Frequency Of Intrusive Memories Research Articles

Exploration of stress reactivity and fear conditioning on intrusive memory frequency in a conditioned-intrusion paradigm

Background and objectivesThe conditioned-intrusion paradigm was designed to provide insight into the relationship between fear conditioning and intrusive memory formation, which is relevant to understanding posttraumatic stress disorder symptoms and treatment. However, boundary conditions of this new paradigm have not been explored and it is currently not known whether findings from this work are valid in a clinical context. MethodsIn the current study, we explored the relationship between stress reactivity to trauma film clips, usual exposure to violent media, renewal of fear conditioning using skin conductance as well as subjective ratings, and the effect of shock versus film clip during conditioning on the frequency of intrusive memories. An adapted fear conditioning paradigm using trauma clips as unconditional stimuli was used, and participants subsequently reported intrusive memories of the trauma clips. ResultsSkin conductance responses to conditioned stimuli paired with shocks and film clips were significantly higher than conditioned stimuli paired with film clips alone. Subjective stress reactivity, previous exposure to violent media, and film valence rating were associated with the frequency of intrusive memories. No aspects of fear conditioning were associated with intrusive memories, and factor analysis suggested the fear conditioning and stress related to film clip viewing were mostly separate constructs. Similarly, content and triggers of intrusive memories were usually film-clip related rather than conditional stimulus related. LimitationsWe did not observe strong conditioning effects of the unconditional stimuli to conditional stimuli, which were shapes rather than high frequency stimuli such as faces. ConclusionsThese findings provide potential boundary conditions for this paradigm and suggest multiple ways in which the validity of the paradigm can be tested in the future.

Using a Novel Gameplay Intervention to Target Intrusive Memories After Work-Related Trauma: Iterative Qualitative Analysis of Intensive Care Unit Staff Experiences.

Many intensive care unit (ICU) staff experience intrusive memories following work-related traumatic events, which can lead to long-term mental health outcomes and impact work functioning. There is a need for interventions that target intrusive memories in this population; however, factors such as mental health stigma and difficulty in fitting interventions into busy schedules can pose barriers. The Brief Gameplay Intervention For National Health Service Intensive Care Unit Staff Affected By COVID-19 Trauma (GAINS) study tested a brief, digital imagery-competing task intervention (including computer gameplay) with the aim of reducing the recurrence of intrusive memories, which holds promise for overcoming some of these barriers. This substudy aims to explore barriers and facilitators to the uptake and practical use of the intervention by ICU staff, along with its acceptability, and iteratively explore the impact of intervention optimizations to further refine the intervention. The GAINS study is a randomized controlled trial comparing access to a brief digital imagery-competing task intervention for 4 weeks with usual care followed by delayed access to the intervention. The participants were ICU staff who worked during the COVID-19 pandemic and experienced intrusive memories. All participants were sent a questionnaire at 4 weeks to gather data about intervention acceptability. Nested within the randomized controlled trial, a subset of 16 participants was interviewed, and data were analyzed using thematic analysis drawing from a framework approach. Both quantitative and qualitative data indicated high acceptability of the intervention. Intervention use data show that, on average, staff were able to target approximately 73% (3.64/4.88) of their intrusive memories and engaged with the Tetris component for the full 20 minutes per session. Overall, on the acceptability questionnaire, staff found the intervention easy to use, helpful, and highly acceptable. The interviews generated four themes: approach to the intervention, positives of the intervention, negatives of the intervention, and improvements and optimizations. Findings highlighted barriers that ICU staff experienced: stigma, feeling weak for seeking help, not wanting colleagues to know they were struggling, and skepticism. However, they provided suggestions on how barriers could be overcome and discussed the advantages of the intervention when compared with other treatments. Although participants described many positive aspects of the intervention, such as being easy to use, enjoyable, and leading to a reduction in the frequency or intensity of intrusive memories, they also raised practical issues for implementation. The intervention has the potential to overcome stigma and reduce the frequency of intrusive memories after traumatic events among ICU staff. Further refinement is needed to improve the adoption and reach of this intervention. A limitation is that we could not interview the National Health Service staff who were unable or unwilling to take part in the trial.

Can placebos reduce intrusive memories?

After traumatic experiences, intrusive memories can flash back and evoke significant distress. Here, we investigated whether the frequency and severity of intrusions can be reduced by the provision of placebo. After the (online) exposure to the trauma-film paradigm, healthy participants (N = 112) received deceptive placebo (DP), open-label placebo (OLP), or no treatment. In the DP group, participants were led to believe to receive a dopamine-modulating drug, which was supposed to disrupt the consolidation of traumatic memories, although they in fact received the same placebo tablets as the OLP group for one week. The results show that the groups did not differ in the frequency of intrusive memories after one week. However, participants receiving OLP reported a significantly reduced intensity of intrusions as compared to DP. Across groups, negative expectations about the intensity and controllability of intrusions were associated with a higher frequency of intrusions, higher distress, higher burden, and more negative appraisal. The results suggest that expectations play an important role in the emergence of intrusive memories and that some of the disabling aspects of intrusive memories can be reduced by placebo. This may carry clinical potential because placebos are an accessible, cost-effective intervention to reduce the risk of intrusive memories.

Visuospatial Working Memory Tasks May Not Reduce the Intensity or Distress of Intrusive Memories

Cognitive interventions involving visuospatial tasks, such as the game “Tetris” have demonstrated efficacy in reducing the frequency of intrusive memories. However, it remains unclear whether these tasks also reduce the perceived intensity and distress of these memories. We investigated whether either of two visuospatial tasks: a Tetris intervention or Digital Corsi task, following the viewing of an analog trauma (film) resulted in decreased intensity and distress for intrusive memories over the following week, when compared to a control condition. Participants (n = 110) were randomly assigned to task conditions after viewing the film. Linear mixed models indicated no between-group differences for reductions in intensity or distress over the course of the week. These findings highlight an important boundary to the benefits of such visuospatial tasks, in that while they may be associated with reductions in intrusion memory frequency, individuals may nonetheless continue to experience distress when intrusions do occur.

Threat memory devaluation by a dual-task intervention: Testing return of fear and intrusive memory over 48 hours

Background and objectivesIn dual-tasking, individuals recall a threat-related memory while performing a demanding dual-task. This is a fruitful approach to reduce the unpleasantness and vividness of aversive memories and to reduce conditioned fear responses. Crucially, it remains unclear whether dual-tasking can also reduce conditioned fear responses and intrusive memories over time. In this pre-registered two-day fear conditioning paradigm, we examined whether a dual-task intervention reduces return of fear and the frequency of intrusive memories of an aversive film over time. MethodsOn Day 1, 76 healthy participants underwent fear acquisition with aversive film clips. They were then randomly allocated to one of three conditions: dual-tasking, memory recall without a dual-task (‘recall only’), or no task. Afterwards, they underwent an extinction phase and were asked to record intrusive film memories over 48 h. On Day 3, return of fear was assessed. ResultsOn Day 1, fear acquisition and extinction were successful. On Day 3, spontaneous recovery and renewal were evident, but, overall, participants reported few intrusions. The dual-task and recall only groups reported reduced unpleasantness of threat memory compared to the no task group, but they did not show reduced (return of) fear responses or fewer intrusions. LimitationsIntrusion frequency was low in all three groups, which limits the detection of intervention effects. ConclusionsEven though dual-tasking and recall only devalued threat memory temporarily compared to no task, these interventions did not reduce (return of) fear responses and intrusions. Future studies could focus on improving the potency of imagery-based interventions.

Investigating the frequency of intrusive memories after 24 hours using a visuospatial interference intervention: a follow-up and extension

ABSTRACT Background: There is a need for effective, low-cost, readily available measures for reducing trauma symptoms so that people exposed to potentially traumatic events can receive help more quickly. A previous study reported that performing an intervention including a visuospatial task shortly after a reminder of a series of unpleasant film clips seen 24 hours earlier reduced the number of intrusive memories over the following week. Objective: This study reports a follow-up and extension of the earlier promising finding. The prediction was that participants performing the visuospatial task immediately after the reminder would report fewer intrusions compared to three other groups who 1) performed no task, and novel conditions who 2) performed the task before the reminder, and 3) performed the task 90 minutes after the reminder. Method: A trauma-analogue method was used, where students (N = 200) watched a series of short films with unpleasant material. Over the following week, they were asked to write down any intrusive memories they experienced in a diary. On the second day they returned to the lab and saw static reminders of the films. They were then randomly allocated to condition, recorded intrusive memories over the following days and returned to the lab for final testing on Day 8. Results: A total of 49 participants did not report any intrusions and were excluded from the analyses. Two more participants were excluded as outliers, leaving a final sample of n = 149. Despite using largely the same materials as the original study there were no significant differences in the number of intrusive memories between the four groups post intervention. Conclusions: Possible explanations include the effect not being as robust as expected, a low number of intrusions across groups, baseline differences in attention, and minor but potentially important differences in procedure between this and the original study.

The influence of ruminative processing mode on the trajectory of intrusive memories following a negative mood induction

Background and objectivesRumination following an event, particularly in an abstract as opposed to concrete processing mode, is associated with increased intrusive memory frequency. However, the temporal trajectory of intrusive memories following abstract and concrete rumination remains unclear. We examined the association between processing mode and the frequency of intrusive memories over a 6-h time period following a negative mood induction. MethodsOne hundred and sixteen community participants watched a video sequence designed to induce negative mood. Participants were then randomised into condition (abstract, concrete or distraction) and completed a verbally mediated task designed to induce the respective processing mode. Participants then completed hourly ratings of rumination and intrusive memories about the video after leaving the laboratory. ResultsNegative mood and intrusive memories were reliably induced. There were no differences in the frequency of intrusive memories between the abstract and concrete conditions. In contrast, participants in the distraction condition reported significantly more sensory intrusive memories than either ruminative condition. Three classes were found among participants following the video (intrusion free, rapid remitters, slow remitters). Condition was not predictive of class membership. LimitationsIt cannot be ruled out that the differences between rumination and distraction conditions were due to task differences. ConclusionsIn contrast to previous findings, our results suggest that any form of rumination about an event (whether in an abstract or concrete mode) may temporarily result in fewer intrusive memories in comparison to distraction. Processing mode does not appear to predict particular trajectories of intrusions following a mood induction.

Written cues provoke involuntary cognitions about a trauma analogue

After trauma people commonly experience intrusive memories and involuntary elaborative cognitions, such as imagined future events. Involuntary elaborative cognitions differ from intrusive memories because they involve the construction of a novel scenario, rather than the retrieval of a specific past event. Presenting multiple, unrelated cues together—compared to isolated cues—might elicit more elaborative cognitions by encouraging the extraction of distinct memory traces to construct a novel event. Conversely, isolated cues might elicit more intrusive memories by encouraging retrieval of a specific memory. We investigated these ideas using a vigilance task consisting of written cues. Participants viewed negative photos and then viewed either no cues, single cues (e.g., knife), or cues presented together as randomly selected triplets (e.g., skull sick hunger). Cues encouraged involuntary cognitions. However, frequency of intrusive memories and involuntary elaborative cognitions did not depend on whether cues were presented singularly or as triplets.

'I Can't Concentrate': A Feasibility Study with Young Refugees in Sweden on Developing Science-Driven Interventions for Intrusive Memories Related to Trauma.

BackgroundThe number of refugees is the highest ever worldwide. Many have experienced trauma in home countries or on their escape which has mental health sequelae. Intrusive memories comprise distressing scenes of trauma which spring to mind unbidden. Development of novel scalable psychological interventions is needed urgently.AimsWe propose that brief cognitive science-driven interventions should be developed which pinpoint a focal symptom alongside a means to monitor it using behavioural techniques. The aim of the current study was to assess the feasibility and acceptability of the methodology required to develop such an intervention.MethodIn this study we recruited 22 refugees (16–25 years), predominantly from Syria and residing in Sweden. Participants were asked to monitor the frequency of intrusive memories of trauma using a daily diary; rate intrusions and concentration; and complete a 1-session behavioural intervention involving Tetris game-play via smartphone.ResultsFrequency of intrusive memories was high, and associated with high levels of distress and impaired concentration. Levels of engagement with study procedures were highly promising.ConclusionsThe current work opens the way for developing novel cognitive behavioural approaches for traumatized refugees that are mechanistically derived, freely available and internationally scalable.

Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma.

Post-traumatic stress disorder (PTSD) involves maladaptive long-term memory formation which underlies involuntary intrusive thoughts about the trauma. Preventing the development of such maladaptive memory is a key aim in preventing the development of PTSD. We examined whether the N-methyl d-aspartate receptor (NMDAR) antagonist gas nitrous oxide (N2O) could reduce the frequency of intrusive memories by inhibiting NMDAR-dependent memory consolidation in a laboratory analogue of psychological trauma. Participants were randomized to inhale N2O (N = 25) or medical air (N = 25) after viewing a negatively valenced emotional film clip ('trauma film'). Participants subsequently completed a daily diary assessing frequency of intrusive thoughts relating to the film clip. A week later, participants completed an explicit memory recall task related to the film. Post-encoding N2O sped the reduction in intrusive memory frequency, with a significant reduction by the next day in the N2O group compared to 4 days later in the air group. N2O also interacted with post-film dissociation, producing increased intrusion frequency in those who were highly dissociated at baseline. Sleep length and quality the night after viewing the film did not differ between the groups. N2O speeds the reduction of intrusive analogue trauma memory in a time-dependent manner, consistent with sleep-dependent long-term consolidation disruption. Further research with this drug is warranted to determine its potential to inoculate against enduring effects of psychological trauma; however, caution is also urged in dissociated individuals where N2O may aggravate PTSD-like symptomatology.

Acute Sleep Deprivation May Reduce Impact of Traumatic Memories

Acute Sleep Deprivation May Reduce Impact of Traumatic Memories

Intrusive memories and depression following recent non-traumatic negative life events in adolescents

Research in adults suggests that intrusive memories are not just found in individuals with post-traumatic stress disorder (PTSD), yet there is little evidence concerning the phenomenology of intrusive memories in children and adolescents. The present study investigated the frequency of intrusive memories following a recent negative event in an adolescent school sample, and considered the application of cognitive theory to understanding the maintenance of intrusive memories of recent negative events, and their role in maintaining depression. High school students (aged 11-18 years; n=231) completed questionnaires concerning affect experienced during a recent negative event, the frequency of subsequent intrusive memories, memory quality, thought suppression, post-traumatic stress and depressive symptoms. Most participants had experienced at least one intrusive memory in the previous week, at similar rates for traumatic events and life events. In non-trauma exposed youth, peri-event affect and memory quality accounted for unique variance in a regression model of intrusive memory frequency, while peri-event affect, memory quality, and intrusive memory frequency accounted for unique variance in a regression model of depression. The study needs replication in younger children. Interview methods may be required to ensure that intrusive memories are being assessed and not intrusive thoughts or ruminations. Intrusive memories are common reaction to negative events in adolescents, and may be involved in maintaining subsequent depressed mood. The nature of event memories may have a role in the maintenance of such psychopathology, and may be a target for psychological interventions in this age group.

Disgust Propensity as a Predictor of Intrusive Cognitions Following a Distressing Film

Although extant research examining predictors of development of Posttraumatic Stress Disorder (PTSD) have focused primarily on fear and anxiety, recent research suggests that a range of different emotional reactions may occur in response to traumatic events. For example, specific aspects of traumatic exposure frequently include either experiencing or witnessing events that may elicit disgust, including injury, death, or sexual assault (e.g., Dalgleish and Power in Behav Res Ther Spec Issue Festschrift Spec Issue John Teasdale 42(9):1069–1088, 2004); McNally in J Anxiety Disord 16(5):561–566, 2002). However, no published research has specifically examined the role of disgust propensity in the development and maintenance of PTSD. Thus, the aim of the present study was to evaluate the relationship between disgust propensity and intrusive symptoms. To this end, 30 undergraduates without symptoms of PTSD were recruited to participate in a distressing film paradigm (for a review of this paradigm see Holmes and Bourne in Acta Psychol 127(3):553–566, 2008). Anxiety, depression, and trait disgust scores were entered hierarchically into a regression equation to predict the number of intrusions during a post-film thought monitoring period. Results indicated that disgust propensity predicted intrusions independent of anxiety and depression. Although still preliminary, results suggest that disgust propensity may be one factor that predicts frequency of intrusive memories after witnessing injury or bodily harm.

Can Imaginal Exposure Reduce Intrusive Memories in Depression? A Case Study

The presence of intrusive memories as an overlapping feature of depression and posttraumatic stress disorder (PTSD) raises the possibility that common therapeutic approaches may be effective. Imaginal exposure (IE) is the gold‐standard treatment for PTSD and directly reduces both PTSD and depression symptoms in traumatized individuals. The objective of this pilot study was to use a single‐case design to trial the use of IE to target intrusive memories of a negative life event as a treatment for major depression. The participant was experiencing depression after a relationship breakup. Pre–posttreatment measures (clinical interview and self‐report) showed a decrease in frequency of intrusive memories and improved mood, such that the participant no longer met diagnostic criteria for major depression at posttreatment or at 6‐month follow‐up. This case is an important first step in demonstrating the possible value of IE as an inclusion in therapy to reduce intrusive memories in patients whose depressive episode is precipitated by a stressor. Further application of IE to additional depressed clients in the context of a case series is needed to provide preliminary evidence of its efficacy as a treatment for depressive disorders.

Individual differences in experiencing intrusive memories: The role of the ability to resist proactive interference

This study explored whether a relatively poor ability to resist or inhibit interference from irrelevant information in working memory is associated with experiencing undesirable intrusive memories. Non-selected participants ( N = 91) completed a self-report measure of intrusive memories, and carried out experimental tasks intended to measure two different types of inhibition: resistance to proactive interference and response inhibition (i.e., the ability to prevent automatically triggered responses). The results showed a significant relationship between inhibition at the cognitive level (i.e., resistance to proactive interference) and the frequency of intrusive memories (especially in the group of female participants) whereas no such relationship with measures of response inhibition emerged. These findings are consistent with the idea that deficient inhibitory control reflects a vulnerability factor for experiencing intrusive memories. Implications for research investigating risk factors for the development of posttraumatic stress disorder (PTSD) are discussed.

Processing memories of anger-eliciting events: The effect of asking ‘why’ from a distance

Preliminary experimental evidence suggests that ruminating about anger-eliciting events exacerbates anger and associated affect. However, no research has investigated the effect of rumination on processing memories of these events. This study examined the impact of manipulating cognitive processing when recalling anger-eliciting events. Participants ( N=60) outlined an anger-related experience and were randomly allocated to recall the event according to an experimental instruction that manipulated recall perspective and emotional focus (distanced-why, distanced-what, immersed-why or immersed-what). Participants completed measures of negative affect and implicit and explicit anger, and returned the following day to complete measures that indexed frequency of intrusive memories of the event and memory-related distress. Contrary to prediction, participants allocated to the distanced-why condition did not report reduced anger. However, participants instructed to think about ‘why’ they experienced the emotions they did during the event (compared with ‘what’ emotions they experienced) reported more intrusions 24 h later, regardless of vantage perspective. These results accord with theoretical models that emphasise the negative impact of a ruminative ‘why’ focus on the processing of past events.