired all subsequent research on human memory. Ebbinghaus stated that there are three kinds of memory, one of which is involuntary. Thus, like Ebbinghaus, Berntsen claims that “involuntary memory is a basic mode of remembering of the personal past” (p. 3, emphasis added).

This mode of remembering is associative and, Berntsen suggests, the evolutionary forerunner of voluntary memory. In keeping with her evolutionary perspective, she concludes that involuntary memory is “unlikely to be specific to humans’ (p. 18). So — other species, too. A very basic mode of remembering.

Special Mechanisms

Nonclinical academics regularly disagree with clinicians about the nature of clinical phenomena. On the one hand, clinicians tend to posit the existence of a special (pathological) mechanism which generates the clinical phenomenon in question. On the other hand, nonclinical academics typically claim that no special mechanism is needed because well-studied universal mechanisms (in this case, the mechanisms of involuntary memory) are quite capable of producing that particular clinical phenomenon (in this case, flashbacks).

A few days ago, we examined Chris Brewin’s explanation of flashbacks. Yup. Brewin uses a special mechanism to explain flashbacks — namely, a pathologically weak connection between (1) overly strong imagistic-sensation memory (S-reps) and (2) weak or nonexistent verbal-contextual memory (C-reps). Thus, according to Brewin, there are (1) fragmented imagistic-sensation memories of the trauma and (2) an impaired narrative of the trauma. As a clinician, Brewin’s model makes a lot of sense to me.

But now, along comes Berntsen (and other memory researchers) who insist that flashbacks are nothing special. Flashbacks, they say, are involuntary, autobiographical memories that predictably follow a trauma. Oh, in case you’re wondering, Brewin is well aware of Berntsen’s research. She and other memory researchers are extensively cited by him in the article that we discussed a few days ago (Brewin, Gregory, Lipton & Burgess,   2010).

Let’s examine Berntsen’s work. Is her account of involuntary autobiographical memories a better (i.e., simpler) explanation of flashbacks than our typical clinical formulations?

Involuntary vs. Voluntary Autobiographical Memories

Berntsen discusses memory in terms of encoding, maintenance, and retrieval. She firmly asserts (and adduces research data which seems to support her claim), that voluntary memory and involuntary do not differ in their encoding or their maintenance. She argues that the only difference is the way they are retrieved.

Memories are voluntarily retrieved via an intentional, top-down, frontal lobe-driven search procedure. In contrast, memories are involuntarily retrieved via a bottom-up, automatic, associative process to a cue that is (usually) encountered quite by accident.

Associative retrieval endows involuntary memory with several notable features. In contrast to voluntary memories, involuntary autobiographical memories are more often specific (i.e., they refer to a particular episode), more often distinctive, tend to have greater relevance to the person’s life story, and more often produce an identifiable emotional impact and/or a noticeable physiological reaction (Think: reliving). In addition, these memories are quicker; they have a shorter latency in response to the cue that triggers them. These features of involuntary autobiographical memory are not just theoretical speculations; they have been demonstrated empirically in study after study.

What Triggers Involuntary Autobiographical Memories?

Berntsen divides her answer to this question into three parts: (1) factors that influence retrieval in both voluntary and involuntary memory, and (2) factors that are substantially unique to involuntary autobiographical memory, and (3) factors that research has shown to be highly associated with the occurrence of involuntary memories.

1.Factors common to both kinds of recall. Berntsen is at pains to enumerate the retrieval factors that are common to both kinds of autobiographical memory. I think she emphasizes these factors because she wants to counter clinicians’ claim that flashbacks are special and different — for example, that the mechanisms of flashbacks are different from those of other forms of memory. She discusses Brewin, Dalgleish & Joseph’s (1996) Situationally Accessible Memory (SAM) system which supposedly stores only memory that “was not fully consciously processed at the time of the event” (Berntsen, 2009, p. 151) — that is emotions, bodily sensations, or fragments of perception (Think: flashbacks). Berntsen says, perhaps with a certain degree of asperity:

This is a radical idea that contradicts what is generally known about attention during encoding and subsequent memory…” (p. 151).

In any case, Berntsen lists several factors that influence the accessibility of both voluntary and involuntary memories: the recency of the event, its emotional intensity, whether it was emotionally positive, its frequency of rehearsal (i.e., how often the person talked or thought about it), its degree of life impact, its novelty, and its distinctiveness. She reviews the experimental evidence which demonstrated these factors to be associated with increased retrieval of such memories, both voluntarily and involuntarily.

2. Factors that are disproportionately conducive to involuntary recall. Based on her research, Berntsen identifies three factors that are especially conducive to triggering an involuntary autobiographical memory: (1) a very infrequent cue that matches only one past event; (2) a cluster of simultaneous cues, several of which simultaneously match aspects of a particular past event; and (3) a commonly occurring cue that evokes a memory that involved that cue as part of a novel or quite distinctive context.

3. Factors that are highly associated with involuntary recall. Finally, Berntsen summarized the results of her research on the correlates of involuntary autobiographical memories. Cues were especially likely to trigger an involuntary memory if they matched a particular part of the memory content. The most frequent triggers of these memories were specific objects, activities, people, and themes.

Berntsen also found that certain states of mind were more likely to evoke involuntary recall. Most generally, involuntary recall is more frequent when a person is relaxed or in an unfocused state of awareness. Also, certain states of mind seem to sensitize the person to cues that might relate to one’s life situation (e.g., current concerns, important unfinished personal business, or a recent especially powerful event). Berntsen concluded that, if a person has a current concern that is highly pressing, then even very vague cues may activate memories that relate to that concern.

Final thoughts

Those of us who know a bit about flashbacks must recognize that many of the above points are associated with flashbacks. Now, we also know that these points are associated with all manner of involuntary autobiographical memories. Berntsen and other memory researchers contend that they have explained flashbacks (without needing to invoke any special mechanisms).

Have they? What do you think? Is there anything about flashbacks that the above account does not adequately explain?

More to come.