Bilateral Stimulation and the Brain | Why it Helps Us Heal
Science is still catching up to what many trauma survivors already know | movement heals.
People often describe bilateral stimulation as calming, focusing, even transformative. But how can something as simple as tapping your legs or watching lights move back and forth help untangle years of trauma?
When people first experience bilateral stimulation | whether through eye movements, alternating taps, or rhythmic tones | they’re often surprised by how something so simple can have such a profound calming effect.
Some describe it as grounding. Others say it helps them process difficult memories more clearly and lessens the emotional intensity.
What Is Bilateral Stimulation?
BLS is any sensory input that moves rhythmically back and forth, left to right, and back again. Bilateral techniques can be visual, tactile or auditory.
Visual — moving your eyes slowly from left to right
Tactile — alternating taps on each hand or thigh, or a butterly hug where your hands slowly tap across your heartspace, moving back and forth from left to right
Auditory — alternating sounds in left and right ears through headphones
BLS is most widely known for its use in Eye Movement Desensitization and Reprocessing (EMDR) therapy, a structured and evidence-based approach to treating trauma. But BLS is also beginning to show up in coaching, nervous system work, and self-regulation tools.
While the sensory input may look simple, its effects on the brain are anything but.
What Does the Research Say?
While the exact mechanism of bilateral stimulation is still being explored, studies show that EMDR (which uses BLS) is highly effective in reducing PTSD symptoms. Brain imaging research has shown:
Decreased activation in the amygdala (the fear center)
Increased connectivity in the prefrontal cortex (responsible for regulation and insight)
More balanced activation across hemispheres during emotional recall
What’s notable is that even though researchers continue to debate why it works, clinical outcomes are consistent: bilateral stimulation helps people process trauma more safely and completely.
What this Means for Healing
If you’re in therapy, your clinician may use bilateral stimulation as part of EMDR or somatic integration. But even outside the therapy room, BLS inspired tools are becoming more accessible — like bilateral music tracks which are found on all major music streaming platforms, tapping exercises that can be done sitting on your couch or while in a work meeting, and rhythmic walking meditations.
Literally, just walking, has immediate benefits and recalibrates both of your brain hemispheres.
What matters most isn’t the specific technique; it’s the rhythm, the alternating pattern, and the intention to connect with yourself gently and with curiosity.
But what’s really happening in the brain during bilateral stimulation? And why is this technique so commonly used in trauma therapy?
While the exact mechanism of bilateral stimulation continues to be debated, emerging neuroscience suggests that alternating stimulation may engage memory networks in a unique way | enabling reprocessing of traumatic experiences, without overwhelm. This allows the body, the nervous system, to slowly move through held past traumas in gentle and approachable ways.
BLS been shown to support emotional regulation, memory processing + reconsolidation, and nervous system stabilization which reduces ones stress response.
Lets examine the emerging neuroscience behind this deceptively simple healing tool.
Theory 1 | Dual-Attention Stimulus
One leading theory is that BLS engages dual attention. Your brain is anchored in the present moment while simultaneously accessing a painful memory. This reduces the likelihood of becoming overwhelmed or re-traumatized. The prefrontal cortex is engaged while simultaneously engaging the limbic/emotional memory networks.
In other words, part of your brain is paying attention to the bilateral rhythm (keeping you grounded), while another part is revisiting emotional material. This division of attention creates a kind of safety buffer that allows you to reprocess the memory with less intensity.
This is especially important for people with CPTSD, who often struggle with emotional flooding, dissociation, or feeling hijacked by trauma states.
Theory 2 | Hemispheric Communication
Another hypothesis is that BLS enhances communication and bridges the 2 hemispheres of the brain, allowing for more holistic integration of experience. Our left (logical/verbal) and right (emotional/sensory) hemispheres are both stimulated which may help integrate memories more completely.
Trauma memories are often stored in fragmented, sensory-heavy ways that are hard to describe or understand. The calibration of both brain hemispheres helps turn chaotic sensations into coherent stories.
Bilateral stimulation may serve as a bridge between the fragmented parts of the self.
Theory 3 | Memory Reconsolidation
When we recall a memory, the brain temporarily opens it for editing similar to when we click into a document. If the conditions are right, the brain can reconsolidate that memory with new emotional information. This is a normal brain function, but trauma often blocks it. BLS may allow for an updated version of stored memories.
BLS may create the right conditions for reconsolidation and the emotional intensity of the memory may soften allowing us to “file” the memory rather than continually reliving it. The story is still there and the body no longer reacts as if the event is happening right now.
Theory 4 | Nervous System Regulation
Beyond memory processing, BLS also appears to support nervous system regulation — soothing thru rhythm. Rhythmic bilateral input mimics natural, soothing experiences such as the sway of walking or rhythm of rocking.
These repetitive motions can activate the parasympathetic nervous system (the “rest and digest” state), helping the body shift out of fight-or-flight or freeze responses.
For those living with trauma; especially chronic or developmental trauma, this kind of embodied safety is vital. The brain is wired for healing. We are learning that the simplest rhythms can help unlock the most profound shifts.
What rhythms already exist in your life that help you feel safe, calm, or clear?
