EMDR therapy works by helping your brain process traumatic memories that got stuck and continue causing problems in your present life. It uses a specific technique called bilateral stimulation, which activates both sides of your brain while you briefly focus on a disturbing memory. This helps your brain finish processing what it couldn’t handle at the time of the trauma.

If you’re researching EMDR before starting therapy, you probably want to understand what actually happens in the brain and why this technique helps. Let’s break down the mechanics.

Your brain is designed to process and file away memories automatically. Most experiences get stored in a way that allows you to think about them without reliving them emotionally. The memory of what you had for dinner last Tuesday exists in your mind, but it doesn’t trigger intense feelings when you recall it.

Traumatic experiences are different. When something overwhelming happens, your brain’s normal filing system can get disrupted. The memory doesn’t get processed completely. Instead of being stored as something that happened in the past, it stays active in a way that feels present and threatening.

This is why trauma survivors can be triggered by sounds, smells, or situations that remind them of the original event. Their bodies react as if the danger is still happening because their brains never got the message that it’s over. EMDR helps your brain complete that interrupted processing.

The signature element of EMDR is bilateral stimulation. This means activating both sides of your brain in an alternating pattern. The most common method involves following your therapist’s fingers with your eyes as they move from side to side. But therapists also use other forms of bilateral stimulation, including tapping on alternating hands or knees, or sounds that alternate between your left and right ears.

Researchers are still studying exactly why bilateral stimulation helps with trauma processing. One leading theory connects it to what happens during REM sleep. When you dream, your eyes move rapidly from side to side, and your brain processes the day’s experiences. Some researchers believe EMDR mimics this natural processing system.

Brain imaging studies show that during EMDR sessions, specific areas become more active. The prefrontal cortex, which handles planning and impulse control, lights up. So does the orbitofrontal cortex, which regulates emotions and social interactions. Your brain isn’t passive during EMDR. It’s actively working to reorganize and resolve the traumatic material.

During the processing phase of EMDR, you hold a disturbing memory in mind while engaging in bilateral stimulation. You don’t have to describe every detail out loud. Your therapist will ask you to notice the image connected to the memory, any negative belief you have about yourself because of it, and where you feel it in your body.

Then the bilateral stimulation begins. After a set of eye movements or taps, your therapist pauses and asks what you notice. You might report a new image, a different feeling, a memory you hadn’t thought about in years, or a physical sensation. Your therapist follows your lead, processing whatever comes up naturally.

This continues until the memory loses its emotional charge. The memory itself doesn’t disappear. You still remember what happened. But thinking about it no longer triggers the same intense fear, shame, or panic. It feels like something that happened in the past rather than something that’s happening right now.

Trauma often leaves people with negative beliefs about themselves. Someone who experienced assault might believe they deserved it or that they’re fundamentally damaged. Someone who survived an accident might believe the world is completely unsafe or that they’re helpless.

These beliefs feel true because they’re connected to the unprocessed traumatic memory. As long as that memory stays stuck, the negative belief stays stuck too.

EMDR addresses this by helping you identify and replace these negative beliefs. Early in treatment, your therapist will help you articulate what negative thing you believe about yourself because of the trauma. They’ll also help you identify a positive belief you’d rather have.

As the traumatic memory gets processed, the negative belief naturally loosens its grip. At the end of the processing work, your therapist helps install the positive belief while you continue bilateral stimulation. For many people, this shift feels profound. A belief they’ve carried for years suddenly feels less true, replaced by something more balanced and accurate.

EMDR follows a structured eight phase approach. The first few phases involve building trust with your therapist, learning about the treatment process, and developing coping skills you can use if emotions get intense. Your therapist will also work with you to identify specific memories to target during processing.

The middle phases involve the actual processing work with bilateral stimulation. After working through target memories, your therapist helps you notice any remaining physical sensations connected to the trauma and process those as well.

The final phase involves checking your progress and making sure the benefits are holding. If you’re curious about the specifics of what happens in the first EMDR session, that article goes into more detail.

One of the things that surprises people about EMDR is how quickly it can work compared to traditional talk therapy. Research shows that many trauma survivors see significant improvement in just a few sessions. Some studies found that 84 to 90 percent of single trauma survivors no longer met criteria for PTSD after only three 90 minute sessions.

Complex trauma or multiple traumatic experiences typically require more time. If you’re wondering how many EMDR sessions you’ll need, that depends on your specific history and situation. But in general, EMDR tends to produce results faster than approaches that rely primarily on talking through trauma.

This efficiency exists because EMDR works directly with how your brain stores memories rather than relying only on verbal processing. You don’t have to describe everything that happened in exhaustive detail. Your brain knows what needs healing, and the bilateral stimulation helps it do that work.

EMDR has been extensively researched and is recognized as a safe and effective treatment by major health organizations worldwide. The World Health Organization, American Psychological Association, and Department of Veterans Affairs all recommend it for trauma treatment.

That said, working with traumatic memories can bring up intense emotions temporarily. A qualified EMDR therapist will prepare you for this and teach you coping techniques before beginning the processing work. They’ll also pace the treatment to keep it manageable.

If you have concerns about safety, learning more about whether EMDR therapy is safe and potential risks of EMDR can help you make an informed decision.

If you are in PA and you’re ready to give it a try, our EMDR therapists in Philadelphia provide both online and in person sessions that guide clients safely through the process.

EMDR requires specialized training beyond what therapists learn in graduate school. When you’re looking for an EMDR provider, you want someone who has completed formal training through an EMDRIA approved program. Understanding what training an EMDR therapist should have helps you ask the right questions when choosing a provider.

EMDR has been around since the late 1980s, and over 100,000 clinicians worldwide have been trained to use it. Finding someone qualified in your area is usually possible, and EMDR can also be done effectively online if that works better for your situation.

EMDR works well for many people, but it’s not the only option for trauma treatment. Some people prefer talk therapy approaches that allow them to verbally process their experiences in detail. Others have situations where a different approach makes more sense.

If you’re trying to decide whether EMDR fits your needs, talking with a therapist who offers it is a good starting point. They can assess your situation and discuss whether EMDR makes sense for what you’re dealing with. Learning more about how to know if EMDR is right for you can also help you think through the decision.

We offer in-person EMDR therapy at our Philadelphia and Haddonfield offices, with online sessions available for clients anywhere in Pennsylvania and New Jersey.

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