Bilateral Stimulation: Definition, Methods, Benefits, and Effectiveness

What Is Bilateral Stimulation?

Bilateral stimulation, drawing from EMDR therapy, is sometimes referred to as “resource installation” or “resource tapping” and is a method of processing traumatic memories and recalling and strengthening resources. These resources can take the form of positive emotional experiences; memories of safety; experiences of power and courage; or images that evoke peace, comfort, safety, courage, or calm. Most commonly, bilateral stimulation is used as a part of EMDR therapy. It helps people recall fragmented traumatic memories to integrate and process them.²

During psychotherapy, therapists often ask their clients to imagine a safe memory or place. When bilateral stimulation is added to this visualization, the process is even more calming and provides a sense of control over a client’s distress. This is referred to as “installing a safe space.” This process can also aid in creating resources involving nurturing figures, protector figures, and inner wisdom figures to help treat clients who experienced childhood trauma.²

What Does Bilateral Stimulation Do?

Bilateral stimulation helps people process traumatic memories. Francine Shapiro, a psychologist who developed EMDR therapy and bilateral stimulation in the late 1980s, found that people who practiced bilateral stimulation could process trauma more quickly than those who didn’t.² The practice increases communication between the left and right hemispheres of the brain.³

Bilateral stimulation increases a client’s and therapist’s ability to access traumatic memories and makes focusing on such memories less unpleasant.⁴ It activates both hemispheres of the brain in a similar way that REM (rapid eye movement) sleep does; like bilateral stimulation, people in REM sleep move their eyes rapidly and process and integrate information.²

During a bilateral stimulation session, the therapeutic process may evoke emotions, bodily sensations, and thoughts associated with a traumatic memory. The person may have dreamlike fantasies or old memories that move quickly in and out of their awareness. The client can try to remain mindfully aware of these various stimuli, if they are tolerable, and perhaps better understand what they might mean in the context of their lives. A sense of non-judgmental awareness and curiosity towards these emerging symptoms may better serve the client not to deny or avoid these symptoms but perhaps eventually come to accept their presence in their lives. These new insights and perspectives on themselves and their lives may increase health and wholeness.²

How Does Bilateral Stimulation Work?

Traumatic memories are not processed and stored the way other memories are because, during a traumatic experience, a person’s information processing system is derailed. This leaves memories fragmented, unprocessed, and can cause symptoms and issues that disrupt a person’s life. Because they are fragmented and unprocessed, even the slightest triggers can induce panic. Bilateral stimulation helps clients process these fragmented memories and reduce the associated symptoms.²

There are several methods used in bilateral stimulation sessions within the paradigm of EMDR therapy. One popular method is called binaural stimulation, a form of sound healing, where the client listens to a beeping sound through headphones that alternate between their left and right ear. Practitioners use binaural beats in about half of their bilateral stimulation sessions.³ Another common method of bilateral stimulation includes rhythmic eye movements. In this method, the client typically follows the therapist’s finger or a technical device with their eyes as it moves in a horizontal motion. Though horizontal movements are the most common, sometimes the direction is vertical, oblique, or ellipsoid.⁵ Research has found that bilateral eye movements can activate the brain to shift into a memory processing mode to access and consolidate traumatic memories.⁴ Additionally, simply tapping a client’s hands or knees, alternating sides, can produce the effects of bilateral stimulation.² Several therapies incorporate tapping into their technique, including emotional freedom techniques (EFT) and thought field therapy (TFT).

Neurologically, bilateral stimulation works by increasing brain activity in the superior colliculus, the part of the brain responsible for integrating visual, auditory, and somatosensory spatial information, and the mediodorsal thalamus, the part of the brain that contributes to cognitive processes like learning and decision making.^6,7,8 This has the effect of making the neurons in the basolateral nucleus of the amygdala, responsible for regulating the consolidation and storage of emotional learning, less easily excitable.^6,9 The effect of this in the client is reduced fear and diminished power of traumatic memories.¹⁰

Conditions That Might Benefit From Bilateral Stimulation

Several conditions can be treated with bilateral stimulation. This process is used to help people process traumatic memories, and as such, children, adolescents, and adults with posttraumatic stress disorder (PTSD) can benefit greatly.⁶ Other conditions caused by adverse childhood experiences and trauma, like emotional eating, can be effectively treated with bilateral stimulation.¹¹ More broadly, EMDR therapy is used to treat many conditions, including anxiety, depression, sexual dysfunction, chronic pain, substance abuse disorders, panic disorder, body dysmorphic disorder, phobias, personality disorders, and grief.¹

Potential Benefits of Using Bilateral Stimulation

Bilateral stimulation as a part of EDMR therapy is a widely accepted practice. Studies have shown that there are numerous benefits to bilateral stimulation, including:²

• better anxiety management
• increased happiness
• increased self-esteem
• higher levels of creativity
• enhanced performance

Research and Effectiveness

Several studies have shown that EMDR therapy that features bilateral stimulation can be highly effective. For instance, a 2009 study by researchers from the Institute for Neurological Research in Buenos Aires, Argentina, investigated whether bilateral stimulation affected chronic pain. They recruited 38 participants with chronic pain and provided them with 12 weekly sessions lasting 90 minutes. The researchers used repeated sets of bilateral stimulation to continuously evoke positive responses in the participants. Through surveys including the Short-Form Health Survey, the researchers determined that the treatment effectively reduced chronic pain, pain-related neglect, and levels of anxiety and depression in the participants.¹²

A 2005 study conducted by researchers from Pitié-Salpêtrière University Hospital in Paris, France, investigated the effect of bilateral stimulation on people with Parkinson’s disease. The researchers administered bilateral stimulation to 18 people with Parkinson’s disease and found that the treatment decreased motor disability. In some participants, it reduced feelings of apathy.¹³

In a 2017 study, researchers in the United Kingdom recruited 13 participants with long-term and recurrent depression to determine whether EMDR therapy and bilateral stimulation could help treat their condition. The participants received up to 20 treatment sessions. The therapists involved used mostly tapping in the bilateral stimulation portion of the intervention and found that these participants required more bilateral stimulation than is common in people with PTSD. At the end of the study, the researchers concluded that EMDR with bilateral stimulation is a feasible treatment for long-term depression.¹⁴

Summary/Key Takeaways

Bilateral stimulation is an integral part of EMDR treatment and an effective therapeutic modality. Those who have experienced trauma can benefit from the increased processing fostered by bilateral stimulation. Though this method is already established as an effective therapeutic intervention, research continues to uncover more applications, including its use in combination with other therapies.¹⁵ Recent research has also shown that bilateral stimulation and EMDR can be conducted over remote sessions.¹⁶ Bilateral stimulation continues to help many people live with trauma; those who want to try this method can start by finding a therapist who practices this technique using the EMDR International Association directory.