A comparison of flashbacks and ordinary autobiographical memories of trauma: cognitive resources and behavioural observations

We investigated predictions derived from the dual representation theory of posttraumatic stress disorder, which proposes that flashbacks and ordinary memories of traumas are supported by different types of representation. Sixty-two participants, meeting DSM-IV 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. Performance on cognitive tasks confirmed predictions that flashback periods would be associated with a specific decrement in visuospatial processing. Contrary to prediction, periods of both flashback and ordinary memory were associated with decrements on a verbal processing task. Independent observer ratings also confirmed that flashback periods were associated with increases in a wide range of autonomic and motor behaviours.     

The organisation and content of trauma memories in survivors of road traffic accidents

We investigated the trauma narratives of 131 road traffic accident survivors prospectively, at 1 week, 6 weeks, and 3 months post-trauma. At 1 and 6 weeks, narratives of survivors with acute stress disorder (ASD) or post-traumatic stress disorder (PTSD) were less coherent and included more dissociation content. By 3 months, their narratives also contained more repetition, more non-consecutive chunks, and more sensory words. Traumatic brain injury was associated with a separate characteristic, confusion, at all three time points. Three aspects of narrative organisation at 1 week--repetition, non-consecutive chunks, and coherence--predicted PTSD severity at 3 months after controlling for initial symptoms. The results suggest both a strong concurrent and predictive relationship between narrative disorganisation and ASD/PTSD but that as people recover from ASD, their narratives do not necessarily become less disorganised.     

Mental time travel after trauma: The specificity and temporal distribution of autobiographical memories and future-directed thoughts

The present study investigated the relationship between trauma exposure and specificity and temporal distribution of autobiographical memories and future-directed thoughts. A group of sexual assault victims were compared with women without previous trauma exposure in relation to specificity of autobiographical memories, as measured by the Autobiographical Memory Task (AMT) and specificity of future-directed thoughts as measured by the Future Cueing Task (FCT). The temporal distribution of future-directed thoughts and autobiographical memories was studied by asking the participants to estimate when each memory reported on the AMT had occurred and when each future event reported on the FCT would occur. The results showed no difference between the trauma group and the controls on specificity of autobiographical memories and future-directed thoughts. In line with a review of Moore and Zoellner (2007), PTSD symptoms as measured by the Impact of Event Scale (IES) correlated negatively with specificity. Furthermore, we observed no difference in temporal distribution of future-directed thoughts or autobiographical memories between trauma exposed participants and controls.     

A comparison of the quality of intrusive memories in post-traumatic stress disorder and depression

As in post-traumatic stress disorder (PTSD), intrusive memories (IMs) also play an important role in depression. Evidence about the comparative quality of IMs in PTSD and depression is limited and inconsistent. A total of 28 adults with PTSD, 29 with depression, and 30 controls identified intrusive and voluntary segments of narrative memories of key events. Self-report and language measures of memory quality were obtained. Depressed and PTSD participants reported higher frequency of IMs and higher IM-related interference than controls. IMs in PTSD participants were distinguished from depressed and control participants by higher self-rated distress, higher self-rated sensory quality, and a higher proportion of sensory words in the narrative. The depressed and control groups did not differ on IM quality. PTSD IM segments had more sensory content than voluntary segments and fewer temporal markers. The IM segments of the depressed and control groups had fewer temporal markers than the voluntary segments. Depression severity predicted fewer sensory words in the IM after considering peri-event dissociation and arousal but did not add to the prediction of other IM qualities. A strong sensory quality is a distinctive feature of IMs in PTSD but not in depression. Basic sensory processes contribute to the intrusiveness of remembering in PTSD but not in depression.     

Characteristics and organization of the worst moment of trauma memories in posttraumatic stress disorder

It has been proposed that the organization of the worst moment in traumatic memories (“hotspots”) is of particular importance for the development of PTSD. However, current knowledge regarding the organization and content of worst moments is incomplete.In the present study, trauma survivors with (n = 25) and without PTSD (n = 54) were asked to indicate the worst moment of their trauma and to give a detailed narrative of the traumatic event. The worst moment and the remaining narrative were analyzed separately with regard to organization and emotional content.Results indicated that worst moments of trauma survivors with PTSD differed from the remaining narrative and from worst moments described by trauma survivors without PTSD in that they were characterized by more unfinished thoughts, more use of the present tense and lower levels of cognitive processing. However, hypotheses regarding differentiating emotional content were not supported. Implications for our theoretical understanding of PTSD and potential therapeutic interventions 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.     

Synaesthesia is linked to more vivid and detailed content of autobiographical memories and less fading of childhood memories

People with synaesthesia have enhanced memory on a wide range of laboratory tests of episodic memory, but very little is known about their real-world memory. This study used a standard measure of autobiographical remembering (the Autobiographical Memory Questionnaire, AMQ) considering four constructs (Recollection, Belief, Impact and Rehearsal) and two time periods (recent memories from adulthood, remote memories from childhood). Synaesthetes reported more Recollection (e.g., sensory detail) and Belief (e.g., confidence) which interacted with time, such that remote memories are reported to be comparatively better preserved in synaesthetes. This cannot be explained by synaesthetes recalling more salient episodes (the groups did not differ in Impact). It suggests instead that childhood memories have a special status in synaesthesia that reflects the different neurodevelopmental trajectory of this group. With regards to Rehearsal, controls tended to report that more recent memories tend to resurface (i.e., adulthood > childhood), but the synaesthetes showed the opposite dissociation (i.e., childhood > adulthood).     

A cross-modal weapon focus effect: The influence of a weapon's presence on memory for auditory information

To examine whether a weapon's presence impairs witnesses' memory for auditory information (as it impairs memory for visual information), we conducted two experiments in which undergraduates watched one version of a videotape depicting a male target who held either a weapon or a neutral object and conversed with a female character. The semantic content of his remarks was either easy or difficult to comprehend. The weapon's presence did not affect voice identification accuracy or memory for the target's vocal characteristics (e.g., pitch, loudness, speech rate) but did worsen memory for semantic content in the Difficult Comprehension condition. Our results can be explained by multiple resource models of attention, which propose separate resource “pools” for different sensory modalities.     

Continuity of phenomenology and (in)consistency of content of meaningful autobiographical memories

Phenomenology is a critical component of autobiographical memory retrieval; it reflects both (a) memory-specific features and (b) stable individual differences. Few studies have tested phenomenology longitudinally. The present work examined the continuity of memory phenomenology in a sample of Italians adults (N = 105) over a 4-week period. Participants retrieved two ‘key’ personal memories, a Turning Point and an Early Childhood Memory, rated the phenomenology of each memory, and completed measures of personality, psychological distress and subjective well-being. Phenomenological ratings were moderately stable over time (median correlation >.40), regardless of memory content. Personality traits, psychological distress and well-being were associated with phenomenology cross-sectionally and with changes in phenomenology over time. These results suggest that how individuals re-experience their most important personal memories is relatively consistent over time and shaped by both trait and state aspects of psychological functioning.     

Characterisation of music-evoked autobiographical memories

Despite music's prominence in Western society and its importance to individuals in their daily lives, very little is known about the memories and emotions that are often evoked when hearing a piece of music from one's past. We examined the content of music-evoked autobiographical memories (MEAMs) using a novel approach for selecting stimuli from a large corpus of popular music, in both laboratory and online settings. A set of questionnaires probed the cognitive and affective properties of the evoked memories. On average, 30% of the song presentations evoked autobiographical memories, and the majority of songs also evoked various emotions, primarily positive, that were often felt strongly. The third most common emotion was nostalgia. Analyses of written memory reports found both general and specific levels of autobiographical knowledge to be represented, and several social and situational contexts for memory formation were common across many memories. The findings indicate that excerpts of popular music serve as potent stimuli for studying the structure of autobiographical memories.     

Incidental retrieval of emotional contexts in post-traumatic stress disorder and depression: an fMRI study

In the present study, we used fMRI to assess patients suffering from post-traumatic stress disorder (PTSD) or depression, and trauma-exposed controls, during an episodic memory retrieval task that included non-trauma-related emotional information. In the study phase of the task neutral pictures were presented in emotional or neutral contexts. Participants were scanned during the test phase, when they were presented with old and new neutral images in a yes/no recognition memory task. fMRI results for the contrast between old and new items revealed activation in a predominantly left-sided network of cortical regions including the left middle temporal, bilateral posterior cingulate, and left prefrontal cortices. Activity common to all three groups when correctly judging pictures encoded in emotional contexts was much more limited. Relative to the control and depressed groups the PTSD group exhibited greater sensitivity to correctly recognised stimuli in the left amygdala/ventral striatum and right occipital cortex, and more specific sensitivity to items encoded in emotional contexts in the right precuneus, left superior frontal gyrus, and bilateral insula. These results are consistent with a substantially intact neural system supporting episodic retrieval in patients suffering from PTSD. Moreover, there was little indication that PTSD is associated with a marked change in the way negatively valenced information, not of personal significance, is processed.     

Cognitive bias in dizziness: Emotional stroop and autobiographical memories

Dizziness is commonly associated with anxiety, and is often caused by a dysfunction of the balance system. While a link between dizziness and both anxiety disorders and depression has been established, less is known about information processing in dizziness. In the first experiment we tested whether 15 patients with dizziness would display an emotional Stroop effect for panic-related words. Also included was a control group of 15 persons. The Stroop task was preceded by ratings of personal relevance of the Stroop words and followed by a surprise free recall of the words. Results showed a Stroop effect for panic-related words in the dizziness group, but the interaction did not reach significance (p?=?0.08). Separate analysis of dizziness-related panic words however resulted in a significant group?×?condition interaction. In the free recall of Stroop words a main effect of word category was found, with more panic-related words being recalled. The second experiment investigated autobiographical memories in 14 patients with dizziness and 14 matched controls. Results showed a group?×?condition interaction with less specific memories being recalled following positive cue-words in the dizziness group. The overall pattern of results suggests that dizziness is related to deficits in information processing, which could be targeted in treatment.     

Physiological, psychological and behavioral consequences of activating autobiographical memories

Activating an autobiographical memory for a specific childhood event can have immediate and robust physiological, psychological, and behavioral consequences. The target behavior was public speaking, a vital skill about which many people are socially anxious. In this study, it was suggested to subjects that they had a positive public speaking experience in early childhood; they then thought about and retrieved details of this true childhood memory. Compared to a control condition in which a different suggestion was made, subjects in the treatment group exhibited superior public speaking performance on the Trier Social Stress Test (TSST). Further, physiological measures of cortisol and a self-report measure of anxiety (STAI-S) reflected a significantly smaller increase in anxiety from before to after the TSST in the treatment than control condition. Activating autobiographical memory for an event increases the accessibility of that memory and consequently affects performance on related behaviors.     

Trauma and autobiographical memory specificity in depressed inpatients

Research on autobiographical memory has shown that clinical depression is associated with a difficulty in retrieving specific autobiographical memories in response to cue words. This study examined the relation between lack of autobiographical memory specificity and self-reported trauma in a group of depressed adults (N = 23). In addition to the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986) participants completed a number of questionnaires assessing the presence of traumatic experiences in the past, level of depression and neuroticism. The number of specific responses was not related to depression severity, but was significantly associated with the presence and severity of reported physical abuse. Participants who had been victim of physical abuse were less specific than participants who had not been confronted with such physical adversities. The results are discussed in the context of a functional hypothesis about the developmental relations between memory specificity, trauma and depression.     

Keeping memories at an arm's length: vantage point of trauma memories

This study investigated the relationship between memory vantage point and avoidance following trauma. Sixty trauma survivors with differing levels of avoidance were interviewed about the vantage point of their memory for trauma, a positive memory, and a neutral memory. Avoidant individuals were more likely to remember their trauma from an observer perspective than individuals with a lower level of avoidance. Avoidance did not influence vantage point for positive or neutral memories. These data support the proposal that adoption of the observer vantage point for trauma memories may serve an avoidant function for people affected by trauma.     

Trauma-related and neutral false memories in war-induced Posttraumatic Stress Disorder

Recent models of cognition in Posttraumatic Stress Disorder (PTSD) predict that trauma-related, but not neutral, processing should be differentially affected in these patients, compared to trauma-exposed controls. This study compared a group of 50 patients with PTSD related to the war in Bosnia and a group of 50 controls without PTSD but exposed to trauma from the war, using the DRM method to induce false memories for war-related and neutral critical lures. While the groups were equally susceptible to neutral critical lures, the PTSD group mistakenly recalled more war-related lures. Both false and correct recall were related more to depression than to self-rated trauma. Implications for accounts of false memories in terms of source-monitoring are discussed.     

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.     

Valence of autobiographical memories: The role of mood, cognitive reappraisal, and suppression

The selective recall of positive memories is thought to be an effective mood repair technique, but little research has examined individual differences in the motivation or ability to implement this strategy. This study examined factors considered likely to impact valenced memory recall: dysphoria and emotion regulation strategies (i.e., cognitive reappraisal and suppression). Dysphoria was related to memory negativity but not positivity, whereas cognitive reappraisal was associated with positivity but not negativity. Suppression was not reliably related to the valence of self-reported memories, but was associated with increased accessibility of negative memories, as indicated by a response time measure. Our results indicate a relationship between cognitive reappraisal and more positive memory and suggest that the experience of dysphoria is more strongly related to negativity than positivity of memory. Our findings highlight the utility of examining emotion regulatory variables, in addition to mood, in the study of valenced memory recall, and underscore the importance of including both behavioral and self-report memory measures.     

Closure of autobiographical memories: The effects of written recounting from first- or third-person visual perspective

Autobiographical memories are recalled with varying degrees of psychological closure. Closure is a subjective assessment of how far a remembered experience feels resolved, and it has been suggested that one predictor of closure is the amount of emotional detail in the memory. Study 1 examined which aspect of emotional detail is important for closure, and showed that open and closed negative memories were distinguished by ratings of emotion evoked during recall, not by remembered emotion from the time of the event. The recall of open memories was accompanied by more intense, more negative, and less positive emotion than the recall of closed memories. Biased retelling of memories has been shown to influence closure and on the basis of evidence that third-person recall serves a distancing function, Study 2 examined whether instructions to repeatedly recount an open memory from a third-person perspective would increase closure compared with a single or repeated recounting from a first-person perspective. While repeated third-person recounting had the greatest influence on closure, there were also increases in the first-person recounting groups. The results suggest that closure can be increased by reporting memories in written narrative form, particularly if repeatedly expressed from the third-person perspective.