Bilateral Stimulation: What It Is and How It Works in EMDR Therapy
Bilateral stimulation refers to rhythmic sensory input that alternates between the left and right sides of the body. It is a core component of Eye Movement Desensitisation and Reprocessing (EMDR) therapy and plays a powerful role in helping the brain process trauma, anxiety, and distressing memories.
In EMDR therapy, bilateral stimulation helps calm the nervous system while supporting the brain’s natural ability to reprocess difficult experiences. It can involve eye movements, tapping, or alternating sounds, all designed to gently activate both hemispheres of the brain.
What Does “Bilateral” Mean?
The word bilateral simply means “affecting both sides.” In the context of EMDR, bilateral stimulation engages both the left and right sides of the brain in a structured and therapeutic way.
Interestingly, we all engage in natural bilateral stimulation every day without realising it. Walking, swimming, running, dancing, or even gently rocking side to side all involve alternating left-right movement.
EMDR therapy harnesses this natural rhythm to support emotional processing and nervous system regulation.
Examples of Bilateral Stimulation
Bilateral stimulation can take many forms, both inside and outside of therapy. Some examples include:
- Following a moving object with your eyes (such as during EMDR eye movements)
- Alternating tapping on your shoulders or knees
- Listening to audio tones that shift between the left and right ear
- Walking or running with steady left-right foot movement
- Rocking gently from side to side
- Rhythmic drumming or alternating hand movements
During EMDR sessions, therapists may use specialised light bars, hand-held pulsers (often called “buzzers”), guided eye movements, or alternating audio tones delivered through headphones.
How Does Bilateral Stimulation Work?
Although research continues to explore the exact mechanisms, bilateral stimulation appears to help the brain integrate traumatic or distressing memories more effectively.
When trauma occurs, memories can become “stuck” in the nervous system. Instead of being processed as past events, they remain emotionally and physiologically active. Bilateral stimulation supports the brain in reprocessing these memories so they can be stored adaptively, reducing their emotional charge.
EMDR also relies on what is known as dual attention. This means the client remains aware of both the distressing memory and the present moment. Bilateral stimulation helps maintain this balance, allowing difficult material to be processed without overwhelming the system.
Slow vs Fast Bilateral Stimulation in EMDR
In EMDR therapy, bilateral stimulation can be delivered at different speeds depending on the phase of treatment.
Slow Bilateral Stimulation
Slower sets are often used in the preparation phase. These help reduce anxiety, stabilise breathing, and build emotional regulation skills. Slow bilateral stimulation can also strengthen positive memories, internal resources, and feelings of safety.
Fast Bilateral Stimulation
Faster sets are typically used during trauma reprocessing. These can activate deeper memory networks and help the brain link distressing memories with updated, more adaptive information. While this phase can feel intense at times, it is carefully guided within a structured therapeutic process.
Does the Type of Bilateral Stimulation Matter?
Eye movements are the most researched form of bilateral stimulation within EMDR. However, tactile stimulation (such as tapping or handheld pulsers) and alternating audio tones are also widely used and effective.
A skilled EMDR therapist will tailor the method to the individual. Some clients prefer eye movements, while others respond better to tactile or auditory stimulation. The key factor is that the stimulation alternates rhythmically between left and right sides.
Conditions That May Benefit from Bilateral Stimulation
Trauma and PTSD
EMDR is internationally recognised as an evidence-based treatment for post-traumatic stress disorder (PTSD). Bilateral stimulation plays a central role in helping traumatic memories lose their intensity and emotional charge.
Anxiety Disorders
EMDR has been shown to be helpful for panic disorder, phobias, obsessive-compulsive patterns, and performance anxiety. By reprocessing the root memory or trigger, clients often experience greater calm and resilience in similar situations.
ADHD and Adverse Childhood Experiences
Some emerging research suggests EMDR may be beneficial for individuals with ADHD who have experienced early adversity. However, bilateral stimulation alone is not considered a standalone treatment for ADHD.
Potential Benefits of Bilateral Stimulation
When used appropriately within EMDR therapy, bilateral stimulation may help:
- Reduce emotional and physiological distress
- Increase relaxation and nervous system regulation
- Improve executive functioning and focus
- Create emotional distance from traumatic memories
- Strengthen coping skills
- Increase resilience
- Improve access to positive beliefs and internal resources
- Reduce symptoms of PTSD, anxiety, and chronic stress
Many clients describe EMDR as helping them “update” old experiences with present-day understanding and perspective.
Is Bilateral Stimulation Safe?
Bilateral stimulation is generally safe when used within a properly structured therapeutic framework. However, EMDR therapy should always be delivered by a trained and accredited clinician.
Occasionally, strong emotions or previously unprocessed memories may surface during therapy. This is why preparation, pacing, and professional guidance are essential parts of the EMDR process.
How to Find an EMDR Specialist
If you are considering EMDR therapy, it is important to work with a therapist who is fully trained in EMDR and experienced in trauma treatment.
At Colchester Counselling & Psychotherapy Practice, we offer professional EMDR therapy delivered by experienced clinicians. You can learn more about our EMDR services and how we work here:
If you would like to explore whether EMDR is right for you, we welcome enquiries and are happy to discuss your needs.
Can You Practice Bilateral Stimulation on Your Own?
EMDR therapy itself should only be carried out by a qualified and trained therapist. Trauma processing requires professional guidance and structure.
However, simple bilateral activities can be helpful in everyday life for calming the nervous system. Walking, gentle rocking, alternating tapping, dancing, or rhythmic drumming can all support regulation.
If you would like guided support, you can also access professionally created bilateral audio recordings here:
Access Bilateral Audio Downloads
These recordings can be used as supportive tools for relaxation and emotional regulation. They are not a replacement for therapy but can complement personal development and wellbeing practices.
Final Thoughts
Bilateral stimulation is a powerful and well-researched component of EMDR therapy. By gently engaging both sides of the brain, it supports the natural processing of trauma and distress.
If you are struggling with trauma, anxiety, or unresolved experiences, EMDR therapy may offer an effective and evidence-based path forward. Working with an experienced clinician can help you move from simply managing symptoms to genuinely resolving the underlying distress.
Dr Tom Barber is an experienced integrative and existential psychotherapist and counsellor, who has been helping people overcome personal challenges for nearly 30 years. He is a bestselling author of 6 books, and spends his time between private clients, teaching and lecturing internationally, writing, and developing programmes to help people improve the quality of their life. Tom is a co-founder of Self Help School, a rich hub of resources and education for people looking for self-improvement. His academic speciality is in the subject of trauma and emotion.
