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.

Eye movement desensitization and reprocessing (EMDR) therapy or supportive counseling prior to exposure therapy in patients with panic disorder: study protocol for a multicenter randomized controlled trial (IMPROVE).

BACKGROUND: Exposure-based therapy is the treatment of choice for anxiety disorders, but many patients do not benefit sufficiently from it. Distressing images of threat related to the future or past may maintain the anxiety symptomatology or impede exposure therapy. An intervention that targets threat-related imagery is eye movement desensitization and reprocessing (EMDR) therapy. The main goal of this multicenter randomized controlled trial is to investigate whether EMDR therapy plus exposure therapy, relative to supportive counseling plus exposure therapy, improves treatment efficacy, tolerability, and adherence in patients with panic disorder. In addition, we will examine potential predictors of optimal treatment allocation, mechanisms of change as well as the long term effects of treatment. Finally, we will assess cost-effectiveness. METHODS: A multicenter randomized controlled trial mixed design will be conducted. Participants will be 50 patients, aged ≥ 18, diagnosed with a panic disorder. They will be randomly assigned to one of two conditions: EMDR therapy (i.e., flashforward strategy) or supportive counseling (each consisting of four weekly sessions of 90 min each) prior to exposure therapy (consisting of eight weekly sessions of 90 min each). Assessments will be made pre-treatment (T1), between-treatments (T2), post-treatment (T3), one month post-treatment (FU1) and six months post-treatment (FU2) by an assessor blind to treatment condition. The primary outcome measure is severity of panic-related symptoms. Secondary outcome measures are: tolerability of exposure therapy (initial avoidance, willingness to start exposure therapy, considered drop-out; no-show and drop-out), related symptomatology (generalized anxiety, depression), and functional impairment. DISCUSSION: The primary goals of this research are to compare the efficacy, tolerability, and adherence of EMDR therapy plus exposure therapy and supportive counseling plus exposure therapy and to identify predictors, moderators, and mediators for treatment success. This multi-center research aims to make a significant contribution to our understanding as to how treatment for patients with anxiety disorders can be optimized, and elucidate who can benefit most from this novel approach. TRIAL REGISTRATION: ISRCTN-ISRCTN29668369: Improving anxiety treatment by modifying emotional memories before real-life exposure. Registered 27 June 2022-retrospectively registered. ISRCTN-ISRCTN29668369.

The effect of imagery rescripting on prospective mental imagery of a feared social situation.

BACKGROUND AND OBJECTIVES: Negative mental imagery appears to play a role in anxiety disorders and can involve aversive memories or anticipated future threats. Modulating aversive memories through imagery rescripting generally reduces negative memory appraisals and associated anxiety. This pre-registered two-day analog study investigated whether imagery rescripting of aversive memories also reduces negative imagery of future threats. METHODS: On Day 1, socially anxious individuals (N = 52) were randomly assigned to imagery rescripting of an aversive memory or progressive relaxation (control condition). Before each intervention, they were asked to imagine a feared social situation that may happen in their future and evaluate this situation. They also rated the aversive memory before and after the intervention phase. The feared future situation was again evaluated at follow-up on Day 2. RESULTS: Unexpectedly, no group differences were found on the main outcome measures. That is, negative memory appraisals reduced after both interventions. Likewise, in both groups, negative details decreased, and positive details increased in prospective mental imagery, and anxiety and avoidance towards the imagined event decreased. On the exploratory measures, the imagery rescripting group showed increased positive appraisals of memory and future threat, and decreased negative future-threat appraisals, compared to the progressive relaxation group. LIMITATIONS: No passive control group was included, so potential time or placebo effects cannot be precluded. CONCLUSIONS: The interventions had similar effects on the main outcomes and influenced mental imagery of future threats. Some differences were found on the exploratory measures that warrant further investigation with a passive control condition.

Future-oriented imagery rescripting facilitates conducting behavioral experiments in social anxiety.

Distressing mental images are common in anxiety disorders and can make it difficult for patients to confront feared situations. This study examined whether imagery rescripting focused on a feared social situation prepares participants to engage in a feared situation. Sixty healthy individuals were asked to formulate a behavioral experiment to test negative beliefs about a social situation they feared. They were assigned to one of two groups: imagery rescripting focused on the feared outcome of the behavioral experiment or no imagery rescripting (i.e., a break). All participants were then asked to complete ratings scales and to conduct the behavioral experiment. Before the behavioral experiment, the imagery rescripting condition, compared to the control condition, showed reduced anticipated probability and severity of the feared outcome, lower anxiety and helplessness levels, and increased willingness to conduct the behavioral experiment. Imagery-based interventions focused on feared outcomes seem promising to prepare anxious individuals to engage in treatment.

Future-Oriented Positive Mental Imagery Reduces Anxiety for Exposure to Public Speaking.

Exposure therapy is the recommended treatment for anxiety disorders, but many anxious individuals are unwilling to expose themselves to feared situations. Episodic simulation of future situations contributes to adaptive emotion regulation and motivates behavior. This study investigated whether future-oriented positive mental imagery reduces anticipatory anxiety and distress during exposure, and increases exposure willingness and duration. Forty-three individuals with moderate public speaking anxiety were randomized to a standardized positive mental imagery exercise about future public speaking or no-task. All participants were then asked to present in a virtual reality environment. Anticipatory anxiety reduced in the positive mental imagery group, but not in the control group. Additionally, the positive mental imagery group reported lower distress during exposure than the control group, but groups did not differ in exposure willingness. Due to limited variance, effects on exposure duration could not be tested. Future-oriented positive mental imagery is promising to prepare individuals for exposure to previously avoided situations.

Verbal suggestions fail to modulate expectations about the effectiveness of a laboratory model of EMDR therapy: Results of two preregistered studies.

BACKGROUND AND OBJECTIVES: For many psychotherapies, like Eye Movement and Desensitization Reprocessing (EMDR) therapy, there is an ongoing discussion about the role of specific versus non-specific mechanisms in their effectiveness However, experimental research directly examining the potential role of non-specific mechanisms is scarce. Here, we address the role of a non-specific factor that is often put forward for EMDR, namely treatment effectiveness expectations, within a laboratory model of EMDR therapy. METHODS: In a lab-based (N = 96) and an online experiment (N = 173), we gave participants verbal instructions to manipulate their treatment expectations. Instructions emphasized EMDR's effectiveness or ineffectiveness. Then, participants were asked to recollect an unpleasant autobiographical memory with or without making eye-movements. RESULTS: In line with previous studies, we found significant reductions of reported vividness and emotionality of negative autobiographical memories in the eye-movements condition. These reductions did not differ between the verbal suggestions conditions in both experiments, suggesting a limited effect of treatment effectiveness suggestions. LIMITATIONS: Treatment effectiveness expectations were not successfully manipulated by the suggestions manipulation. This suggests that treatment expectations may be more difficult to influence than anticipated, thus limiting the interpretation of our findings. CONCLUSIONS: These findings tentatively corroborate the results of two earlier reports, suggesting that the effects of verbal suggestions about treatment effectiveness in a laboratory model of EMDR therapy may be limited.

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

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

Enhancing extinction with response prevention via imagery-based counterconditioning: Results on conditioned avoidance and distress.

BACKGROUND AND OBJECTIVES: Maladaptive avoidance is a core characteristic of anxiety-related disorders. Its reduction is often promoted using extinction with response prevention (ExRP) procedures, but these effects are often short-lived. Research has shown that pairing a feared stimulus with a stimulus of an incompatible valence (i.e., counterconditioning) may be effective in reducing fear. This laboratory study tested whether positive imagery during ExRP (i.e., imagery counterconditioning protocol) can also reduce avoidance. METHODS: In the counterconditioning procedure, participants imagined a positive sound. There were four phases. First, participants were presented with squares on a computer screen of which one (CS+) was paired with an aversive sound and another (CS-) was not. Second, they learned to avoid the negative sound in the presence of the CS+, via a key press. Third, they were assigned to either the Counterconditioning (that was asked to imagine a positive sound during ExRP) or No Counterconditioning group (standard ExRP). Finally, they performed a test phase that consisted of two parts: in the first part, avoidance responses were available for each CS and in the second part, these responses were prevented. RESULTS: The Counterconditioning intervention resulted in a short-lived reduction of distress associated with the CS+. However, groups did not differ in avoidance or distress during the test phases. LIMITATIONS: US-expectancy ratings were collected only at the end of the experiment. CONCLUSIONS: The results indicate that positive imagery during ExRP may be effective in reducing distress during the intervention. Explanations for the persistence of avoidance and fear are discussed.

Induction of conditioned avoidance via mental imagery.

There is a growing interest on how mental imagery may be involved in the onset and maintenance of anxiety-related disorders. Here, we used an experimental design to investigate whether a key symptom across anxiety-related disorders, namely avoidance, can be induced via mental imagery. Healthy participants first learned that one neutral stimulus (A) was associated with a mild electric shock and two other neutral stimuli (B and C) were not. They then learned to cancel the shock when A was presented, by pressing a button on a keyboard ('behavioral avoidance'). Next, they were asked to imagine that stimulus B was followed by the shock (i.e., without actual B or shock presentations; Experiment 1; N = 66) or they were shown B and asked to imagine the shock (i.e., without actual shock presentations; Experiment 2; N = 60). Finally, in the test phase, they were shown each of the three stimuli (without the shock) and given the opportunity to make the avoidance response. Results showed that participants tended to avoid B in the test phase in Experiment 1, even though it had never been presented with the shock but not in Experiment 2. We discuss how the findings may explain the acquisition of avoidance in the presentation of innocuousstimuli across anxiety-related disorders.

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.

A review on mental imagery in fear conditioning research 100 years since the 'Little Albert' study.

Since the seminal 'Little Albert' study by Watson and Rayner (1920), fear conditioning has become one of the most commonly used paradigms for studying the etiology of anxiety-related disorders. In a fear conditioning procedure, a (neutral) conditioned stimulus (CS) is paired with an aversive unconditioned stimulus (US), resulting in fear-related conditioned responses (CRs) to the CS. Whereas fear conditioning research initially focused on observable elements in the environment (i.e., CSs, USs, and their contingency) and their effects (i.e., CRs), subsequent research indicated that attention should also be given to unobservable mental events (e.g., intrusive memories of aversive outcomes) to more fully account for the symptomatology of anxiety disorders. In this paper, we review the research relating to four major research questions on the relationship between mental imagery and fear conditioning: (1) Can mental imagery substitute for actual stimulus administration? (2) Can mental imagery inflate CRs? (3) Can fear conditioning result in the installment of mental images as CRs (i.e., intrusions)? (4) Can mental imagery-based interventions reduce CRs? For all these research questions, tentative confirmatory evidence has been found and these findings corroborate contemporary conditioning theories. Nonetheless, we point to several open questions and methodological issues that require further research.

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.

Renewal of conditioned fear responses using a film clip as the aversive unconditioned stimulus.

BACKGROUND AND OBJECTIVES: Pavlovian fear conditioning paradigms are valuable to investigate fear learning and the return of extinguished fear in the lab. However, their validity is limited, because the aversive stimuli (e.g., electric shocks) typically lack the modalities and complexity of real-world aversive experiences. To overcome this limitation, we examined fear acquisition, extinction and contextual renewal using an audiovisual unconditioned stimulus (US). METHOD: On day 1, 50 healthy participants completed an acquisition phase in a specific context (i.e., desk or bookcase, 'context A'). Pictures of colored lamps served as conditioned stimuli and an aversive film clip was used as US. On day 2, extinction took place in the same context ('context A') or in a different context ('context B'). Afterwards, renewal was tested in the acquisition context (AAA vs. ABA design). RESULTS: As hypothesized, fear acquisition and extinction, as measured by US expectancy ratings, fear potentiated startle (FPS), and skin conductance responses (SCRs), were successful. Most importantly, conditioned responding was renewed on all measures in the ABA condition, but not in the AAA condition. Differential renewal (i.e., larger renewal for CS + than for CS-) was only observed for US expectancy ratings. LIMITATIONS: The return of conditioned responses was non-differential for FPS and SCR. CONCLUSIONS: The current set-up enables investigation of fear renewal using an audiovisual US. Future studies can utilize this paradigm to investigate interventions that aim to reduce fear renewal by modifying the US memory, such as Eye Movement Desensitization and Reprocessing and imagery rescripting.

Dual-tasking during recall of negative memories or during visual perception of images: Effects on vividness and emotionality.

BACKGROUND AND OBJECTIVES: Several treatments are effective in reducing symptoms of post-traumatic stress disorder. We tested the effectiveness of an experimental intervention that consists of elements from two of these: virtual reality (VR) exposure therapy and eye movement desensitization and reprocessing. The latter is characterized by a dual-task approach: the patient holds a traumatic memory in mind while simultaneously making voluntary eye movements, resulting in reduced vividness and emotionality of the traumatic memory. If the experimental intervention is effective, it could provide a useful approach for highly avoidant individuals. METHODS: Participants recalled negative memories induced by a VR paradigm. The experimental group viewed VR screenshots that represented these negative memories while carrying out a dual-task. One control group recalled negative memories while carrying out the same dual-task (a standard dual-task condition) and another merely viewed the VR screenshots. Pre-to-post changes in self-rated memory vividness/emotionality were measured. RESULTS: The results indicate that viewing a screenshot only was outperformed by both dual-task interventions in terms of reductions in vividness/emotionality. Furthermore, the dual-task interventions had a comparable impact on vividness, but the screenshot variant led to greater decreases in emotionality. LIMITATIONS: Changes in memory vividness/emotionality were only assessed shortly after the interventions and no measures of avoidance behavior were included in the study. CONCLUSIONS: Looking at an image in VR that represents a memory while carrying out a dual-task may be at least as effective as recalling the memory during the dual-task. Interestingly, visually supporting a negative memory does not seem to prevent memory degrading by dual-tasking.

The Effects of ß-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 ß-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.

Eye movement during recall reduces objective memory performance: An extended replication.

Eye Movement Desensitization and Reprocessing (EMDR) therapy for posttraumatic stress disorder involves making eye movements (EMs) during recall of a traumatic image. Experimental studies have shown that the dual task decreases self-reported memory vividness and emotionality. However valuable, these data are prone to demand effects and little can be inferred about the mechanism(s) underlying the observed effects. The current research aimed to fill this lacuna by providing two objective tests of memory performance. Experiment I involved a stimulus discrimination task. Findings were that EM during stimulus recall not only reduces self-reported memory vividness, but also slows down reaction time in a task that requires participants to discriminate the stimulus from perceptually similar stimuli. Experiment II involved a fear conditioning paradigm. It was shown that EM during recall of a threatening stimulus intensifies fearful responding to a perceptually similar yet non-threat-related stimulus, as evidenced by increases in danger expectancies and skin conductance responses. The latter result was not corroborated by startle EMG data. Together, the findings suggest that the EM manipulation renders stimulus attributes less accessible for future recall.

Degrading traumatic memories with eye movements: a pilot functional MRI study in PTSD.

BACKGROUND: Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder (PTSD). During EMDR, the patient recalls traumatic memories while making eye movements (EMs). Making EMs during recall is associated with decreased vividness and emotionality of traumatic memories, but the underlying mechanism has been unclear. Recent studies support a "working-memory" (WM) theory, which states that the two tasks (recall and EMs) compete for limited capacity of WM resources. However, prior research has mainly relied on self-report measures. METHODS: Using functional magnetic resonance imaging, we tested whether "recall with EMs," relative to a "recall-only" control condition, was associated with reduced activity of primary visual and emotional processing brain regions, associated with vividness and emotionality respectively, and increased activity of the dorsolateral prefrontal cortex (DLPFC), associated with working memory. We used a randomized, controlled, crossover experimental design in eight adult patients with a primary diagnosis of PTSD. A script-driven imagery (SDI) procedure was used to measure responsiveness to an audio-script depicting the participant's traumatic memory before and after conditions. RESULTS: SDI activated mainly emotional processing-related brain regions (anterior insula, rostral anterior cingulate cortex (ACC), and dorsomedial prefrontal cortex), WM-related (DLPFC), and visual (association) brain regions before both conditions. Although predicted pre- to post-test decrease in amygdala activation after "recall with EMs" was not significant, SDI activated less right amygdala and rostral ACC activity after "recall with EMs" compared to post-"recall-only." Furthermore, functional connectivity from the right amygdala to the rostral ACC was decreased after "recall with EMs" compared with after "recall-only." CONCLUSIONS: These preliminary results in a small sample suggest that making EMs during recall, which is part of the regular EMDR treatment protocol, might reduce activity and connectivity in emotional processing-related areas. This study warrants replication in a larger sample. HIGHLIGHTS OF THE ARTICLE: Script driven imagery (SDI) before and after recall of traumatic memories is feasible to investigate working mechanisms of degrading of traumatic memories with eye movements (EMs) in PTSD. Right amygdala and rostral ACC activity was significantly lower after "recall with EMs" than after "recall-only". Functional connectivity from amygdala to rostral ACC was decreased after "recall with EMs" vs. "recall-only". This study warrants replication in a larger sample.

Blurring emotional memories using eye movements: individual differences and speed of eye movements.

BACKGROUND: In eye movement desensitization and reprocessing (EMDR), patients make eye movements (EM) while recalling traumatic memories. Making EM taxes working memory (WM), which leaves less resources available for imagery of the memory. This reduces memory vividness and emotionality during future recalls. WM theory predicts that individuals with small working memory capacities (WMCs) benefit more from low levels of taxing (i.e., slow EM) whereas individuals with large WMC benefit more from high levels of taxing (i.e., fast EM). OBJECTIVE: We experimentally examined and tested four prespecified hypotheses regarding the role of WMC and EM speed in reducing emotionality and vividness ratings: 1) EM-regardless of WMC and EM speed-are more effective compared to no dual task, 2) increasing EM speed only affects the decrease in memory ratings irrespective of WMC, 3) low-WMC individuals-compared to high-WMC individuals-benefit more from making either type of EM, 4) the EM intervention is most effective when-as predicted by WM theory-EM are adjusted to WMC. METHOD: Undergraduates with low (n=31) or high (n=35) WMC recalled three emotional memories and rated vividness and emotionality before and after each condition (recall only, recall + slow EM, and recall + fast EM). RESULTS: Contrary to the theory, the data do not support the hypothesis that EM speed should be adjusted to WMC (hypothesis 4). However, the data show that a dual task in general is more effective in reducing memory ratings than no dual task (hypothesis 1), and that a more cognitively demanding dual task increases the intervention's effectiveness (hypothesis 2). CONCLUSIONS: Although adjusting EM speed to an individual's WMC seems a straightforward clinical implication, the data do not show any indication that such a titration is helpful.

The effects of eye movements on emotional memories: using an objective measure of cognitive load.

BACKGROUND: Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. The working memory (WM) theory explains its efficacy: recall of an aversive memory and making eye movements (EM) both produce cognitive load, and competition for the limited WM resources reduces the memory's vividness and emotionality. The present study tested several predictions from WM theory. OBJECTIVE: We hypothesized that 1) recall of an aversive autobiographical memory loads WM compared to no recall, and 2) recall with EM reduces the vividness, emotionality, and cognitive load of recalling the memory more than only recall or only cognitive effort (i.e., recall of an irrelevant memory with EM). METHOD: Undergraduates (N=108) were randomly assigned to one of three conditions: 1) recall relevant memory with EM, 2) recall relevant memory without EM, and 3) recall irrelevant memory with EM. We used a random interval repetition task to measure the cognitive load of recalling the memory. Participants responded to randomly administered beeps, with or without recalling the memory. The degree to which participants slow down during recall provides an index of cognitive load. We measured the cognitive load and self-reported vividness and emotionality before, halfway through (8×24 s), and after (16×24 s) the intervention. RESULTS: Reaction times slowed down during memory recall compared to no recall. The recall relevant with EM condition showed a larger decrease in self-reported vividness and emotionality than the control conditions. The cognitive load of recalling the memory also decreased in this condition but not consistently more than in the control conditions. CONCLUSIONS: Recall of an aversive memory loads WM, but drops in vividness and emotionality do not immediately reduce the cognitive load of recalling the memory. More research is needed to find objective measures that could capture changes in the quality of the memory.

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.