The Emotionality of a Memory: The Working Mechanisms Behind EMDR

Have you ever wondered how a person who has experienced or witnessed a traumatic event eventually goes back to baseline? How can the mind make sense of such a deeply distressing thing? How can it ever get over such an event? 

Trauma itself can be understood as an emotionally painful experience that overwhelms a person’s capacity to cope, a perpetual state of feeling profoundly out of control (Manzoni et al., 2021). Traumatic experiences may include life-threatening events, but also physical, emotional, or sexual abuse, neglect, and chronic exposure to household dysfunction o conflict. Regardless of form, these experiences can shatter one’s sense of safety, trust, and predictability of the world. After exposure to trauma, it is normal to develop strong emotional and physiological reactions; it is a normal response to an abnormal experience. However, when these reactions persist and begin to dominate daily life, they may evolve into Post-Traumatic Stress Disorder (PTSD). PTSD represents a disruption in the brain’s ability to process and integrate overwhelming experiences into normal autobiographical memory. Instead of being stored as part of the past, traumatic events remain vividly alive in the nervous system, replaying through flashbacks, nightmares, intrusive thoughts, and intense physiological reactions. The body and mind respond as if the danger is still happening in the present (Kazdin & Weisz, 2003).

The disorder is characterized by intrusive symptoms (like the headlights rushing towards Anna); avoidance symptoms; hyperarousal; and negative changes in thoughts and mood.

At the core of PTSD lies the way maladaptive memories are encoded. According to the Adaptive Information Processing (AIP) model, PTSD symptoms develop when traumatic experiences, and therefore their memories, are encoded in a dysfunctional and maladaptive way, causing persistent re-experiencing and fear responses (de Jongh et al., 2024). Traumatic memories tend to be stored as vivid sensory and emotional fragments rather than coherent narratives. The brain fails to integrate these experiences properly, leaving them “stuck” in a raw, unprocessed state. These vivid, easily triggered memories perpetuate the distress, as reminders of the trauma continuously reactivate the same physiological and emotional responses that were experienced originally.

While interventions such as Trauma-Focused Cognitive Behavioural Therapy (TF-CBT) are widely used to treat PTSD, one particularly intriguing approach is Eye Movement Desensitization and Reprocessing (EMDR) therapy. EMDR is widely recognized for its unique ability to facilitate emotional healing, often long after the original traumatic event. Based on the AIP model, the therapy follows an eight-phase protocol targeting PTSD symptoms and the anxiety linked to future threats.

The treatment begins with establishing a strong therapeutic alliance, which involves creating a trusting and secure client-therapist relationship. Once this crucial step is achieved, the process continues with the collaborative discussion of treatment goals, expectations, and EMDR psychoeducation. The client also learns emotional regulation and grounding techniques to manage distress, as explicit retrieval of traumatic memories forms the core of the process (Hase et al., 2018).

Once the target traumatic memory is identified, including its associated images, beliefs, feelings, and bodily sensations, the Desensitization phase begins. Here, the mechanism of dual-attention bilateral stimulation plays a central role. This involves the client recalling the traumatic memory while simultaneously engaging in sets of eye movements, alternating taps, or auditory tones.

According to the working memory taxation hypothesis, this dual-tasking reduces the vividness and emotional intensity of the memory. Working memory can perform multiple tasks across different domains (e.g., verbal, visuospatial, problem-solving), but each has a limited capacity. When a person retrieves a traumatic image while simultaneously performing a demanding visuospatial task, such as tracking the therapist’s moving fingers, the competition for working memory resources makes it difficult to fully retain the vividness of the memory. Consequently, when the memory is reconsolidated back into long-term storage, it is integrated in a less distressing and more adaptive form.

Another proposed mechanism, the interhemispheric interaction hypothesis, suggests that inducing horizontal eye movements increases communication between the brain’s hemispheres, thereby enhancing memory integration and emotional regulation. Some studies have found that horizontal eye movements improve episodic memory accessibility more effectively than vertical movements or fixation (de Jongh et al., 2024).

The last part of EMDR involves the installation of a positive cognition that the client wants to associate with the traumatic event until it feels completely true.  This process involves the replacement of the negative self-belief associated with the trauma (“I am powerless”) with an adaptive one (“I am in control now”). Finally, returning to a state of calm in the present.

So, what happens to the emotionality of the memory? EMDR does not delete or erase traumatic memories, but rather transforms how they are experienced. Through reprocessing, the memory shifts from being a vivid, emotionally charged fragment to an integrated, coherent narrative belonging to the past. The emotional and physiological charge attached to the event diminishes, enabling the person to recall the memory without having to relive it. In other words, the memory remains, but the emotional pain is no longer dominant. This transformation reflects the brain’s remarkable capacity for adaptive information processing, turning raw survival responses into meaningful, tolerable recollections that no longer govern the present.

EMDR is more than just an intervention. It demonstrates that while we cannot change the past, we can change our relationship to it. Through the brain’s natural ability to reorganize and heal, emotional memories lose their power to overwhelm, and the person regains agency over their inner world. Anna knows she cannot change what happened to her, but she can patiently teach her body what no longer needs to be feared, slowly taking back control of her life.