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Dissociative amnesia is a diagnosis category that implies a proposed mechanism (often called dissociation) by which amnesia is caused by psychogenic means, such as trauma, and that amnesia is reversible later. Dissociative amnesia is listed in some of the most influential diagnostic manuals. Authors have noted the similarities in definition to repressed memories. Dissociative amnesia is a disputed category and phenomenon, and here I discuss the plausibility that this cognitive mechanism evolved. I discuss some general conditions by which cognitive functions will evolve, that is, the relatively continuous adaptive pressure by which a cognitive ability would clearly be adaptive if variation produced it. I discuss how adaptive gene mutations typically spread from one individual to the whole species. The article also discusses a few hypothetical scenarios and several types of trauma, to examine the likely adaptive benefits of blocking out memories of trauma, or not. I conclude that it is unlikely that dissociative amnesia evolved, and invite further development of these ideas and scenarios by others. Dissociative amnesia is a presumed memory phenomenon involving the storage of traumatic experiences, followed by a period of no conscious awareness, with later recall possible. It is also a diagnostic category in the influential Diagnostic and Statistical Manual of Mental Disorders. This current paper questions whether this extraordinary type of memory mechanism could have evolved in humans, by examining several different scenarios. The article is unable to identify a plausible consistent advantage that would have led to dissociative amnesia genes to spread throughout a population. [ABSTRACT FROM AUTHOR]

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. A patient with autobiographical memory loss but without gross neurological abnormalities may be diagnosed with dissociative amnesia, i.e., amnesia with a psychological origin. In this article, I argue that the absence of apparent neurological symptoms does not mean that a patient's amnesia is caused by psychological factors. Only when a medical history, neuropsychological testing, and brain scans rule out a neurological origin of the memory loss, a patient may genuinely suffer from dissociative amnesia. [ABSTRACT FROM AUTHOR]

The controversy over alleged repressed and recovered memories of childhood sexual abuse (CSA) was among the most contentious ever to embroil psychology and psychiatry. Adapting paradigms from cognitive psychology, my research group tested hypotheses pertinent to repressed memory and false memory interpretations of recovered memories. We tested adults who: (1) report recovering memories of CSA after not having thought about their abuse for years; (2) report never having forgotten their CSA; (3) believe they harbor "repressed" memories of CSA; and (4) deny having been sexually abused. We tested hypotheses about mechanisms that might figure in the inability to recall memories of one's abuse and those that might render one susceptible to developing false memories of abuse. The purpose of this article is to summarize this work. Finally, I draw on the work of Lionel Penrose to speculate about why the popularity of the concept of repressed memories of trauma—or its synonym, dissociative amnesia for trauma—may be rising today. Experimental cognitive psychology research has failed to support claims that people possess the capacity to repress memories of trauma. Lionel Penrose's viral model of "fads" may explain the persistence (or resurgence) in belief in repression. [ABSTRACT FROM AUTHOR]

Autobiographical‐episodic memory is considered to be the most complex of the five long‐term memory systems. It is autonoetic, which means, self‐reflective, relies on emotional colorization, and needs the features of place and time; it allows mental time traveling. Compared to the other four long‐term memory systems—procedural memory, priming, perceptual, and semantic memory—it develops the latest in phylogeny and ontogeny, and is the most vulnerable of the five systems, being easily impaired by brain damage and psychiatric disorders. Furthermore, it is characterized by its fragility and proneness to distortion due to environmental influences and subsequent information. On the brain level, a distinction has to be made between memory encoding and consolidating, memory storage, and memory retrieval. For encoding, structures of the limbic system, with the hippocampus in its center, are crucial, for storage of widespread cortical networks, and for retrieval again a distributed recollection network, in which the prefrontal cortex plays a crucial role, is engaged. Brain damage and psychiatric diseases can lead to what is called "focal retrograde amnesia." In this context, the clinical picture of dissociative or functional or psychogenic amnesia is central, as it may result in autobiographical‐emotional amnesia of the total past with the consequence of an impairment of the self as well. The social environment therefore can have a major impact on the brain and on autobiographical‐episodic memory processing. This article is categorized under:Psychology > Memory [ABSTRACT FROM AUTHOR]

In a bibliometric analysis, we used the PubMed search engine to count the number of publications identified by the search term "dissociative amnesia" for the years 2011–2020. We then counted publications from the same decade for five representative comparison disorders: "panic disorder," "anorexia nervosa," "obsessive–compulsive disorder," "attention deficit hyperactivity disorder," and "bipolar disorder." Our search yielded only 89 publications for "dissociative amnesia," and only seven of these involved localized or selective amnesia for specific events. By contrast, we found between 3000 and 21,000 publications for each of the five comparison disorders during 2011–2020. We performed several additional secondary analyses, all of which suggested that the diagnosis of "localized or selective dissociative amnesia" has generated little scientific interest in recent years. Examining possible hypotheses to explain this lack of interest, it appears most likely that the concept of localized or selective dissociative amnesia is not widely accepted among scientists at present. [ABSTRACT FROM AUTHOR]

In three studies, we examined whether beliefs in repressed memory and dissociative amnesia could be changed. Participants provided agreement ratings to statements related to repressed memory and dissociative amnesia. Then, they received a university course which included education on the science of memory. Following this, participants had to re‐rate the statements. In Study 3, at Times 1 and 2, participants also received a case vignette on a therapy‐induced recovered memory and rated several statements related to this case. Participants who received education on the science of memory were less likely to agree with statements endorsing repressed memory and dissociative amnesia—and participants were more likely to state that the case vignette involved a false memory. Providing education on the science of memory can help people (e.g., legal professionals, people from the general population) to use critical thinking on the topic of repressed memory and dissociative amnesia. [ABSTRACT FROM AUTHOR]

Abstract: This is a case study involving a female patient (NN) with complete loss of autobiographical memory and identity despite normal neurological assessment. To test the hypothesis that patients with dissociative amnesia (DA) possess the ability to covertly process facial identities they are unaware of, we conducted functional magnetic resonance imaging (fMRI) and assessed skin conductance responses (SCR) to (a) strangers, (b) celebrities, and (c) familiar faces not seen since the onset of DA. We also performed associative face‐name memory tasks to test the patient's ability to learn and recall newly learned face‐name pairs. Although NN did not recognize any of the faces of her friends and relatives, their images triggered a stronger involvement of the left fusiform gyrus, the bilateral hippocampus/amygdala region, the orbitofrontal cortex, the middle temporal regions, and the precuneus, along with higher SCR. During recollection of previously learned face‐name pairs, NN (compared to healthy controls) demonstrated a weaker involvement of the hippocampus. Our findings suggest that, in DA, specific arousal systems remain capable of being activated by familiar faces outside of conscious awareness. The decreased activation observed in the hippocampus demonstrates that the functioning of memory‐sensitive regions may be impaired by trauma. [ABSTRACT FROM AUTHOR]

Background: Differences in attentional processes have been linked to the development and maintenance of psychopathology. Shifts in such processes have been described by the constructs Dissociation and Absorption. Dissociation occurs when external and/or internal stimuli are excluded from consciousness due to discrepant, rather than unitary, manifestations of cognitive awareness [Erdelyi MH. 1994: Int J Clin Exp Hypnosis 42:379–390]. In contrast, absorption can be conceptualized by a focus on limited stimuli, to the exclusion of other stimuli, because of unifying, rather than discrepant, manifestations of cognitive awareness. The Dissociative Experiences Scale [DES; Bernstein EM, Putnam FW. 1986: J Nerv Ment Dis 174:727–735] and Tellegen Absorption Scale [TAS; Tellegen A, Atkinson G. 1974: J Abnorm Psychol 83:268–277] are common measures of each construct; however, no factor analyses are available for the TAS and despite accepted overlap, no one has assessed the DES and TAS items simultaneously. Previous research suggests the constructs and factor structures need clarification, possibly including more parsimonious item inclusion [Lyons LC, Crawford HJ. 1997: Person Individ Diff 23:1071–1084]. The purpose of this study was to evaluate the factor structure of the DES and TAS and create a psychometrically stable measure of Dissociation and Absorption. Methods: This study included data from an undergraduate (n=841; 76% women) and a community sample (n=233; 86% women) who each completed the DES and TAS. Results: Exploratory factor analyses [Osborne JW (ed). 2008: Best Practices in Quantitative Methods. Los Angeles: Sage Publications Inc.] with all DES and TAS items suggested a 15-item 3-factor solution (i.e., imaginative involvement, dissociative amnesia, attentional dissociation). Confirmatory factor analyses resulted in excellent fit indices for the same solution. Conclusions: The items and factors were conceptualized in line with precedent research as the Attentional Resource Allocation Scale (ARAS). Comprehensive results, implications, and future research directions are discussed. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Objective: Trauma-exposed individuals with post-traumatic stress disorder (PTSD) display reduced amygdala and hippocampal size and impaired cognition. However, studies on trauma-exposed individuals with dissociative amnesia (DA) or dissociative identity disorder (DID) are lacking. Method: Twenty-three young women who had experienced severe childhood sexual/physical abuse, diagnosed with DA/DID or PTSD, and 25 healthy control subjects were subjected to 3D structural magnetic resonance imaging of amygdala and hippocampus and a clinical and neuropsychological investigation. Results: Compared with controls, trauma-exposed subjects with PTSD ( n = 10) displayed significantly reduced amygdala and hippocampal size and significantly impaired cognition. By contrast, trauma-exposed subjects with DA or DID ( n = 13) displayed normal amygdala and hippocampal size and normal cognition. Conclusion: We report for the first time volumetric results in subjects with DA/DID without PTSD as comorbid diagnosis. Our results indicate preserved amygdala and hippocampal size and preserved cognition in subjects with these disorders. [ABSTRACT FROM AUTHOR]

A 34-year-old man without a past history of any psychiatric or neurological disorder developed severe anterograde amnesia following a psychological trauma. Initial assessment of neuropsychological functions 3 months after the psychological trauma indicated severe memory deficits for acquiring new information in both verbal and visual modalities with widespread cognitive deficits in attention, executive functions, and intellectual ability. Importantly, working and remote memory were intact. The case illustrates that psychogenic anterograde amnesia might be associated with a wider range of cognitive deficits. Possible neurobiological explanations are discussed to explain large cognitive impairments associated with anterograde psychogenic amnesia. [ABSTRACT FROM AUTHOR]