EMDR Protocol: Mechanism, Evidence, and Clinical Application

Category: Emotional Healing | Level: Jaguar (West) — Medicine Wheel

---

A Walk in the Park That Changed Psychiatry

In 1987, Francine Shapiro was a psychology doctoral student walking through a park in Los Gatos, California. She noticed that certain disturbing thoughts she had been mulling over suddenly lost their emotional charge. Paying close attention, she realized her eyes had been making spontaneous rapid lateral movements — side to side — as she walked and thought. The thoughts were still there, but the distress attached to them had dissolved.

Most people would have dismissed this as a quirk of the afternoon. Shapiro did not. She began experimenting systematically — first on herself, then on friends and colleagues, then on Vietnam veterans and sexual assault survivors. What she found was so striking, and so difficult to explain within existing therapeutic frameworks, that it provoked equal parts fascination and hostility from the clinical world. Eye Movement Desensitization and Reprocessing — EMDR — was born from that afternoon walk, and three decades later it stands as one of the most extensively researched and internationally endorsed treatments for post-traumatic stress disorder.

The Adaptive Information Processing Model

EMDR rests on a theoretical framework Shapiro called the Adaptive Information Processing (AIP) model. The core premise: the brain has an innate information-processing system that moves experience toward adaptive resolution — integrating new information into existing memory networks, extracting useful learning, and discarding what is no longer needed. This is what happens during normal memory consolidation. You have a difficult day, you sleep on it, and by morning the sharp edges have softened. The event has been processed.

Trauma disrupts this system. When an experience overwhelms the processing capacity — through intensity, helplessness, or developmental vulnerability — the memory gets stored in its raw, unprocessed form. It retains its original sensory vividness: the images, sounds, smells, body sensations, and emotions remain as fresh as the moment of occurrence. It is not filed in past-tense memory. It remains present-tense experience, easily triggered and immune to rational reassurance.

This is why a combat veteran can know intellectually that they are safe in their living room while their body responds to a car backfire as if they are under fire. The memory has not been processed. It is stored in state-specific form — fragmented, sensory, and disconnected from the adaptive information that would update it: “That was then. This is now. I survived.”

EMDR’s mechanism, according to the AIP model, is to restart the stalled processing system. By activating the traumatic memory while simultaneously engaging in bilateral stimulation, the brain’s natural processing capacity is rekindled. The memory begins to move — linking to adaptive information, losing its sensory intensity, and eventually taking its place as a normal autobiographical memory: something that happened, rather than something that is still happening.

The Eight Phases

EMDR is not a single technique. It is a comprehensive, structured eight-phase treatment protocol. The bilateral stimulation that captures public attention is only one component, nested within a carefully sequenced clinical framework.

Phase 1: History and Treatment Planning

A thorough assessment of the client’s history, current symptoms, and readiness for EMDR processing. The clinician identifies target memories — the specific experiences that are driving current symptoms. This is not random. EMDR targets memories in a precise sequence: the earliest related memory, the current triggers, and a future template for adaptive behavior.

Shapiro emphasized that current symptoms are understood as manifestations of inadequately processed past experience. Depression, anxiety, phobias, and relationship difficulties are not discrete disorders — they are the present-day effects of unprocessed memories that continue to exert influence from the past.

Phase 2: Preparation

The client is educated about the EMDR process and equipped with self-regulation resources. This includes establishing a “safe place” or “calm place” visualization, container exercises for managing disturbing material between sessions, and techniques for self-stabilization. The therapeutic alliance is solidified. The client must feel sufficiently safe and resourced before any trauma processing begins.

This phase may take one session or many, depending on the complexity of the trauma history and the client’s current capacity for affect regulation. Rushing past preparation is the most common clinical error in EMDR practice.

Phase 3: Assessment

The clinician activates the target memory by identifying its components:

• Image: The visual representation that captures the worst part of the memory.
• Negative cognition (NC): The irrational, self-referencing belief attached to the memory — “I am powerless,” “I am worthless,” “It was my fault.”
• Positive cognition (PC): The adaptive belief the client would prefer to hold — “I have choices now,” “I am worthy,” “I did the best I could.”
• Validity of Cognition (VoC): On a scale of 1-7, how true the positive cognition feels right now (not how true it is logically).
• Emotion: What emotion arises when holding the image and negative cognition together.
• Subjective Units of Disturbance (SUD): On a scale of 0-10, the intensity of the disturbance.
• Body location: Where in the body the disturbance is felt.

This structured activation ensures that the memory is accessed in its totality — cognitive, emotional, somatic, and sensory dimensions simultaneously.

Phase 4: Desensitization

This is the phase most people associate with EMDR. The client holds the target memory in mind — image, negative cognition, body sensation — while simultaneously following the clinician’s fingers (or other bilateral stimulus) with their eyes, back and forth, in sets of approximately 24-36 passes.

After each set, the client reports whatever comes up — new images, thoughts, emotions, body sensations, other memories. The clinician says simply: “Go with that.” Another set begins. The process continues until the SUD score drops to 0 or 1.

What typically occurs is a rapid, nonlinear unfolding. The memory network opens up. Associated memories surface. Emotions shift — from terror to anger to grief to acceptance, sometimes within a single session. Body sensations move and change. The client is not analyzing the trauma. They are metabolizing it.

Phase 5: Installation

Once the disturbance has been fully processed, the positive cognition identified in Phase 3 is “installed” — strengthened and paired with the original memory through additional bilateral stimulation. The VoC is measured again. The goal is a VoC of 6 or 7 — the positive belief now feels true, not just logically correct, when the original memory is recalled.

Phase 6: Body Scan

The client holds the target memory and the positive cognition together while scanning their body from head to feet. Any residual tension, discomfort, or unusual sensation is targeted with additional bilateral stimulation until the body is clear. This phase ensures that the processing is complete at the somatic level — that the body, not just the mind, has released the trauma.

Phase 7: Closure

Every session ends with stabilization, regardless of whether processing is complete. If the target memory has not been fully processed, the clinician uses the safe place exercise and containment strategies to help the client return to equilibrium. The client is oriented to what to expect between sessions — new memories, dreams, insights, or emotional shifts may continue as processing unfolds.

Phase 8: Reevaluation

Each subsequent session begins with reevaluation of previously processed targets. Has the SUD remained at 0? Has the VoC held at 7? Are there new targets that have emerged? Reevaluation ensures thoroughness and catches incomplete processing before moving forward.

Why Does Bilateral Stimulation Work?

This remains the most debated question in EMDR research. Multiple mechanisms have been proposed, and the evidence suggests they are not mutually exclusive.

Working Memory Taxation

The dual-attention hypothesis, supported by research from Marcel van den Hout and Iris Engelhard at Utrecht University, proposes that holding a traumatic memory in mind while simultaneously tracking eye movements taxes working memory. Working memory has limited capacity. When it is loaded with two tasks — memory recall and eye tracking — the emotional vividness of the memory degrades. It becomes less vivid, less distressing, more like a faded photograph than a live broadcast.

This is elegant. The mechanism does not require repression or avoidance. It allows the memory to be held and recalled, but with reduced emotional intensity — creating the conditions for adaptive processing.

The Orienting Response

Bilateral stimulation triggers the orienting response — the reflexive attending behavior that occurs when something new enters the sensory field. The orienting response is incompatible with the freeze response. By repeatedly activating the orienting reflex, EMDR may help the nervous system shift out of the defensive state in which the traumatic memory is stored.

REM-Like Processing

Robert Stickgold at Harvard proposed that the lateral eye movements in EMDR mimic the saccadic eye movements of REM (Rapid Eye Movement) sleep — the stage during which emotional memories are processed and consolidated. EMDR may be activating the same memory-processing mechanisms that operate during dreaming, but in a waking state where the therapist can guide the process.

Sleep researchers have demonstrated that REM deprivation produces accumulation of unprocessed emotional material, which manifests as increased emotional reactivity and impaired memory consolidation. EMDR may be providing a supplementary processing window for memories that the normal REM cycle cannot resolve.

Interhemispheric Communication

Some researchers, including Marco Pagani at the Institute of Cognitive Sciences and Technologies in Rome, have proposed that bilateral stimulation enhances communication between the brain’s hemispheres. EEG studies during EMDR show increased coherence between hemispheric activity. Traumatic memories tend to be stored predominantly in the right hemisphere (sensory, emotional, nonverbal). Full processing may require integration with left-hemisphere functions (language, logic, temporal sequencing). Bilateral stimulation may facilitate this cross-hemispheric integration.

The Clinical Evidence

EMDR has accumulated one of the most robust evidence bases in psychotherapy. Key landmarks:

• Van der Kolk et al. (2007): A randomized controlled trial comparing EMDR, fluoxetine (Prozac), and pill placebo for PTSD. EMDR produced significantly larger reductions in PTSD symptoms than fluoxetine. At follow-up, 75% of adult-onset PTSD patients in the EMDR group were asymptomatic, compared to none in the fluoxetine group.
• Shapiro (2014): A comprehensive meta-analysis reviewing over two decades of EMDR research, demonstrating consistent efficacy across single-incident and complex trauma, with effects maintained at long-term follow-up.
• World Health Organization (2013): Listed EMDR as one of only two recommended treatments for PTSD in adults, children, and adolescents (the other being cognitive-behavioral therapy with a trauma focus).
• American Psychological Association (2017): Designated EMDR as a strongly recommended treatment for PTSD.
• Department of Veterans Affairs/Department of Defense (2017): Listed EMDR as a strongly recommended first-line treatment for PTSD.

Advanced Techniques

The Floatback Technique

When a current trigger activates distress but the client cannot identify the origin, the clinician uses the floatback. The client holds the current image, the negative cognition, and the associated body sensation, then allows their mind to “float back” through time to the earliest memory that holds the same constellation of image, belief, and sensation. The earliest memory becomes the primary processing target — addressing the root rather than the branches.

Resource Development and Installation (RDI)

Developed by Andrew Leeds, RDI uses bilateral stimulation to strengthen positive internal resources — memories of mastery, connection, safety, or competence — before trauma processing begins. This is particularly important for complex trauma clients whose history contains few stabilizing experiences. RDI builds the internal scaffolding that will support the client during the more demanding processing phases.

The Flash Technique

Developed by Philip Manfield, the Flash Technique addresses a critical clinical challenge: how to begin processing memories that are so disturbing the client cannot tolerate even brief activation. In the Flash Technique, the client focuses on a positive, engaging memory while the clinician delivers rapid bilateral stimulation. At intervals, the client is asked to “flash” — bring the disturbing memory to mind for the briefest possible moment, then return immediately to the positive focus. This reduces the disturbance level without the client having to sustain exposure to the traumatic material.

EMDR and Somatic Processing

Though EMDR was developed as an information-processing model rather than a body-based therapy, somatic processing is woven throughout the protocol. The body scan in Phase 6 is explicitly somatic. The assessment phase identifies body location of disturbance. During desensitization, body sensations are tracked and processed with the same rigor as cognitive and emotional content.

Clinicians who integrate Somatic Experiencing principles with EMDR find that the body often holds processing that the mind has completed. A client may report zero disturbance cognitively while their shoulders remain clenched or their gut remains knotted. Targeting these somatic residues with bilateral stimulation completes the processing at every level.

EMDR in the Larger Landscape

How does EMDR compare to other trauma therapies? Prolonged Exposure (PE) requires sustained imaginal reliving of the traumatic event — typically 45-60 minutes of continuous narrative exposure per session. EMDR processing is briefer, less verbally demanding, and does not require detailed narration. For clients who cannot or will not describe their trauma in words — whether due to dissociation, shame, alexithymia, or the preverbal nature of early trauma — EMDR offers a pathway that does not depend on the verbal channel.

Cognitive Processing Therapy (CPT) works primarily at the cognitive level — identifying and restructuring maladaptive beliefs. EMDR addresses cognition, emotion, sensation, and imagery simultaneously, and its effects on belief systems emerge organically through processing rather than through deliberate cognitive restructuring.

Somatic Experiencing works primarily through the body’s activation and discharge cycles. EMDR works through the memory networks themselves, using the body as one channel among several.

None of these approaches are antagonists. The skilled clinician holds them as complementary tools, selecting the approach — or integration of approaches — that best serves the person sitting across from them.

In the Medicine Wheel, the Jaguar moves through the forest of the psyche, metabolizing what has been frozen, digesting what has been stuck. EMDR is one of the clearest clinical translations of this ancient principle: healing happens not through avoidance of the wound but through its complete metabolic processing — allowing the intelligence of the nervous system to do what it was always designed to do, if only given the right conditions.

What frozen memory might begin to move if your nervous system were given the right conditions to process it?