What Is Bilateral Stimulation?

Bilateral stimulation (BLS) is a rhythmic, alternating sensory input that engages both hemispheres of the brain. Originally developed by Dr Francine Shapiro in 1987 as the core mechanism of EMDR (Eye Movement Desensitisation and Reprocessing) therapy, BLS is now recognised as a powerful technique for emotional regulation and trauma processing.

How It Works

BLS activates the brain's natural information processing system, similar to what occurs during REM sleep. The alternating left-right stimulation is believed to:

• Engage both hemispheres of the brain, improving communication between emotional and rational processing regions
• Calm the amygdala, the brain's fight-or-flight centre, reducing the intensity of distressing emotions
• Tax working memory, reducing the vividness and emotional charge of intrusive thoughts or memories
• Activate the parasympathetic nervous system, shifting the body from a stress response into a calmer state

Three Modes

• Visual — Follow the dot with your eyes as it moves left and right. This is the most researched form of BLS and mirrors the eye movements used in EMDR therapy
• Audio — Alternating tones between left and right ears (requires headphones). Useful if eye movements feel uncomfortable or activating
• Both — Combined visual and auditory stimulation. Many people find this the most immersive experience

When to Use

• Emotional regulation — When feeling overwhelmed, anxious, or triggered, BLS can help return you to your window of tolerance
• Grounding — As a self-soothing technique to stay present during moments of dissociation or distress
• Resource installation — To strengthen positive memories, affirmations, or safe-place imagery (under therapist guidance)
• Stress relief — Short sessions can reduce everyday anxiety and promote calm

Speed Guide

• Slow — Best for grounding, emotional regulation, and highly activated states
• Medium — General purpose, suitable for most uses
• Fast — Mimics the speed used in EMDR desensitisation phases; more taxing on working memory

The 5-4-3-2-1 Grounding Technique

If you feel overwhelmed at any point, pause and notice:

• 5 things you can see
• 4 things you can feel
• 3 things you can hear
• 2 things you can smell
• 1 thing you can taste

This sensory awareness exercise brings you back to the present moment and helps regulate your nervous system.

Evidence Base

EMDR is recognised as an effective treatment for PTSD by the World Health Organization, the American Psychological Association, and the Phoenix Australia Centre for Posttraumatic Mental Health. Over 30 randomised controlled trials support its efficacy, and bilateral stimulation has been shown to:

• Significantly reduce amygdala activation during emotional processing
• Increase serotonin and dopamine availability
• Produce outcomes comparable to in-person delivery when used remotely
• Maintain treatment effects at 6-12 month follow-up

This tool is for wellbeing support and is not a substitute for professional therapy. If you experience persistent distress, please contact your healthcare provider or call Lifeline on 13 11 14 (Australia).