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 facto...
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2017-11-01
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| Series: | European Journal of Psychotraumatology |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/20008198.2017.1328954 |
| _version_ | 1828065811341770752 |
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| author | Marianne Littel Kevin van Schie Marcel A. van den Hout |
| author_facet | Marianne Littel Kevin van Schie Marcel A. van den Hout |
| author_sort | Marianne Littel |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-10T23:19:25Z |
| format | Article |
| id | doaj.art-055761c27c7a435484a3d65841a4d34b |
| institution | Directory Open Access Journal |
| issn | 2000-8066 |
| language | English |
| last_indexed | 2024-04-10T23:19:25Z |
| publishDate | 2017-11-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | European Journal of Psychotraumatology |
| spelling | doaj.art-055761c27c7a435484a3d65841a4d34b2023-01-12T15:31:28ZengTaylor & Francis GroupEuropean Journal of Psychotraumatology2000-80662017-11-018010.1080/20008198.2017.13289541328954Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories?Marianne Littel0Kevin van Schie1Marcel A. van den Hout2Erasmus University RotterdamUtrecht UniversityUtrecht UniversityBackground: 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.http://dx.doi.org/10.1080/20008198.2017.1328954emdreye movementsexpectancy effectsprior knowledgebayesian approach |
| spellingShingle | Marianne Littel Kevin van Schie Marcel A. van den Hout Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories? European Journal of Psychotraumatology emdr eye movements expectancy effects prior knowledge bayesian approach |
| title | Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories? |
| title_full | Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories? |
| title_fullStr | Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories? |
| title_full_unstemmed | Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories? |
| title_short | Exploring expectation effects in EMDR: does prior treatment knowledge affect the degrading effects of eye movements on memories? |
| title_sort | exploring expectation effects in emdr does prior treatment knowledge affect the degrading effects of eye movements on memories |
| topic | emdr eye movements expectancy effects prior knowledge bayesian approach |
| url | http://dx.doi.org/10.1080/20008198.2017.1328954 |
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