What is Bilateral Stimulation?
Bilateral Stimulation, often shortened to BLS, simply means gently stimulating the left and right sides of the body in an alternating rhythm.
In EMDR therapy with children this can be done in several ways, including:
moving the eyes from side to side
alternating taps on the hands, knees or shoulders
listening to sounds that alternate between the left and right ear
drumming
sword fighting
marching
holding small tactile buzzers that gently vibrate from one hand to the other.
Why is BLS used in EMDR?
EMDR helps the brain work with experiences, emotions, thoughts and body sensations that may have become "stuck" or continue to trigger a strong response even though the danger or difficult experience has passed. During trauma or overwhelming experiences, information may not be processed and integrated in the same way as ordinary memories. Later, something that reminds the brain of the original experience can activate parts of that memory network, including emotions, body sensations, beliefs or survival responses. Bilateral stimulation is one part of the EMDR process that appears to support the brain's natural information-processing system while the person remains aware that they are here, now and safe.
Researchers are still studying exactly why BLS is helpful. There are several theories, including effects on attention, working memory, orienting responses and the way emotional memories are reconsolidated. It is therefore best understood as one component of EMDR rather than something that works by itself.
Why do you use the tactile buzzers throughout therapy?
Although people often associate bilateral stimulation with processing traumatic memories, I may use gentle tactile BLS at different stages of EMDR therapy. The purpose changes depending on what we are doing.
Building safety and regulation
Before working with difficult material, we spend time developing skills that help the nervous system feel settled and organised. Gentle, slower BLS can sometimes accompany calming imagery, grounding exercises, breathing, positive memories or other resources. For some children, the predictable left-right rhythm itself feels organising and helps them notice their body without becoming overwhelmed.
Strengthening helpful experiences
BLS can be used briefly while a child focuses on something they would like their brain to remember more strongly. This is sometimes described as strengthening or installing a resource.
Supporting dual attention
An important part of EMDR is being able to notice something difficult while also knowing that it is happening in the therapy room, in the present moment. The buzzers can provide a gentle physical reminder of the present, "part of my brain is noticing the memory, and another part of my brain knows I am sitting here with my therapist". This is particularly useful for children who can become very absorbed in thoughts, memories or strong emotions.
During memory processing
When we are specifically processing a difficult experience, BLS is usually delivered in short sets. We periodically stop, check what the child is noticing - perhaps an image, thought, feeling, body sensation, memory or sometimes nothing at all - and decide together whether to continue.
Helping the session finish well
If difficult material has been activated but processing is not complete, BLS may also be incorporated into grounding or containment strategies before the child leaves the session.
Why tactile buzzers rather than always using eye movements?
There is no single form of bilateral stimulation that is right for everyone. I particularly like tactile buzzers with children and adolescents because they are, gentle and predictable, easy to adjust in speed and intensity, less demanding than visually tracking something, useful whether the child's eyes are open or closed, compatible with drawing, talking, play and other therapeutic activities, easy to stop immediately, often experienced as grounding and regulating.
Some children prefer eye movements, tapping or no BLS during particular activities. We can change the method at any time.
Does BLS mean my child is processing trauma every time the buzzers are on?
No. This is an important distinction. Using the buzzers does not automatically mean that we are accessing or processing a traumatic memory. At different points in therapy I may use them simply to support: grounding regulation orientation to the present positive experiences confidence coping strategies body awareness attachment or connection resources.
When we are specifically processing distressing memories, I will explain what we are doing and make sure the child has sufficient preparation and support. Your child remains in control. EMDR should be collaborative. Children are encouraged to tell me if they want the buzzers slower or faster, stronger or softer, moved to a different position, paused or stopped completely. We also establish a clear stop signal, so the child knows they can pause the process at any time without having to explain why.
The aim is not to make a child relive an experience or force them through distress. The aim is to help their brain approach difficult material in a carefully paced, developmentally appropriate and tolerable way, while maintaining connection with the safety of the present.
