Amnesia, flashbacks, nightmares, and dissociation in aging concentration camp survivors

False memories in forensic psychology: do cognition and brain activity tell the same story?

One of the most important problems in forensic psychology is the impossibility of reliably discriminating between true and false memories when the only prosecution evidence comes from the memory of a witness or a victim. Unfortunately, both children and adults can be persuaded that they have been victims of past criminal acts, usually of a sexual nature. In adults, suggestion often occurs in the context of suggestive therapies based on the belief that traumatic events are repressed, while children come to believe and report events that never occurred as a result of repeated suggestive questioning. Cognitive Researchers have designed false memory paradigms (i.e., misinformation effect, Deese-Roediger-McDermott paradigm, event implantation paradigm) to first form false memories and then determine whether it is possible to reliably differentiate between false and true memories. In the present study, we review the contribution of cognitive research to the formation of false memories and the neuropsychological approaches aimed to discriminate between true and false memories. Based on these results, we analyze the applicability of the cognitive and neuropsychological evidence to the forensic setting.

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.

Dissociative Amnesia? It Might be Organic Memory Loss!

This article discusses the possibility of practitioners who mistake organic memory loss for dissociative amnesia. It starts with the case of a young man with complete retrograde amnesia due to a traumatic head injury. Because he did not show any gross neurological abnormalities, a neurologist thought his amnesia had a psychological origin. An extensive neuropsychological examination revealed that the man did have an organic reason for his amnesia. Next, the existence of dissociative memory loss as well as isolated organic retrograde amnesia is considered. While cases of organic memory loss are well-documented, there is hardly any evidence for dissociative amnesia. It is argued that organic memory loss might be mistakenly taken for dissociative amnesia. In line with the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, practitioners are advised to rule out the possibility of organic memory loss, before diagnosing a patient with dissociative amnesia.

Believing in dissociative amnesia relates to claiming it: a survey of people's experiences and beliefs about dissociative amnesia

Dissociative amnesia is one of the most controversial categories in the field of psychiatry and clinical psychology. Self-reports of dissociative amnesia in the general population, and beliefs about this topic, have so far not been subjected to empirical scrutiny. Here, we surveyed a sample from the general population (N = 1017), revealing that about a tenth (n = 102) claimed to have experienced dissociative amnesia. Some claims pertained to amnesia for traumatic autobiographical experiences (e.g., sexual assault), while other claims reflected memory loss for experiences that can be regarded as non-traumatic or non-stressful (e.g., dissociative amnesia for an anniversary). Importantly, many participants believed in the existence of dissociative amnesia, and those who claimed dissociative amnesia indicated even more belief in this phenomenon than the rest of the sample. Finally, many participants indicated to have at least once claimed to have feigned memory loss in their life, and that they experienced some form of forgetting when trying to retrieve events for which they lied upon. Overall, our findings suggest that claiming dissociative amnesia goes hand in hand with believing in dissociative amnesia.

Teaching psychology students to change (or correct) controversial beliefs about memory works

Therapists, judges, law enforcement, and students often believe in the existence of automatic and unconscious repression. Such a belief can be perilous as it might lead therapists to suggestively search for repressed memories leading to false memories. Recovering therapy-induced false memories of criminal acts can have serious consequences. Here, we tested whether erroneous beliefs in repressed memories can be corrected. Surveying two cohorts of Forensic and Legal Psychology Master's students, we examined whether education about the science of (eyewitness) memory can correct erroneous beliefs in repressed memories. Students assessed memory statements before taking a course on eyewitness memory, six weeks after the course exam, and 18 or 6 months later, respectively (Ns = 33-74 per cohort and measurement). As expected, students in both cohorts on average initially strongly agreed with the statement that memories of traumatic events can be unconsciously blocked, but strongly disagreed with the statement after the course. Belief-corrections also persisted after the longer delay. These findings show that educating people about the science of (eyewitness) memory can be effective in correcting false and controversial memory beliefs in general and the existence of repressed memories in specific.

What science tells us about false and repressed memories

What does science tell us about memory phenomena such as false and repressed memories? This issue is highly pressing as incorrect knowledge about these memory phenomena might contribute to egregious effects in the courtroom such as false accusations of abuse. In the current article, we provide a succinct review of the scientific nature of false and repressed memories. We demonstrate that research has shown that about 30% of tested subjects formed false memories of autobiographical experiences. Furthermore, this empirical work has also revealed that such false memories can even be implanted for negative events and events that allegedly occurred repeatedly. Concerning the controversial topic of repressed memories, we show that plausible alternative explanations exist for why people claim to have forgotten traumatic experiences; explanations that do not require special memory mechanisms such as the unconscious blockage of traumatic memories. Finally, we demonstrate that people continue to believe that unconscious repression of traumatic incidents can exist. Disseminating scientifically articulated knowledge on the functioning of memory to contexts such as the courtroom is necessary as to prevent the occurrence of false accusations and miscarriages of justice.

The Return of the Repressed: The Persistent and Problematic Claims of Long-Forgotten Trauma

Can purely psychological trauma lead to a complete blockage of autobiographical memories? This long-standing question about the existence of repressed memories has been at the heart of one of the most heated debates in modern psychology. These so-called memory wars originated in the 1990s, and many scholars have assumed that they are over. We demonstrate that this assumption is incorrect and that the controversial issue of repressed memories is alive and well and may even be on the rise. We review converging research and data from legal cases indicating that the topic of repressed memories remains active in clinical, legal, and academic settings. We show that the belief in repressed memories occurs on a nontrivial scale (58%) and appears to have increased among clinical psychologists since the 1990s. We also demonstrate that the scientifically controversial concept of dissociative amnesia, which we argue is a substitute term for memory repression, has gained in popularity. Finally, we review work on the adverse side effects of certain psychotherapeutic techniques, some of which may be linked to the recovery of repressed memories. The memory wars have not vanished. They have continued to endure and contribute to potentially damaging consequences in clinical, legal, and academic contexts.

Combat Posttraumatic Stress Disorder and Quality of Life: Do Somatic Comorbidities Matter?

A vast number of veterans with posttraumatic stress disorder (PTSD) have chronic somatic comorbidities. However, their relationship with quality of life (QoL) has received little attention. We aimed to compare QoL of veterans with similar intensity of PTSD but different number of chronic somatic disorders. Of 129 veterans, 78% had at least one somatic disorder, and they reported lower QoL across all domains than veterans without somatic comorbidities. The greatest effect size was observed on social relationship (d = 0.65), it was notable on environment (d = 0.4) and psychological health (d = 0.38), and it was not relevant on physical health (d = 0.05). There was a negative correlation between the number of somatic disorders and scores on psychological health (rs = -0.217, p = 0.014), social relationships (rs = -0.248, p = 0.005), and environment (rs = -0.279, p = 0.001). The QoL of war veterans decreases significantly with the number of comorbid somatic conditions, particularly on the nonphysical domains of QoL.

Psychometric Properties of the Online Arabic Versions of BDI-II, HSCL-25, and PDS

Abstract. The Beck Depression Inventory (BDI-II), Hopkins Symptom Checklist (HSCL-25), and Posttraumatic Diagnostic Scale (PDS) are three widely applied clinical instruments for assessing depression, anxiety, and posttraumatic stress symptoms, respectively. Use of online-based psychological help and assessment is rapidly growing which necessitates the need for the validation of online assessment. To address these needs, data from 1,544 Arabic mother tongue treatment-seeking participants, who filled in the Arabic versions of these instruments online, was analyzed in two steps. In the first step, exploratory structural equation modeling (ESEM) was used to scrutinize factorial validity and eliminate items. In the second step, we examined the interrelationships between the latent factors (dimensions) using confirmatory factor analysis (CFA) of multitrait-multimethod (MTMM) data. Results show an acceptable to good fit of the hypothesized model, providing some first insights into the factorial and construct validity of the Arabic versions of BDI-II, HSCL-25, and PDS under consideration of cultural-specific aspects. Present evidence speaks for construct validity of the three instruments and the reliability and usefulness of online assessment.

Are C-reps contextual representations? A reply to Brewin and Burgess

Brewin and Burgess (2013) argue that our recent papers investigating the role of contextual representations in intrusive memories do not pose a challenge to dual-representation theory as originally claimed (Pearson, 2012; Pearson, Ross, & Webster, 2012). Here I point out that their alternative explanation for our results can be rejected using data already published in both papers. I also argue that their definition of what constitutes a contextual representation renders their revised dual-representation theory incompatible with experimental results that have previously been argued in the literature to support it. Valuable though their contribution is, it does not impact on our main conclusion that abstract contextual representations serve to increase intrusive memories for traumatic material.

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.

Autobiographical integration of trauma memories and repressive coping predict post-traumatic stress symptoms in undergraduate students

What differentiates those who are able to adapt well to adverse life events (i.e., persons who are resilient) from those who are not (e.g., persons who develop post-traumatic stress symptoms)? Previous work suggests that enhanced autobiographical integration of trauma memories is associated with more severe post-traumatic stress symptoms. Extending this line of work, the present study looked at whether the integration of trauma memories, repressive coping and cognitive reactivity are related to post-traumatic stress symptomatology following negative life events among otherwise healthy young adults (N = 213). Results show that while enhanced integration of trauma memories and high levels of dissociation are related to elevated levels of post-traumatic stress, people who generally engage in repressive coping report fewer post-traumatic stress symptoms.

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.

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.

Psychometric qualities of the German version of the Posttraumatic Diagnostic Scale (PTDS)

In the present study, the psychometric properties of the German version of the Posttraumatic Diagnostic Scale (PTDS; A. Ehlers, R. Steil, H. Winter, & E. B. Foa, 1996) were evaluated in a sample of 143 trauma survivors. To investigate convergent and discriminant validity of this questionnaire, the authors assessed posttraumatic stress disorder (PTSD), anxiety, depression symptoms, and social phobia. Internal consistencies of the PTDS and its subscales as well as their association with related measures show that the German PTDS is a reliable and valid instrument for the assessment of posttraumatic stress symptoms. A 3-factor structure was found that is, however, not exactly in concordance with the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000) formulation (Reexperiencing, Avoidance, and Hyperarousal) but rather comprises a Reexperiencing/Avoidance factor; an Emotional Numbing/Hyperarousal factor; and a 3rd factor, consisting of Hypervigilance and an Exaggerated Startle Response. The findings are discussed with respect to their equivalency to the original PTDS, core symptoms of PTSD, and desirable future research.

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.

Traumatic memories of war veterans: not so special after all

Several authors have argued that traumatic experiences are processed and remembered in a qualitatively different way from neutral events. To investigate this issue, we interviewed 121 Croatian war veterans diagnosed with posttraumatic stress disorder (PTSD) about amnesia, intrusions (i.e., flashbacks and nightmares), and the sensory qualities of their most horrific war memories. Additionally, they completed a self-report scale measuring dissociative experiences. In contrast to what one would expect on the basis of theories emphasizing the special status of traumatic memories, amnesia, and high frequency intrusions were not particularly typical for our sample of traumatized individuals. Moreover, traumatic memories were not qualitatively different from neutral memories with respect to their stability and sensory qualities. The severity of PTSD symptoms was not significantly correlated with dissociative experiences. Our findings do not support the existence of special memory mechanisms that are unique to experiencing traumatic events.

Tracking scientific interest in the dissociative disorders: a study of scientific publication output 1984-2003

OBJECTIVE

We attempted to track scientific interest in dissociative amnesia and dissociative identity disorder by estimating the annual output of publications regarding these entities over the last 20 years.

METHODS

Using a standard medical index, PsycINFO, we counted the number of indexed publications involving dissociative amnesia and dissociative identity disorder listed for each year. We then compared these rates with those of well-established diagnoses such as anorexia nervosa, alcohol abuse, and schizophrenia. We also systematically reviewed all publications involving dissociative amnesia that appeared in 2003.

RESULTS

Annual publications involving dissociative amnesia and dissociative identity disorder rose from low levels in the 1980's to a sharp peak in the mid 1990's, followed by an equally sharp decline to only about one quarter of their peak levels by 2002 and 2003. In contrast, all of the 25 comparison diagnoses in our survey showed constant or steadily rising publication rates; none showed the 'bubble' pattern of the dissociative disorders. Of the 34 papers involving dissociative amnesia identified by PsycINFO for 2003, 10 (32%) appeared skeptical of the validity of dissociative amnesia and/or recovered-memory therapy. Despite a detailed search using multiple medical indices and search terms, we could find only 13 explicit cases of individuals with dissociative amnesia worldwide in the 2003 literature.

CONCLUSIONS

Dissociative amnesia and dissociative identity disorder have not generated consistent scientific interest over the years, but instead apparently enjoyed a brief period of fashion that now has waned. Overall, our observations suggest that these diagnostic entities presently do not command widespread scientific acceptance.

Retrieval and emotional processing of traumatic memories in posttraumatic stress disorder: Peripheral and central correlates

Posttraumatic stress disorder (PTSD) is thought to be characterized by dysfunctional memory processes, i.e., the automatic re-experiencing of the traumatic event and the inability to consciously recall facts about the traumatic event, as well as altered emotional processing of trauma-relevant cues. The present study examined the cerebral mechanisms underlying the cued recall of trauma-specific memories and the emotional processing of the presented cues in 16 PTSD patients, 15 trauma-exposed subjects without PTSD and 16 healthy controls. Subjects received questions about their specific trauma as well as other disastrous and neutral events while the electroencephalogram and heart rate were measured. The PTSD patients showed no impairment in trauma-specific declarative memory compared to non-PTSD subjects but had some deficits in general declarative memory as assessed by the Wechsler Memory Scale-Revised. Compared to healthy control subjects, PTSD patients displayed increased P300 and late positive complex amplitudes to trauma-specific questions, indicating enhanced emotional processing of these cues. In line with their behavioral performance, both trauma-exposed groups showed decreased terminal contingent negative variation amplitudes to trauma-specific questions over frontal electrodes reflecting altered memory retrieval. Within-group comparisons revealed that only the PTSD group but not the other groups showed a differentiation between trauma-specific and neutral questions with respect to the LPC, tCNV and P300. Concordantly with previous studies, PTSD patients showed elevated resting heart rate compared to the healthy controls. These findings are discussed in the context of current models of the role of declarative memory in the development and maintenance of PTSD.