TIRCIA · EMDR
Resource Development and Installation (RDI)
Do eye movements really strengthen positive memories?
By Marie-Agnès Thulliez · Author · Publishing Director11-minute read
Resource Development and Installation (RDI) is one of the most widely taught tools in EMDR. Before working on traumatic memories, the therapist helps the client to call up positive experiences, such as a moment of pride, an act of courage or a supportive person, and then “installs” them with short sets of bilateral stimulation. The tool is intuitive and widely used. But what do we actually know about its effectiveness, and about the role of eye movements in this work?
In brief
- RDI was described in 2002 by Deborah Korn and Andrew Leeds to help the most fragile clients stabilise before reprocessing.
- Its effectiveness has yet to be evaluated in controlled trials: the available data rest on clinical cases.
- The available experiments show that eye movements weaken positive memories, at least in volunteers without any disorder, just as they weaken painful memories.
- Calling up resources remains clinically useful. The open question concerns bilateral stimulation: brief, closely monitored, or left out altogether.
1. RDI: where does it come from, and what is it for?
RDI was formalised by Deborah Korn and Andrew Leeds on the basis of two cases of women with complex PTSD, for whom direct reprocessing of memories seemed premature (Korn and Leeds, 2002). Its aim is to strengthen, before work on traumatic memories begins, states of calm, competence or connection that the client can draw on.
It belongs to the preparation phase of the EMDR protocol, alongside the safe place and the container exercise. It is mainly offered to clients who find intense emotions hard to tolerate, dissociate easily or lack positive experiences to hold on to.
2. The protocol, step by step
| Step | What the therapist does with the client |
|---|---|
| 1. Identify a need | Identify a current difficult situation and the quality that is missing to cope with it: calm, courage, confidence, the ability to say no. |
| 2. Find a resource | Look for a memory in which this quality was present (mastery resource), a person who embodies it (relational resource) or an image that symbolises it (symbolic resource). |
| 3. Develop the resource | Clarify the image, the emotions and the bodily sensations, and often a word or phrase that sums it up. |
| 4. Check | Make sure the resource is experienced as positive and does not stir up a painful memory. |
| 5. Install | Add short sets of slow bilateral stimulation, for as long as the resource keeps growing stronger. |
| 6. Link to the target situation | Imagine the difficult situation with the resource available. |
In practice, bilateral stimulation is just one step among others. Steps 1 to 4, finding, exploring and refining a positive experience with an attentive therapist, make up the core of the work.
3. What do the data say about its effectiveness?
The data remain limited. The founding article rests on two clinical cases (Korn and Leeds, 2002). In 2009, Andrew Leeds himself reviewed resource-focused procedures in EMDR and in other trauma psychotherapies, and concluded that controlled studies were needed, as none existed (Leeds, 2009). To date, no randomised trial has shown that RDI improves the outcome of EMDR therapy.
The question of its effectiveness therefore remains open: for now, its value rests on clinical experience rather than on trial evidence. The best-documented question is narrower: what do eye movements do to a positive memory?
4. What do eye movements do to a positive memory?
Two hypotheses compete. According to the interhemispheric interaction hypothesis, bilateral stimulation is thought to promote communication between the two hemispheres and to strengthen the pleasant emotions linked to the memory. According to the working memory hypothesis, following an eye movement while recalling a memory taxes a working memory of limited capacity: the memory becomes less vivid and less emotionally charged, whether it is negative or positive (van den Hout and Engelhard, 2012).
As early as 2001, a Dutch team had observed that after eye movements, negative memories became less negative, but also that positive memories became less positive (van den Hout et al., 2001).
The study by Hornsveld and colleagues
To test the RDI procedure directly, Hellen Hornsveld and her colleagues ran an experiment published in 2011 (Hornsveld et al., 2011):
The design
- 53 students, with no particular disorder, recalled three positive memories associated with pride, perseverance and self-confidence.
- Three conditions: horizontal eye movements, vertical eye movements, or simple recall of the memory.
- Before and after, they rated the vividness of the memory, how pleasant it was and the felt strength of the positive quality.
The result: eye movements, both horizontal and vertical, reduced the vividness, pleasantness and felt strength of the positive memories. This is exactly what the working memory hypothesis predicts. The fact that vertical movements produce the same effect, even though they do not involve alternation between the two hemispheres, runs counter to the interhemispheric hypothesis.
5. A debate that remains open
The developers of RDI replied that the experiment did not test RDI as it is practised: students rather than clients, a single session, and a procedure reduced to stimulation, with no exploration of the resource and no link to a target situation (Leeds and Korn, 2012). They proposed comparing RDI with and without eye movements in clients.
The authors of the study maintained their position: their results are consistent with a coherent body of research on working memory. They recommend suspending the use of eye movements in RDI and in the safe place until their added value has been demonstrated (Hornsveld et al., 2012).
Other avenues have been suggested, such as the pace of the movements or the direction of attention: a presentation at the 2014 EMDR Europe conference linked inward-directed attention with more vivid imagery (Ichii, 2014). To our knowledge, these preliminary results have not been published in a peer-reviewed journal. The comparative trial in clients, called for by both teams, has yet to be carried out.
6. RDI in the stabilisation debate
RDI has long been associated with the idea that clients with complex presentations must first be stabilised before their memories are treated. This idea is now being discussed. A critical analysis of the guidelines on complex PTSD points out that there is no evidence that a prior stabilisation phase is necessary or that it improves outcomes (De Jongh et al., 2016). In clients with a psychotic disorder, EMDR and prolonged exposure delivered without prior stabilisation were effective and did not worsen symptoms (van den Berg et al., 2015).
RDI can therefore have its place, while remaining a flexible option that keeps the path to memory work open, rather than a compulsory step that postpones it indefinitely. On this debate, see our article Do we really need to “stabilise” before treating trauma?
7. In practice
For the practitioner
- Keep the heart of the work: finding, exploring and naming a resource together with the client supports the alliance and gives them a sense of mastery.
- Use stimulation sparingly: if it is used, in short, slow sets. Long sets risk weakening the resource.
- Monitor the effect: after each set, ask whether the resource feels stronger, the same or weaker. If it weakens, stop and return to simple recall.
- Anchor in other ways: a keyword, a posture, an object or a written phrase can help the client to reconnect with the resource between sessions.
- Keep reprocessing in view: RDI exists to make reprocessing possible, and works best as a bridge towards it.
Clinical vignette
A fictional case, composed from common clinical situations.
Nadia, 45, seeks help for memories of childhood abuse. She says she does not feel able to “talk about all that” and fears being overwhelmed. The therapist first suggests looking for a moment when she felt strong. Nadia recalls the day she obtained her nursing diploma, against all the odds. Together they refine the image (the school corridor, the results sheet), the sensation (her shoulders straightening) and a phrase: “I held on.”
The therapist offers two short sets of eye movements. After the second, Nadia says: “It’s a bit less clear.” The therapist stops the stimulation and returns to simple recall, then to the phrase. Nadia leaves with the phrase written on a card. Three sessions later, reprocessing of the memories can begin; she uses the card at the end of difficult sessions.
What is established, and what is not
- Established: eye movements reduce the vividness and emotional intensity of memories, both positive and negative, at least in non-clinical participants.
- Not established: the effect of RDI on the outcome of EMDR therapy, for lack of controlled trials.
- Not established: the need for a prior stabilisation phase in most clients.
- Still to be done: comparing RDI with and without bilateral stimulation in clients.
Frequently asked questions
Should RDI be abandoned?
No. Guided recall of resources remains a useful clinical tool. According to the available data, it is the sets of bilateral stimulation that bring no strengthening and may weaken the resource.
Does this apply to the safe place?
Yes, by the same reasoning: the authors of the 2011 study recommend the same caution with eye movements in the safe place exercise.
Do tapping or sounds make a difference?
The data are very limited. A small study of 15 volunteers used alternating tactile vibrations while participants recalled pleasant memories: they reported accessing the memories more easily and feeling more relaxed, with no change in the felt strength of the resource (Amano and Toichi, 2016). Research on working memory shows that other dual tasks have effects similar to those of eye movements, though generally less marked.
In one sentence
Calling up a resource helps; eye movements, for their part, tend rather to weaken it, at least in volunteers without any disorder.
RDI keeps its place as a tool for building the alliance and preparing for reprocessing, provided stimulation is used sparingly and memory work stays on the horizon.
References
- De Jongh, A., Resick, P. A., Zoellner, L. A., et al. (2016). Critical analysis of the current treatment guidelines for complex PTSD in adults. Depression and Anxiety, 33(5), 359-369. Link
- Hornsveld, H. K., Houtveen, J. H., Vroomen, M., Kapteijn, I., Aalbers, D., & van den Hout, M. A. (2011). Evaluating the effect of eye movements on positive memories such as those used in Resource Development and Installation. Journal of EMDR Practice and Research, 5(4), 146-155. Link French translation: Journal of EMDR Practice and Research, 2013, 7(1), E1-E11. Link
- Hornsveld, H. K., de Jongh, A., & ten Broeke, E. (2012). Stop the use of eye movements in resource development and installation, until their additional value has been proven: A rejoinder to Leeds and Korn (2012). Journal of EMDR Practice and Research, 6(4), 174-178. Link
- Amano, T., & Toichi, M. (2016). The role of alternating bilateral stimulation in establishing positive cognition in EMDR therapy: A multi-channel near-infrared spectroscopy study. PLoS One, 11(10), e0162735. Link
- Ichii, M. (2014). Effect of eye movements in RDI (resource development and installation) procedure. Presentation, 15th EMDR Europe Conference, Edinburgh. Link
- Korn, D. L., & Leeds, A. M. (2002). Preliminary evidence of efficacy for EMDR resource development and installation in the stabilization phase of treatment of complex posttraumatic stress disorder. Journal of Clinical Psychology, 58(12), 1465-1487. Link
- Leeds, A. M. (2009). Resources in EMDR and other trauma-focused psychotherapy: A review. Journal of EMDR Practice and Research, 3(3), 152-160. Link
- Leeds, A. M., & Korn, D. L. (2012). A commentary on Hornsveld et al. (2011): A valid test of resource development and installation? Absolutely not. Journal of EMDR Practice and Research, 6(4), 170-173. Link
- van den Berg, D. P. G., de Bont, P. A. J. M., van der Vleugel, B. M., et al. (2015). Prolonged exposure vs eye movement desensitization and reprocessing vs waiting list for posttraumatic stress disorder in patients with a psychotic disorder: A randomized clinical trial. JAMA Psychiatry, 72(3), 259-267. Link
- van den Hout, M. A., & Engelhard, I. M. (2012). How does EMDR work? Journal of Experimental Psychopathology, 3(5), 724-738. Link
- van den Hout, M., Muris, P., Salemink, E., & Kindt, M. (2001). Autobiographical memories become less vivid and emotional after eye movements. British Journal of Clinical Psychology, 40(2), 121-130. Link
This article summarises the scientific evidence available at the date of publication. It is no substitute for clinical training, supervision, or the advice of a health professional.
