The Science Behind Neuromatrix

Neuromatrix is powered by photobiomodulation (PBM) – a non-invasive, science-backed therapy that uses targeted light to stimulate cellular activity in the brain.

Photobiomodulation has been studied for several decades. Laboratory work has focused on how near-infrared light is absorbed by mitochondria and on downstream effects on cellular energy metabolism, blood flow and oxidative stress. Human studies, many of them small, have explored tPBM in healthy adults and in people with a range of neurological and psychiatric conditions. The picture that emerges is very promising. Results vary across studies, dosing is not standardized, and larger controlled trials are still needed. Below we summarize representative studies by research area and link to each paper.

The Neuromatrix is inspired by the powerful scientific potential of light-based neurostimulation. Explore the science. Empower your mind. 

About the research on this page

This page summarizes published research on transcranial photobiomodulation (tPBM), the use of red and near-infrared light applied to the head. It is provided for education, so that you can read the primary sources yourself. The studies below used many different devices, wavelengths, power levels, pulse settings, delivery sites and treatment schedules. The Neuromatrix headset was not used in any of these studies Clinical studies of the Neuromatrix are being initiated.  Nothing on this page is a claim that the Neuromatrix headset produces these effects, or that it can diagnose, treat, cure or prevent any condition. The Neuromatrix headset is a general wellness product.

Research in healthy adults

  • A systematic review and meta-analysis of sham-controlled tPBM studies in young healthy adults (Salehpour et al., 2019) reported improvements on some cognitive measures relative to sham; the authors noted that the studies were few, small and varied in their methods.
  • A sham-controlled study of a single session of 1064 nm near-infrared laser applied to the forehead of healthy adults (Barrett & Gonzalez-Lima, 2013) reported better performance on attention and memory tasks and more positive mood ratings in the treated group than in the sham group.

References:

Salehpour, F., Majdi, A., Pazhuhi, M., Ghasemi, F., Khademi, M., Pashazadeh, F., Hamblin, M. R., & Cassano, P. (2019). Transcranial photobiomodulation improves cognitive performance in young healthy adults: A systematic review and meta-analysis. Photobiomodulation, Photomedicine, and Laser Surgery, 37(10), 635–643. (Link)
Barrett, D. W., & Gonzalez-Lima, F. (2013). Transcranial infrared laser stimulation produces beneficial cognitive and emotional effects in humans. Neuroscience, 230, 13–23. (Link)

Research in people with dementia and Alzheimer’s disease

  • A small placebo-controlled pilot trial of a 1060–1080 nm near-infrared helmet in people with dementia (Berman et al., 2017) reported improvements on some cognitive measures relative to sham.
  • A case series of five people with mild to moderately severe dementia who used transcranial plus intranasal pulsed 810 nm light over 12 weeks (Saltmarche et al., 2017) reported improved cognitive scores, sleep and behaviour; there was no control group.
  • A pilot trial that randomized eight people with dementia to 12 weeks of home-administered transcranial and intranasal near-infrared light or usual care (Chao, 2019) reported changes on cognitive and behavioural scales and in cerebral perfusion and resting-state connectivity in the treated group; the study was small and had no sham condition.

References:

Berman, M. H., Halper, J. P., Nichols, T. W., & Hamblin, M. R. (2017). Photobiomodulation with near infrared light helmet in a pilot, placebo-controlled clinical trial in dementia patients testing memory and cognition. Journal of Alzheimer’s Disease, 58(2), 443–453. (Link)
Saltmarche, A. E., Naeser, M. A., Ho, K. F., Hamblin, M. R., & Lim, L. (2017). Significant improvement in cognition in mild to moderately severe dementia cases treated with transcranial plus intranasal photobiomodulation: Case series report. Photomedicine and Laser Surgery, 35(8), 432–441. (Link)
Chao, L. L. (2019). Effects of home photobiomodulation treatments on cognitive and behavioral function, cerebral perfusion, and resting-state functional connectivity in patients with dementia: A pilot trial. Photobiomodulation, Photomedicine, and Laser Surgery, 37(3), 133–141. (Link)

Research in people with depression and anxiety

  • A systematic review (Caldieraro & Cassano, 2019) concluded that early studies of tPBM for major depression were encouraging but small, and called for larger controlled trials.
  • An open-label pilot study of 10 patients with major depression and anxiety who received a single near-infrared treatment to the forehead (Schiffer et al., 2009) reported lower depression and anxiety scores two and four weeks later; there was no control group.
  • A narrative review (Salehpour & Rasta, 2017) discussed proposed mechanisms and the early clinical evidence for tPBM in major depression and suggested that controlled trials were warranted.
  • A broader narrative review of brain photobiomodulation (Salehpour et al., 2018) summarized proposed mechanisms, including effects on cerebral blood flow and inflammation observed mainly in laboratory and animal studies.

References:

Caldieraro, M. A., & Cassano, P. (2019). Transcranial and systemic photobiomodulation for major depressive disorder: A systematic review of efficacy, tolerability and biological mechanisms. Journal of Affective Disorders, 243, 262–273. (Link)
Schiffer, F., Johnston, A. L., Ravichandran, C., et al. (2009). Psychological benefits 2 and 4 weeks after a single treatment with near infrared light to the forehead: A pilot study of 10 patients with major depression and anxiety. Behavioral and Brain Functions, 5, 46. (Link)
Salehpour, F., & Rasta, S. H. (2017). The potential of transcranial photobiomodulation therapy for treatment of major depressive disorder. Reviews in the Neurosciences, 28(4), 441–453. (Link)
Salehpour, F., Mahmoudi, J., Kamari, F., Sadigh-Eteghad, S., Rasta, S. H., & Hamblin, M. R. (2018). Brain photobiomodulation therapy: A narrative review. Molecular Neurobiology, 55(8), 6601–6636. (Link)

Research in people with Parkinson’s disease

  • A prospective proof-of-concept study of 12 people with Parkinson’s disease who received transcranial, intranasal, neck and abdominal photobiomodulation over 12 weeks (Liebert et al., 2021) reported improvements on some measures of mobility, fine motor skill, cognition and sleep; there was no control group.
  • A three-year follow-up case series of participants from that study who continued home treatment (Liebert et al., 2023) reported that the changes observed earlier were largely maintained.
  • A five-year follow-up (Liebert et al., 2024) again reported that clinical signs remained stable or improved in participants who continued treatment; the authors noted the small sample and the absence of a control group.

References:

Liebert, A., Bicknell, B., Laakso, E. L., et al. (2021). Improvements in clinical signs of Parkinson’s disease using photobiomodulation: A prospective proof-of-concept study. BMC Neurology, 21(1), 326. (Link)
Liebert, A., et al. (2023). Improvements in the clinical signs of Parkinson’s disease using photobiomodulation: A 3-year follow-up case series. Medical Research Archives, 11(3). (Link)
Liebert, A., Bicknell, B., Laakso, E. L., et al. (2024). Improvements in clinical signs and symptoms of Parkinson’s disease using photobiomodulation: A five-year follow-up. BMC Neurology, 24, 381. (Link)

Research in people with COVID-19 brain fog

  • A small clinical report of people with post-COVID-19 brain fog treated with either transcranial or whole-body photobiomodulation (Bowen & Arany, 2023) reported reduced self-rated brain-fog symptoms after treatment; there was no control group.
  • Two further studies examined acute COVID-19 rather than brain fog, using light applied to the body rather than the head. A randomized controlled trial of a home-use device (Lim et al., 2024) reported faster symptom recovery in the treated group, and a small double-blind placebo-controlled pilot study (Marashian et al., 2022) reported changes in serum cytokine levels in people with mild to moderate COVID-19. Neither study involved transcranial light or cognition.

References:

Bowen, R., & Arany, P. R. (2023). Use of either transcranial or whole-body photobiomodulation treatments improves COVID-19 brain fog. Journal of Biophotonics, 16(8), e202200391. (Link)
Lim, L., Hosseinkhah, N., Van Buskirk, M., et al. (2024). Photobiomodulation treatment with a home-use device for COVID-19: A randomized controlled trial for efficacy and safety. Photobiomodulation, Photomedicine, and Laser Surgery, 42(6), 393–403. (Acute COVID-19; systemic, non-transcranial light.) (Link)
Marashian, S. M., Hashemian, M., Pourabdollah, M., et al. (2022). Photobiomodulation improves serum cytokine response in mild to moderate COVID-19: The first randomized, double-blind, placebo controlled, pilot study. Frontiers in Immunology, 13, 929837. (Acute COVID-19; systemic, non-transcranial light.) (Link)

Research in people with traumatic brain injury

  • An open-protocol pilot study of 11 people with chronic mild traumatic brain injury who received 18 sessions of transcranial red and near-infrared LED treatment (Naeser et al., 2016) reported improvements on some tests of executive function and memory and in self-reported sleep; there was no control group.
  • A perspective article (Dos Santos et al., 2018) reviewed the rationale for transcranial LED therapy after traumatic brain injury and proposed directions for future research; it did not report a new clinical trial.

References:

Naeser, M. A., Martin, P. I., Ho, M. D., Krengel, M. H., Bogdanova, Y., Knight, J. A., Yee, M. K., Zafonte, R., Frazier, J., Hamblin, M. R., & Koo, B. B. (2016). Transcranial, red/near-infrared light-emitting diode therapy for treatment of chronic, mild traumatic brain injury: A pilot study. Photomedicine and Laser Surgery, 34(2), 58–73. (Link)
Dos Santos, J. G. R. P., Paiva, W. S., & Teixeira, M. J. (2018). Transcranial light-emitting diode therapy for neuropsychological improvement after traumatic brain injury: A new perspective for diffuse axonal lesion management. Medical Devices: Evidence and Research, 11, 139–146. (Link)

Fear and stress responses: animal and Gulf War Illness research

  • A 2023 study in rats (Zhao et al.) examined whether pulsed 810 nm transcranial laser light affected fear-related behaviour after a stress procedure; animal findings do not establish effects in people.
  • A sham-controlled pilot study in veterans with Gulf War Illness (Martin et al., 2021) examined transcranial LED photobiomodulation for cognitive symptoms and reported mixed results, with improvements on some cognitive measures. This was a study of cognition in Gulf War Illness, not of post-traumatic stress disorder.

References:

Zhao, H., Li, Y., Luo, T., et al. (2023). Preventing post-traumatic stress disorder (PTSD) in rats with pulsed 810 nm laser transcranial phototherapy. Translational Psychiatry, 13(1), 281. (Rat study.) (Link)
Martin, P. I., Chao, L. L., Krengel, M., Ho, M., Yee, M. K., Lew, R. A., Knight, J., Hamblin, M. R., & Naeser, M. A. (2021). Transcranial photobiomodulation to improve cognition in Gulf War Illness. Frontiers in Neurology, 11, 574386. (Gulf War Illness cognition study.) (Link)

Research in people with ADHD

  • A set of case studies (Stephan et al., 2022) described a small number of individuals with ADHD who received transcranial photobiomodulation and reported changes in attention-related symptoms; case studies have no control group and cannot establish effectiveness.
  • A review of photobiomodulation for brain disorders (Hamblin, 2016) summarized proposed mechanisms, including effects on mitochondrial function, oxidative stress and inflammation, and noted that most evidence came from laboratory, animal and small human studies.

References:

Stephan, W., Banas, L. J., Brierley, W., & Hamblin, M. R. (2022). Efficacy of photobiomodulation for attention deficit hyperactivity disorder (ADHD): Case studies. World Journal of Neuroscience, 12(3), 136–143. (Link)
Hamblin, M. R. (2016). Shining light on the head: Photobiomodulation for brain disorders. BBA Clinical, 6, 113–124. (Link)

Neuromatrix and this research

The Neuromatrix headset delivers pulsed near-infrared light at 810 nm and 1070 nm across the head. It was designed with this body of research in mind, but it has not itself been studied in a clinical trial, and the findings above should not be read as findings about the headset. We are working toward our own studies and will publish results here as they become available.

Learn about the headset →