The trauma film paradigm as an experimental psychopathology model of psychological trauma: intrusive memories and beyond

The relationship between REM sleep prior to analog trauma and intrusive memories

Intrusive memories are a common experience following trauma exposure but can develop into a symptom of posttraumatic stress disorder (PTSD). Recent research has observed a relationship between sleep disturbance and intrusive memory frequency following analog trauma exposure and disruptions in rapid eye movement (REM) sleep are found to contribute to emotional dysregulation and an amplified reaction to negative emotional stimuli. The current study examined the association between REM sleep prior to analog trauma and intrusive memories. To manipulate REM sleep, 27 healthy adults (MAge = 25.4, standard deviation = 2.89) were randomized to either a circadian misalignment (CM) condition or normal control (NC) condition for 4 nights. In CM, participants slept normally for 2 nights followed by a 4-hour phase advance on night 3 and an additional 4-hour phase advance on night 4. In NC, participants had 8-hour sleep opportunities each night. On day 5, participants watched a trauma film and kept an intrusive memory diary for the next 3 days. Greater REM sleep percentage (p = .004) and REM efficiency (p = .02) across 4 nights prior to analog trauma, independent of the group, were significantly associated with fewer intrusive memories in the 3 days after viewing the film. Findings suggest REM sleep may serve to protect individuals against experiencing intrusive memories. This is consistent with evidence suggesting REM sleep influences emotional memory regulation. Occupations (e.g. emergency services/military personnel) who experience circadian disruptions likely to decrease REM sleep (e.g. from shift work) may be at heightened risk of experiencing intrusive memories after trauma exposure, and thus at increased risk of developing PTSD.

Physical activity indexed using table tennis skills modulates the neural dynamics of involuntary retrieval of negative memories

Memory intrusion is a characteristic of posttraumatic stress disorder manifesting as involuntary flashbacks of negative events. Interference of memory reconsolidation using cognitive tasks has been employed as a noninvasive therapy to prevent subsequent intrusive retrieval. The present study aims to test whether physical activity, with its cognitive demands and unique physiological effects, may provide a novel practice to reduce later involuntary retrieval via the reconsolidation mechanism. In addition, the study investigates the EEG representation of neural function in interpreting the interplay of intrusion and recognition. Eighty-seven participants were tested on successive sessions comprised encoding (Day 0), reconsolidation (24-hr) and priming retrieval (Day 7) in a between-subject design with random assignment to 3 different groups: whole-body exercise, sensorimotor engagement and sitting groups. Of the key results, when involuntary retrieval was subsequently triggered by relevant stimuli, reduced subjective recognition was observed, and working memory maintenance was shortened, indicated by shorter Negative Slow Wave duration. The study implicates the potential neurophysiological mechanism of cognitive and behavioral interventions, specifically those aimed at reducing intrusion frequency through the reconsolidation mechanism; these are proposed to facilitate accelerated recovery from involuntary memories.

A preliminary study of disaster media use as a coping mechanism and the psychological impact of the 2014 Sewol ferry disaster

Background: The 2014 Sewol ferry disaster is the only South Korean mass casualty incident broadcasted in real time and the first instance of the nation collectively experiencing a disaster through social media. Compared to the large body of literature on disaster media as a stressor, its role as a coping tool remains underexplored.Objective: We explored the associations between coping styles in disaster media use and the psychological impact of the Sewol ferry disaster among the South Korean general public.Method: A paper-based survey of the nationwide general population (N = 876) evaluated disaster media use from the perspective of the approach-avoidance model of coping and assessed levels of posttraumatic distress and perceived growth. Participants were divided into three groups based on their coping orientation towards the media around the Sewol ferry disaster: approach-oriented (i.e. actively seeking out event-related news; n = 282; 32.2%), avoidance-oriented (i.e. intentionally avoiding event-related news; n = 69; 7.9%), and neutral (neither seeking nor avoiding event-related news; n = 474; 54.1%). The levels of posttraumatic distress and perceived growth were compared between these groups with ANCOVA controlling for age, sex, and/or the date of survey participation.Results: Approach-oriented disaster media use was associated with both elevated posttraumatic distress and perceived growth, while avoidance-oriented disaster media use was associated with elevated posttraumatic distress without significant perceived growth. The neutral group reported the lowest levels of both posttraumatic distress and perceived growth.Conclusions: The findings demonstrated that not posttraumatic distress but perceived growth was the distinguishing factor between the two coping styles in disaster media use. This suggests the potential benefits of approach-oriented disaster media use, considering the salutogenic role of perceived growth in the recovery process. Future longitudinal research is required to determine the predictive role of disaster media use as coping.

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

BACKGROUND AND OBJECTIVES

The 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.

METHODS

In 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.

RESULTS

Skin 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.

LIMITATIONS

We did not observe strong conditioning effects of the unconditional stimuli to conditional stimuli, which were shapes rather than high frequency stimuli such as faces.

CONCLUSIONS

These 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.

Forget me not: The effect of doxycycline on human declarative memory

Investigations into neuroprotective drugs are in high demand for the treatment of neurodegenerative diseases, such as multiple sclerosis or Alzheimer's disease, but also psychiatric disorders, such as depression, trauma, and substance use. One potential drug class being investigated are tetracyclines impacting on a variety of neuroprotective mechanisms. At the same time, tetracyclines like doxycycline have been suggested to affect human fear and spatial memory as well as reducing declarative memory retention. Based on the assumed necessity for synaptic consolidation in hippocampus-dependent learning, we hypothesised declarative memory may be similarly impaired by doxycycline as fear and spatial memory. Therefore, in this study we investigate the potential diminishing effects of doxycycline on consolidation of declarative memory in healthy humans. Additionally, to test for effect specificity we assessed motor memory, sustained attention, and processing speed. We administered a neuropsychological test battery in three independent randomized placebo-controlled double-blind trials (RCTs), in which healthy young volunteers (total N = 252) either received a single oral dose doxycycline (200 mg, n = 126) or placebo (n = 126) in a between-subject design. We found no evidence for a detrimental effect of doxycycline on declarative memory; instead, doxycycline improved declarative learning (p-value=0.022, Cohen's d=0.15) and memory consolidation (p=0.040, d=0.26). Contrarily, doxycycline slightly reduced motor learning (p=0.001, d=0.10) but subtly strengthened long-term motor memory (p=0.001, d=0.10). These results suggest that doxycycline can improve declarative learning and memory without having long term negative effects on other cognitive domains in healthy humans. Our results give hope to further investigate doxycycline in neuroprotective treatment applications.

Convergence of real-time and retrospective assessments: A systematic investigation of naturally occurring and experimentally induced intrusions

BACKGROUND AND OBJECTIVES

Ecological momentary assessment is a popular method for monitoring symptoms in real-time. Especially for fleeting experiences, such as intrusions, real-time assessments may be more accurate than retrospective estimates. However, there are concerns regarding reactivity effects associated with real-time assessments and, conversely, the reliance on bias-prone retrospective assessments in clinical science and practice. In this study we used a between-groups design to examine whether real-time intrusion assessments influence retrospective reports (aim 1). Then, we investigated whether real-time and retrospective assessments systematically differed within individuals (aim 2).

METHODS

Over two weeks, 150 non-clinical individuals provided weekly retrospective intrusion assessments, while the majority (n = 102) additionally reported their intrusions in real-time, via smartphones. We examined both naturally occurring intrusions, which individuals experience in their everyday lives, and intrusions related to a standardized stressor (i.e., Trier Social Stress Test), taking place halfway.

RESULTS

Using Bayesian statistics, we found that assessing intrusions in real-time did not convincingly affect retrospective reports, and there was no strong evidence that real-time and retrospective intrusion assessments differed. However, the evidence of absence was inconclusive for some measures. Real-time and retrospectively reported intrusion frequencies and distress were strongly associated with one another.

LIMITATIONS

Future research is advised to replicate these findings with larger samples, for other types of stressors, in clinical populations, and over extended assessment periods.

CONCLUSIONS

The general agreement between real-time and retrospective assessments of intrusions is encouraging, tentatively suggesting that researchers and clinicians can flexibly select the assessment method that best suits their objectives.

Active contextualization reduces traumatic memory intrusions via memory integration

Traumatic memory intrusions, the involuntary retrieval of unwanted memories, significantly impact mental health. The dual representation theory proposes that the origin of intrusion lies in the overactivated sensory memory not being integrated with the corresponding contextual memory, highlighting the crucial associations between memory contextualization and intrusion. To test this, our study investigated whether enhancing memory contextualization could effectively reduce intrusion. After experiencing analogue trauma with the trauma film paradigm, 96 healthy participants were randomly allocated to three intervention groups: active contextualization (AC) in which participants actively retrieve and restructure film content, passive contextualization (PC) in which participants passively restudy content-matched pre-contextualized information, and working memory taxation (WM) in which participants performed a working memory dual-task. Diary recordings over the subsequent week revealed a significant reduction in intrusion frequency in the AC group compared to both the PC group and a no-intervention control group. Furthermore, comparing AC with WM, a well-established laboratory intervention on intrusion, established a superior efficacy of the AC intervention in reducing intrusions. Finally, analyses of the explicitly recollected film memories identified the critical element of active contextualization to be memory integration induced by active memory retrieval. Together, our findings suggest that active contextualization causally diminishes intrusions, providing novel insights into the regulation of the contextual memory system in intrusion intervention.

People experience similar intrusions about past and future autobiographical negative experiences

We know much about people's problematic reactions-such as distressing intrusions-to negative, stressful, or traumatic past events. But emerging evidence suggests people react similarly to negative and potentially-traumatic future events. Given similar processes underlie remembering the past and imagining the future more generally, we wondered how similar involuntary memories, or intrusions, are for experienced vs. anticipated events. We focused primarily on intrusions because they are a transdiagnostic reaction to traumatic events. We asked subjects to report either a very stressful event they had experienced in the past 6 months, or one they anticipated they could experience in the next 6 months. We measured the frequency of intrusions about these reported events, and intrusions' phenomenological characteristics (such as emotional intensity), negative appraisals about their meaning, and reactions to them more generally. Overall, we found intrusions about experienced vs. anticipated autobiographical events were similarly troubling. This pattern supports the idea that anticipating the future can be aversive and elicit post-traumatic-stress-like symptoms, just as remembering the past can. Our findings have implications for theoretical models of traumatic-stress and treatment of traumatic-stress symptoms.

Behavioural profiling following acute stress uncovers associations with future stress sensitivity and past childhood abuse

Background: Individuals greatly differ in their responses to acute stress, ranging from resilience to vulnerability that may yield stress-related psychopathology. Stress-related psychopathologies involve, by definition, substantial modifications across multiple behavioural domains, including impaired cognitive, affective and social functioning. Nevertheless, and despite extensive investigation of individual variability in stress responsivity, no study to date simultaneously assessed the impact of acute stress across multiple behavioural domains within a given individual.Objective: To address this critical gap, 84 healthy female participants (mean age 24.45 ± 3.02, range 19-35) underwent an established acute stress induction procedure and completed three behavioural tasks, probing the functional domains of positive, cognitive and social processing, both before and after the acute stress procedure.Method: A novel behavioural profiling algorithm was implemented to identify individuals whose performance was substantially impacted by stress across all three functional domains.Results: Approximately 30% of participants exhibited substantial deviation in their performance from before to after stress in all three tasks, hereon defined as stress-affected. Stress-affected participants did not differ in their psychological and physiological responses to the acute stress procedure from the other stress-unaffected 70% of the sample. However, follow-up assessments in 66 of these participants revealed higher levels of stress six months following the procedure among the stress-affected compared to the stress-unaffected group. Stress-affected individuals also reported more aversive childhood experiences, such that the odds of participants who were sexually abused at an early age to be affected behaviourally by acute stress later in life increased by more than five-fold.Conclusions: Taken together, these findings suggest that being affected by acute stress across multiple functional domains is associated with future stress sensitivity and past childhood sexual abuse. Probing individual differences in the impact of acute stress across domains of functionality may better align with the multi-dimensional nature of stress responsivity, uncovering latent vulnerability.

Reducing intrusive memories and promoting posttraumatic growth with Traveler: A randomized controlled study

Over recent decades, serious games have become a promising intervention approach for addressing psychological problems by providing users with computerized, engaging, and interactive experiences. An innovative serious game, Traveler, has been developed specifically as an intervention tool for managing posttraumatic responses immediately after trauma. The game incorporates the principle of visuospatial interference, the core elements of Tetris, such as spatial displacement and mental rotation, and the critical phases of eye movement desensitization and reprocessing. To test the intervention efficacy and feasibility of Traveler, we conducted a randomized controlled trial involving 105 young adults. Participants were randomly assigned into three groups: a wait-list control group, a group undergoing five-session written exposure therapy, or a group engaging in one session of Traveler gameplay. Outcome measures included intrusive memories (i.e. vividness of traumatic images, disgust at traumatic images, flashback frequency, and flashback impact) and posttraumatic growth measured by the Posttraumatic Growth Inventory. Traveler significantly outperformed the control and written exposure therapy groups in reducing intrusive memories and enhancing posttraumatic growth, with effects persisting at a 30-day follow-up. Thus, Traveler offers a promising brief and early intervention technique for addressing posttraumatic responses. Yet, its clinical applicability requires further investigation.

How does malingered PTSD affects continuous performance task performance?

The purpose of this study was to determine how malingered PTSD behavior affects the performance of a continuous performance task (CPT). An analog trauma group, two malingering groups (with or without educational intervention), and a control group were organized according to simulation design. During the CPT, the numbers of errors and response time indicators along with post-error slowing (PES) and recovery (PER) process were measured. Results are as follows: First, the analog trauma group showed deficits of response inhibition and a higher level of PES compared to the control group. Second, malingered PTSD caused a significant number of errors, inconsistent performance, and no PES. Third, there was a significantly more impaired and inconsistent performance in the low level of knowledge of disability. Finally, a discriminant accuracy of more than 90% appeared in the discriminant analysis of all group comparison conditions. Taken together, the results of this study show that post-error behavior indicators are affected by malingered PTSD, and differences according to the degree of knowledge of PTSD can also be confirmed. These results are expected to be used as basic data for the development of tasks for the detection of malingerers in clinical scenes in the future.

Digital Media to Support Healing from Trauma: A Conceptual Framework Based on Mindfulness

Digital media which involve narrative storytelling are increasingly used in nursing and health research, including clinical applications such as cinematherapy. A pilot study was conducted on how digital media self-accessed by marginalized individuals may be beneficial toward mindfulness and healing from trauma. Qualitative interviews were conducted with individuals (n = 8) who self-reported marginalizations via: race; gender; rural geography; socioeconomic status; indigenous or colonial experience; survivor of abuse; experiences of homelessness; or disability. Results indicated that trauma-narratives often organically emerge through discussions on digital media, with notable intersections with mindfulness-based practices and interventions. First, digital media can create a mindfulness of trauma as valid to discuss and disseminate. Mindfulness of authentic resolution also emerged as critical, as trauma may be employed in media narratives for attention or sympathy with no intent to support healing. Participant responses illustrate value in being mindful of individuals with severe trauma, who may be less likely to benefit from digital media. Digital media can foster sense-of-belonging and community-building amidst isolation; additionally, parasocial relationships may help foster supportive identities and ideologies on vulnerability. Findings are outlined in a preliminary conceptual framework, toward supporting future digital media with intent to create mindfulness or heal trauma.

Can Listening to a Verbal Trauma Report Induce Intrusions? - Replication of a Randomized Trial

Recent evidence suggests that indirect verbal exposure to traumatic events can be sufficient to cause intrusions and other posttraumatic stress symptoms. In this study, we used a verbal trauma report to experimentally induce intrusions and a tactile task to manipulate the putative processes underlying intrusion development. Our findings indicate that the verbal report indeed induced intrusive recall. Moreover, the verbal report induced negative mood, state anxiety, and state dissociation, with mood and state dissociation predicting intrusion development. Additionally, the tactile task interfered with intrusion formation as indicated by the primary diary measure, but not the retrospective self-report. However, these results await further replication as this and previous trials suffered from limited statistical power. The findings support the reports by trauma therapists who experience secondary traumatization. They also challenge the assumption that all intrusions develop bottom-up from low-level sensory input via sensory representations. Future studies should explore differential processes for intrusion development based on their modality.

A systematic review and meta-analysis of experimental methods for modulating intrusive memories following lab-analogue trauma exposure in non-clinical populations

Experiencing trauma leads to intrusive memories (IMs), a hallmark symptom of post-traumatic stress disorder (PTSD), which also occurs transdiagnostically. Understanding why IMs increase or decrease is pivotal in developing interventions to support mental health. In this preregistered meta-analysis (PROSPERO: CRD42021224835), we included 134 articles (131 techniques, 606 effect sizes and 12,074 non-clinical participants) to investigate how experimental techniques alter IM frequency, intrusion-related distress and symptoms arising from lab-analogue trauma exposure. Eligible articles were identified by searching eight databases until 12 December 2023. To test potential publication biases, we employed methods including Egger's test and three-parameter selection models. We employed three-level multilevel modelling and meta-regressions to examine whether and how experimental techniques would modulate IM frequency and associated outcomes. Results showed that techniques (behavioural, pharmacological, neuromodulation) significantly reduced intrusion frequency (g = 0.16, 95% confidence interval [0.09, 0.23]). Notably, techniques aimed to reduce IMs also ameliorated intrusion-related distress and symptoms, while techniques that increased IMs exacerbated these related outcomes, thus highlighting IM's centrality in PTSD-like symptoms. Techniques tapping into mental imagery processing (for example, trauma reminder followed by playing Tetris) reduced intrusions when administered immediately after, or at a delayed time after trauma. Although our meta-analysis is limited to symptoms induced by lab-analogue trauma exposure, some lab-based results have now generalized to real-world trauma and IMs, highlighting the promising utility of lab-analogue trauma paradigms for intervention development.

Imagery rescripting: The value of an added positive emotion component

BACKGROUND AND OBJECTIVES

Imagery Rescripting (ImRs) aims to reduce trauma-related negative emotions and intrusions. Positive emotions during ImRs may aid coping with the consequences of trauma, but protocols vary in the extent to which they explicitly target such positive emotions. We used a multiple-day design with a trauma film paradigm to investigate whether adding an explicit positive emotion component to ImRs improved intervention effects in a non-clinical sample. In addition, we explored potentially differential effects on high, medium, and low arousal positive affect.

METHODS

Participants (n = 105) were randomly assigned to either a standard ImRs condition, to an ImRs condition with an added explicit positive emotion component targeting joy (ImRs+), or to a non-intervention control (NIC) condition. Participants watched a trauma film on day 1, received the condition-specific intervention on day 2, and completed additional post-assessments of positive and negative affect on day 3. In addition, participants recorded intrusions from the trauma film from day 1 until day 3.

RESULTS

Compared to standard ImRs and NIC, ImRs + significantly increased positive affect. Exploratory analyses showed that this increase concerned medium and high, but not low arousal positive affect. No significant between-group differences were found for negative affect and intrusion-related outcomes.

LIMITATIONS

Floor effects for intrusions and negative affect limited our ability to fully investigate the potential benefits of targeting positive affect.

CONCLUSIONS

Adding a positive emotion component to ImRs reliably improved positive affect. More research is needed to determine whether explicitly targeting positive affect improves efficacy of ImRs for intrusion-related outcomes.

How Making Consent Procedures More Interactive can Improve Informed Consent: An Experimental Study and Replication

Prospective research participants do not always retain information provided during consent procedures. This may be relatively common in online research and is considered particularly problematic when the research carries risks. Clinical psychology studies using the trauma film paradigm, which aims to elicit an emotional response, provide an example. In the two studies presented here, 112-126 participants were informed they would be taking part in an online study using a variant of this paradigm. The information was provided across five digital pages using either a standard or an interactive format. In both studies, compared to the control condition, participants in the interactive condition showed more retention of information. However, this was only found for information about which they had been previously asked via the interactive format. Therefore, the impact of adding interactivity to digital study information was limited. True informed consent for an online study may require additional measures.

Testing an Imagery Rescripting Exercise Targeting Fear of Self

A feared possible self refers to the unwanted characteristics that a person may possess or develop. We tested an experimental paradigm to target fear of possible self using imagery rescripting. A student sample (n = 91), with moderate obsessive-compulsive disorder symptoms, engaged in written and audio-guided exercises to evoke episodic future mental imagery that represented their feared possible self. Participants were then randomized between imagery rescripting or neutral imagery control tasks. The results revealed no difference between conditions in fear of self or general obsessional beliefs following the manipulation. State anxiety and the urge to neutralize the imagery reduced more in the control condition than in the rescripting condition. These findings suggest that the current paradigm is emotionally engaging but not effective at addressing fear of self as measured. Methodological improvements such as removing a written component of the rescripting task and idiosyncratic measuring of fear of self are proposed.

Imagery rescripting and extinction: Effects on US expectancy, US revaluation, and the generalization of fear reduction

Exposure therapy consists of exposing patients to their fears and thereby diminishing their harm expectancies (i.e., extinction or expectancy learning). Although effective for many anxiety patients, its long-term success depends on the generalization of these harm expectancies to other stimuli. However, research shows that this generalization of extinction is limited. Besides decreasing harm expectancies, fear reduction may also be achieved by changing the meaning of an aversive memory representation (US revaluation). Imagery rescripting (ImRs) may be more successful in generalizing fear reduction because it allegedly works through US revaluation. The current experiment aimed to test working mechanisms for ImRs and extinction (revaluation and expectancy learning, respectively), and to examine generalization of fear reduction. In a fear conditioning paradigm, 113 healthy participants watched an aversive film clip that was used as the US. The manipulation consisted of imagining a script with a positive ending to the film clip (ImRs-only), extinction (extinction-only), or both (ImRs + extinction). Results showed enhanced US revaluation in ImRs + extinction. US expectancy decreased more strongly in the extinction conditions. Generalization of fear reduction was found in all conditions. Our results suggest different working mechanisms for ImRs and exposure. Future research should replicate this in (sub)clinical samples.

Trauma film viewing and intrusive memories: Relationship between salivary alpha amylase, endocannabinoids, and cortisol

The endogenous cannabinoid (ECB) system is a small molecule lipid signalling system that is involved in stress response activation and is associated with PTSD, but it is unclear whether salivary ECBs are part of the sympathetic nervous system response to stress. We conducted an adapted trauma film paradigm, where participants completed a cold pressor test (or control) while watching a 10-minute trauma film. We also collected saliva and hair samples and tested them for ECBs, cortisol, and salivary alpha amylase (sAA). As hypothesised, there were significant positive correlations between sAA activity and salivary ECB levels, particularly 2-arachidonoyl glycerol (2-AG), though ECBs were not correlated with sAA stress reactivity. Participants who had a significant cortisol response to the trauma film/stressor reported less intrusive memories, which were also less distressing and less vivid. This effect was moderated by arachidonoyl ethanolamide (AEA), where decreases in AEA post-stress were associated with more intrusive memories in cortisol non-responders only. This study provides new evidence for the role of ECBs in the sympathetic nervous system.

Hitting the Rewind Button: Imagining Analogue Trauma Memories in Reverse Reduces Distressing Intrusions

Background

Intrusive re-experiencing of trauma is a core symptom of posttraumatic stress disorder. Intrusive re-experiencing could potentially be reduced by 'rewinding', a new treatment approach assumed to take advantage of reconsolidation-updating by mentally replaying trauma fast-backward.

Methods

The present analogue study was the first to investigate 'rewinding' in a controlled laboratory setting. First, 115 healthy women watched a highly aversive film and were instructed to report film-related intrusions during the following week. Twenty-four hours after film-viewing, participants reporting at least one intrusion (N = 81) were randomly allocated to an intervention (fast-backward, or fast-forward as active control condition) or a passive control condition. Intervention groups reactivated their trauma memory, followed by mentally replaying the aversive film either fast-backward or fast-forward repeatedly.

Results

Results indicate that replaying trauma fast-backward reduced intrusion load (intrusion frequency weighted for intrusion distress) compared to the passive group, whereas replaying fast-forward did not. No above-threshold differences between fast-backward and fast-forward emerged.

Conclusion

Present findings strengthen the view that 'rewinding' could be a promising intervention to reduce intrusions.

The effect of a visuospatial interference intervention on posttraumatic intrusions: a cross-over randomized controlled trial

Background: Intrusive memories form a core symptom of Posttraumatic Stress Disorder (PTSD). Based on concepts of visuospatial interference and memory-updating accounts, technological innovations aim to attenuate such intrusions using visuospatial interventions.Objective: This study aims to test the effect of a visuospatial Tetris-based intervention versus a verbal condition (Wiki) and a never-targeted control (no intervention) on intrusion frequency.Method: A randomized crossover trial was conducted including N = 38 PTSD patients who had at least 3 distinct intrusive memories of trauma. After both 2 weeks (intervention 1) and 4 weeks (intervention 2), one of the three memories was randomly selected and either the visuospatial intervention (memory reminder of a traumatic memory + Tetris) or verbal condition (reading a Wikipedia article + answering questions) was performed on their first memory in randomized order. In the week 4 session, the patient conducted the other intervention condition on their second memory (crossover). The third memory was never targeted (no intervention). Daily occurrence of intrusions over 8 weeks was collected using a diary and analysed using mixed Poisson regression models.Results: Overall, there was no significant reduction in intrusion frequency from either intervention compared to each other, and to no intervention control (relative risk Tetris/Wiki: 0.947; p = .31; relative risk no intervention/Tetris: 1.060; p = .15; relative risk no intervention/Wiki: 1.004; p = .92).Conclusions: There was no effect of either intervention on intrusions when administered in a crossover design where participants received both interventions. Design shortcomings and consequences for future studies are discussed.

Turning pain into strength: prosocial behaviours in coping with trauma

Background: Various coping strategies have been shown to alleviate the negative effects of trauma, yet the significance of prosocial behaviour in this realm has been notably underexplored. The present study explored the hypothesis that engaging in prosocial behaviour mitigates the impacts of trauma by promoting a sense of competence and relatedness, post-traumatic growth (PTG), and reconstruction of meaning.Methods: Three consecutive studies were conducted with college students to compare differences in consequence of prosocial behaviours between a trauma group and a control group. Study 1 (N = 96) used self-reported experiences of traumatic vs non-traumatic events; Study 2 (N = 43) used exposure vs. no exposure to video of an earthquake; Study 3 (N = 20) used a randomized controlled trial (RCT) of a prosocial-themed intervention vs. no intervention. Outcomes in all studies were assessed by self-report questionnaires.Results: Trauma damaged participants' sense of competence and meaningfulness. Prosocial behaviour relieved the impact of trauma on meaning, specifically manifested in the individuals' sense of meaningfulness and their search for meaning. Group interventions with a prosocial theme (based on effect size results) reduced post-traumatic stress disorder (PTSD) and enhanced PTG in victims. The promoting effect on PTG persisted a month later, and its enhancing effect on meaning manifested with a delay.Conclusion: Prosocial behaviour can potentially serve as a beneficial strategy for individuals coping with trauma because it helps enhance meaning and promotes PTG in victims. This conclusion is supported by laboratory experiments and a tentative small-scale intervention study, which provide an innovative perspective for future trauma interventions.

When does imagery rescripting become a double-edged sword? - Investigating the risk of memory distortion through imagery rescripting in an online Trauma film study

Imagery Rescripting (ImRs) has proven effective in reducing involuntary emotional memories. However, it is unclear whether and when it may lead to reduced accuracy of voluntary memory. Although previous analogue studies suggest that ImRs does not pose a general risk regarding memory distortion, it can not be ruled out that ImRs could cause memory impairment under certain risk conditions. In our three-day online trauma film study we investigated in a healthy sample (N = 267) whether specific instructions during ImRs as typically provided in clinical practice (i.e., detailed imagery with a sensory focus) increase the risk of memory distortions. Additionally, we examined whether the completeness of the original memory moderates these instruction effects. Contrary to our expectations, a sensory focus during ImRs was associated with higher memory accuracy in a recognition task, independently of the quality of the original memory. These results extend previous findings by suggesting that ImRs does not even impair memory performance when the quality of the original memory is poor and when the production of sensory-rich images is specifically encouraged. Our results question current practices employed to assess witness statement credibility, which are partly based on concerns that trauma-focused interventions like ImRs undermine memory accuracy.

The effectiveness of two novel approaches to prevent intrusions: A pilot study comparing Tetris_dualtask and imagery rescripting to control

BACKGROUND AND OBJECTIVES

Post-traumatic stress disorder (PTSD) is a global health problem. Although effective treatments for it exist, early interventions that prevent PTSD from developing are lacking. The aim of this pilot analogue trauma study was to compare the effects of two potential early intervention strategies, namely Tetris_dualtask and imagery rescripting (IR) to a no-intervention control group on intrusion frequency and the vividness and emotionality of aversive film memory.

METHODS

Sixty healthy students were subjected to the trauma film paradigm and randomly allocated to either: Tetris_dualtask, IR or no-intervention. Main outcomes were the number of film-related intrusions at one week and vividness and emotionality ratings of the most aversive film memory. Secondary outcomes were PTSD-like symptoms, intrusion intensity, and explicit film memory.

RESULTS

The Tetris_dualtask group reported significant fewer intrusions compared to the no-intervention group; whereas the IR group did not. No effect was found on vividness and emotionality ratings, PTSD-like symptoms, intrusion intensity, and explicit memory.

LIMITATIONS

The sample size was small, and analogue trauma in healthy individuals was examined, thus generalizability may be limited. Also, to increase comparability between interventions, the duration of Tetris_dualtask and IR was standardized. As a result, the IR intervention was shorter compared to other studies, which might have decreased its efficacy.

CONCLUSIONS

The results of this pilot study suggest that playing Tetris during retrieval of traumatic images, might hold potential as an early intervention strategy to reduce intrusions in the early aftermath of trauma and adversity. However, future large-scale replication research is needed.

Social evaluative stress enhances central detail memory, reduces false memory, and results in intrusive memories that last for days

Few studies have quantified what an individual remembers about a laboratory-controlled stressor. Here, we aimed to replicate previous work by using a modified version of the Trier Social Stress Test (TSST) to quantify participant memory for a stressful experience. We also aimed to extend this work by quantifying false and intrusive memories that ensued. One hundred and seven participants were exposed to the TSST (stress) or the friendly TSST (f-TSST; no stress). The TSST required participants to deliver a ten-minute speech in front of two laboratory panel members as part of a mock job interview; the f-TSST required participants to casually converse with the panel members about their interests. In both conditions, the panel members interacted with (central) or did not interact with (peripheral) several objects sitting on a desk in front of them. The next day, participants' memory for the objects was assessed with recall and recognition tests. We also quantified participants' intrusive memories on Days 2, 4, 6, and 8. Stressed participants recalled more central objects and exhibited greater recognition memory, particularly for central objects, than controls. Stress also led to less false recall and more intrusive memories on Days 2 and 4. Consistent with previous work, these findings suggest that participants exhibit enhanced memory for the central details of a stressful experience; they also extend prior work by showing that participants exposed to a stressor have less false memories and experience intrusive memories for several days following the event. The modified TSST paradigm used here may be useful for researchers studying not only what participants remember about a stressful event but also their susceptibility to intrusive memory formation.

Exploring the 'mood congruency' hypothesis of attention allocation - An eye-tracking study

BACKGROUND

The 'mood-congruency' hypothesis of attention allocation postulates that individuals' current emotional states affect their attention allocation, such that mood-congruent stimuli take precedence over non-congruent ones. This hypothesis has been further suggested as an underlying mechanism of biased attention allocation in depression.

METHODS

The present research explored the mood-congruency hypothesis using a novel video-based mood elicitation procedure (MEP) and an established eye-tracking attention allocation assessment task, elaborating prior research in the field. Specifically, in Study 1 (n = 91), a video-based MEP was developed and rigorously validated. In study 2 (n = 60), participants' attention allocation to sad and happy face stimuli, each presented separately alongside neutral faces, was assessed before and after the video-based MEP, with happiness induced in one group (n = 30) while inducing sadness in the other (n = 30).

RESULTS

In Study 1, the MEP yielded the intended modification of participants' current mood states (eliciting either sadness or happiness). Study 2 showed that while the MEP modified mood in the intended direction in both groups, replicating the results of Study 1, corresponding changes in attention allocation did not ensue in either group. A Bayesian analysis of pre-to-post mood elicitation changes in attention allocation supported this null finding. Moreover, results revealed an attention bias to happy faces across both groups and assessment points, suggestive of a trait-like positive bias in attention allocation among non-selected participants.

CONCLUSION

Current results provide no evidence supporting the mood-congruency hypothesis, which suggests that (biased) attention allocation may be better conceptualized as a depressive trait, rather than a mood-congruent state.

Making sense of the cancer journey: Pediatric cancer survivors' and their parents' autobiographical memories

PURPOSE

Youth diagnosed with acute lymphoblastic leukemia (ALL) and their caregiver's experience a myriad of challenges in all domains of health that extend beyond treatment. Yet, little is known about how the cancer experience, and recollections associated with the experience, impact survivorship. We explored pediatric ALL survivors' and their caregivers' autobiographical memories of the cancer experience from diagnosis onwards.

METHODS

Survivors of ALL, and one of their caregivers, were recruited through a local clinic. Survivors and their caregivers completed a demographic survey and semi-structured, private, one-on-one interviews. Demographic information were analyzed using descriptive statistics. Interviews were transcribed verbatim and analyzed using reflexive thematic analysis at the level of the individual and dyad.

RESULTS

Insights from survivors (N = 19; Mage = 15.3 years) and their caregivers (n = 19; Mage = 45.4 years) were captured. Analyses generated two themes contingent on role (i.e., survivor or caregiver): (1) It is hard to recall my cancer experience and (2) We did as much as we could to manage our child's cancer experience and two unified themes (present in both survivors and their caregivers): (3) It took a village to get through the cancer experience and (4) The cancer diagnosis and experience has had a lasting impact.

CONCLUSIONS

Findings highlight the varied and long-lasting ways cancer impacts survivors of pediatric ALL and their caregivers. Survivors had difficultly remembering their experience or felt that information was withheld and were acutely aware of their caregiver's distress. Caregivers were cautious and intentionally limited the information they shared.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors desired to be included within, or told about, decisions related to their healthcare and were acutely aware of their caregiver's distress. Efforts should be made to communicate with survivors (from diagnosis onward) openly and to consider strategies to minimize the short- and long-term impacts of pediatric ALL among survivors and their caregivers.

An investigation of the mechanisms underlying the link between abstract reasoning and intrusive memories: A trauma analogue study

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

The aversiveness of intrusiveness: Evidence from involuntary musical imagery

OBJECTIVE

Intrusive thoughts are characterized by a sense of intrusiveness of foreign entry into cognition. While not always consisting of negative content, intrusive thoughts are almost solely investigated in that context. Involuntary Musical Imagery (INMI) offers a promising alternative, as it is a type of involuntary cognition that can be used to evaluate intrusiveness without negative content.

METHODS

In Study 1, 200 participants completed self-report questionnaires to assess several aspects of intrusiveness: meta-awareness, control, repetitiveness, frequency, and subjective experience of INMI. In Study 2, 203 participants completed self-report questionnaires to explore the clinical characteristics (depression, stress, anxiety, and rumination) which might mediate the connection between INMI frequency and INMI negative experience.

RESULTS

Study 1 revealed, through exploratory factor analysis, that intrusiveness shares variance with the negative experience of INMI but not with INMI frequency. In Study 2, ruminative thinking was found to mediate the relationship between frequent INMI and the negative experience of INMI.

CONCLUSION

These results suggest that INMI might be used to investigate intrusiveness in the lab without the potential confound of negative emotions. In addition, the results suggest that neither the content nor the frequency of intrusive thoughts can solely explain why these thoughts are aversive to some but not others. Ruminative style might be the missing link to explain how and why these intrusive thoughts become aversive and obsessive. In other words, we suggest that the cause for intrusiveness lies not in the thought or repetitiveness, but in the thinker.

Decontextualized fear memories? Stronger conditioned fear responses during extinction learning and extinction recall in a safe context predict the development of long-term analog intrusions

BACKGROUND

Difficulties in the context-dependent modulation of conditioned fear are known for posttraumatic stress disorder and may explain the occurrence of intrusive memories in safe contexts. The current study therefore investigated if reduced context-dependent modulation of conditioned fear and its underlying neural circuitry constitute risk factors for the development of analog intrusions in response to an experimental trauma.

METHODS

Eighty-five healthy women participated in the trauma film paradigm to investigate the development of analog intrusions as well as explicit memory for an experimental trauma after one week and three months, respectively. Before, participants underwent a context-dependent fear conditioning paradigm during functional magnetic resonance imaging with fear acquisition in context A and extinction training in context B on a first day, as well as extinction recall in context B and fear renewal in a novel context C one day later. Skin conductance responses (SCRs) and blood oxygen level dependent responses were main outcome measures.

RESULTS

In addition to stronger fear acquisition in context A, stronger conditioned fear responses in the safe context B, as indicated by stronger conditioned SCRs or stronger activation of fear expressing regions during extinction learning and recall, predicted the development of long-term analog intrusions.

CONCLUSIONS

Stronger fear responses in safe and danger contexts were risk factors for the development of long-term analog intrusions and point to decontextualized fear memories and difficulties in the context-dependent modulation of conditioned fear. Altered fear conditioning processes and reduced storage of contextual information may cause the occurrence of fear independent of context.

Psychophysiological reactions during the trauma-film paradigm and their predictive value for intrusions

Background: Adequate adaptation of the autonomic nervous system (ANS) is crucial in potentially life-threatening situations. The defence cascade provides a descriptive model of progressing dominant physiological reactions in such situations, including cardiovascular parameters and body mobility. The empirical evidence for this model is scarce, and the influence of physiological reactions in this model for predicting trauma-induced intrusions is unresolved.Objectives: Using a trauma-film paradigm, we aimed to test physiological reactions to a highly stressful film as an analogue to a traumatic event along the defence cascade model. We also aimed to examine the predictive power of physiological activity for subsequent intrusive symptoms.Method: Forty-seven healthy female participants watched a stressful and a neutral film in randomized order. Heart rate (HR), heart rate variability (HRV), and body sway were measured. Participants tracked frequency, distress, and quality of subsequent intrusions in a diary for 7 consecutive days.Results: For the stressful film, we observed an initial decrease in HR, followed by an increase, before the HR stabilized at a high level, which was not found during the neutral film. No differences in HRV were observed between the two films. Body sway and trembling frequency were heightened during the stressful film. Neither HR nor HRV predicted subsequent intrusions, whereas perceived distress during the stressful film did.Conclusions: Our results suggest that the physiological trauma-analogue response is characterized by an orientation response and subsequent hyperarousal, reaching a high physiological plateau. In contrast to the assumptions of the defence cascade model, the hyperarousal was not followed by downregulation. Potential explanations are discussed. For trauma-associated intrusions in the subsequent week, psychological distress during the film seems to be more important than physiological distress. Understanding the interaction between physiological and psychological responses during threat informs the study of ANS imbalances in mental disorders such as post-traumatic stress disorder.

Examining the role of trait anxiety and attentional bias to negative information in intrusion vulnerability following an emotionally negative event

BACKGROUND AND OBJECTIVES

Research shows that individuals with heightened trait anxiety are more likely to experience intrusions; however, the mechanism that accounts for this relationship is unclear. Two alternative hypotheses were tested to determine the nature of the associations between trait anxiety, attentional bias to negative information, and intrusion vulnerability.

METHODS

Intrusions were elicited using the trauma film paradigm, and post-event attentional bias to negative information was assessed using the dot-probe task. Participants then completed a week-long intrusions diary.

RESULTS

Results showed that attentional bias to negative information mediated the effect of heightened trait anxiety on elevated intrusion frequency. It was also revealed that heightened trait anxiety was associated with elevated intrusion-related distress, though attentional bias to negative information did not mediate this relationship.

LIMITATIONS

Our sample was comprised of undergraduate students who were not selected based on a previous pathology. Replication in clinical samples is warranted.

CONCLUSIONS

These findings provide new insight regarding individual differences in the experience of intrusions and suggest that both the frequency and distress associated with intrusions could represent clinical targets.

Effects of oral contraceptives on intrusive memories: a secondary analysis of two studies using the trauma film paradigm in healthy women

Background: Women are more likely to develop post-traumatic stress disorder (PTSD) than men. Recent research suggests an impact of oral contraceptive (OC) intake on PTSD and intrusive memories, a hallmark symptom of PTSD. Although a majority of women use OCs at some point in their lives, the effects on PTSD pathogenesis are only poorly understood.Objective: In the current paper, we aimed to investigate the impact of OC intake on the acquisition and consolidation of intrusive memories in healthy women after watching a trauma film paradigm.Methods: We performed a secondary analysis of a pooled dataset (N = 437) of two previously conducted and published studies investigating the effect of oxytocin on the development of intrusive memories.Results: Women taking OCs showed an attenuated decline of intrusive memories over time after having watched the trauma film compared to naturally cycling women (F(2.75, 1167) = 3.79, p = .03, η p 2  = .01).Conclusion: These findings indicate that the intake of OCs is associated with the development of intrusive memories after a trauma film paradigm. This indication emphasizes the need to further investigate the complex impact of OCs and gonadal hormones on fear learning processes and PTSD.

Effects of imagery rescripting and imaginal exposure on voluntary memory

Trauma-focused imagery-based interventions, such as Imagery Rescripting (ImRs) and Imaginal Exposure (ImE), are effective in reducing involuntary re-experiencing in PTSD. However, it has been suggested that they may impair voluntary memory. This study investigates whether ImRs and ImE distort voluntary memory of an analogue trauma. We presented a trauma film to N = 120 healthy participants (Session 1) and randomly allocated them to one of two intervention conditions (receiving one session of ImRs or ImE) or to a no-intervention control condition (NIC) afterwards (Session 2). Voluntary memory was assessed using a free recall (Sessions 2 and 3), and a cued recall as well as a recognition task (both Sessions 3 and 4). The ImRs and ImE groups did not differ from NIC in the cued recall task and the recognition task. However, ImE (compared to ImRs and NIC) led to an increase in correct reported details in the free recall. In sum, the current findings do not suggest that ImRs or ImE impair voluntary memory.

Context reexposure to bolster contextual dependency of emotional episodic memory

Contextual overgeneralization of emotional memory is a core aspect of anxiety disorders. Identifying methods to enhance contextual dependency of emotional memory is therefore of significant clinical interest. Animal research points to a promising approach: reexposure to the context in which fear is acquired reduces generalization to other contexts. However, the exact conditions for this effect are unknown, complicating translation to effective interventions. Most notably, exposure to a context that resembles-but is not identical to-the learning context may diminish contextual dependency of memory by integration of additional contextual cues. Here, we therefore assessed in a large-scale study (N = 180) whether context reexposure enhances contextual dependency of emotional episodic memory whereas exposure to a similar context impairs it. We also tested whether relatively strong memory retrieval during context (re)exposure amplifies these effects. We replicated prior research showing that correct recognition depends on context and contextual dependency is lower for emotional than neutral memories. However, exposure to the encoding context or a similar context did not affect contextual dependency of memory, and retrieval strength did not interact with such effects. Thorough insight into factors underlying the effects of context (re)exposure on contextual dependency seems key to eventually attain a memory recontextualization intervention.

Reading others' social appraisals after viewing an aversive film online impacts mood but not intrusive memories

Exposure to aversive footage online can affect our well-being, but to what extent does reading others' appraisals of this content modulate our affective responses? In a pre-registered online study (N = 170), we used a digital trauma film paradigm as an analogue for the naturalistic exposure to aversive visual content online. We investigated whether online social reappraisal about the film influenced acute affective responses and subsequent intrusive memories. First, we examined whether the digital trauma film paradigm induced similar affective responses as in-lab experiments (within-subjects; change in negative mood and intrusive memories of the film during seven days). Participants reported a negative mood change and experienced intrusive memories of the film, extending findings from in-lab experiments. Next, we tested a social reappraisal manipulation that provides written comments from (fictitious) previous participants (between-subjects; reading positive, negative, or no comments) modulated participants' affective responses. As predicted, relative to controls and negative comments, reading positive comments decreased negative mood. However, reading negative comments did not increase negative mood. Contrary to predictions, the social reappraisal manipulation did not modulate the number of intrusive memories. Findings suggest the benefit of positive social reappraisal for mitigating negative mood, but not intrusive memories following aversive film content online.

Challenging memories reduces intrusive memories and the memory amplification effect

This study scrutinizes the influence of attenuating beliefs about the veracity of traumatic experiences on the manifestation of intrusive recollections and the memory amplification effect. Participants were exposed to distress-inducing visual stimuli, subsequently rating their emotional status pre and post exposure. They engaged in a recognition task, identifying scenarios within the stimuli. Participants' recall was contested, casting doubt about the occurrence of certain scenes. Subsequently, they maintained a daily log of intrusive memories over a week. A second session reiterated the same process. This method effectively diminished the certainty in the participants' traumatic memories. Scenes whose occurrence was contested demonstrated a significant decline in both intrusive memories and memory amplification when juxtaposed with uncontested ones. Interestingly, no significant correlation emerged between the diminished belief in traumatic incidents and reductions in intrusive memory or memory amplification. Thus, this study advocates that interrogating the veracity of traumatic recollections can mitigate the prevalence of intrusive memories and the memory amplification effect, suggesting a novel potential therapeutic approach for trauma-related disorders.

To sleep or not to sleep, that is the question: A systematic review and meta-analysis on the effect of post-trauma sleep on intrusive memories of analog trauma

Distressing intrusive memories of a traumatic event are one of the hallmark symptoms of posttraumatic stress disorder. Thus, it is crucial to identify early interventions that prevent the occurrence of intrusive memories. Both, sleep and sleep deprivation have been discussed as such interventions, yet previous studies yielded contradicting effects. Our systematic review aims at evaluating existing evidence by means of traditional and individual participant data (IPD) meta-analyses to overcome power issues of sleep research. Until May 16th, 2022, six databases were searched for experimental analog studies examining the effect of post-trauma sleep versus wakefulness on intrusive memories. Nine studies were included in our traditional meta-analysis (8 in the IPD meta-analysis). Our analysis provided evidence for a small effect favoring sleep over wakefulness, log-ROM = 0.25, p < .001, suggesting that sleep is associated with a lower number of intrusions but unrelated to the occurrence of any versus no intrusions. We found no evidence for an effect of sleep on intrusion distress. Heterogeneity was low and certainty of evidence for our primary analysis was moderate. Our findings suggest that post-trauma sleep has the potential to be protective by reducing intrusion frequency. More research is needed to determine the impact following real-world trauma and the potential clinical significance.

The dilemma of trauma-focused therapy: effects of imagery rescripting on voluntary memory

Trauma-focused imagery-based interventions are suspected to alter or even distort declarative voluntary memory of a traumatic event, especially if they involve the active modification of imagery, e.g., as used in imagery rescripting (ImRs). However, systematic research is lacking so far. To investigate whether ImRs modifies voluntary memory of a standardized autobiographical aversive event (Trier Social Stress Test) (Session 1), healthy participants (N = 100) were randomly assigned to either an intervention condition receiving one session of ImRs or to a no-intervention control condition (NIC) (Session 2). Voluntary memory was examined using a free recall (Sessions 2 and 3) and a cued recall (Sessions 3 and 4). Although voluntary memory tended to deteriorate over time, contrary to expectations, this effect was not associated with ImRs. Remarkably, the number of correct details in free recall even improved in ImRs but not in NIC. This challenges the view that ImRs alters voluntary memory.

Challenges and considerations for treating PTSD with medicinal cannabis: the Australian clinician's perspective

INTRODUCTION

Preclinical and experimental research have provided promising evidence that medicinal cannabis may be efficacious in the treatment of posttraumatic stress disorder (PTSD). However, implementation of medicinal cannabis into routine clinical therapies may not be straightforward.

AREAS COVERED

In this review, we describe some of the clinical, practical, and safety challenges that must be addressed for cannabis-based treatment of PTSD to be feasible in a real-world setting. These issues are especially prevalent if medicinal cannabis is to be combined with trauma-focused psychotherapy.

EXPERT OPINION

Future consideration of the clinical and practical considerations of cannabis use in PTSD therapy will be essential to both the efficacy and safety of the treatment protocols that are being developed. These issues include dose timing and titration, potential for addiction, product formulation, windows of intervention, and route of administration. In particular, exposure therapy for PTSD involves recall of intense emotions, and the interaction between cannabis use and reliving of trauma memories must be explored in terms of patient safety and impact on therapeutic outcomes.

Effect of sleep manipulations on intrusive memories after exposure to an experimental analogue trauma: A meta-analytic review

Sleep plays an important role in memory processing and is disrupted in individuals with post-traumatic stress disorder (PTSD). A growing body of research has experimentally investigated how sleep - or lack thereof - in the early aftermath of a traumatic experience contributes to intrusive memory formation. The aim of this meta-analytic review was to examine the effects of various experimental sleep manipulations (e.g., sleep deprivation, daytime naps) on intrusive memories following exposure to an experimentally induced analogue traumatic event. Eight eligible studies were systematically identified through PsycInfo and PubMed and provided sufficient data to contribute to a meta-analysis of the effects of sleep versus wakefulness on intrusive memory frequency. Sleep was found to reduce intrusive memory frequency when compared to wakefulness at a small but significant effect size (Hedge's g = 0.29). There was no evidence of publication bias and heterogeneity of effect sizes across studies was moderate. Results suggest that sleep plays a protective role in the aftermath of exposure to a traumatic event with implications for early post-trauma intervention efforts.

Kindled emotions: Commemoration and the importance of meaning making, support and recognition

Commemorative events, organized in the aftermath of war or large-scale violence, can have an emotional impact on those who are attending. We examined several characteristics that might influence this impact. In a quasi-experimental pretest-posttest study, participants (n = 307) watched footage of the broadcast of the Dutch National Commemoration, in which World War II is remembered. A control group of 48 participants watched the commemoration broadcast live on Remembrance Day. They were matched for age, gender, war experience and migration background with 48 participants from the study group who watched the footage, to conduct a comparability check. We found some evidence that watching the footage was comparable to watching the commemoration live on Remembrance Day in terms of emotional response and experience of psychosocial factors. Participants in the footage sample (n = 307) responded with an increase of negative and decrease of positive emotions. Individual characteristics were limitedly related to the emotional response; posttraumatic stress symptom severity predicted increased negative emotions. Experiencing meaning making, support and, to a lesser extent, recognition through commemorating was related to experiencing more positive emotions. The findings indicate these psychosocial factors may buffer the emotional distress elicited by commemoration and contribute to important cognitive and social benefits. Practical implications are discussed.

Bilateral eye movements disrupt the involuntary perceptual representation of trauma-related memories

Bilateral eye movement (EM) is a critical component in eye movement desensitization and reprocessing (EMDR), an effective treatment for post-traumatic stress disorder. However, the role of bilateral EM in alleviating trauma-related symptoms is unclear. Here we hypothesize that bilateral EM selectively disrupts the perceptual representation of traumatic memories. We used the trauma film paradigm as an analog for trauma experience. Nonclinical participants viewed trauma films followed by a bilateral EM intervention or a static Fixation period as a control. Perceptual and semantic memories for the film were assessed with different measures. Results showed a significant decrease in perceptual memory recognition shortly after the EM intervention and subsequently in the frequency and vividness of film-related memory intrusions across one week, relative to the Fixation condition. The EM intervention did not affect the explicit recognition of semantic memories, suggesting a dissociation between perceptual and semantic memory disruption. Furthermore, the EM intervention effectively reduced psychophysiological affective responses, including the skin conductance response and pupil size, to film scenes and subjective affective ratings of film-related intrusions. Together, bilateral EMs effectively reduce the perceptual representation and affective response of trauma-related memories. Further theoretical developments are needed to elucidate the mechanism of bilateral EMs in trauma treatment.

Multisensory processing of emotional cues predicts intrusive memories after virtual reality trauma

Research has shown that high trait anxiety can alter multisensory processing of threat cues (by amplifying integration of angry faces and voices); however, it remains unknown whether differences in multisensory processing play a role in the psychological response to trauma. This study examined the relationship between multisensory emotion processing and intrusive memories over seven days following exposure to an analogue trauma in a sample of 55 healthy young adults. We used an adapted version of the trauma film paradigm, where scenes showing a car accident trauma were presented using virtual reality, rather than a conventional 2D film. Multisensory processing was assessed prior to the trauma simulation using a forced choice emotion recognition paradigm with happy, sad and angry voice-only, face-only, audiovisual congruent (face and voice expressed matching emotions) and audiovisual incongruent expressions (face and voice expressed different emotions). We found that increased accuracy in recognising anger (but not happiness and sadness) in the audiovisual condition relative to the voice- and face-only conditions was associated with more intrusions following VR trauma. Despite previous results linking trait anxiety and intrusion development, no significant influence of trait anxiety on intrusion frequency was observed. Enhanced integration of threat-related information (i.e. angry faces and voices) could lead to overly threatening appraisals of stressful life events and result in greater intrusion development after trauma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10055-023-00784-1.

Investigating features that contribute to evaluations of intrusiveness for thoughts and memories

What makes a thought feel intrusive? One possibility is that traumatic experiences are the primary cause of intrusive thoughts and memories. Another possibility is that experiences of intrusiveness arise from the features involved with re-experiencing. We investigated several features that may lead a thought to feel intrusive: task-congruence, repetition, and affective content. In Experiment 1, participants listened to popular song clips expected to become stuck in one's head. In Experiment 2, participants were cued to recall their own autobiographical memories. We found that both songs and autobiographical memories replaying mentally felt more intrusive when they were incongruent with the current task, cued repeatedly, and had negative emotional content. Additionally, even liked songs and positive autobiographical memories were evaluated as highly intrusive under some conditions. Based on these findings, we argue that intrusiveness is not limited to traumatic thoughts, but rather is a context-dependent evaluation influenced by a variety of features.

A systematic review and meta-analysis of the effect of cognitive interventions to prevent intrusive memories using the trauma film paradigm

There is an unmet need for effective early interventions that can relieve initial trauma symptoms and reduce symptoms of posttraumatic stress disorder (PTSD). We evaluated the efficacy of cognitive interventions compared to control in reducing intrusion frequency and PTSD symptoms in healthy individuals using the trauma film paradigm, in which participants view a film with aversive content as an experimental analogue of trauma exposure. A systematic literature search identified 41 experiments of different cognitive interventions targeting intrusions. In the meta-analysis, the pooled effect size of 52 comparisons comparing cognitive interventions to no-intervention controls on intrusions was moderate (g = -0.46, 95% CI [-0.61 to -0.32], p < .001). The pooled effect size of 16 comparisons on PTSD symptoms was also moderate (g = -0.31, 95% CI [-0.46 to -0.17], p < .001). Both visuospatial interference and imagery rescripting tasks were associated with significantly fewer intrusions than controls, whereas verbal interference and meta-cognitive processing tasks showed nonsignificant effect sizes. Interventions administered after viewing the trauma film showed significantly fewer intrusions than controls, whereas interventions administered during film viewing did not. No experiments had low risk of bias (ROB), 37 experiments had some concerns of ROB, while the remaining four experiments had high ROB. To the best of our knowledge, this is the first meta-analysis investigating the efficacy of cognitive interventions targeting intrusions in non-clinical samples. Results seem to be in favour of visuospatial interference tasks rather than verbal tasks. More research is needed to develop an evidence base on the efficacy of various cognitive interventions and test their clinical translation to reduce intrusive memories of real trauma.

Using a daily diary for monitoring intrusive memories of trauma: A translational data synthesis study exploring convergent validity

OBJECTIVE

Intrusive memories are a core feature of posttraumatic stress disorder and have transdiagnostic relevance across mental disorders. Establishing flexible methods to monitor intrusions, including patterns and characteristics, is a key challenge. A daily diary has been developed in experimental settings to provide symptom count data, without the need for retrospective self-report over extended time periods (e.g., 1 week, 1 month). We conducted an exploratory, pre-registered data synthesis investigating convergence between the diary and questionnaire measures of intrusive symptoms long used in clinical practice (Impact of Event Scale, IES, and revised version, IES-R, Intrusion subscale).

RESULTS

Utilising datasets using the daily diary from 11 studies (4 real-world trauma studies, seven analogue trauma studies; total N = 578), we found significant positive associations between the diary and IES/IES-R Intrusion subscale. Exploratory analyses indicated that the magnitude of this association was stronger for the IES (vs. the IES-R), and in individuals with real-world (vs. analogue) trauma.

CONCLUSION

This study provides first evidence of convergent validity of a daily diary for monitoring intrusions with a widely used questionnaire. A diary may be a more flexible methodology to obtain information about intrusions (frequency, characteristics, triggers, content), relative to questionnaires which rely on retrospective reporting of symptoms over extended timeframes. We discuss potential benefits of daily monitoring of intrusions in clinical and research contexts.

Disgust and fear reactions uniquely affect intrusions and posttraumatic stress symptoms

Disgust reactions commonly occur during/following trauma and predict posttraumatic stress (PTS) symptoms. Yet, disgust is not mentioned in DSM-5 PTSD criteria. To investigate disgust's clinical significance in PTSD, we measured the relationship between disgust (and fear) reactions to a personal trauma, and problematic intrusion characteristics (e.g., distress) and intrusion symptom severity. We focused on intrusions because they are a transdiagnostic PTSD symptom, though we also measured overall PTS symptoms to replicate prior work. Participants (N = 471) recalled their most traumatic/stressful event from the past six months. They then rated disgust and fear reactions to this event and completed the Posttraumatic Stress Disorder Checklist-5. Participants who had experienced intrusions about their event in the past month (n = 261) rated these intrusions on several characteristics (e.g., distress, vividness). We found stronger traumatic event-related disgust reactions were associated with more problematic intrusion characteristics, higher intrusion symptom severity, and higher overall PTS symptom severity. Notably, disgust reactions uniquely predicted these variables after statistically controlling for fear reactions. We conclude disgust reactions to trauma may be similarly pathological to fear reactions for intrusion and broader PTS symptoms. Therefore, PTSD diagnostic manuals and treatments should recognize disgust as a trauma-relevant emotion.

The effect of sleep on intrusive memories in daily life: a systematic review and meta-analysis of trauma film experiments

STUDY OBJECTIVES

To synthesize the literature on the effect of sleep versus wake on the frequency and distress of intrusive memories in everyday life after watching film clips with distressing content as a proxy for traumatic experiences.

METHODS

We conducted a systematic review by searching PubMed and PsychInfo. The last search was conducted on January 31, 2022. We included experimental studies comparing sleep and wake groups on intrusions using ecological diary methods, whereas studies lacking a wake control condition or relying solely on intrusion-triggering tasks or retrospective questionnaires were excluded. Meta-analyses were performed to evaluate the results. Risks of biases were assessed following the Cochrane guidelines.

RESULTS

Across 7 effect sizes from 6 independent studies, sleep (n = 192), as compared to wake (n = 175), significantly reduced the number of intrusive memories (Hedges' g = -0.26, p = .04, 95% CI [-0.50, -0.01]), but not the distress associated with them (Hedges' g = -0.14, p = .25, 95% CI [-0.38, 0.10]).

CONCLUSIONS

Although the results suggest that sleep reduces the number of intrusions, there is a strong need for high-powered pre-registered studies to confirm this effect. Risks of biases in the reviewed work concern the selection of the reported results, measurement of the outcome, and failure to adhere to the intervention. Limitations with the current meta-analysis include the small number of studies, which comprised only English-language articles, and the fact that it was not pre-registered.