Helinä Häkkänen, psychologist and psychotherapist | August 2026
Many people considering EMDR therapy ask the same question: how does EMDR work? The question is understandable. EMDR, or Eye Movement Desensitization and Reprocessing, can sound unusual at first because it involves processing difficult memories while the client follows a moving stimulus with their eyes or receives another form of bilateral stimulation.
At its core, EMDR therapy is based on the idea that the brain has a natural ability to process experiences. Most difficult events gradually become part of a person’s life story. We may remember what happened, but the memory no longer disturbs us in the same way. Sometimes, however, an experience is too overwhelming, frightening, shame-inducing or emotionally intense. In these situations, the brain’s natural information processing may become disrupted. The memory can remain stored in the mind and body in a form that continues to activate emotions, bodily reactions, thoughts and behavioural patterns in the present.
EMDR therapy helps the brain reprocess these memories in a structured and safe way. Important concepts include the AIP model, bilateral stimulation, the working memory hypothesis and EMDR’s mechanism of action. Together, they help explain why a painful memory can remain disturbing — and how its emotional intensity can begin to decrease.
In this article, we explain how EMDR therapy works. If you are interested in eye movement therapy, you can continue reading on Mindroot’s EMDR therapy service page or contact us to ask whether EMDR could be suitable for your situation.
How does EMDR therapy work?
Most often, bilateral stimulation means side-to-side eye movements. The client follows a moving stimulus with their eyes while keeping the memory in mind. Bilateral stimulation can also be provided through alternating sounds or tactile stimulation. The goal is not to erase the memory. The goal is to help the brain process the memory again, so that it can connect with broader, more realistic and more adaptive information.
For example, a person may rationally know that they were not responsible for what happened, but the memory may still feel like guilt, shame or danger in the body. EMDR therapy works with this gap between what the person knows and what the nervous system still reacts to.
After successful EMDR processing, clients often describe the memory as more distant, less vivid, less disturbing or better organised. The event is still remembered, but it no longer feels as if it is happening in the present.
The AIP model in EMDR therapy
The AIP model stands for Adaptive Information Processing. It is the central theoretical model behind EMDR therapy.
According to the AIP model, human beings have a natural capacity to process experiences and connect them to broader memory networks. When this process works well, even a difficult experience can gradually settle into the past. The person remembers what happened, but the memory no longer repeatedly disturbs the present.
In traumatic or highly stressful situations, this natural processing can become blocked. The experience may remain stored in the mind and body in a form that still contains the emotions, thoughts, sensations and bodily reactions from the original event.
In this case, the memory is not simply a memory. It is an active memory network that can be triggered in the present.
A sound, facial expression, smell, place, touch or situation may activate the old memory network. The present situation may be safe, but the nervous system reacts as if the old threat has returned.
From the perspective of the AIP model, the aim of EMDR therapy is to help an unprocessed memory connect with a more adaptive memory network. In practice, this means that the memory can begin to connect with information that was not fully available at the time of the event:
Why can a traumatic memory feel like the present?
Many clients describe the same contradiction before starting EMDR therapy: “I know it is over, but it does not feel that way.”
This sentence captures something essential about trauma memory. The person may know that the event has ended, but that knowledge is not fully connected to the memory network where fear, shame, helplessness or worthlessness still lives.
A traumatic or highly stressful memory can become activated in the body before the person has time to think rationally. The heart may start racing, breathing may change, the body may tense, the mind may become foggy, or the person may feel an urgent need to escape. In that moment, the person is not reacting only to the present. They are also reacting to what the past has taught the body.
This is why insight alone is not always enough. A person may understand their experience very well and still react to it strongly. EMDR therapy works with this difference between rational understanding and emotional or bodily memory.
What is bilateral stimulation?
Bilateral stimulation means alternating stimulation of both sides of the body or perceptual field. In EMDR therapy, this may include:
- side-to-side eye movements
- alternating sounds through headphones
- alternating tactile stimulation in the hands
- therapist-guided tapping or another rhythmic stimulus
The best-known form is eye movement, which is why EMDR is sometimes described as eye movement therapy. However, EMDR is not based only on eye movements. What matters is that the client holds the memory, or part of the memory, in mind while attention is also directed toward a repeated bilateral stimulus.
Many people ask why the eyes are moved in EMDR therapy. A simple way to explain it is this: during EMDR processing, the mind is doing two things at the same time. It is bringing up a difficult memory and following a stimulus. This may support memory processing and reduce the emotional intensity of the memory.
Bilateral stimulation is not a separate technique used on its own. It is part of a wider EMDR treatment process that includes assessment, preparation, target memory selection, safe processing and follow-up.
The working memory hypothesis in EMDR
The working memory hypothesis is one of the main explanations for how EMDR therapy may reduce the emotional intensity of disturbing memories.
Working memory refers to the limited mental capacity we use to hold information actively in mind in the present moment. When a person recalls a disturbing memory, that memory takes up working memory capacity. If another task is performed at the same time, such as following a moving stimulus with the eyes, working memory becomes further taxed.
This is thought to affect how vivid and emotionally intense the memory remains. When holding the memory in mind and following the stimulus compete for the same limited capacity, the memory may become less vivid and less emotionally powerful.
In practice, the client may notice that an initially sharp mental image becomes more distant, less clear or less physically activating. Sometimes the memory seems to lose its grip. It does not disappear, but it no longer feels as powerful.
The working memory hypothesis does not explain everything that happens in EMDR therapy, but it helps explain why eye movements and other forms of bilateral stimulation can play an important role in reducing the emotional intensity of a memory.
What is EMDR’s mechanism of action?
When discussing EMDR’s mechanism of action, it is important to be precise. EMDR therapy has been widely studied, especially in the treatment of post-traumatic stress disorder, but its exact mechanism is still understood through several complementary models.
One explanation is related to the AIP model. From this perspective, EMDR helps an unprocessed memory connect with broader and healthier memory networks.
Another explanation is related to working memory. Holding the memory in mind while receiving bilateral stimulation taxes working memory, which may reduce the vividness and emotional intensity of the memory.
A third explanation is related to dual awareness. In EMDR therapy, the client is connected both to the past memory and to the safety of the present therapy situation. The client is not fully in the past, but they are not avoiding it either. This can help the nervous system update the experience: It happened then, but I am here now.
EMDR therapy is therefore not simply about moving the eyes. It is about activating a memory in a safe therapeutic setting while supporting the brain’s information processing, so that the memory can become less disturbing and better integrated.
Why EMDR therapy is not just exposure
EMDR therapy is sometimes compared to exposure therapy because both involve facing difficult material. However, EMDR is not the same as prolonged exposure.
In EMDR therapy, the client usually does not need to describe the traumatic event at length and repeatedly. The therapist needs to understand enough about what is being processed, but the core of EMDR is not repeated storytelling. It is memory processing.
The client holds in mind the essential parts of the memory: the image, the negative belief, the emotion and the bodily sensation. After that, the process is allowed to unfold. New thoughts, memories, bodily sensations or insights may arise. The therapist follows the process and ensures that the work remains safe.
For many clients, this is reassuring. EMDR therapy does not require the most difficult experiences to be described in detail again and again.
Why the body matters in EMDR therapy?
Difficult memories are not stored only as words or images. They may also be stored as bodily reactions.
A client may say that the memory feels like pressure in the chest, a lump in the throat, tension in the stomach, numbness in the hands or restlessness in the legs. Sometimes the body reacts before a clear image or thought appears in the mind.
In EMDR therapy, bodily sensations are important because they show where the disturbance appears in the present. When the memory begins to process, the bodily reaction may also change. Breathing may deepen, shoulders may lower, pressure in the chest may ease or restlessness may decrease.
This is one reason why EMDR therapy can feel different from ordinary conversation. The work does not happen only at the level of words. Emotions, images, bodily sensations and memory networks are all involved.
Can EMDR work if the memory is unclear?
Not all memories are clear. Sometimes the client has only a feeling, a bodily reaction or fragmented images. Sometimes they do not know where their anxiety, shame, fear or shutdown originally comes from.
EMDR therapy can also be used in these situations, but it requires care. Sometimes the work begins with the present-day reaction: in what situation the feeling becomes activated, what thought is connected to it and where it is felt in the body. This can lead to earlier memories or memory networks connected to the current symptom.
Everything does not need to be known in advance. At the same time, it is important that treatment proceeds with enough stability and that the therapist assesses when memory processing is safe to begin.
Does EMDR erase memories?
One common misunderstanding is that EMDR therapy erases memories. It does not. The purpose of EMDR is not forgetting.
Often the memory remains, but its emotional charge changes. The person may remember what happened, but the memory no longer brings up the same fear, shame, guilt or shutdown. It may feel more distant, calmer or more clearly in the past.
This is an important distinction. Healthy processing does not mean that what happened is minimised or denied. On the contrary, after EMDR therapy, the person can often look at what happened more clearly because the memory no longer pulls them in with the same force.
What happens in an EMDR session?
Before actual memory processing begins, the therapist explores the client’s situation, symptoms, background and resources. EMDR therapy always includes preparation. It is important that the client understands what is being done and why.
When a target memory is selected, the therapist may ask questions such as:
- What image represents the worst part of the memory?
- What negative belief about yourself is connected to this memory?
- What would you like to believe about yourself now instead?
- What emotions does the memory bring up?
- How disturbing does the memory feel on a scale from 0 to 10?
- Where do you feel it in your body?
After this, bilateral stimulation begins. The therapist asks the client to notice what happens in the mind or body. The process may move through memories, thoughts, emotions, bodily reactions or new perspectives. Not everything needs to be analysed out loud.
What matters is that the client remains sufficiently stable and knows they can stop the work at any time.
Summary: how does EMDR therapy work?
EMDR therapy is based on the idea that difficult experiences can remain stored in the mind and body as unprocessed memories. When this happens, they may become activated in the present as emotions, thoughts, bodily reactions and behavioural patterns.
The AIP model explains how these memories may remain separate from more adaptive information. EMDR therapy aims to help them connect with broader and healthier memory networks.
Bilateral stimulation, such as eye movements, sounds or tactile stimulation, supports this process. According to the working memory hypothesis, holding the memory in mind while following a simultaneous stimulus taxes working memory, which may reduce the vividness and emotional intensity of the memory.
EMDR’s mechanism of action is not one simple process. It involves memory activation, working memory taxation, bodily processing, safe dual awareness and the connection of new, more adaptive information to an old memory.
In short: EMDR does not change the past and it does not erase the memory. It helps the mind and body process the memory again, so that the past can begin to feel like the past.
Next, you can visit Mielenjuuri’s EMDR therapy service page or contact us_if you would like to discuss whether EMDR treatment could be suitable for your situation.
More EMDR articles:
- How Does EMDR Therapy Work? The AIP Model, Bilateral Stimulation and the Brain’s Ability to Process Information
- How does EMDR treatment proceed? The eight phases of the process
- What is EMDR therapy used for? Help with trauma, anxiety, depression and burnout
- Is EMDR therapy effective? A review of the research evidence
- Specialized applications of EMDR therapy: from sport psychology to forensic psychology
- The history of EMDR therapy: from Francine Shapiro’s discovery to a global treatment method
