Traumatic memories of war veterans: not so special after all

A scientometric and descriptive review on the debate about repressed memories and traumatic forgetting

Recent work suggests that the debate surrounding repressed memory and traumatic forgetting continues today. To further investigate this debate, we performed preregistered scientometric analyses on publications on the debate about repressed memory to provide information about its bibliometric evolution. Furthermore, we reviewed these publications to highlight the different positions taken by scholars on this debate. We reviewed 434 publications extracted from Scopus and Web of Science from 1969 to 2022. Our scientometric analyses permitted us to visualize the development of the publications on repressed memories and identify the terminology used to label this phenomenon. We identified three waves of publications (i.e., 1994-2000; 2003-2009; 2012-2021) showing that there is a recent peak of scholarly attention into this topic. 40% of scholars supported the phenomenon of repressed memory while 29% did not. Moreover, although in the last wave of publications, 35% of articles included critical arguments against the existence of repressed memory, a sizable number of publications (21%) supported ideas in favour of repressed memory. Finally, we observed that the term dissociative amnesia is another expression used to refer to the phenomenon. Our results provide additional evidence that the debate on repressed memories (and dissociative amnesia) is far from being over.

A proposal for augmenting the measurement of index events in PTSD assessment using event centrality

BACKGROUND: Standard practice in assessing and diagnosing posttraumatic stress disorder (PTSD) entails identifying a single "worst" index event as the basis for symptom inquiry. Determining a single event can be challenging for clinicians and clients when multiple traumas are considered equally distressing. Additionally, it can be difficult to distinguish potential index events based on distress given the cumulative effect of repeated trauma exposure. This calls for the development of approaches that build on existing selection methods (e.g., worst event method). OBJECTIVE/CONCLUSIONS: In this article, we propose an innovative approach for identifying and measuring index events that utilizes the construct of event centrality to expand the parameters by which index events are selected. Event centrality assesses the degree to which traumatic events are perceived as integral to one's personal identity and worldviews. Given its role in the etiology and maintenance of PTSD symptoms, this construct also approximates the emotional impact of trauma. Incorporating validated measures of event centrality into PTSD assessments would provide an objective strategy for identifying index events in a way that may increase the reliability of diagnosis. Our proposed strategy may also have a positive impact on the therapeutic process and treatment outcomes.

The importance of context: evidence that contextual representations increase intrusive memories

BACKGROUND AND OBJECTIVES

Intrusive memories appear to enter consciousness via involuntary rather than deliberate recollection. Some clinical accounts of PTSD seek to explain this phenomenon by making a clear distinction between the encoding of sensory-based and contextual representations. Contextual representations have been claimed to actively reduce intrusions by anchoring encoded perceptual data for an event in memory. The current analogue trauma study examined this hypothesis by manipulating contextual information independently from encoded sensory-perceptual information.

METHOD

Participants' viewed images selected from the International Affective Picture System that depicted scenes of violence and bodily injury. Images were viewed either under neutral conditions or paired with contextual information.

RESULTS

Two experiments revealed a significant increase in memory intrusions for images paired with contextual information in comparison to the same images viewed under neutral conditions. In contrast to the observed increase in intrusion frequency there was no effect of contextual representations on voluntary memory for the images. The vividness and emotionality of memory intrusions were also unaffected.

LIMITATIONS

The analogue trauma paradigm may fail to replicate the effect of extreme stress on encoding postulated to occur during PTSD.

CONCLUSIONS

These findings question the assertion that intrusive memories develop from a lack of integration between sensory-based and contextual representations in memory. Instead it is argued contextual representations play a causal role in increasing the frequency of intrusions by increasing the sensitivity of memory to involuntary retrieval by associated internal and external cues.

Dissociation and memory fragmentation in post-traumatic stress disorder: an evaluation of the dissociative encoding hypothesis

Several prominent theories of post-traumatic stress disorder (PTSD) posit that peritraumatic dissociation results in insufficient encoding of the trauma memory and that persistent dissociation prevents memory elaboration, resulting in memory fragmentation and PTSD. In this review we summarise the empirical literature on peritraumatic and trait dissociation and trauma narrative fragmentation as measured by meta-memory and rater/objective coding. Across 16 studies to date, the association between dissociation and fragmentation was most prominent when examining peritraumatic dissociation and patient's own ratings of memory fragmentation. This relationship did not hold when examining trait dissociation or rater-coded or computer-generated measures of fragmentation. Thus initial evidence points more towards a strong self-reported association between constructs that is not supported on more objective fragmentation coding. Measurement overlap, construct ambiguity, and exclusion of potential confounds may underlie lack of a strong association between dissociation and objective-rated fragmentation.

Autobiographical memory for stressful events: the role of autobiographical memory in posttraumatic stress disorder

To provide the three-way comparisons needed to test existing theories, we compared (1) most-stressful memories to other memories and (2) involuntary to voluntary memories (3) in 75 community dwelling adults with and 42 without a current diagnosis of posttraumatic stress disorder (PTSD). Each rated their three most-stressful, three most-positive, seven most-important and 15 word-cued autobiographical memories, and completed tests of personality and mood. Involuntary memories were then recorded and rated as they occurred for 2 weeks. Standard mechanisms of cognition and affect applied to extreme events accounted for the properties of stressful memories. Involuntary memories had greater emotional intensity than voluntary memories, but were not more frequently related to traumatic events. The emotional intensity, rehearsal, and centrality to the life story of both voluntary and involuntary memories, rather than incoherence of voluntary traumatic memories and enhanced availability of involuntary traumatic memories, were the properties of autobiographical memories associated with PTSD.

The coherence of memories for trauma: evidence from posttraumatic stress disorder

Participants with posttraumatic stress disorder (PTSD) and participants with a trauma but without PTSD wrote narratives of their trauma and, for comparison, of the most-important and the happiest events that occurred within a year of their trauma. They then rated these three events on coherence. Based on participants' self-ratings and on naïve-observer scorings of the participants' narratives, memories of traumas were not more incoherent than the comparison memories in participants in general or in participants with PTSD. This study comprehensively assesses narrative coherence using a full two (PTSD or not) by two (traumatic event or not) design. The results are counter to most prevalent theoretical views of memory for trauma.

"Hotspots" in trauma memories in the treatment of post-traumatic stress disorder: a replication

"Hotspots" refer to memories of detailed moments of peak emotional distress during a traumatic event. This study investigates hotspot frequency, and the emotions and cognitions contained in hotspots of memory for trauma, to replicate a previous study in this area (Holmes, Grey, & Young, 2005). Participants were patients receiving treatment for post-traumatic stress disorder (PTSD) at a specialist outpatient clinic after experiencing a range of traumatic events. The main finding was that, after fear, the most common emotions reported were anger and sadness. Cognitions related to psychological threat to the self were more common than those related to physical threat.

Memory in posttraumatic stress disorder: properties of voluntary and involuntary, traumatic and nontraumatic autobiographical memories in people with and without posttraumatic stress disorder symptoms

One hundred fifteen undergraduates rated 15 word-cued memories and their 3 most negatively stressful, 3 most positive, and 7 most important events and completed tests of personality and depression. Eighty-nine also recorded involuntary memories online for 1 week. In the first 3-way comparisons needed to test existing theories, comparisons were made of memories of stressful events versus control events and involuntary versus voluntary memories in people high versus low in posttraumatic stress disorder (PTSD) symptom severity. For all participants, stressful memories had more emotional intensity, more frequent voluntary and involuntary retrieval, but not more fragmentation. For all memories, participants with greater PTSD symptom severity showed the same differences. Involuntary memories had more emotional intensity and less centrality to the life story than voluntary memories. Meeting the diagnostic criteria for traumatic events had no effect, but the emotional responses to events did. In 533 undergraduates, correlations among measures were replicated and the Negative Intensity factor of the Affect Intensity Measure correlated with PTSD symptom severity. No special trauma mechanisms were needed to account for the results, which are summarized by the autobiographical memory theory of PTSD.

A memory-based model of posttraumatic stress disorder: evaluating basic assumptions underlying the PTSD diagnosis

In the mnemonic model of posttraumatic stress disorder (PTSD), the current memory of a negative event, not the event itself, determines symptoms. The model is an alternative to the current event-based etiology of PTSD represented in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000). The model accounts for important and reliable findings that are often inconsistent with the current diagnostic view and that have been neglected by theoretical accounts of the disorder, including the following observations. The diagnosis needs objective information about the trauma and peritraumatic emotions but uses retrospective memory reports that can have substantial biases. Negative events and emotions that do not satisfy the current diagnostic criteria for a trauma can be followed by symptoms that would otherwise qualify for PTSD. Predisposing factors that affect the current memory have large effects on symptoms. The inability-to-recall-an-important-aspect-of-the-trauma symptom does not correlate with other symptoms. Loss or enhancement of the trauma memory affects PTSD symptoms in predictable ways. Special mechanisms that apply only to traumatic memories are not needed, increasing parsimony and the knowledge that can be applied to understanding PTSD.

The effect of emotional stress on involuntary and voluntary conscious memories

Clinical theories of post-traumatic stress disorder often claim that intrusive (involuntary) memories favour emotionally stressful material and that these memories come with more sensory imagery and emotional reliving compared to voluntary memories. However, these assumptions have not been verified experimentally. Here we obtained recordings of emotional reactions to aversive pictures at the time of encoding, as well as records of involuntary and voluntary memories of these pictures in a subsequent diary study. A comparison of individual ratings, obtained during encoding, of pictures recalled involuntarily and voluntarily showed that emotional stress at encoding increased overall accessibility, independent of whether recall was voluntary or involuntary. However at the time of recall, voluntary memories scored higher on narrative content and on measures of imagery. The findings are compatible with research on emotion and memory in general, but challenge clinical claims of differential involuntary versus voluntary access to emotionally stressful events.

Are memories for sexually traumatic events "special"? A within-subjects investigation of trauma and memory in a clinical sample

According to a long-standing clinical tradition, sexually traumatic experiences are processed and recalled differently from other experiences, often leading to memory impairment. In this study, we compared the characteristics of traumatic memories for sexual violence and two other types of emotional experiences. N=44 women recruited from a local sexual trauma agency were asked to recall and describe three autobiographical events: sexual abuse/assault, a non-sexual trauma, and a positive emotional event. The characteristics of the three memory types were compared on both subjective and objective measures. Further, the potential influences of level of traumatic impact and dissociation were assessed. Results indicated that memories for sexual trauma were not impaired or fragmented relative to other memories. Instead, memories for sexual trauma were associated with a remarkably high level of vividness, detail, and sensory components. Further, high levels of traumatic impact were not associated with memory impairment. Implications for the ongoing traumatic memory debate are discussed.

The reappearance hypothesis revisited: recurrent involuntary memories after traumatic events and in everyday life

Recurrent involuntary memories are autobiographical memories that come to mind with no preceding retrieval attempt and that are subjectively experienced as being repetitive. Clinically, they are classified as a symptom of posttraumatic stress disorder. The present work is the first to systematically examine recurrent involuntary memories outside clinical settings. Study 1 examines recurrent involuntary memories among survivors of the tsunami catastrophe in Southeast Asia in 2004. Study 2 examines recurrent involuntary memories in a large general population. Study 3 examines whether the contents of recurrent involuntary memories recorded in a diary study are duplicates of, or differ from, one another. We show that recurrent involuntary memories are not limited to clinical populations or to emotionally negative experiences; that they typically do not come to mind in a fixed and unchangeable form; and that they show the same pattern regarding accessibility as do autobiographical memories in general. We argue that recurrent involuntary memories after traumas and in everyday life can be explained in terms of general and well-established mechanisms of autobiographical memory.

Anxious and nonanxious children’s recall of a repeated or unique event

The current study examined 4- and 5-year-olds' memory for an event that was experienced once or was the first in a sequence of four similar events. The event was private swimming lessons for beginners that, because of natural variation in fear of water, were experienced as stressful for some children and not stressful for others. Consistent with much previous research, there was evidence that repeat-event children remembered less than did single-event children. There was some evidence for a beneficial influence of stress on resistance to suggestions. No other effects of stress were found in either the single- or repeat-event children. Implications for the debate on the influence of stress on memory and for children's testimony are discussed.

Malingering of PTSD: forensic and diagnostic considerations, characteristics of malingerers and clinical presentations

OBJECTIVE

This paper aims to study the detection of individuals malingering posttraumatic stress disorder (PTSD) in criminal and civil situations.

METHOD

A brief history of PTSD and its rise to prominence in legal circles are discussed. The characteristics of individuals who malinger and particularly those who fake PTSD are discussed. Diagnostic dilemmas inherent to the condition, such as the definition of a traumatic exposure, what constitutes a PTSD flashback and the potential for normal symptom exaggeration, are explored.

RESULTS

The typical presentation of malingered symptoms is presented to help clinicians detect commonly seen malingering patterns. Suggestions for interview techniques, Minnesota Multiphasic Personality Inventory test values and sources of collateral information to help detect malingering are reviewed.

CONCLUSION

The paper concludes with a review of the typical presentations of malingered PTSD symptoms and a reminder that physicians need to distinguish legitimate symptoms from faked or embellished presentations.