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.
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.
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.
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.
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.
•Outcome expectations are thought to partly explain psychotherapy effectivity.•Few studies have addressed this for EMDR therapy.•We report result of two laboratory analogue studies (N = 96; N = 173).•Treatment effectivity suggestions were not effective to change expectations.•Intervention effects were not moderated by treatment effectivity suggestions.
This article presents norms of valence/pleasantness, activity/arousal, power/dominance, and age of acquisition for 4,300 Dutch words, mainly nouns, adjectives, adverbs, and verbs. The norms are based ...on ratings with a 7-point Likert scale by independent groups of students from two Belgian (Ghent and Leuven) and two Dutch (Rotterdam and Leiden-Amsterdam) samples. For each variable, we obtained high split-half reliabilities within each sample and high correlations between samples. In addition, the valence ratings of a previous, more limited study (Hermans & De Houwer, Psychologica Belgica, 34:115-139,
1994
) correlated highly with those of the present study. Therefore, the new norms are a valuable source of information for affective research in the Dutch language.
Suppressing retrieval of unwanted memories can cause forgetting, an outcome often attributed to the recruitment of inhibitory control. This suppression-induced forgetting (SIF) generalizes to ...different cues used to test the suppressed content (cue-independence), a property taken as consistent with inhibition. But does cue-independent forgetting necessarily imply that a memory has been inhibited? Tomlinson et al. (Proc Natl Acad Sci 106:15588-15593, 2009) reported a surprising finding that pressing a button also led to cue-independent forgetting, which was taken as support for an alternative interference account. Here we investigated the role of inhibition in forgetting due to retrieval suppression and pressing buttons. We modified Tomlinson et al.'s procedure to examine an unusual feature they introduced that may have caused memory inhibition effects in their experiment: the omission of explicit task-cues. When tasks were uncued, we replicated the button-press forgetting effect; but when cued, pressing buttons caused no forgetting. Moreover, button-press forgetting partially reflects output-interference effects at test and not a lasting effect of interference. In contrast, SIF occurred regardless of these procedural changes. Collectively, these findings indicate that simply pressing a button does not induce forgetting, on its own, without confounding factors that introduce inhibition into the task and that inhibition likely underlies SIF.
Eye movement desensitization and reprocessing (EMDR) is an efficacious treatment for post-traumatic stress disorder. In EMDR, patients recall a distressing memory and simultaneously make eye ...movements (EM). Both tasks are considered to require limited working memory (WM) resources. Because this leaves fewer resources available for memory retrieval, the memory should become less vivid and less emotional during future recall. In EMDR analogue studies, a standardized procedure has been used, in which participants receive the same dual task manipulation of 1 EM cycle per second (1 Hz). From a WM perspective, the WM taxation of the dual task might be titrated to the WM taxation of the memory image. We hypothesized that highly vivid images are more affected by high WM taxation and less vivid images are more affected by low WM taxation. In study 1, 34 participants performed a reaction time task, and rated image vividness, and difficulty of retrieving an image, during five speeds of EM and no EM. Both a high WM taxing frequency (fast EM; 1.2 Hz) and a low WM taxing frequency (slow EM; 0.8 Hz) were selected. In study 2, 72 participants recalled three highly vivid aversive autobiographical memory images (n = 36) or three less vivid images (n = 36) under each of three conditions: recall + fast EM, recall + slow EM, or recall only. Multi-level modeling revealed a consistent pattern for all outcome measures: recall + fast EM led to less emotional, less vivid and more difficult to retrieve images than recall + slow EM and recall only, and the effects of recall + slow EM felt consistently in between the effects of recall + fast EM and recall only, but only differed significantly from recall + fast EM. Crucially, image vividness did not interact with condition on the decrease of emotionality over time, which was inconsistent with the prediction. Implications for understanding the mechanisms of action in memory modification and directions for future research are discussed.
Research on retrieval suppression has produced varying results concerning whether negatively valenced memories are more or less suppressible than neutral memories. This variability may arise if, ...across studies, participants adopt different approaches to memory control. Cognitive and neurobiological research points to two mechanisms that achieve retrieval suppression: thought-substitution and direct suppression (Benoit & Anderson, 2012; Bergström, de Fockert, & Richardson-Klavehn, 2009). Using the Think/No-think paradigm, this study examined whether participants can inhibit neutral and negatively valenced memories, using a uniform direct suppression strategy. Importantly, when strategy was controlled, negative and neutral items were comparably inhibited. Participants reported high compliance with direct suppression instructions, and success at controlling awareness predicted forgetting. These findings provide the first evidence that direct suppression can impair negatively valenced events, and suggest that variability in forgetting negative memories in prior studies is unlikely to arise from difficulty using direct suppression to control emotionally negative experiences.
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).
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.
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.
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.
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.
•There is a linear relationship between memory taxation and memory degradation.•One day later there is some, yet unconvincing, evidence for this linear pattern.•No inverted U-curve relationship was observed between taxation and degradation.
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.
•We examined whether stress boosts the long-term effects of degraded memories.•Dual-task interventions robustly produce immediate memory degrading effects.•Immediate memory degrading effects dissolve over time (24h later).•The stress manipulation increased cardiovascular/neuroendocrine stress responses.•Acute stress did not boost potential long-term effects of dual-task interventions.
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).
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.
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).
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).
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.
In this direct replication of Houben, Otgaar, Roelofs, and Merckelbach (Clinical Psychological Science, 6, 610–616, 2018), we tested whether making eye movements during memory recall increases ...susceptibility to creating false memories. Undergraduates (N = 206) watched a video of a car crash, after which they recalled the video with or without simultaneously making eye movements. Next, participants received misinformation about the video. Finally, during the critical test, they were questioned about video details. The results showed that making eye movements did not increase endorsement of misinformation (i.e., false memory), nor did it reduce (correct) memory details or memory vividness and emotionality. Random variation in sampling or measurement, low reliability of the test instrument, and observer-expectancy effects may explain discrepancies between study effects. Only multiple direct replications by different (independent) laboratories with standardized instruments will allow for assessing whether the effect is robust and largely independent of random variation and moderators.
After unpleasant events, people often experience intrusive memories that undermine their peace of mind. In response, they often suppress these unwanted memories from awareness. Such efforts may fail, ...however, when inhibitory control demands are high due to the need to sustain control, or when fatigue compromises inhibitory capacity. Here we examined how sustained inhibitory demand affected intrusive memories in the Think/No-Think paradigm. To isolate intrusions, participants reported, trial-by-trial, whether their preceding attempt to suppress retrieval had triggered retrieval of the memory they intended to suppress. Such counter-intentional retrievals provide a laboratory model of the sort of involuntary retrieval that may underlie intrusive memories. Using this method, we found that longer duration trials increased the probability of an intrusion. Moreover, on later No-Think trials, control over intrusions suddenly declined, with longer trial durations triggering more relapses of items that had been previously been purged. Thus, the challenges of controlling retrieval appear to cause a decline in control over time, due to a change in state, such as fatigue. These findings raise the possibility that characteristics often true of people with psychiatric disorders - such as compromised sleep, and increased demand on control - may contribute to difficulties in suppressing intrusive memories.
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