A comparison of flashbacks and ordinary autobiographical memories of trauma: content and language

We investigated hypotheses derived from the dual representation theory of posttraumatic stress disorder, which proposes that flashbacks and ordinary memories of trauma are supported by different types of representation. Sixty-two participants meeting diagnostic criteria for posttraumatic stress disorder completed a detailed written trauma narrative, and afterwards identified those sections in the narrative that had been written in flashback and ordinary memory periods. As predicted, flashback periods were characterised by greater use of detail, particularly perceptual detail, by more mentions of death, more use of the present tense, and more mention of fear, helplessness, and horror. In contrast, ordinary memory sections were characterised by more mention of secondary emotions such as guilt and anger.     

PTSD易感性人格特质、工作记忆能力和创伤期间认知加工对模拟创伤闪回的影响

基于模拟创伤研究范式, 采用道路交通事故影片对159名健康大学生进行模拟创伤, 考察PTSD易感性人格特质(特质焦虑、特质分离和神经质)、工作记忆能力(注意控制和工作记忆容量)和创伤期间认知加工(数据驱动加工和概念加工)对模拟创伤后不同时段闪回的影响。运用结构方程模型分析数据, 结果发现：(1)数据驱动加工正向预测不同时段闪回(即时闪回、一周闪回和触发闪回)的数量、生动性、痛苦度以及一周侵入频率; (2)神经质正向预测触发闪回痛苦度, 注意控制和工作记忆容量负向预测一周侵入频率; (3)概念加工在注意控制与即时闪回痛苦度之间起中介作用。研究结果提示：数据驱动加工是创伤后不同时段闪回的主要影响因素; 概念加工主要作用于早期急性应激反应, 注意控制是其保护因素; 神经质和工作记忆能力对闪回具有较长期的影响, 且工作记忆能力具有一定的保护作用。     

Source memory errors associated with reports of posttraumatic flashbacks: a proof of concept study

Flashbacks are involuntary, emotion-laden images experienced by individuals with posttraumatic stress disorder (PTSD). The qualities of flashbacks could under certain circumstances lead to source memory errors. Participants with PTSD wrote a trauma narrative and reported the experience of flashbacks. They were later presented with stimuli from flashback and non-flashback parts of their narrative, mixed with foils from the narrative of another participant, and judged whether they belonged to their own narrative. They also reported whether stimuli elicited a flashback during this recognition test. Overall reporting a flashback at test was associated with significantly better recognition performance. Flashbacks were occasionally reported to foil stimuli, which were then likely to be wrongly attributed to the person's own narrative. This provides proof of concept of a cognitive mechanism that could potentially account for some cases of false trauma memories.     

A cognitive neuroscience account of posttraumatic stress disorder and its treatment

Recent research in the areas of animal conditioning, the neural systems underlying emotion and memory, and the effect of fear on these systems is reviewed. This evidence points to an important distinction between hippocampally-dependent and non-hippocampally-dependent forms of memory that are differentially affected by extreme stress. The cognitive science perspective is related to a recent model of posttraumatic stress disorder, dual representation theory, that also posits separate memory systems underlying vivid reexperiencing versus ordinary autobiographical memories of trauma. This view is compared with other accounts in the literature of traumatic memory processes in PTSD, and the contrasting implications for therapy are discussed.     

An fMRI investigation of posttraumatic flashbacks

Flashbacks are a defining feature of posttraumatic stress disorder (PTSD), but there have been few studies of their neural basis. We tested predictions from a dual representation model of PTSD that, compared with ordinary episodic memories of the same traumatic event, flashbacks would be associated with activity in dorsal visual stream and related areas rather than in the medial temporal lobe. Participants with PTSD, with depression but not PTSD, and healthy controls were scanned during a recognition task with personally relevant stimuli. The contrast of flashbacks versus ordinary episodic trauma memories in PTSD was associated with increased activation in sensory and motor areas including the insula, precentral gyrus, supplementary motor area, and mid-occipital cortex. The same contrast was associated with decreased activation in the midbrain, parahippocampal gyrus, and precuneus/posterior cingulate cortex. The results were discussed in terms of theories of PTSD and dual-process models of recognition.     

Specificity of episodic and semantic aspects of autobiographical memory in relation to symptoms of posttraumatic stress disorder (PTSD)

Two studies examined the relationship between the ability to access specific autobiographical material in memory and presence/symptoms of posttraumatic stress. In Study 1, a sample of refugees with a diagnosis of posttraumatic stress disorder (PTSD) completed the Autobiographical Memory Test (AMT) in which they had to generate specific episodic autobiographical memories in response to emotion-related cue words. Results showed that reduced specificity of memories on the AMT was associated with an increased frequency of trauma-related flashbacks but with reduced use of effortful avoidance to deal with trauma-related intrusions in the day-to-day. Study 2 examined retrieval of semantic autobiographical information from previous lifetime periods in groups of cancer survivors with posttraumatic stress and healthy controls. The cancer survivors were able to generate fewer specific semantic details about the personal past compared to the controls. The more symptomatic survivors showed the greatest memory impairment. The data from both studies are discussed in terms of compromised access to specific autobiographical material in distressed trauma survivors reflecting a process of affect regulation.     

Autobiographical memory for shame or guilt provoking events: Association with psychological symptoms

The diagnostic criteria for posttraumatic stress disorder (PTSD) specify that a qualifying traumatic stressor must incite extreme peritraumatic fear, horror, or helplessness. However, research suggests that events inciting guilt or shame may be associated with PTSD. We devised a web-based survey in which non-clinical participants identified an event associated with shame or guilt and completed questionnaire measures of shame, guilt, PTSD, and depression. In addition, we assessed characteristics of memory for the event, including visual perspective and the centrality of the memory to the participant’s autobiographical narrative (CES). Shame predicted depression and PTSD symptoms. There was no association between guilt and psychological symptoms after controlling statistically for the effects of shame. CES predicted the severity of depression and PTSD symptoms. In addition, CES mediated the moderating effect of visual perspective on the relationship between emotional intensity and PTSD symptoms. Our results suggest shame is capable of eliciting the intrusive and distressing memories characteristic of PTSD. Furthermore, our results suggest aversive emotional events are associated with psychological distress when memory for those events becomes central to one’s identity and autobiographical narrative.     

Attachment Disruptions,IQ, and PTSD in African American Adolescents: A Traumatology Perspective

Attachment disruptions, other traumas, posttraumatic stress disorder (PTSD), and intelligence quotient (IQ) were measured in a sample of 181 African American adolescents. Path analysis was utilized to test the effects of different types of attachment disruptions on IQ and PTSD. Findings supported that mother and father abandonments and being in foster care are associated with decreased perceptual reasoning, processing speed, and working memory, and increased discrepancy between perceptual and verbal toward decreased perceptual reasoning. Such suppression and discrepancy contribute to poor academic achievement. Results validated the traumatology perspective on attachment disruptions as traumas that are associated with PTSD, suppression of most IQ potentials, and with potential brain hemispheric desynchronization. The ramifications of these results for helping African American adolescents are discussed.     

Conceptual and perceptual priming and dissociation in chronic posttraumatic stress disorder

Cognitive models of posttraumatic stress disorder (PTSD) assert that memory processes play a significant role in PTSD (see e.g., Ehlers & Clark, 2000). Intrusive reexperiencing in PTSD has been linked to perceptual processing of trauma-related material with a corresponding hypothesized lack of conceptual processing. In an experimental study that included clinical participants with and without PTSD (N = 50), perceptual priming and conceptual priming for trauma-related, general threat, and neutral words were investigated in a population with chronic trauma-induced complaints as a result of the Troubles in Northern Ireland. The study used a new version of the word-stem completion task (Michael, Ehlers, & Halligan, 2005) and a word-cue association task. It also assessed the role of dissociation in threat processing. Further evidence of enhanced perceptual priming in PTSD for trauma stimuli was found, along with evidence of lack of conceptual priming for such stimuli. Furthermore, this pattern of priming for trauma-related words was associated with PTSD severity, and state dissociation and PTSD group made significant contributions to predicting perceptual priming for trauma words. The findings shed light on the importance of state dissociation in trauma-related information processing and posttraumatic symptoms.     

创伤后应激障碍的双重表征理论及其进展

创伤后应激障碍(PTSD)的双重表征理论认为创伤引起了可回忆的言语记忆和可回忆的情境记忆两类记忆。这两类记忆能够解释PTSD,比如再现创伤和情绪加工。创伤的情绪加工可能合出现成功完成、慢性加工和过早抑制加工三个结果。最后本文讨论了该理论在研究设计、临床实践和解释实验数据方面的应用。     

Visual Feedback in Written Imaginal Exposure for Posttraumatic Stress: A Preliminary Study

This study investigated the visual feedback hypothesis, which states that visual feedback from written trauma narratives contributes to the efficacy of written imaginal exposure for posttraumatic stress via the reuptake of traumatic content during production of the narrative. We tested a college sample (n = 61) with clinically elevated posttraumatic stress as measured with the Impact of Events Scale. Participants were randomly assigned to a writing with visual feedback condition, a writing without visual feedback condition, or a control condition. The hypothesis was not supported: Writing with and without visual feedback equally reduced intrusion and avoidance symptoms. Exploratory analyses, however, showed increased intrusion symptoms immediately after writing with visual feedback, which was in contrast with decreased symptom levels in the other conditions. These findings are in line with previous findings regarding immediate symptom development following writing interventions for posttraumatic stress and call for further exploration of the visual feedback hypothesis.     

时间距离对记叙文倒叙信息表征的影响

采用移动窗口技术和探测——再认范式探讨了时间距离对记叙文倒叙信息表征的影响。本研究分为两个实验：实验1考察了在近时间距离条件下读者如何表征倒叙信息,结果发现读者会根据时间顺序,把倒叙信息整合到他们的表征中去,支持时间顺序假设;实验2考察了在远时间距离条件下读者如何表征倒叙信息,结果发现读者会根据文本叙述顺序,将倒叙信息作为背景信息整合到该事件中去,支持背景假设。上述结果表明,时间距离是影响读者如何对倒叙信息进行表征的重要因素。     

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.     

Patterns of On-line Resource Allocation to Narrative Text by Younger and Older Readers

Younger and older adults read narrative texts word by word for immediate recall. There were no age differences in recall performance, showing that older adults were effective in narrative memory. Analysis of reading times demonstrated the existence of interindividual variability in sensitivity to text demands, which was predictive of subsequent memory performance. Contrary to the view that older readers do not encode text analytically, for these naturalistic narratives both younger and older adults optimized memory through the allocation of processing resources to the construction of a proposition-based representation of content. Overall, attentiveness to narrative structure also facilitated narrative memory, but this relationship was more reliable among older readers.     

Multi-level mental representations of written,auditory, and audiovisual text in children and adults

We examined whether the comprehension of narrative texts differed between auditory, audiovisual, and written text presentations in a sample of 8- and 10-year-olds and adults. Based on multi-level theories of text comprehension that assume text comprehension to involve at least three levels of mental representation, we applied a sentence recognition task that enabled the separate assessment of the memory of the text surface, text base, and the situation model. Results indicate that 8-year-olds benefit from audiovisual and auditory text presentations in comparison with written text presentations in terms of their memory of situation model information. For 10-year-olds and adults, their text comprehension did not differ between audiovisual, auditory, and written text presentations. Additionally, the mode of text presentation had no effect on the memory of text surface and text base information.     

The representation of color and form in long-term memory

Color and form are elementary stimulus encoding dimensions that have effects on the representation of visual stimuli at early processing stages. Little is known, however, about their effects on visual long-term memory. In three experiments we investigated whether color is part of the memory representation, whether color and form are bound in the memory representation, and the effect of color context on memory performance. Experimental results suggest that color is part of the memory representation and that color and form can be represented separately in memory and accessed independently. We suggest that the binding of color and form is a deliberate strategic act that requires focal attention, not a natural consequence of processing visual stimuli. We compare our results with the predictions of two computational memory models regarding feature binding. The effect of color context was not straightforward; however, results are consistent with the encoding specificity principle.     

Associations between Thematic Content and Memory Detail in Trauma Narratives

This study examined whether thematic content (e.g., fear, anger, alienation, self‐blame, and spirituality) in trauma narratives predicted memory detail. Trauma‐specific memory models suggest that trauma narrative themes are associated with much sensory detail; general autobiographical memory models suggest that themes are associated with little context detail. Seventy‐one narratives from a diverse community sample exposed to a variety of traumatic events (e.g., sexual assault, natural disasters) were coded for themes and detail. Analyses controlled for narrative length, childhood or adulthood occurrence, self‐reported post‐traumatic stress disorder, depression and dissociation symptoms. Fear themes were associated with greater sensory detail; anger and spirituality themes were associated with less context detail. Findings support a link between thematic content and detail, and may partially explain why details in memory for traumatic events sometimes appear better and other times worse than memory for other events. Memory models may benefit from specification based on themes in trauma narratives. Copyright © 2013 John Wiley & Sons, Ltd.     

Is the centralization of potentially traumatic events always negative? An expansion of the Centrality of Events Scale

The autobiographical memory model of posttraumatic stress disorder (PTSD) argues that centralizing a traumatic event into one's life story is a maladaptive process associated with increased PTSD symptoms. Current measures of event centralization make no reference to whether individuals centralize the event in a positive or negative way. This study examined 400 undergraduate participants using a modified version of the Centrality of Events Scale composed of 2 factors measuring both positive and negative event centralization. Exploratory factor analysis confirmed the 2‐factor structure. Negative event centralization was associated with PTSD symptoms to a greater degree than was positive event centralization, and negative event centralization mediated the relationship between neuroticism and PTSD symptoms. Combined, these results suggest that the effect of event centralization is dependent on the valence with which the individual centralizes the event. The relationship shown between negative event centralization and PTSD symptoms supports the autobiographical memory model of PTSD.     

Why did adolescents have sleep problems after earthquakes? Understanding the role of traumatic exposure,fear, and PTSD

To examine the relationships between trauma exposure, fear, post‐traumatic stress disorder, and sleep problems in adolescents, 746 adolescent survivors of the 2008 Wenchuan earthquake in China were assessed at 1 year (T1) and 1.5 years (T2) after the earthquake using a trauma exposure questionnaire, a fear questionnaire, a child posttraumatic stress disorder symptom scale, and a subscale on child sleep problems. The results showed that T1 trauma exposure were not directly associated with sleep problems at T1 and T2, but played a positive role in sleep problems at both T1 and T2 indirectly through T1 posttraumatic stress disorder and T1 fear. T1 trauma exposure was also positively and indirectly associated with T2 sleep problems through T1 posttraumatic stress disorder via T1 sleep problems, or through T1 fear via the path from T1 posttraumatic stress disorder to T1 sleep problems. These findings indicated that fear and posttraumatic stress disorder 1 year after the earthquake played a mediating role in the relationship between trauma exposure at 1 year after the earthquake, and sleep problems at both 1 year and 1.5 years after the earthquake, respectively. In particular, posttraumatic stress disorder also had a multiple mediating effect in the path from trauma exposure to sleep problems via fear. Furthermore, the findings indicated that sleep problems were relatively stable between 1 and 1.5 years after an earthquake.     

Reliving,emotions, and fragmentation in the autobiographical memories of veterans diagnosed with PTSD

Fifty veterans diagnosed with posttraumatic stress disorder (PTSD) each recalled four autobiographical memories: one from the 2 years before service, one non‐combat memory from the time in service, one from combat, and one from service that had often come as an intrusive memory. For each memory, they provided 21 ratings about reliving, belief, sensory properties, reexperiencing emotions, visceral emotional responses, fragmentation, and narrative coherence. We used these ratings to examine three claims about traumatic memories: a separation of cognitive and visceral aspects of emotion, an increased sense of reliving, and increased fragmentation. There was evidence for a partial separation of cognitive judgments of reexperiencing an emotion and reports of visceral symptoms of the emotion, with visceral symptoms correlating more consistently with scores on PTSD tests. Reliving, but not fragmentation of the memories, increased with increases in the trauma relatedness of the event and with increases in scores on standardized tests of PTSD severity. Copyright © 2004 John Wiley & Sons, Ltd.