What Is Bilateral Stimulation? How It Calms Your Nervous System and Ways to Incorporate BLS into Your Life.
Ever notice how a good cry feels a little more manageable after a long walk? Or how the dishes somehow untangle your thoughts better than sitting still ever does? That's not a coincidence. Your nervous system has an old, reliable reset button, and you've probably been pressing it your whole life without knowing its name: bilateral stimulation.
If you've heard of EMDR (Eye Movement Desensitization and Reprocessing) therapy, you've likely heard the term "bilateral stimulation," or BLS, tossed around. It sounds clinical — and in an EMDR session, it is a specific, intentional tool. But the underlying concept isn't new, and it isn't confined to a therapist's office. Your body has been generating its own version of it for as long as you've been alive, through rocking, walking, even dreaming.
Let's talk about what bilateral stimulation actually is, why your nervous system responds to it, and the everyday ways you're likely already using it.
What Is Bilateral Stimulation?
Bilateral stimulation refers to any rhythmic, alternating input to the left and right sides of the body or brain: left, right, left, right. It can be visual (eyes tracking side to side), auditory (alternating sound between ears), or physical (tapping, movement, touch).
In EMDR, we use bilateral stimulation with intention, often through a lightbar that guides your eyes back and forth, alternating tones through headphones, or gentle tapping. This structured BLS supports the brain in processing memories or experiences that got "stuck," helping your nervous system finish something it started but couldn't complete on its own.
Here's the part we love pointing out to clients: your body has been generating its own version of BLS long before EMDR existed as a modality. Anything that creates a steady, alternating left-right rhythm can have a similar calming, organizing effect on your nervous system, no lightbar required.
Why Bilateral Stimulation Matters for Nervous System Regulation
To understand why BLS works, it helps to understand a bit about how your nervous system operates. When you experience stress, fear, or overwhelm, your body shifts into a protective state: fight, flight, freeze, or fawn. That's a normal, adaptive response. The trouble starts when your nervous system gets stuck there, long after the actual danger has passed.
Bilateral stimulation appears to support communication between the brain's two hemispheres, which helps with the kind of integration that lets you process an experience instead of staying flooded by it. Rhythmic, alternating movement also tends to activate your parasympathetic nervous system, the "rest and digest" side of your stress response, which is a big part of why rocking a baby, going for a swim, or listening to a steady beat can feel so settling.
In other words, BLS isn't soothing only because it feels nice (though it often does). It's soothing because your nervous system is, quite literally, built to read rhythm and alternation as a cue of safety.
Natural Forms of Bilateral Stimulation You're Already Using
You don't need special equipment to access the benefits of BLS. Here are some of the most common natural forms, several of which are probably already part of your week.
Rocking
Swaying in a hammock, rocking in a chair, or shifting your weight gently from foot to foot: this back-and-forth motion is one of the oldest, most instinctive forms of BLS. It's often the first form of regulation we ever experience, since it's frequently how we were soothed as infants.
Exercise and Sports
Running, walking, swimming, cycling: any activity with a steady, alternating left-right pattern counts. This is part of why a walk can shift your mood even when it doesn't "solve" anything, and why so many people describe a run as clearing their head.
Reading
As your eyes move slowly back and forth across a page, you're engaging in a mild, visual form of bilateral stimulation. This is one reason curling up with a book can feel regulating in a way that scrolling a phone (with its quick, erratic eye movements) usually doesn't.
Listening to BLS or Rhythmic Music
Music mixed to alternate between your left and right ear, sometimes marketed specifically as "BLS music," mimics the alternating pattern used in EMDR sessions. Even without specialized tracks, music with a steady, alternating rhythm can have a similar calming effect. Listening with headphones is important, so the music/sounds directly stimulate one ear and then the other - rather than through speakers where both ears are engaged at the same time.
Dreaming (REM Sleep)
During REM (rapid eye movement) sleep, your eyes move rapidly back and forth as your brain processes and consolidates the day's experiences. This is actually part of the inspiration behind EMDR: the lightbar used in sessions is designed to mimic REM, giving your waking brain access to a similar processing mechanism.
Back Rubs and Scratches
A back-and-forth back rub, or someone scratching your back in slow, alternating strokes, is a physical, touch-based form of BLS. It's a big part of why this kind of touch can feel so disproportionately calming: your nervous system is registering the rhythm, not just the affection behind it.
Other Natural BLS You Might Not Have Considered
The butterfly hug: crossing your arms over your chest and gently, alternately tapping each shoulder. This is often taught as a self-soothing technique precisely because it's a portable, on-demand form of BLS.
Drumming or rhythmic tapping: tapping your knees, a table, or a drum in an alternating left-right pattern.
Dancing: especially styles with a clear alternating step pattern.
Rowing, paddling, or canoeing: the steady, alternating pull is BLS built right into the activity.
Raking, kneading dough, or other repetitive back-and-forth chores: which may explain why "mindless" tasks like these can feel oddly therapeutic.
How This Connects Back to EMDR
None of this means natural BLS replaces EMDR, and we want to be upfront about that. EMDR is a structured, evidence-based therapy that uses bilateral stimulation in a very specific, clinically supported way to help process trauma and distressing memories. It's not the same as a walk around the block.
What natural BLS can do is support your nervous system's baseline capacity for regulation, day to day. Think of it as maintenance, not treatment. If you're carrying something heavier that a walk or a good book can't quite touch, that's often a sign it's worth exploring with support, whether that's through EMDR, Brainspotting, or another approach that fits what you're carrying.
Frequently Asked Questions About BLS
What is bilateral stimulation?
Bilateral stimulation (BLS) is any rhythmic, alternating input to the left and right sides of the body or brain, such as alternating eye movement, sound, or touch. It's used intentionally in EMDR therapy and also occurs naturally in everyday activities like walking or rocking.
Is bilateral stimulation the same as EMDR?
No. EMDR is a structured therapy that uses bilateral stimulation as one of its tools to help process trauma and distressing memories. Bilateral stimulation on its own, like rocking or listening to alternating music, can support nervous system regulation, but it isn't a substitute for EMDR therapy.
Can I do bilateral stimulation on my own at home?
Yes. Natural forms like walking, reading, listening to rhythmic music, or using the butterfly hug technique can support day-to-day regulation. If you're working through more significant distress or trauma, working with a trained EMDR therapist is recommended.
Why does rocking or rhythmic movement feel calming?
Rhythmic, alternating movement appears to activate the parasympathetic nervous system, the part of your body responsible for rest and recovery, which is part of why activities like rocking, walking, or swimming can feel so settling.
A Gentle Reminder
Your nervous system is smart. It's been finding ways to regulate itself, often without your permission or awareness, for your entire life. Noticing the BLS you already have access to (a walk, a book, a hammock) can be a genuinely useful tool. And if you find yourself needing more support than a hammock can offer, that's not a failure. That's just information about what you're working with.
Begin Healing With Conscious Roots Counseling
We specialize in trauma-informed, compassionate care for adults. Our therapists offer:
Online and in-person options across Cincinnati, OH
A gentle, attuned approach at your pace
Tools to build safety, connection, and self-trust
If you're ready to get started, visit our therapy for EMDR page to learn more detailed information about our approach, or contact us to set up an appointment.
Written by Jenny Liu, LPCC-S
Owner and Therapist at Conscious Roots Counseling
You can email her: jenny@conscious-roots.com
