On EMDR: Measuring the working memory taxation of various types of eye (non-)movement conditions
Description
Background and objective:
A recent large randomized controlled trial employing different forms of eye (non-)movements in Eye Movement Desensitization and Reprocessing (EMDR) showed that fixating eyes on a therapist's moving or non-moving hand led to equal reductions in symptoms of post-traumatic stress disorder (PTSD). However, numerous EMDR lab analogue studies found that eye movements produce larger memory effects than eyes stationary. These beneficial effects are typically explained by differences in working memory (WM) taxation. We tested the degree of WM taxation of several eye (non-)movement conditions used in the clinical trial.
Methods:
All participants (N = 40) performed: (1) eyes moving by following the experimenter's moving finger, (2) eyes fixed on the experimenter's stationary finger, (3) eyes closed, or (4) looking unfocused into the room. Simultaneously they performed a simple reaction time task. Reaction times are an objective index of the extent to which different dual attention tasks tax WM.
Results:
Eyes moving is more taxing than eyes fixed, while eyes fixed did not differ from eyes unfocused. All conditions were more taxing than eyes closed. Limitations We studied WM taxation in a laboratory setting; no clinical interventions were applied.
Conclusions:
In line with previous lab studies, making eye movements was more taxing than eyes fixed. We discuss why this effect was not observed for reductions in PTSD symptoms in the clinical trial (e.g., differences in dependent variables, sample population, and intervention duration). For more comprehensive future insights, we recommend integration of mechanistically focused lab analogue studies and patient-oriented clinical studies.
A recent large randomized controlled trial employing different forms of eye (non-)movements in Eye Movement Desensitization and Reprocessing (EMDR) showed that fixating eyes on a therapist's moving or non-moving hand led to equal reductions in symptoms of post-traumatic stress disorder (PTSD). However, numerous EMDR lab analogue studies found that eye movements produce larger memory effects than eyes stationary. These beneficial effects are typically explained by differences in working memory (WM) taxation. We tested the degree of WM taxation of several eye (non-)movement conditions used in the clinical trial.
Methods:
All participants (N = 40) performed: (1) eyes moving by following the experimenter's moving finger, (2) eyes fixed on the experimenter's stationary finger, (3) eyes closed, or (4) looking unfocused into the room. Simultaneously they performed a simple reaction time task. Reaction times are an objective index of the extent to which different dual attention tasks tax WM.
Results:
Eyes moving is more taxing than eyes fixed, while eyes fixed did not differ from eyes unfocused. All conditions were more taxing than eyes closed. Limitations We studied WM taxation in a laboratory setting; no clinical interventions were applied.
Conclusions:
In line with previous lab studies, making eye movements was more taxing than eyes fixed. We discuss why this effect was not observed for reductions in PTSD symptoms in the clinical trial (e.g., differences in dependent variables, sample population, and intervention duration). For more comprehensive future insights, we recommend integration of mechanistically focused lab analogue studies and patient-oriented clinical studies.
Format
Journal
Language
English
Original Work Citation
van Veen, S. C., Kang, S., & van Schie, K. (2019, June). On EMDR: Measuring the working memory taxation of various types of eye (non-)movement conditions. Journal of Behavior Therapy and Experimental Psychiatry, 101494
Citation
“On EMDR: Measuring the working memory taxation of various types of eye (non-)movement conditions,” Francine Shapiro Library, accessed May 7, 2024, https://francineshapirolibrary.omeka.net/items/show/25993.