How eye movements in EMDR work: changes in memory vividness and emotionality

Can neutral episodic memories become emotional? Evidence from facial expressions and subjective feelings

Maladaptive emotional memories are a transdiagnostic feature of mental health problems. Therefore, understanding whether and how emotional memories can change might help to prevent and treat mental disorders. We tested whether neutral memories of naturalistic events can retroactively acquire positive or negative affect, in a preregistered three-day Modification of Valence in Episodes (MOVIE) paradigm. On Day 1, participants (N = 41) encoded memories of neutral movie scenes, representing lifelike naturalistic experiences. On Day 2, they retrieved each episode before viewing a happy, sad, or neutral scene from the same movie (yielding a within-subjects design with a neutral-negative, neutral-positive, and neutral-neutral condition). On Day 3, participants again retrieved each memory from Day 1. We assessed the affective tone of episodes through facial expressions of positive and negative affect (using facial electromyography, fEMG) and through self-reported feelings. Positive updating of neutral episodes led to increased expressions of positive affect, whereas negative updating led to increased self-reported negative feelings. These results suggest that complex neutral episodic memories can retroactively acquire an affective tone, but the effects were modest and inconsistent across affect readouts. Future research should investigate alternative approaches to updating emotional memories that produce more profound changes in the valence of memories.

The working mechanisms of imagery rescripting and eye movement desensitization and reprocessing: Findings from a randomised controlled trial

We studied the mechanisms of eye movement desensitization and reprocessing (EMDR) and imagery rescripting (ImRs). We hypothesized that EMDR works via changes in memory vividness, that ImRs works via changes in encapsulated beliefs (EB), and that both treatments work via changes in memory distress. Patients (N = 155) with childhood-related posttraumatic stress disorder (Ch-PTSD) received 12 sessions of EMDR or ImRs. The vividness, distress, and EB related to the index trauma were measured with the Imagery Interview. PTSD severity was assessed with the Impact of Events Scale-Revised and the Clinician-Administered PTSD Scale for DSM-5. We conducted mixed regressions and Granger causality analyses. EMDR led to initially stronger changes in all predictors, but only for distress this was retained until the last assessment. No evidence for vividness as a predictive variable was found. However, changes in distress and EB predicted changes in PTSD severity during ImRs. These findings partially support the hypothesized mechanisms of ImRs, while no support was found for the hypothesized mechanisms of EMDR. Differences in the timing of addressing the index trauma during treatment and the timing of assessments could have influenced the findings. This study provides insight into the relative effectiveness and working mechanisms of these treatments.

Examining the roles of visual imagery and working memory in the retrieval of autobiographical memories using a dual-task paradigm

The retrieval of autobiographical memories involves the construction of mental representations of past personal events. Many researchers examining the processes underlying memory retrieval argue that visual imagery plays a fundamental role. Other researchers, however, have argued that working memory is an integral component involved in memory retrieval. The goal of this study was to resolve these conflicting arguments by comparing the relative contributions of visual imagery and working memory during the retrieval of autobiographical memories in a dual-task paradigm. While following a moving dot, viewing a dynamic visual noise (DVN), or viewing a blank screen, 95 participants recalled their memories and subsequently rated them on different memory characteristics. The results suggest that inhibiting visual imagery by having participants view DVN merely delayed memory retrieval but did not affect the phenomenological quality of the memories retrieved. Taxations to the working memory by having participants follow a moving dot, on the contrary, resulted in only longer retrieval latencies and no reductions in the specificity, vividness, or the emotional intensity of the memories retrieved. Whereas the role of visual imagery during retrieval is clear, future studies could further examine the role of working memory during retrieval by administering a task that is less difficult or by recruiting a larger sample than this study. The results of this study seem to suggest that both visual imagery and working memory play a role during the retrieval of autobiographical memory, but more research needs to be conducted to determine their exact roles.

Factors that contribute to an inability to remember an important aspect of a traumatic event

Dissociative amnesia is controversial. We tested other factors that could contribute to an inability to remember an important aspect of a traumatic event: how traumatic the event was, organic amnesia, dissociative state, childhood amnesia, expression suppression, sleep disturbance, repeated experiences, and ordinary forgetting. Trauma survivors who reported an inability to remember an important aspect of a traumatic event rated the event as traumatic as trauma survivors who reported no such inability to remember. Moreover, all cases of an inability to remember an important aspect of the traumatic event could be explained by at least one factor other than dissociative amnesia. These findings are contrary to dissociative amnesia. Compared to participants who reported no inability to remember an important aspect of the traumatic event, participants who did report an inability to remember were more likely to (1) have felt disconnected from their body during the traumatic event, which may have altered memory encoding, (2) have experienced sleep problems in the year after the traumatic event, which may have reduced memory consolidation, and (3) have experienced the traumatic event repeatedly, which may have led to less detailed memories. These findings have implications for the inclusion of dissociative amnesia in the DSM.

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.

Omitting continuous memory recall from dual-task interventions does not reduce intervention effectiveness

In Eye Movement Desensitization and Reprocessing a patient recalls a traumatic memory, while simultaneously performing a dual-task (e.g., making horizontal eye movements, tapping a pattern). Earlier lab studies show that increasing the load of a dual-task -and leaving fewer resources for memory recall-results in larger decreases in memory vividness and emotionality compared to control conditions. Therefore, we investigated whether it is necessary to continuously and deliberately recall the memory next to performing high taxing dual-tasks. In two online experiments, participants (N = 172, N = 198) recalled a negative autobiographical memory and were randomly assigned to (1) Memory Recall + Dual-Tasks, (2) Dual-Tasks Only, or (3) No Intervention Control. The dual-tasks were complex pattern tapping and spelling out loud. Before and after the intervention the memory was rated on vividness, emotionality, and accessibility. High taxing dual-tasks, regardless of whether there was continuous memory recall, resulted in the largest reductions in all dependent variables compared to control. Unexpectedly, there was no evidence that the addition of continuous memory recall added to these reductions. These results suggest that continuous memory recall might not, or only minimally be needed for the beneficial effects of the dual-task procedure in EMDR might not be beneficial per se. We discuss the necessity of memory (re)activation, alternative explanations, and implications for practice.

Game-matching background music has an add-on effect for reducing emotionality of traumatic memories during reconsolidation intervention

INTRODUCTION

Hospital is a stressful place of employment, and a high proportion of healthcare workers, especially the ICU (Intensive Care Unit) nurses were found to be at risk of PTSD. Previous studies showed that taxing working memory through visuospatial tasks during the reconsolidation process of aversive memories can reduce the number of intrusions afterwards. However, the finds could not be replicated by some researches, indicating there may be some boundary conditions that are subtle and complex.

METHODS

We performed a randomized controlled trial (ChiCTR2200055921; URL: www.chictr.org.cn). In our study, a series of ICU nurses or probationers who performed a cardiopulmonary resuscitation (CPR) were enrolled and instructed to play a visuospatial music tapping game ("Ceaseless Music Note", CMN; Beijing Muyuan Technology Co., Ltd., Beijing, China) at the fourth day after CPR. The numbers of intrusions each day were recorded from the first to the seventh days (24 h×6 day), and the vividness and emotionality of CPR memories were rated at the 4th and 7th days. These parameters were compared between different groups (game with background sound; game with sound off; sound only; none).

RESULTS

The game-matching background music can have an add-on effect for single tapping game with no sound in reducing the emotionality of previous aversive memories.

DISCUSSION

We proposed that flow experience (the subjective experience of effortless attention, reduced self-awareness, and enjoyment, and may be induced by optimal skill-demands compatibility in challenging tasks) as a key boundary condition for successful reconsolidation intervention.

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn, identifier: ChiCTR2200055921.

Constant installation of present orientation and safety (CIPOS) - subjective and physiological effects of an ultrashort-term intervention combining both stabilizing and confrontational elements

Objectives

Constant Installation of Present Orientation and Safety (CIPOS) is a Eye Movements Desensitization and Reprocessing (EMDR)-derived technique, which is often used to prepare for the treatment of post-traumatic stress disorder (PTSD). It differs from the latter by involving cyclically recurring exercises in reorientation to the present, interspersed between brief periods of exposure to the traumatic material.While EMDR is well established as a therapeutic method, the efficacy and mechanisms of action of CIPOS have not been investigated so far. In this pilot study, an experimental setting was used to record the subjective and physiological effects of the CIPOS intervention compared to a control condition with pure mental exposition.

Methods

The study was performed on 30 healthy volunteers aged from 20 to 30 years. Distress was induced using audio files of subjectively stressful situations. Subjective distress was measured via the Subjective Units of Distress Scale (SUD), while physiological indicators (noise-induced startle reflex, skin conductance level) were used as measures for objective stress. For each condition, pre- and post-intervention comparisons were calculated.

Results

In both groups, startle reflex potentiation and mean skin conductance level significantly decreased. In the group with CIPOS intervention, but not in the control group, a significant decrease in the SUD value was found.

Conclusion and significance

The results show that the CIPOS technique is as effective as pure mental exposition in reducing physiological stress. In addition, a superiority in reducing subjective distress (indicating a simplified reassessment of the stressful material) was found compared to pure mental exposition. Possible explanations of these effects are discussed.

Boosting long-term effects of degraded memories via acute stress

Combining recall of an emotional memory with simultaneous horizontal eye movements (i.e., Recall + EM) reduces memory aversiveness. However, the long-term persistence of this effect is inconsistent across studies. Given that stress may aid in the consolidation of memories, we examined whether acute stress can boost the long-term effects of degraded memories. To test this, participants recalled two negative memories, which were assigned to a Recall + EM or Recall Only condition. Before and after each intervention they rated memory aversiveness (i.e., immediate effects) followed by a stress-induction or control procedure. After a 24h-period, participants rated each memory again (i.e., long-term effects). We found that Recall + EM produces immediate effects but that these effects dissolve over time. Moreover, acute stress did not boost potential long-term effects of Recall + EM. Degraded memories were not retained better by applying stress. We discuss these results and how long-term effectiveness may still be achieved.

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We examined whether stress boosts the long-term effects of degraded memories.

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Dual-task interventions robustly produce immediate memory degrading effects.

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Immediate memory degrading effects dissolve over time (24h later).

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The stress manipulation increased cardiovascular/neuroendocrine stress responses.

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Acute stress did not boost potential long-term effects of dual-task interventions.

No evidence for disruption of reconsolidation of conditioned threat memories with a cognitively demanding intervention

Simultaneous execution of memory retrieval and cognitively demanding interventions alter the subjective experience of aversive memories. This principle can be used in treatment to target traumatic memories. An often-used interpretation is that cognitive demand interferes with memory reconsolidation. Laboratory models applying this technique often do not meet some important procedural steps thought necessary to trigger reconsolidation. It remains therefore unclear whether cognitively demanding interventions can alter the reconsolidation process of aversive memories. Here, 78 (41 included) healthy participants completed an established 3-day threat conditioning paradigm. Two conditioned stimuli were paired with a shock (CS+ s) and one was not (CS-). The next day, one CS+ (CS+ R), but not the other (CS+), was presented as a reminder. After 10 min, participants performed a 2-back working memory task. On day three, we assessed retention. We found successful acquisition of conditioned threat and retention (CS+ s > CS-). However, SCRs to the CS+ R and the CS+ during retention did not significantly differ. Although threat conditioning was successful, the well-established cognitively demanding intervention did not alter the reconsolidation process of conditioned threat memories. These findings challenge current views on how cognitively demand may enhance psychotherapy-outcome.

A Systematic Review of Treatment Interventions for Individuals With Intellectual Disability and Trauma Symptoms: A Review of the Recent Literature

Individuals with intellectual disabilities (IDs) are at increased susceptibility to adverse life experiences and trauma sequelae. There is a disparate range of therapeutic interventions for post-traumatic stress disorder (PTSD) and associated symptoms. This systematic review aimed to appraise the effectiveness of both cognitive behavioral therapy (CBT) and eye movement desensitization and reprocessing (EMDR) for PTSD and associated symptoms for both adults and children with mild, moderate, or severe intellectual delay. A systematic search, in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, of the PsychInfo, PubMed, Cochrane Database of Systematic Reviews, and MEDLINE databases were performed, and all relevant articles published between 2010 and March 2020 were included. A total of 11 articles were included, eight that focused on EMDR and three on CBT. The methodological quality of many of these articles was generally weak. Tentative findings suggest that EMDR and CBT are both acceptable and feasible treatment options among adults and children with varying levels of intellectual delay, but no firm conclusions can be drawn regarding effectiveness due to small sample sizes, lack of standardized assessment, and a paucity of methodological rigorous treatment designs. This review highlights the continued use of therapeutic approaches with clients presenting with IDs and PTSD. It adds to the extant literature by providing an expansive and broad overview of the current effectiveness of both EMDR and CBT. Further high-quality research is needed to provide more conclusive findings regarding treatment effectiveness and modifications to treatment needed with this population.

The effect of twice-weekly versus once-weekly sessions of either imagery rescripting or eye movement desensitization and reprocessing for adults with PTSD from childhood trauma (IREM-Freq): a study protocol for an international randomized clinical trial

Background

Trauma-focused treatments for posttraumatic stress disorder (PTSD) are commonly delivered either once or twice a week. Initial evidence suggests that session frequency affects treatment response, but very few trials have investigated the effect of session frequency. The present study’s aim is to compare treatment outcomes of twice-weekly versus once-weekly sessions of two treatments for PTSD related to childhood trauma, imagery rescripting (ImRs) and eye movement desensitization and reprocessing (EMDR). We hypothesize that both treatments will be more effective when delivered twice than once a week. How session frequency impacts treatment response, whether treatment type moderates the frequency effect, and which treatment type and frequency works best for whom will also be investigated.

Methods

The IREM-Freq trial is an international multicenter randomized clinical trial conducted in mental healthcare centers across Australia, Germany, and the Netherlands. We aim to recruit 220 participants, who will be randomized to one of four conditions: (1) EMDR once a week, (2) EMDR twice a week, (3) ImRs once a week, or (4) ImRs twice a week. Treatment consists of 12 sessions. Data are collected at baseline until one-year follow-up. The primary outcome measure is clinician-rated PTSD symptom severity. Secondary outcome measures include self-reported PTSD symptom severity, complex PTSD symptoms, trauma-related cognitions and emotions, depressive symptoms, dissociation, quality of life, and functioning. Process measures include memory, learning, therapeutic alliance, motivation, reluctance, and avoidance. Additional investigations will focus on predictors of treatment outcome and PTSD severity, change mechanisms of EMDR and ImRs, the role of emotions, cognitions, and memory, the optimization of treatment selection, learned helplessness, perspectives of patients and therapists, the network structure of PTSD symptoms, and sudden treatment gains.

Discussion

This study will extend our knowledge on trauma-focused treatments for PTSD related to childhood trauma and, more specifically, the importance of session frequency. More insight into the optimal session frequency could lead to improved treatment outcomes and less dropout, and in turn, to a reduction of healthcare costs. Moreover, the additional investigations will broaden our understanding of how the treatments work and variables that affect treatment outcome.

Trial registration

Netherlands Trial Register NL6965, registered 25/04/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05712-9.

The effectiveness of dual-task interventions for modulating emotional memories in the laboratory: A meta-analysis

Dual-tasks (e.g., making horizontal eye-movements) while recollecting a memory are often used both in the lab and the clinic (such as in EMDR therapy) to attenuate emotional memories and intrusive mental images. According to working memory theory, dual-task interventions are effective because they limit cognitive resources available for the processing of emotional memories. However, there is still ongoing debate about the extent to which and under what conditions dual-task interventions are effective to interfere with emotional memories. In this meta-analysis, we assessed k = 53 laboratory studies investigating the effects of dual-task interventions on negative and positive memories. The effects were measured with the raw mean reduction in vividness and emotionality self-report ratings of emotional memories before compared to after the intervention on 100-point rating scales. Results showed that the dual-task interventions made both negative and positive memories less vivid (mean reduction negative images = 9.18, 95% CI [7.06, 11.29]; mean reduction positive images = 11.73, 95% CI [8.59, 14.86]) and less emotional (mean reduction negative images = 6.22, 95% CI [4.50, 7.94]; mean reduction positive images = 6.71, 95% CI [2.21, 11.20]). Several moderators were tested and are discussed in the light of working memory theory.

Differential Effects of Comorbid Psychiatric Disorders on Treatment Outcome in Posttraumatic Stress Disorder from Childhood Trauma

Patients with posttraumatic stress disorder (PTSD) frequently have comorbid diagnoses such as major depressive disorder (MDD) and anxiety disorders (AD). Studies into the impact of these comorbidities on the outcome of PTSD treatment have yielded mixed results. The different treatments investigated in these studies might explain the varied outcome. The purpose of this study was to examine the impact of these comorbidities on the outcome of two specific PTSD treatments. MDD and AD were analyzed as predictors and moderators in a trial comparing 12 sessions of either eye movement desensitization and reprocessing (EMDR) or imagery rescripting (IR) in 155 adult patients with PTSD from childhood trauma. The primary outcome was reduction of PTSD symptoms (clinician-administered PTSD Scale for DSM-5, CAPS-5) assessed at eight-week follow-up and a secondary outcome was self-report PTSD symptoms (Impact of Event Scale, IES-R). MDD was not a predictor of treatment outcome but did have a significant moderator effect. Patients with MDD showed a better outcome if they were treated with IR, whereas patients without MDD improved more in the EMDR condition. No impact of AD emerged. It seems essential to consider comorbid MDD when planning PTSD treatment to improve treatment outcomes. More research is needed to replicate our findings and focus on different kinds of PTSD treatments and other comorbidities.

Does an unconditioned stimulus memory devaluation procedure decrease disgust memories and conditioned disgust? Results of two laboratory studies

Research has demonstrated that disgust can be installed through classical conditioning by pairing neutral conditioned stimuli (CSs) with disgusting unconditioned stimuli (USs). Disgust has been argued to play an important role in maintaining fear-related disorders. This maintaining role may be explained by conditioned disgust being less sensitive to extinction (i.e., experiencing the CS in the absence of the US). Promising alternatives to extinction training are procedures that focus on the devaluation of US memory representations. In the current study, we investigated whether such devaluation procedures can be successful to counter conditioned disgust. We conducted two laboratory studies (N = 120 and N = 51) in which disgust was conditioned using audio-visual USs. Memory representations of the USs were devalued by having participants recall these USs while they performed a taxing eye-movement task or executed one of several control tasks. The results showed successful conditioned disgust acquisition. However, no strong evidence was obtained that an US memory devaluation procedure modulates disgust memory and diminishes conditioned disgust as indicated by subjective, behavioral, or psychophysiological measures. We discuss the relevance of our results for methodological improvements regarding US memory devaluation procedures and disgust conditioning.

Does valence contribute to the effects of dual tasking in aversive autobiographical memory? Some unexpected findings

BACKGROUND AND OBJECTIVES

Lab experiments show that engaging in a working memory task while recalling an aversive memory reduces emotionality and vividness of memories. Studies targeting lab induced negative memory with valenced secondary tasks show promise, but work is needed on autobiographical memories to make it more in line with the original dual tasking research and PTSD treatment in clinical populations. In this study, we address this gap by evaluating differential effectiveness of valenced dual tasks on emotionality and vividness of aversive autobiographical memories.

METHODS

University students (N = 178) recalled an aversive autobiographical memory while rating either positive pictures, negative pictures, or while looking at a cross in the exposure only condition. Participants were randomized to one of three aforementioned conditions and rated their memories before and after each intervention on emotionality and vividness.

RESULTS

Against expectations, memories became more emotional and vivid regardless of condition. With regard to vividness, this effect was characterized by an interaction effect: memories became more vivid in the exposure only condition than in the combined dual tasking conditions. All effect sizes were small.

LIMITATIONS

Working memory load in the dual tasking conditions might have been insufficient.

CONCLUSIONS

The current study did not extend findings with regard to (valenced) dual tasking and revealed a possible sensitization effect of script driven autobiographical memory induction. Our study highlights the importance of aspects such as the total amount of exposure and characteristics of memory induction, specifically the addition of a script driven approach to the usual self-initiated memory activation in dual tasking research.

Eye Movement Desensitization (EMD) to reduce posttraumatic stress disorder-related stress reactivity in Indonesia PTSD patients: a study protocol for a randomized controlled trial

Background

Posttraumatic stress disorder (PTSD) may develop after exposure to a traumatic event. Eye Movement Desensitization and Reprocessing (EMDR) is an evidence-based psychological treatment for PTSD. It is yet unclear whether eye movements also reduce stress reactivity in PTSD patients. This study aims to test whether eye movements, as provided during Eye Movement Desensitization (EMD), are more effective in reducing stress reactivity in PTSD patients as compared to a retrieval-only control condition.

Methods

The study includes participants who meet criteria of PTSD of the public psychological services in Jakarta and Bandung, Indonesia. One hundred and ten participants are randomly assigned to either an (1) Eye Movement Desensitization group (n = 55) or (2) retrieval-only control group (n = 55). Participants are assessed at baseline (T0), post-treatment (T1), 1 month (T2), and at 3 months follow-up (T3). Participants are exposed to a script-driven imagery procedure at T0 and T1. The primary outcome is heart rate variability (HRV) stress reactivity during script-driven imagery. Secondary outcomes include heart rate (HR), pre-ejection period (PEP), saliva cortisol levels, PTSD symptoms, neurocognitive functioning, symptoms of anxiety and depression, perceived stress level, and quality of life.

Discussion

If the EMD intervention is effective in reducing stress reactivity outcomes, this would give us more insight into the underlying mechanisms of EMDR’s effectiveness in PTSD symptom reduction.

Trial registration

ISRCTN registry ISRCTN55239132. Registered on 19 December 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05100-3.

Taxing working memory to modulate mental imagery of the 9/11 terrorist attacks following media exposure during childhood: a pilot study in young adult UK residents

BACKGROUND AND OBJECTIVES

Media trauma in civilians is linked to intrusive imagery-based memory symptoms. We investigated whether mental imagery of the 9/11 terrorist attacks following media exposure is dampened by taxing working memory (WM).

METHODS

Forty-five young adult UK residents, who were exposed to the 9/11 terrorist attacks as children via the media, identified a personally-relevant mental image of the attacks. They were then randomly allocated to: (1) recall + Tetris, (2) recall + eye movements (EMs), or (3) recall-only. Ratings on imagery vividness and emotionality were provided at three time points: pre-, post-manipulations, and at 24-hr follow-up.

RESULTS

Repeated measures ANOVAs revealed that recall + Tetris and recall + EMs (relative to recall-only) significantly reduced imagery vividness and emotionality from pre- to post-manipulations, but not to follow-up.

LIMITATIONS

A passive control group is needed to fully rule out the role of natural memory decay; the follow-up was exploratory and took place outside the laboratory with reduced experimental control.

CONCLUSIONS

Aversive memory imagery from media trauma in civilians can be dampened by taxing WM, at least temporarily, which could be therapeutically useful. The use of such cognitive techniques may also hold relevance for public health approaches to address the impact of collective trauma.

The messy landscape of eye movements and false memories

Eye-Movement Desensitisation and Reprocessing (EMDR) therapy is a common treatment for PTSD. However, skeptics like James Ost question the theoretical underpinnings, highlight inconsistency of empirical findings surrounding the efficacy of such therapy, and warn against unknown drawbacks. Little is known about the impact of the eye movements, a critical component in EMDR, on susceptibility to false memories, and the existing literature is contradictory. We review the literature and present new findings to help tell the story of the effects of eye movements on memory. Taken as a whole, this small body of work suggests that eye movements do not reliably affect susceptibility to misinformation, nor do they appear to enhance memory, but they do seem to increase spontaneous false memories.

Side effects of induced lateral eye movements during aversive ideation

BACKGROUND AND OBJECTIVES

Eye Movement Desensitization and Reprocessing (EMDR) is a treatment for posttraumatic stress disorder. It uses a dual-task approach, in which patients recall an aversive memory while making lateral eye movements. Research has shown that this 'eye movements' intervention reduces subjective memory vividness and emotionality. This study examined whether it also reduces memory accuracy on a visual discrimination task.

METHODS

Participants (68 undergraduates) underwent an aversive conditioning phase, in which two pictures of male faces were followed by shock. Then they recalled one face with (experimental condition) and one without (control condition) making lateral eye movements. Finally, they completed a stimulus discrimination test with slightly different faces shortly after the intervention and one day later.

RESULTS

Results showed that the eye movements intervention led to increased false-positive rates one day later.

LIMITATIONS

Our intervention targeted newly formed memory rather than consolidated memory.

CONCLUSIONS

The results inform theory about EMDR's mechanisms of change and suggest that the treatment may have side effects regarding memory accuracy.

Making eye movements during imaginal exposure leads to short-lived memory effects compared to imaginal exposure alone

BACKGROUND AND OBJECTIVES

A plethora of eye movement desensitization and reprocessing (EMDR) analogue studies has shown that, in the short term, making eye movements (EM) during brief imaginal exposure ("recall + EM") blurs memories more than just imaginal exposure ("recall only"). Yet, results of the few studies that included a follow-up test are inconsistent. We improved this paradigm's ecological validity by including an extended intervention phase and multiple assessments per phase. We hypothesized that recall + EM results in larger immediate and 24 h reductions in memory vividness, negative valence, and distress than recall alone. We explored the persistence of the effects, as well as the predictive value of memory characteristics and individual differences.

METHODS

Students (N = 100) selected a negative autobiographical memory and were randomized to recall + EM or recall alone; both interventions lasted 32 intervals of 24s. During the interventions they rated the memory after every four intervals.

RESULTS

After 4 × 24s intervention, recall + EM resulted in memory deflation, while recall only caused memory inflation. After the full intervention (i.e., 32 × 24s), both conditions resulted in immediate and 24 h reductions on all outcome measures. Crucially, memory effects in the recall + EM condition partially relapsed 24 h later, while the effects in the recall only condition persisted. Change patterns were hardly explained by predictive variables.

LIMITATIONS

We used a non-clinical sample; replication in clinical samples is warranted.

CONCLUSION

Making EM during imaginal exposure leads to short-lived effects compared to imaginal exposure alone. However, EM may offer a response aid for those who avoid imaginal exposure.

Arresting visuospatial stimulation is insufficient to disrupt analogue traumatic intrusions

Intrusive memories are a core symptom of Post-Traumatic Stress Disorder (PTSD). A growing body of analogue studies using trauma films suggest that carrying out specific demanding tasks (e.g., playing the video game Tetris, pattern tapping) after the analogue trauma can reduce intrusive memories. To examine the mechanism behind this effect, we tested whether mere engagement with attention-grabbing and interesting visual stimuli disrupts intrusive memories, and whether this depends on working memory resources and/or the concurrent activation of trauma film memories. In a total sample of 234 healthy participants, we compared no-task control conditions to a perceptual rating task with visually arresting video clips (i.e., non-emotional, complex, moving displays), to a less arresting task with non-moving, blurred pictures (Study 1), and to more demanding imagery tasks with and without repetitive reminders of the trauma film (Study 2). Generally, we found moderate to strong evidence that none of the conditions lead to differences in intrusion frequency. Moreover, our data suggest that intrusive memories were neither related to individual differences in working memory capacity (i.e., operation span performance; Study 1), nor to the degree of engagement with a visuospatial task (i.e., one-week recognition performance; Study 2). Taken together, our findings suggest that the boundary conditions for successful interference with traumatic intrusions may be more complex and subtle than assumed. Future studies may want to test the role of prediction errors during (re-)consolidation, deliberate efforts to suppress thoughts, or the compatibility of the task demands with the individual's skills.

No evidence for the inverted U-Curve: More demanding dual tasks cause stronger aversive memory degradation

BACKGROUND AND OBJECTIVES

Simultaneously making eye movements and recalling a memory leads to competition in working memory (WM), which reduces memory vividness and emotionality. The dose-response relationship between WM taxation and aversive memory degradation is predicted to be either linear (i.e., more cognitively demanding tasks exhibit stronger effects) or follow an inverted U-curve (i.e., there should not be too little, but also not too much taxation).

METHODS

Participants (N = 44) recalled four aversive autobiographical memories under four conditions that differed in WM taxation: complex, intermediate, simple, or no counting. Before and after each intervention, and at 24 h follow-up, participants recalled the aversive memory and rated it on vividness and unpleasantness. Using a Bayesian approach the linear and inverted U-shape relationships were directly compared.

RESULTS

Pretest to posttest drops in vividness and unpleasantness became larger with increased WM taxation of the counting conditions. There was no support for either hypotheses from pretest to follow-up for memory unpleasantness, whereas for memory vividness anecdotal evidence was found for a linear relationship.

LIMITATIONS

A reaction time (RT) task was used to select counting tasks of varying difficulties. However, the validity of this task appears to be compromised under very strenuous conditions. Higher levels of WM taxation might have been possible with more difficult counting tasks.

CONCLUSIONS

There is strong evidence for a linear dose-response relationship between WM taxation and memory degradation immediately after the intervention, and some unconvincing evidence for this pattern one day later. There was no evidence for an inverted U-curve.

Real vs. immersive-virtual emotional experience: Analysis of psycho-physiological patterns in a free exploration of an art museum

Virtual reality is a powerful tool in human behaviour research. However, few studies compare its capacity to evoke the same emotional responses as in real scenarios. This study investigates psycho-physiological patterns evoked during the free exploration of an art museum and the museum virtualized through a 3D immersive virtual environment (IVE). An exploratory study involving 60 participants was performed, recording electroencephalographic and electrocardiographic signals using wearable devices. The real vs. virtual psychological comparison was performed using self-assessment emotional response tests, whereas the physiological comparison was performed through Support Vector Machine algorithms, endowed with an effective feature selection procedure for a set of state-of-the-art metrics quantifying cardiovascular and brain linear and nonlinear dynamics. We included an initial calibration phase, using standardized 2D and 360° emotional stimuli, to increase the accuracy of the model. The self-assessments of the physical and virtual museum support the use of IVEs in emotion research. The 2-class (high/low) system accuracy was 71.52% and 77.08% along the arousal and valence dimension, respectively, in the physical museum, and 75.00% and 71.08% in the virtual museum. The previously presented 360° stimuli contributed to increasing the accuracy in the virtual museum. Also, the real vs. virtual classifier accuracy was 95.27%, using only EEG mean phase coherency features, which demonstrates the high involvement of brain synchronization in emotional virtual reality processes. These findings provide an important contribution at a methodological level and to scientific knowledge, which will effectively guide future emotion elicitation and recognition systems using virtual reality.

The effects of dual-tasks on intrusive memories following analogue trauma

Patients with post-traumatic stress disorder frequently and involuntarily experience intrusions, which are strongly linked to the trauma hotspot. Voluntary memory characteristics (i.e., vividness and unpleasantness) of this hotspot can be reduced by performing a dual-task, such as making horizontal eye movements, which is frequently used in Eye Movement Desensitization and Reprocessing. We tested whether such dual-task interventions would also reduce involuntary memory (i.e., intrusions). Moreover, we examined if changes in hotspot vividness and unpleasantness predicted intrusion frequency. Additionally, we examined whether the effects were dependent on dual-task modality. We tested this in three experiments. Participants watched a trauma film and performed one of the interventions 10-min post-film (1) Recall + Eye movements, (2) Recall + Counting, or (3) No-Task Control. Before and after the intervention, participants rated the hotspot vividness and unpleasantness. They recorded intrusive memories about the film in a diary for a week. Unexpectedly, we found that hotspot vividness and unpleasantness ratings were not affected by the intervention. However, the prolonged (experiment 2), but not standard (experiment 1), dual-task interventions resulted in a lower number of intrusions, regardless of modality. However, this effect was not replicated in experiment 3. We discuss potential explanations and present suggestions for future research.

Stochastic resonance as a proposed neurobiological model for Eye Movement Desensitization and Reprocessing (EMDR) therapy

EMDR therapy is recommended in several guidelines in the International field of psychological trauma. The dual attention stimuli/alternating bilateral stimulation (DAS/ABS) element of EMDR therapy has no proposed mechanism of action agreed upon, which explains the rapid shifts in cognitions and dysfunctional traumatic memory networks that are central to its observable efficacy. This paper discusses an innate, biological mechanism found in biological systems, including the human nervous system that may explain the efficacy of DAS/ABS. This mechanism is stochastic resonance (SR). SR is observed to make unintelligible, subthreshold signals intelligible and facilitates signal transmission. It provides a potential mechanism for discrimination and the selective focusing of attention, which are important factors in effective psychotherapy for the psychologically traumatised individual. The body/mind complex aims to achieve the functional encoding of memories in the neocortex and a key structural crossroads in this process is the thalamus. Activity in the thalamus is decreased in Post-Traumatic Stress Disorder (PTSD) compared to non-PTSD patients and a form of 'gating' is known to occur at the thalamic level. This 'gating' is adaptive and it is postulated to protect the higher neocortical systems in times of trauma. Although the model is initially somewhat counterintuitive, Stochastic Resonance; a form of random 'noise', can be considered 'helpful randomness' and when present in the thalamus SR can help filter and control sensitivity to incoming signals; helping to discriminate what is communicated. Naturally occurring SR is normally present as a result of descending cortico-thalamic activity, but appears attenuated as a result of exposure to trauma. The view of 'noise' in the current era of cell phones and High Definition is generally negative with science going to significant lengths to clean up signals: i.e. removing noise from them. We do not want white noise in our music or during our cell phone calls. However, some researchers invite us to consider that not all noise is bad and the downward cortico-thalamic 'noise' is an example of this category of 'helpful noise'. This paper will discuss the potential role of SR, as the mechanism by which DAS/ABS generates a random (stochastic) signal, facilitating a return to functional memory processing, where there is a lack of naturally occurring noise from the descending cortico-thalamic connections because of exposure to trauma. Modelling the mechanism as SR will facilitate further study into EMDR therapy and this will hopefully encourage perspicacity, where there has previously been derision.

Turning negative memories around: Contingency versus devaluation techniques

BACKGROUND AND OBJECTIVES

It is assumed that fear responses can be altered by changing the contingency between a conditioned stimulus (CS) and an unconditioned stimulus (US), or by devaluing the present mental representation of the US. The aim of the present study was to compare the efficacy of contingency- and devaluation-based intervention techniques on the diminishment in - and return of fear. We hypothesized that extinction (EXT, contingency-based) would outperform devaluation-based techniques regarding contingency measures, but that devaluation-based techniques would be most effective in reducing the mental representation of the US. Additionally, we expected that incorporations of the US during devaluation would result in less reinstatement of the US averseness.

METHODS

Healthy participants received a fear conditioning paradigm followed by one of three interventions: extinction (EXT, contingency-based), imagery rescripting (ImRs, devaluation-based) or eye movement desensitization and reprocessing (EMDR, devaluation-based). A reinstatement procedure and test followed the next day.

RESULTS

EXT was indeed most successful in diminishing contingency-based US expectancies and skin conductance responses (SCRs), but all interventions were equally successful in reducing the averseness of the mental US representation. After reinstatement EXT showed lowest expectancies and SCRs; no differences were observed between the conditions concerning the mental US representation.

LIMITATIONS

A partial reinforcement schedule was used, resulting in a vast amount of contingency unaware participants. Additionally, a non-clinical sample was used, which may limit the generalizability to clinical populations.

CONCLUSION

EXT is most effective in reducing conditioned fear responses.

How Does Eye Movement Desensitization and Reprocessing Therapy Work? A Systematic Review on Suggested Mechanisms of Action

Background: Eye movement desensitization and reprocessing [EMDR] is an innovative, evidence-based and effective psychotherapy for post-traumatic stress disorder [PTSD]. As with other psychotherapies, the effectiveness of EMDR contrasts with a limited knowledge of its underlying mechanism of action. In its relatively short life as a therapeutic option, EMDR has not been without controversy, in particular regarding the role of the bilateral stimulation as an active component of the therapy. The high prevalence of EMDR in clinical practice and the dramatic increase in EMDR research in recent years, with more than 26 randomized controlled trials published to date, highlight the need for a better understanding of its mechanism of action.

Methods: We conducted a thorough systematic search of studies published until January 2018, using PubMed, ScienceDirect, Web of Knowledge and Scopus databases that examined the mechanism of action of EMDR or provided conclusions within the framework of current theoretical models of EMDR functioning.

Results: Eighty-seven studies were selected for review and classified into three overarching models; (i) psychological models (ii) psychophysiological models and (iii) neurobiological models. The evidence available from each study was analyzed and discussed. Results demonstrated a reasonable empirical support for the working memory hypothesis and for the physiological changes associated with successful EMDR therapy. Recently, more sophisticated structural and functional neuroimaging studies using high resolution structural and temporal techniques are starting to provide preliminary evidence into the neuronal correlates before, during and after EMDR therapy.

Discussion: Despite the increasing number of studies that published in recent years, the research into the mechanisms underlying EMDR therapy is still in its infancy. Studies in well-defined clinical and non-clinical populations, larger sample sizes and tighter methodological control are further needed in order to establish firm conclusions.

Changing negative autobiographical memories in the lab: a comparison of three eye-movement tasks

There is strong evidence that executing eye-movement (EM) tasks that load working memory (WM) while thinking of an emotional memory reduces the emotionality and vividness of this memory. According to WM theory, EM tasks that load WM more should be more effective to devalue emotional memories. In this study, we compared three EM tasks: dot tracking, letter identification, and a combination of dot tracking and letter identification. First, participants completed a reaction time (RT) task to assess the WM load of the three EM tasks relative to a control task (viewing a black screen). Then, participants were asked to think of a negative autobiographical memory while executing one of these EM tasks and asked to recall another negative memory while executing the control task. Before and after each task, participants rated emotionality and vividness of the memory. All EM tasks slowed down RTs relative to the control task, and the letter identification task induced the largest RTs. Reductions of vividness relative to the control task, however, were comparable across the EM tasks, and there were no reliable reductions of emotionality. We discuss these findings in light of the WM theory and alternative theories for the effects of dual-task interventions.

The effect of bilateral eye-movements versus no eye-movements on sexual fantasies

BACKGROUND AND OBJECTIVES

Bilateral eye-movements (EMs) and visual mental imagery both require working memory resources. When performed together, they compete for these resources, which can cause various forms of mental imagery to become impaired (e.g., less vivid). This study aimed to examine whether EMs impair sexual fantasies (a form of mental imagery) in the same manner.

METHODS

Eighty undergraduates (40 males, 40 females) took part in four counterbalanced conditions: (1) EMs and an experience-based sexual fantasy; (2) EMs and an imagination-based sexual fantasy; (3) experience-based sexual fantasy only; and (4) imagination-based sexual fantasy only. In each condition, the vividness, emotionality, and arousability of the sexual fantasy were rated pre- and post-task. All three variables were predicted to decrease in the EM conditions.

RESULTS

Sexual fantasies were reported as less vivid, positive, and arousing after performing concurrent EMs relative to fantasising only, for both memory- and imagination-based sexual fantasies. There were no gender differences. Demand did not appear to account for the effects.

LIMITATIONS

Self-report measures were used rather than objective measures. Working memory taxation and capacity were not directly assessed. Also, negatively appraised sexual fantasies were not targeted and a 'no intervention' control was not included.

CONCLUSIONS

Bilateral EMs were effective at impairing the phenomenological properties of sexual mental imagery, extending the literature on EM effects. Given the potential clinical implications, future research should focus on validating and extending these results, for example, by targeting negatively appraised sexual fantasies (including problematic and offense-related) and incorporating a 'no intervention' condition.

Changes in brain connectivity following exposure to bilateral eye movements

The present research assessed how engaging in bilateral eye movements influences brain activity. Participants had their resting-state brain activity recorded with electroencephalography (EEG) before and after they performed 30 s of bilateral eye movements or a center-control manipulation. We assessed differences in change scores for absolute power and coherence between the eye-movement and center-control conditions. A main effect for handedness was present for EEG power in the theta and beta frequency bands, with inconsistent-handed participants displaying a greater increase than consistent-handed participants in both frequency bands. For theta, the increase in power for inconsistent handers was specific to participants in the bilateral eye-movement condition, whose increase in theta power exceeded the increase in theta power for consistent-handed participants regardless of condition. In contrast, for coherence, a main effect for condition was present for the delta frequency band, with participants in the control condition exhibiting a significant drop in posterior delta coherence pre to post. We suggest that the maintenance of posterior delta coherence over time may be an important factor in sustaining attention. Further, the malleability of EEG power for inconsistent-handed participants reveals the importance of individual-differences variables in the potential for behavioral manipulations to change brain activity.

Effects of heart rate variability biofeedback during exposure to fear-provoking stimuli within spider-fearful individuals: study protocol for a randomized controlled trial

Background

Specific phobias are among the most common anxiety disorders. Exposure therapy is the treatment of choice for specific phobias. However, not all patients respond equally well to it. Hence, current research focuses on therapeutic add-ons to increase and consolidate the effects of exposure therapy. One potential therapeutic add-on is biofeedback to increase heart rate variability (HRV). A recent meta-analysis shows beneficial effects of HRV biofeedback interventions on stress and anxiety symptoms. Therefore, the purpose of the current trial is to evaluate the effects of HRV biofeedback, which is practiced before and utilized during exposure, in spider-fearful individuals. Further, this trial is the first to differentiate between the effects of a HRV biofeedback intervention and those of a low-load working memory (WM) task.

Methods

Eighty spider-fearful individuals participate in the study. All participants receive a training session in which they practice two tasks (HRV biofeedback and a motor pseudo-biofeedback task or two motor pseudo-biofeedback tasks). Afterwards, they train both tasks at home for 6 days. One week later, during the exposure session, they watch 16 1-min spider video clips. Participants are divided into four groups: group 1 practices the HRV biofeedback and one motor pseudo-task before exposure and utilizes HRV biofeedback during exposure. Group 2 receives the same training, but continues the pseudo-biofeedback task during exposure. Group 3 practices two pseudo-biofeedback tasks and continues one of them during exposure. Group 4 trains in two pseudo-biofeedback tasks and has no additional task during exposure. The primary outcome is fear of spiders (measured by the Fear of Spiders Questionnaire and the Behavioral Approach Test). Secondary outcomes are physiological measures based on electrodermal activity, electrocardiogram and respiration.

Discussion

This RCT is the first one to investigate the effects of using a pre-trained HRV biofeedback during exposure in spider-fearful individuals. The study critically contrasts the effects of the biofeedback intervention with those of pseudo-tasks, which also require WM capacity, but which do not have a physiological base. If HRV biofeedback is effective in reducing fear of spiders, it would represent an easy-to-use tool to improve exposure-therapy outcomes.

Trial registration

Deutsches Register Klinischer Studien, DRKS00012278. Registered on 23 May 2017, amendment on 5 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2554-2) contains supplementary material, which is available to authorized users.

Development and testing of TraumaGameplay: an iterative experimental approach using the trauma film paradigm

Background: Vivid trauma-related intrusions are a hallmark symptom of posttraumatic stress disorder (PTSD), and may be involved in its onset. Effective interventions to reduce intrusions and to potentially prevent the onset of subsequent PTSD are scarce. Studies suggest that playing the videogame Tetris, shortly after watching aversive film clips, reduces subsequent intrusions. Other studies have shown that taxing working memory (WM) while retrieving an emotional memory reduces the memory's vividness and emotionality. Objective: We developed TraumaGameplay (TGP), a gaming app designed to reduce intrusions. This paper describes two successive experiments to determine whether playing TGP without memory retrieval (regular TGP) or TGP with memory retrieval (dual-task TGP) reduces intrusion frequency at one week compared to a no-game control. Method: For both experiments, healthy university students were recruited. Experiment 1: 92 participants were exposed to a trauma film and randomized to (1) regular TGP1 (n = 31), (2) dual-task TGP1 (n = 31) or (3) control (n = 30). In experiment 2, 120 healthy students were exposed to a trauma film and randomized to (1) regular TGP2 (n = 30), (2) dual-task TGP2 (n = 29), (3) recall only (n = 31) or (4) control (n = 30). Results: We found no significant difference between conditions on the number of intrusions for either playing regular TGP or dual-task TGP in both experiment 1 and experiment 2. Conclusion: Our results could not replicate earlier promising findings from preceding experimental research. Several reasons may underpin this difference ranging from the visuospatial videogame used in our experiments to the method of the experiment to the difficulties of replicability in general.

The Effects of β-Adrenergic Blockade on the Degrading Effects of Eye Movements on Negative Autobiographical Memories

BACKGROUND

Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. During EMDR, patients make horizontal eye movements (EMs) while simultaneously recalling a traumatic memory, which renders the memory less vivid and emotional when it is later recalled again. Recalling highly emotional autobiographical memories enhances noradrenergic neurotransmission. Noradrenaline (NA) strengthens memory (re)consolidation. However, memories become less vivid after recall+EMs. Therefore, NA might either play no significant role or serve to strengthen memories that are degraded by EMs. The present study was designed to test the latter hypothesis. We predicted that blocking NA would abolish the memory degrading effects of EMs.

METHODS

Fifty-six healthy participants selected three negative autobiographical memories. One was then recalled while making EMs, one was recalled without EMs, and one was not recalled. Vividness and emotionality of the memories as well as heart rate and skin conductance level during memory retrieval were measured before, directly after, and 24 hours after the EM task. Before the task, participants received a placebo or the noradrenergic β-receptor blocker propranolol (40 mg).

RESULTS

There were no effects of EMs on memory emotionality or psychophysiological measures in the propranolol and placebo groups. However, in the placebo group, but not in the propranolol group, memory vividness significantly decreased from pretest to posttest and follow-up after recall+EMs relative to the control conditions.

CONCLUSIONS

Blocking NA abolished the effects of EMs on the vividness of emotional memories, indicating that NA is crucial for EMDR effectiveness and possibly strengthens the reconsolidation of the degraded memory.

Bilateral Alternating Auditory Stimulations Facilitate Fear Extinction and Retrieval

Disruption of fear conditioning, its extinction and its retrieval are at the core of posttraumatic stress disorder (PTSD). Such deficits, especially fear extinction delay, disappear after alternating bilateral stimulations (BLS) during eye movement desensitization and reprocessing (EMDR) therapy. An animal model of fear recovery, based on auditory cued fear conditioning and extinction learning, recently showed that BLS facilitate fear extinction and fear extinction retrieval. Our goal was to determine if these previous results found in animals can be reproduced in humans. Twenty-two healthy participants took part in a classical fear conditioning, extinction, and extinction recall paradigm. Behavioral responses (fear expectations) as well as psychophysiological measures (skin conductance responses, SCRs) were recorded. The results showed a significant fear expectation decrease during fear extinction with BLS. Additionally, SCR for fear extinction retrieval were significantly lower with BLS. Our results demonstrate the importance of BLS to reduce negative emotions, and provide a successful model to further explore the neural mechanisms underlying the sole BLS effect in the EMDR.

Treatment of Intrusive Suicidal Imagery Using Eye Movements

Suicide and suicidal behavior are major public health concerns, and affect 3–9% of the population worldwide. Despite increased efforts for national suicide prevention strategies, there are still few effective interventions available for reducing suicide risk. In this article, we describe various theoretical approaches for suicide ideation and behavior, and propose to examine the possible effectiveness of a new and innovative preventive strategy. A model of suicidal intrusion (mental imagery related to suicide, also referred to as suicidal flash-forwards) is presented describing one of the assumed mechanisms in the etiology of suicide and the mechanism of therapeutic change. We provide a brief rationale for an Eye Movement Dual Task (EMDT) treatment for suicidal intrusions, describing techniques that can be used to target these suicidal mental images and thoughts to reduce overall behavior. Based on the available empirical evidence for the mechanisms of suicidal intrusions, this approach appears to be a promising new treatment to prevent suicidal behavior as it potentially targets one of the linking pins between suicidal ideation and suicidal actions.

Imagery rescripting and eye movement desensitisation and reprocessing for treatment of adults with childhood trauma-related post-traumatic stress disorder: IREM study design

BACKGROUND

Post-traumatic stress disorder (PTSD) that originates from childhood trauma experiences can develop into a chronic condition that has lasting effects on an individual's functioning and quality of life. While there are evidence-based guidelines for treating adult onset PTSD, treatments for adults with childhood trauma-related PTSD (Ch-PTSD) are varied and subject to ongoing debate. This study will test the effectiveness of two trauma-focused treatments, imagery rescripting (ImRs) and eye movement desensitisation and reprocessing (EMDR) in participants with Ch-PTSD. Both have been found effective in treatment of adult PTSD or mixed onset PTSD and previous research indicates they are well-tolerated treatments. However, we know less about their effectiveness for treating Ch-PTSD or their underlying working mechanisms.

METHODS

IREM is an international multicentre randomised controlled trial involving seven sites across Australia, Germany and the Netherlands. We aim to recruit 142 participants (minimum of n = 20 per site), who will be randomly assigned to treatment condition. Assessments will be conducted before treatment until 1-year follow-up. Assessments before and after the waitlist will assess change in time only. The primary outcome measure is change in PTSD symptom severity from pre-treatment to 8-weeks post-treatment. Secondary outcome measures include change in severity of depression, anger, trauma-related cognitions, guilt, shame, dissociation and quality of life. Underlying mechanisms of treatment will be assessed on changes in vividness, valence and encapsulated belief of a worst trauma memory. Additional sub-studies will include qualitative investigation of treatment experiences from the participant and therapists' perspective, changes in memory and the impact of treatment fidelity on outcome measures.

DISCUSSION

The primary aims of this study are to compare the effectiveness of EMDR and ImRs in treating Ch-PTSD and to investigate the underlying working mechanisms of the two treatments. The large-scale international design will make a significant contribution to our understanding of how these treatments address the needs of individuals with Ch-PTSD and therefore, potentially improve their effectiveness.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12614000750684 . Registered 16 July 2014.

Psychocutaneous disease: Pharmacotherapy and psychotherapy

Building a strong therapeutic alliance with the patient is of utmost importance in the management of psychocutaneous disease. Optimal management of psychocutaneous disease includes both pharmacotherapy and psychotherapy. This article reviews psychotropic medications currently used for psychocutaneous disease, including antidepressants, antipsychotics, mood stabilizers, and anxiolytics, with a discussion of relevant dosing regimens and adverse effects. Pruritus management is addressed. In addition, basic and complex forms of psychotherapy, such as cognitive-behavioral therapy and habit-reversal training, are described.

Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories?

Background: Eye movement desensitization and reprocessing (EMDR) is an effective psychological treatment for posttraumatic stress disorder. Recalling a memory while simultaneously making eye movements (EM) decreases a memory's vividness and/or emotionality. It has been argued that non-specific factors, such as treatment expectancy and experimental demand, may contribute to the EMDR's effectiveness. Objective: The present study was designed to test whether expectations about the working mechanism of EMDR would alter the memory attenuating effects of EM. Two experiments were conducted. In Experiment 1, we examined the effects of pre-existing (non-manipulated) knowledge of EMDR in participants with and without prior knowledge. In Experiment 2, we experimentally manipulated prior knowledge by providing participants without prior knowledge with correct or incorrect information about EMDR's working mechanism. Method: Participants in both experiments recalled two aversive, autobiographical memories during brief sets of EM (Recall+EM) or keeping eyes stationary (Recall Only). Before and after the intervention, participants scored their memories on vividness and emotionality. A Bayesian approach was used to compare two competing hypotheses on the effects of (existing/given) prior knowledge: (1) Prior (correct) knowledge increases the effects of Recall+EM vs. Recall Only, vs. (2) prior knowledge does not affect the effects of Recall+EM. Results: Recall+EM caused greater reductions in memory vividness and emotionality than Recall Only in all groups, including the incorrect information group. In Experiment 1, both hypotheses were supported by the data: prior knowledge boosted the effects of EM, but only modestly. In Experiment 2, the second hypothesis was clearly supported over the first: providing knowledge of the underlying mechanism of EMDR did not alter the effects of EM. Conclusions: Recall+EM appears to be quite robust against the effects of prior expectations. As Recall+EM is the core component of EMDR, expectancy effects probably contribute little to the effectiveness of EMDR treatment.

Towards an exposure-dependent model of post-traumatic stress: longitudinal course of post-traumatic stress symptomatology and functional impairment after the 2011 Oslo bombing

BACKGROUND

Our understanding of the dynamics of post-traumatic stress symptomatology and its link to functional impairment over time is limited.

METHOD

Post-traumatic stress symptomatology (Post-traumatic Checklist, PCL) was assessed three times in 1-year increments (T1, T2, T3) following the Oslo bombing of 22 July, 2011, in directly (n = 257) and indirectly exposed (n = 2223) government employees, together with demographics, measures of exposure and work and social adjustment. The dynamics of post-traumatic stress disorder symptom cluster interplay were examined within a structural equation modelling framework using a cross-lagged autoregressive panel model.

RESULTS

Intrusions at T1 played a prominent role in predicting all symptom clusters at T2 for the directly exposed group, exhibiting especially strong cross-lagged relationships with avoidance and anxious arousal. For the indirectly exposed group, dysphoric arousal at T1 played the most prominent role in predicting all symptom clusters at T2, exhibiting a strong relationship with emotional numbing. Emotional numbing seemed to be the main driver behind prolonged stress at T3 for both groups. Functional impairment was predominately associated with dysphoric arousal and emotional numbing in both groups.

CONCLUSIONS

For directly exposed individuals, memories of the traumatic incident and the following intrusions seem to drive their post-traumatic stress symptomatology. However, as these memories lose their potency over time, a sequela of dysphoric arousal and emotional numbing similar to the one reported by the indirectly exposed individuals seems to be the main driver for prolonged post-traumatic stress and functional impairment. Findings are discussed using contemporary models within an exposure-dependent perspective of post-traumatic stress.

Are addiction-related memories malleable by working memory competition? Transient effects on memory vividness and nicotine craving in a randomized lab experiment

BACKGROUND AND OBJECTIVES

Experimental research suggests that working memory (WM) taxation reduces craving momentarily. Using a modified Eye Movement Desensitization and Reprocessing (EMDR) procedure, prolonged reductions in craving and relapse rates in alcohol dependence have been demonstrated. Modified EMDR-procedures may also hold promise in smoking cessation attempts. A proof-of-concept study was conducted to narrow the gap between WM-taxation experiments and clinical EMDR studies. To this end the clinical EMDR-procedure was modified for use in a laboratory experiment.

METHODS

Daily smokers (n = 47), abstaining overnight, were allocated (by minimization randomization) to one of two groups using a parallel design. In both cases a modified EMDR-procedure was used. In the experimental group (n = 24) eye movements (EM) were induced while control group participants (n = 23) fixed their gaze (not taxing WM). During 6 min trials, craving-inducing memories were recalled. Craving, vividness of target memories, and smoking behavior were assessed at several variable-specific time-points between baseline (one week pre-intervention) and one week follow-up.

RESULTS

The experimental group showed significant immediate reductions of craving and vividness of targeted memories. However, these effects were lost during a one-week follow-up period.

CONCLUSIONS

A limited dose of WM-taxation, in the form of EM in a modified EMDR-procedure, resulted in transient effects on memory vividness and nicotine craving. EM provide a valuable way of coping with the acute effects of craving during smoking cessation attempts. Other aspects of the EMDR-procedure may provide additional effects. Component and dose-response studies are needed to establish the potential of EMDR-therapy in smoking cessation.

Degrading emotional memories induced by a virtual reality paradigm

BACKGROUND AND OBJECTIVES

In Eye Movement and Desensitization and Reprocessing (EMDR) therapy, a dual-task approach is used: patients make horizontal eye movements while they recall aversive memories. Studies showed that this reduces memory vividness and/or emotionality. A strong explanation is provided by working memory theory, which suggests that other taxing dual-tasks are also effective. Experiment 1 tested whether a visuospatial task which was carried out while participants were blindfolded taxes working memory. Experiment 2 tested whether this task degrades negative memories induced by a virtual reality (VR) paradigm.

METHODS

In experiment 1, participants responded to auditory cues with or without simultaneously carrying out the visuospatial task. In experiment 2, participants recalled negative memories induced by a VR paradigm. The experimental group simultaneously carried out the visuospatial task, and a control group merely recalled the memories. Changes in self-rated memory vividness and emotionality were measured.

RESULTS

The slowing down of reaction times due to the visuospatial task indicated that its cognitive load was greater than the load of the eye movements task in previous studies. The task also led to reductions in emotionality (but not vividness) of memories induced by the VR paradigm.

LIMITATIONS

Weaknesses are that only males were tested in experiment 1, and the effectiveness of the VR fear/trauma induction was not assessed with ratings of mood or intrusions in experiment 2.

CONCLUSIONS

The results suggest that the visuospatial task may be applicable in clinical settings, and the VR paradigm may provide a useful method of inducing negative memories.

The efficacy of eye movement desensitization and reprocessing for post-traumatic stress disorder and depression among Syrian refugees: results of a randomized controlled trial

BACKGROUND

Previous research indicates a high prevalence of post-traumatic stress disorder (PTSD) and depression among refugees. Eye movement desensitization and reprocessing (EMDR) is an effective treatment for PTSD for victims of natural disasters, car accidents or other traumatic events. The current study examined the effect of EMDR on symptoms of PTSD and depression by comparing the treatment with a wait-list control condition in Syrian refugees.

METHOD

Adult refugees located in Kilis Refugee Camp at the Turkish-Syrian border with a PTSD diagnosis were randomly allocated to either EMDR (n = 37) or wait-list control (n = 33) conditions. All participants were assessed with the Mini-International Neuropsychiatric Interview Plus at pre-intervention, at 1 week after finishing the intervention and at 5 weeks after finishing the intervention. The main outcome measures were the Harvard Trauma Questionnaire (HTQ) and the Impact of Event Scale-Revised. The Beck Depression Inventory and the Hopkins Symptoms Checklist-25 were included as secondary outcome measures. The Trial Registration no. is NCT01847742.

RESULTS

Mixed-model analyses adjusted for the baseline scores indicated a significant effect of group at post-treatment indicating that the EMDR therapy group showed a significantly larger reduction of PTSD symptoms as assessed with the HTQ. Similar findings were found on the other outcome measures. There was no effect of time or group × time interaction on any measure, showing that the difference between the groups at the post-treatment was maintained to the 5-week follow-up.

CONCLUSIONS

EMDR may be effective in reducing PTSD and depression symptoms among Syrian refugees with PTSD located in a refugee camp.

Imagery Rescripting: The Impact of Conceptual and Perceptual Changes on Aversive Autobiographical Memories

Background

Imagery rescripting (ImRs) is a process by which aversive autobiographical memories are rendered less unpleasant or emotional. ImRs is thought only to be effective if a change in the meaning-relevant (semantic) content of the mental image is produced, according to a cognitive hypothesis of ImRs. We propose an additional hypothesis: that ImRs can also be effective by the manipulation of perceptual features of the memory, without explicitly targeting meaning-relevant content.

Methods

In two experiments using a within-subjects design (both N = 48, community samples), both Conceptual-ImRs—focusing on changing meaning-relevant content—and Perceptual-ImRs—focusing on changing perceptual features—were compared to Recall-only of aversive autobiographical image-based memories. An active control condition, Recall + Attentional Breathing (Recall+AB) was added in the first experiment. In the second experiment, a Positive-ImRs condition was added—changing the aversive image into a positive image that was unrelated to the aversive autobiographical memory. Effects on the aversive memory’s unpleasantness, vividness and emotionality were investigated.

Results

In Experiment 1, compared to Recall-only, both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in unpleasantness, and Perceptual-ImRs led to greater decreases in emotionality of memories. In Experiment 2, the effects on unpleasantness were not replicated, and both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in emotionality, compared to Recall-only, as did Positive-ImRs. There were no effects on vividness, and the ImRs conditions did not differ significantly from Recall+AB.

Conclusions

Results suggest that, in addition to traditional forms of ImRs, targeting the meaning-relevant content of an image during ImRs, relatively simple techniques focusing on perceptual aspects or positive imagery might also yield benefits. Findings require replication and extension to clinical samples.