What is bilateral stimulation? How it works, and how to try it

Where it comes from

Bilateral stimulation comes from EMDR. In 1989, Francine Shapiro described a procedure that used rhythmic side-to-side eye movements while a person held a memory in mind. Today people practise the left-right rhythm on its own, with their hands, a video or a screen. Practising it at home isn't EMDR therapy. It's a practice you run yourself.

Types of bilateral stimulation

• Visual: your eyes follow a dot, ball or light moving from side to side, without turning your head.
• Auditory: a tone plays in one ear, then the other. Headphones make the switch clear.
• Tactile: you tap alternate knees, hands or shoulders, like the butterfly hug.
• Movement: everyday left-right rhythms such as walking.

How does it work?

"By just following someone's fingers?" is a fair question. One leading idea comes from researchers who study working memory, the small mental space you use to hold things in mind. When you hold a memory while following a moving dot, both compete for that space, and in lab studies memories recalled this way tended to feel less vivid afterwards. Those were lab studies, not self-practice or any app, including ours.

You may also read that it "balances the two sides of the brain" or copies REM sleep. Those ideas are popular, but they aren't settled.

What does it feel like?

Usually gentler than people expect. You might notice your thoughts move from one thing to the next, your attention settle on the rhythm, or very little at all. All of that is normal. There's no wrong way to do it.

Is bilateral music the same as binaural beats?

No. Bilateral audio alternates: a sound plays in your left ear, then your right. Binaural beats play two slightly different tones in both ears at once. Only the alternating kind is bilateral stimulation.

Try it at home

The butterfly hug (about 1 minute)

1. Cross your arms over your chest, hands resting near the opposite collarbones.
2. Tap slowly, left hand then right hand, and breathe normally.
3. After 30 to 60 seconds, stop and notice how you feel.

Follow the ball (about 3 minutes)

1. Open Mend's free guided video and follow the moving ball. Turn the sound on if you'd like the tones too.
2. Bring something light to mind, around a 2 or 3 out of 10. It doesn't need to be a memory.
3. Follow the ball with your eyes for about 30 seconds, then pause and breathe. Repeat two or three times.
4. Finish by looking around the room and naming five things you can see.

Practise with Mend

Mend is a self-guided, EMDR-informed bilateral stimulation practice for adults to use at home. It's for when sessions cost too much, no one nearby offers them, there's a waitlist, or you'd rather not open up to a person.

A Mend session starts with a free worksheet to choose your focus: a memory, a feeling, a body sensation or a trigger. Then you follow the moving ball through three parts: your focus, the belief you'd rather hold, and a closing check-in to wind down.

• Free: the guided video, with a recorded voice, on YouTube or ad-free here by email.
• Plans: add a computer-generated voice guide that talks you through, answers questions and slows or pauses the ball. Complete is US$39 a month with the voice included; Connected is US$19 a month on your own ChatGPT Plus or Pro. Both renew monthly, cancel any time.

Mend isn't crisis support. If a session leaves you feeling worse, or you find it hard to stay present, stop and talk to a qualified practitioner.

Ready when you are

Not sure you're doing it right? Get talked through every step, at home, on your schedule.

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