We’ll keep posting research papers here as we come across them. If you know of a paper that isn’t listed here, message us at hi@waven.app!
Overview
Bilateral Stimulation has been mostly researched in the context of Eye Movement Desensitization and Reprocessing (EMDR) for the treatment of post-traumatic stress disorder (PTSD). The next section covers research regarding the efficacy of EMDR for trauma, and the one after will cover Bilateral Stimulation stand-alone for general nervous system regulation.
Research on EMDR
At least 30 randomized controlled trials exist showing that EMDR is effective for PTSD, and that effects persist at follow-up. We only cite the most important meta reviews here, plus a few that make a noteworthy additional point.
Overview of EMDR:
Shapiro, F. (2014). The role of eye movement desensitization and reprocessing (EMDR) therapy in medicine: Addressing the psychological and physical symptoms stemming from adverse life experiences. The Permanente Journal, 18(1), 71–77.
Gold-standard review of PTSD treatments. Concludes that EMDR and trauma-focused CBT are effective:
Bisson, J. I., Roberts, N. P., Andrew, M., Cooper, R., & Lewis, C. (2013). Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. Cochrane Database of Systematic Reviews, 2013(12), CD003388.
Meta-analysis of randomized controlled trials showing EMDR reduces PTSD symptoms:
Chen, Y.-R., Hung, K.-W., Tsai, J.-C., Chu, H., Chung, M.-H., Chen, S.-R., Liao, Y.-M., Chang, Y.-C., & Chou, K.-R. (2014). Efficacy of eye-movement desensitization and reprocessing for patients with posttraumatic stress disorder: A meta-analysis of randomized controlled trials. PLOS ONE, 9(8), e103676.
Eye movements reduce the vividness and emotional intensity of emotional memories:
Lee, C. W., & Cuijpers, P. (2013). A meta-analysis of the contribution of eye movements in processing emotional memories. Journal of Behavior Therapy and Experimental Psychiatry, 44(2), 231–239.
Working-memory hypothesis for how bilateral stimulation reduces the vividness and emotionality of distressing memories:
van den Hout, M. A., & Engelhard, I. M. (2012). How does EMDR work?. Journal of Experimental Psychopathology, 3(5), 724–738.
WHO recommending EMDR therapy as a treatment for PTSD:
World Health Organization. (2013). Guidelines for the management of conditions specifically related to stress. Geneva: World Health Organization.
Research on Bilateral Stimulation
There is much less research on the efficacy of Bilateral Stimulation applied standalone, with most studies being lab experiments, not therapy trials. Notably there is one very high impact publication in the journal Nature, albeit on mice (Nature’s impact factor is 64 – one of the highest ranked journals worldwide).
The existing human literature broadly supports three claims: 1. bilateral stimulation taxes working memory, 2. this reduces vividness and emotionality of memories, 3. this can reduce intrusive recall and emotional arousal. Almost none test relaxation as the primary outcome.
Nature study showing visual bilateral stimulation reduced fear response in mice:
Baek, J., et al. (2019). Neural circuits underlying EMDR therapy in a mouse model of fear. Nature, 566, 339–343.
Study showing that bilateral stimulation can enhance access to positive memories and increase relaxation-related neural activity:
Amano, T., et al. (2016). The role of alternating bilateral stimulation in establishing positive cognition in EMDR therapy. Journal of Behavior Therapy and Experimental Psychiatry.
Suggests that bilateral eye movements trigger an orienting response followed by physiological de-arousal:
Barrowcliff, A. L., Gray, N. S., MacCulloch, M. J., Freeman, T. C. A., & MacCulloch, S. (2003). Horizontal rhythmical eye movements consistently diminish the arousal provoked by auditory stimuli. British Journal of Clinical Psychology, 42(3), 289–302.
Experimental evidence that eye movements reduce the vividness and emotional intensity of negative memories:
van den Hout, M. A., & Engelhard, I. M. (2012). How does EMDR work?. Journal of Experimental Psychopathology, 3(5), 724–738.
Experimental study showing that bilateral eye movements can reduce later intrusive memories after exposure to distressing film material:
Xu, Z., et al. (2023). Bilateral eye movements disrupt the involuntary perceptual memory of traumatic films. Journal of Behavior Therapy and Experimental Psychiatry.
Experimental comparison showing that eye movements impose greater working-memory load than auditory tones during memory recall:
van den Hout, M., Engelhard, I., Beetsma, D., Slofstra, C., Hornsveld, H., Houtveen, J., & Leer, A. (2011). EMDR: Eye movements superior to beeps in taxing working memory. Journal of Behavior Therapy and Experimental Psychiatry, 42(3), 304–311.
Neuroimaging study showing that bilateral stimulation alters activity in brain regions associated with emotional processing:
Herkt, D., et al. (2014). The neural signature of EMDR stimulation. PLOS ONE, 9(8), e106350.
Experimental study showing that dual tasks such as eye movements weaken emotional memory representations:
Engelhard, I. M., van Uijen, S. L., & van den Hout, M. A. (2010). The impact of taxing working memory on negative memories. Journal of Behavior Therapy and Experimental Psychiatry, 41(1), 29–34.
Experimental research supporting the working-memory account of EMDR and showing reductions in emotional distress during dual-task recall:
Gunter, R. W., & Bodner, G. E. (2008). How eye movements affect unpleasant memories. Journal of Experimental Psychology: Learning, Memory, and Cognition, 34(5), 1091–1100.
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