Can light penetrate the human skull and reach the brain? This question often arises among both skeptics and scientists.

The answer is yes but with caveats; this requires an appropriate wavelength (nm) and sufficient irradiance (mW/cm²) In this demonstration with a real human skull, the Vielight Neuro, emitting 810 nm near-infrared light at an industry-leading irradiance of 250 mW/cm², clearly passes through the skullcap.

With the highest irradiance in the brain photobiomodulation field and the most published research in the industry, Vielight has set the benchmark for depth of penetration and the most published brain photobiomodulation studies.

Watch the video here:

Firstly, why deliver light energy through the skull?

The discovery that red to near infrared light energy produces beneficial effects within neurons is groundbreaking. Near-infrared light stimulates a photosensitive enzyme, cytochrome c oxidase, that’s found within mitochondria – which leads to increased cellular energy, leading to a process known as “brain photobiomodulation”. By stimulating cytochrome oxidase activity, transcranial photobiomodulation increases neuronal energy levels – leading to increased gamma brain oscillations, brain plasticity and cognitive flexibility.^[1]

However, this non-invasive, chemical-free brain enhancing stimulation wouldn’t be possible, if near infrared light energy couldn’t reach the brain in the first place.

810nm light energy penetration through a human skull with the Vielight Neuro.

What is near infrared light energy?

Near infrared light (NIR) energy is part of the electromagnetic spectrum – which are waves (or photons) of the electromagnetic field, radiating through space, carrying electromagnetic radiant energy. At this day and age, several existing technologies depend on the ability of electromagnetic energy to penetrate solid objects. Several examples include WiFi, mobile data, radar and navigation satellites.

Figure 1 The electromagnetic spectrum

The depth or the power of penetration by light energy depends on the wavelength in the electromagnetic spectrum. Thus, the longer the wavelength, the greater the ability for photons to penetrate an object. For example, near infrared light is found around the center of the electromagnetic spectrum.

Does 810 nm or 1064 nm (1070nm) penetrate deeper into the brain?

According to a transcranial brain photobiomodulation (PBM) study by Harvard Medical School, Department of Psychiatry, the 810nm wavelength has been found to be superior to other wavelengths, which includes higher wavelengths in the 1070nm range for penetration and dosimetry.

According to this study by Harvard Medical School, the order of penetration and dosimetry effectiveness is:

1. 810 nm – consistently highest across all age groups and regions

2. 850 nm and 1064 nm – next most effective in most cases

3. 670 nm and 980 nm – lesser deposition overall

This Harvard study is also supported by another brain PBM dosimetry study by leading Chinese universities, comparing 660 nm, 810 nm, 880 nm and 1064 nm. They discovered that the distribution of photon fluence at 660 and 810 nm within the brain was much wider and deeper than 980 and 1064 nm.

The distribution of photon fluence at 660 nm, 810 nm, 980 nm and 1064 nm. Wang P, Li T. “Which wavelength is optimal for transcranial low-level laser stimulation?” J. Biophotonics. 2019; 12:e201800173. https://doi.org/10.1002/jbio.201800173

The differences in dosimetry is supported by a well-established biological principle, the body’s first optical window. While, the 1064 and 1070nm wavelengths are longer and scatter less than 810nm, they are more strongly absorbed by water, which is abundant in biological tissues. This increased absorption by water can lead to reduced photonic availability and tissue penetration despite the longer wavelength, which the Harvard Medical study and Peking Medical University study reveal.

The near infrared window or body’s optical window. Image source: Wang, Erica & Kaur, Ramanjot & Fierro, Manuel & Austin, Evan & Jones, Linda & Jagdeo, Jared. (2019). Safety and penetration of light into the brain. 10.1016/B978-0-12-815305-5.00005-1.

• Water Absorption: Light absorption by water increases significantly beyond ~950 nm, and water is abundant in biological tissue. At 1064 nm, absorption by water becomes substantial, which attenuates the light more than at 810 nm. This increased absorption reduces the effective depth of penetration, especially for energy reaching specific chromophores like cytochrome c oxidase (CCO).
• Cytochrome c Oxidase (CCO) Absorption: Mitochondria’s CCO’s absorption spectrum peaks around 810 nm, with a notable decrease in absorption beyond 1000 nm. This means that 810 nm light is more readily absorbed by CCO compared to 1070 nm.

Expanding on the 810nm light penetration study by Harvard Medical School

In order to reach the brain transcranially, NIR light energy must bypass several barriers – skin, blood, water and bone.

In a 2020 study comparing 810nm with 1070nm by researchers from the Harvard Psychiatry Department, they combined similar tissues together to create a simplified head model. This model contains eight different brain tissues: white matter (WM), gray matter (GM), CSF, skull, muscles, skin/muscles, fat, and blood vessels.^[5]

This study involved the simulation of light deposition at five wavelengths commonly used in NIR applications—670, 810, 850, 980, and 1064 (1070) nm. These wavelengths have been widely used in published studies in photobiomodulation, many of which correspond to the absorption spectra of different tissues within the human body.

Figure 3
The average (bars) and peak (dots) energy deposition (penetration) after positioning the LED light source.
The left brain shows the ROIs that receiving the highest (red) and second highest (orange) energy deposition; the right brain shows the energy deposition map on the cortical surface.
(a) fluence at the F3-F4 sites
(b) fluence at the  Fp1–FpZ–Fp2 sites

Figure 4
The average (bars) and peak (dots) energy deposition (penetration) after positioning the intranasal light source in the: (a) nostril, (b) mid-nose, and (c) close to the nose ceiling (in proximity of the cribriform plate)
The left brain shows the ROIs that receiving the highest (red) and second highest (orange) energy deposition; the right brain shows the energy deposition map on the cortical surface.
(a) Nostril position
(b) Mid-nose position
(c) Cribiform plate

Figure 5

Plots of the normalized energy deposition results for (a) the nostril illumination, (b) the mid-nose illumination, and (c) the cribriform plate illumination.
All results are simulated with the optical properties at 810 nm.

Conclusively, they found that the wavelength plays an important role in determining the magnitude of the energy deposition. In general, there was a clear trend showing that 810 nm offered the highest light penetration onto the brain, followed closely by 1064 and 850 nm.

Additionally, a study done in 2012 by the State University of New York, Downstate Medical Center, compared the transmission of NIR LED light (830nm) versus visible red LED light (633nm) through soft tissue, bone, water and blood.

Here were their results from their study on the penetration of NIR light through a human head^[3]:

Figure 3. Percent Penetrance of Light through Coronal Sections of Cadaver Skull, Bone Only.

Figure 4. Percent Penetrance of Light through Sagittal Sections of Cadaver Skull with Intact Soft Tissue.

Figure 5. Percent Penetrance of Light through Various Concentrations of Blood.

Figure 6. Percent Penetrance of Light through Human Cheek in vivo. 

These findings demonstrate that NIR light measurably penetrates skin, bone and brain tissue in a human head model. On the other hand, there isn’t as much transmission of red light in the same conditions.

As mentioned earlier, quite a few technologies depend on the diffusion of light energy through these barriers. For example, brain imaging technology known as near infrared spectroscopy (NIRS). NIRS involves detecting changes in blood hemoglobin concentrations associated with neural activity within cortical brain tissue.  Fundamentally, this technology is based on the penetration of NIR light through the cranium and into the brain, reaching up to 4 cm of depth.

Emphasis on the intranasal channel

The intranasal channel is an important gateway for light energy to reach the ventral prefrontal cortex of the brain. Otherwise, this area is inaccessible through the cranium. Furthermore, the ventral prefrontal cortex plays a role in emotional responses, decision making and self control – which play important roles in performance and mental balance.

Watch how Vielight’s patented intranasal technology can reach deep brain structures through the nasal channel:

MoreMore emphasis on the intranasal channel

Additionally, a study on the intranasal diffusion of NIR light through a human head was done by the Institute of Chemical Sciences and Engineering in Switzerland. This study demonstrated that it is possible to illuminate deep brain tissues transcranially and intranasally.^[4] The measurement of the fluence rate distribution was, once again, carried out on a human cadaveric head.

Figure 7 View on the 3D mesh of the skull

This study quantifies the light distribution within brain tissue when illuminating from the nasal cavity with a controlled energy deposition.

Figure 8 (a) Fluence rate distribution at 671 nm. (b) Fluence rate distribution at 808 nm.

The results obtained from the study suggests that light at 810 nm is the better choice. This is due to less absorption and reduced scattering at 810 nm in all tissue types. The increased light propagation at the 810 nm wavelength improves the penetration and diffusion rate of photons into deeper brain regions.

Figure 9 Transmission of light energy through a human cadaver with the Vielight Neuro.

Conclusion

The penetration of light energy into the brain is highly dependent on the wavelength. In light of this, several studies support the ability of near infrared light (808 – 820nm) to penetrate through the skull and up to 4 cm into brain tissue. Thus, these studies help to answer the question: “Can light penetrate the brain?” with a “Yes.”

Figure 9 The light penetration difference among different wavelengths and the effects on cellular mechanisms.

Only the wavelengths in the near-infrared window of 600–850nm is absorbed by the mitochondrial electron transfer chain and leads to upregulation of the neuronal respiratory capacity. Source : Mol Neurobiol. 2018 Aug; 55(8): 6601–6636.

References

1. Gonzalez-Lima, F; Barrett, Douglas; “Augmentation of cognitive brain functions with transcranial lasers”, Frontiers in Systems Neuroscience : doi:10.3389/fnsys.2014.00036
2. Smith, Andrew M.; Mancini, Michael C.; Nie, Shuming (2009). “Bioimaging: Second window for in vivo imaging”. Nature Nanotechnology. 4(11): 710–711. doi:1038/nnano.2009.326. ISSN 1748-3387. PMC 2862008
3. Jagdeo JR, Adams LE, Brody NI, Siegel DM (2012) Transcranial Red and Near Infrared Light Transmission in a Cadaveric Model. PLoS ONE 7(10): e47460. https://doi.org/10.1371/journal.pone.0047460
4. Pitzschke, Andreas & Lovisa, B & Seydoux, O & Zellweger, M & Pfleiderer, M & Tardy, Y & Wagnières, Georges. (2015). Red and NIR light dosimetry in the human deep brain. Physics in medicine and biology. 60. 2921-2937. 10.1088/0031-9155/60/7/2921.
5. Yuan Y, Cassano P, Pias M, Fang Q. Transcranial photobiomodulation with near-infrared light from childhood to elderliness: simulation of dosimetry. Neurophotonics. 2020 Jan;7(1):015009. doi: 10.1117/1.NPh.7.1.015009. Epub 2020 Feb 24. PMID: 32118086; PMCID: PMC7039173.

Many neuroscience publications indicate that the brain is modular and composed of different networks

The key to successful brain stimulation (and brain photobiomodulation) is to focus on networks that hold the most importance to your objective.

The Default Mode Network (DMN) is a collection of brain regions that are active when an individual is at rest or not focused on the external environment. Research has linked the DMN to various cognitive functions and mental states, including:

1. Mind-Wandering and Daydreaming: The DMN is associated with spontaneous thoughts that occur when the mind is not focused on the task at hand. It plays a role in mind-wandering and daydreaming activities.
2. Self-Referential Thinking: It’s involved in self-referential thoughts, introspection, and mental simulations about oneself, such as autobiographical memory retrieval, envisioning the future, or contemplating one’s characteristics and emotions.
3. Social Cognition: The DMN is implicated in processes related to understanding others’ mental states, empathy, theory of mind (the ability to attribute mental states to oneself and others), and social awareness.
4. Memory Processing: It plays a role in consolidating memories, particularly those related to personal experiences and episodic memory.
5. Creative Thinking: Some studies suggest that the DMN is involved in creative thinking processes, as it allows the brain to make connections between different ideas and concepts.
6. Mental Health Conditions: Dysfunctions in the DMN have been associated with various mental health conditions, including depression, anxiety disorders, schizophrenia, and Alzheimer’s disease. Changes in the activity or connectivity within the DMN have been observed in individuals with these conditions.

Understanding the functions of the DMN provides insights into various aspects of cognition, consciousness, and mental health. However, research in this field is ongoing, and there’s still much to learn about the exact roles and interactions of the DMN in different cognitive processes and conditions.

What is the Default Mode Network?

Figure 1 – Regions of the Default Mode Network

The Default Mode Network (DMN) is a network of highly interconnected brain regions responsible for internal modes of cognition.

The DMN has been linked to the general health of the brain and is involved in various domains of cognitive and social processing.

The term “default” initially arose from the discovery of the network’s heightened activity during idle periods (aka. when you are not actively thinking), implying that this network is active by default. Since then, additional research has shown this to be a misnomer. The DMN is also active when your brain is engaged in thinking, such as remembering one’s past or thinking about what might happen in the future.^{[41, 42, 43]}

The DMN includes hubs such as the Medial Prefrontal Cortex (mPFC), the Ventromedial Prefrontal Cortex(vMPFC), the Precuneus, the Inferior Parietal Lobule(IPL), Lateral Temporal Cortex (LTC) and the Posterior cingulate cortex(pCC). Findings from diffusion MRI and resting state fMRI show that neurons in the DMN regions are linked to each other through large tracts of axons and this causes activity in these areas to be correlated with one another. ^[22],[23]

The roles of the Default Mode Network

The Default Mode Network (DMN) plays several crucial roles concerning brain functions. Its roles are linked to what defines us as human beings from a cognitive perspective. It plays several vital tasks in memory functions, imagination, self-referencing, and socializing. Who you are as a person is theorized to be stored within these hubs.

The DMN is likely the neurological basis for the self ^[22]

• Autobiographical information: Memories of collection of events and facts about one’s self
• Self-reference: Referring to traits and descriptions of one’s self
• Self-emotional state: Reflecting about one’s own emotional state

Thinking about others ^[23]

• Theory of mind: Thinking about the thoughts of others and what they might or might not know
• Emotions of other: Understanding the emotions of other people and empathizing with their feelings
• Moral reasoning: Determining a just and an unjust result of an action

Remembering the past and thinking about the future ^[23]

• Remembering the past: Recalling events that happened in the past
• Imagining the future: Envisioning events that might happen in the future
• Episodic memory: Detailed memory related to specific events in time
• Story comprehension: Understanding and remembering a narrative

The Value of Targeting the Default Mode Network with Pulsed 810nm NIR energy

Since its discovery, interest has grown in the clinical utility and implications of the DMN. The clinical significance of the DMN has been established or implicated in neurological and neuropsychiatric disorders. Therefore, maintaining the health and improving the performance of the DMN is of particular value. This is why the Vielight Neuro is designed to deliver NIR light transcranially using four diodes targeted at the DMN.

Dysfunction of the DMN has been associated with Alzheimer’s disease, autism, schizophrenia, depression and other neurologic diseases,  Parkinson’s, ^{[25] [26]} multiple sclerosis (MS) ^[27] and post-traumatic stress disorder (PTSD). ^[28]  Targeting  the DMN via PBM may therefore be an important therapeutic strategy in the treatment of these diseases. The table below summarizes the research done to date using Vielight technology for various diseases related to the DMN.

Summary of DMN findings in neurological and neuropsychiatric conditions.

Anatomy of the DMN: roles of the hubs

The DMN is composed of several hubs that also perform their own individualized tasks.
This is an introduction to the different hubs of the DMN and what their roles are in the human brain.

Medial prefrontal cortex (mPFC)

The medial prefrontal cortex is located within the brain’s frontal lobe. This region is located behind the forehead.

Figure 2- Prefrontal Cortex

The medial prefrontal cortex plays a regulatory role in several cognitive functions including attention, inhibitory control, habit formation and working, spatial and long-term memory. ^[1]

The mPFC is a common region of injury in traumatic brain injury.

Ventromedial prefrontal cortex (vmPFC)

The ventromedial prefrontal cortex is also located within the brain’s frontal lobe. This region is located right above the eyes and nose.

The ventromedial prefrontal cortex plays a role in decision-making, self-control, and the regulation of emotional responses. ^{[2, 3]}

It is also involved in the cognitive evaluation of morality. ^[4]

Precuneus

The precuneus is a small section of the superior parietal lobe and it is thought to be the core hub of the DMN. ^[9]

It is involved in several vital cognitive and visuospatial roles as outlined below.

Figure 3 – Precuneus

Cognitive roles:
• Self-consciousness (such as self awareness) ^[5]
• Spatial memory (remembering different locations as well as spatial relations between objects) ^[6]
• Episodic memory (remembering everyday events) ^[7]
• Source memory (remembering the origin of a memory or of knowledge) ^[8]

Visuospatial:
• Motor imagery. ^[10] Motor imagery is used in sport training as mental practice of action, neurological rehabilitation.
• Motor coordination. ^[11]
Motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended actions, like running or throwing.

Inferior parietal lobule (IPL)

Figure 4 – Inferior Parietal Lobule

The inferior parietal lobule is located on the left and right side of the rear-half of the brain.

The IPL supports some of the most distinctive human mental capacities:

• Language
• Pattern learning
• Mathematical operations ^[12]
• Perception of emotions in facial stimuli

The inferior parietal lobe is a foremost convergence zone of diverse mental capacities, several of which are potentially most developed in the human species.

Targeting the IPL with PBM holds great potential to improve cognitive performance in professions that require mathematical or analytical ability.

Posterior cingulate cortex

The posterior cingulate cortex (pCC) can be found around the midline of the brain.

The pCC forms a central node in the default mode network of the brain.

Figure 5 – Posterior Cingulate Cortex

It is highly connected and communicates with various brain networks simultaneously and is involved in diverse functions. ^[13]

Cerebral blood flow and metabolic rate in the pCC are approximately 40% higher than average across the brain. ^{[14], [15]}

Memory

The pCC has been linked to:

• Spatial memory (remembering different locations as well as spatial relations between objects)
• Autobiographical memories (autobiographical memory is a memory system consisting of episodes recollected from an individual’s life)
  the pCC does not show this activity when affected by Alzheimer’s Disease. ^[21]
• Working memory performance (abnormalities of the ventral pCC is related to a decline) ^[17]

Intrinsic control networks

The pCC has also been strongly implicated as a key part of several intrinsic control networks. ^{[14], [15]}

• The dorsal attention network(control of visual attention and eye movement)
• The frontoparietal control network (involved in executive motor control). ^[14]

Meditation

The pCC has been found to be activated during self-related thinking and deactivated during meditation and undistracted, effortless mind wandering. ^[20] These results track closely with findings about the role of the pCC in the DMN.

Temporal lobes

The temporal lobes (TL) sit behind the ears and are the second largest lobe.

Figure 6 – Temporal Lobes

The TL is involved in processing sensory input for:

• Visual processing (complex stimuli such as faces and scenes)
• Auditory processing (processes signals from the ears into meaningful units such as speech and words)
• Language comprehension
• Visual memory (visual memoryis the ability to remember what something looks like)

The dominant temporal lobe, which is the left side in most people, is involved in understanding language and learning and remembering verbal information.

The non-dominant lobe, which is typically the right temporal lobe, is involved in learning and remembering non-verbal information (e.g. visuo-spatial material and music).

For language learners and musicians, a well-performing temporal lobe plays a crucial role in maximizing performance in these areas.

Hippocampal area

The hippocampus can be found within the temporal lobes.

Figure 7 – Hippocampal Area

The hippocampus plays important roles in the formation of:

• short-term memory to long-term memory
• spatial memory that enables navigation.

In Alzheimer’s disease (and other forms of dementia), the hippocampus is one of the first regions of the brain to suffer damage ^[18] short-term memory loss and disorientation are included among the early symptoms.

While a relatively small subregion within the temporal lobes, the hippocampal area plays important roles in memory and is an region of interest in concurrent neurological research.

Conclusion: Engineering pathway for brain photobiomodulation of the DMN

At Vielight, our thesis behind the Vielight Neuro was to select the DMN and its hubs because of its and their many important roles in human cognitive processes, such as self-awareness, memory, emotions, imagination, mathematical and language processing.

Additionally, through our patented intranasal technology, we are able to reach the vMPFC with pulsed 810nm NIR energy, an advantage that is unique to the Vielight Neuro versus anything else out there.

To read more on the Vielight Neuro’s design, follow this link: https://www.vielight.com/understanding-the-vielight-neuro/

References

1. Jobson DD, Hase Y, Clarkson AN, Kalaria RN. The role of the medial prefrontal cortex in cognition, ageing and dementia. Brain Commun. 2021 Jun 11;3(3):fcab125. doi: 10.1093/braincomms/fcab125. PMID: 34222873; PMCID: PMC8249104.
2. Boes AD, Grafft AH, Joshi C, Chuang NA, Nopoulos P, Anderson SW (December 2011). “Behavioral effects of congenital ventromedial prefrontal cortex malformation”. BMC Neurology. 11(151): 151. doi:1186/1471-2377-11-151. PMC 3265436
3. Bechara A, Tranel D, Damasio H (November 2000). “Characterization of the decision-making deficit of patients with ventromedial prefrontal cortex lesions”. Brain. 123 ( Pt 11) (11): 2189–202. doi:1093/brain/123.11.2189. PMID11050020
4. Koenigs M, Young L, Adolphs R, Tranel D, Cushman F, Hauser M, Damasio A (April 2007). “Damage to the prefrontal cortex increases utilitarian moral judgements”. Nature. 446(7138): 908–11. Bibcode:446..908K. doi:10.1038/nature05631
5. Lou HC, Luber B, Crupain M, Keenan JP, Nowak M, Kjaer TW, Sackeim HA, Lisanby SH (2004). “Parietal cortex and representation of the mental Self”. Proceedings of the National Academy of Sciences of the United States of America. 101(17): 6827–32. Bibcode:.101.6827L. doi:10.1073/pnas.0400049101. PMC 404216. PMID 15096584
6. Wallentin M, Roepstorff A, Glover R, Burgess N (2006). “Parallel memory systems for talking about location and age in precuneus, caudate and Broca’s region”. NeuroImage. 32 (4): 1850–64. CiteSeerX 10.1.1.326.8669. doi:10.1016/j.neuroimage.2006.05.002. PMID 16828565
7. Lundstrom BN, Petersson KM, Andersson J, Johansson M, Fransson P, Ingvar M (2003). “Isolating the retrieval of imagined pictures during episodic memory: activation of the left precuneus and left prefrontal cortex”. NeuroImage. 20 (4): 1934–43. doi:10.1016/j.neuroimage.2003.07.017. hdl:11858/00-001M-0000-0013-39A9-E. PMID 14683699
8. Lundstrom BN, Ingvar M, Petersson KM (2005). “The role of precuneus and left inferior frontal cortex during source memory episodic retrieval”. NeuroImage. 27 (4): 824–34. doi:10.1016/j.neuroimage.2005.05.008. hdl:11858/00-001M-0000-0013-3A7E-4. PMID 15982902
9. Cavanna AE (2007). “The precuneus and consciousness”. CNS Spectrums. 12(7): 545–52. doi:1017/S1092852900021295. PMID 17603406
10. Cavanna A, Trimble M (2006). “The precuneus: a review of its functional anatomy and behavioural correlates”. Brain. 129 (Pt 3): 564–83. doi:10.1093/brain/awl004. PMID 16399806
11. Wenderoth N, Debaere F, Sunaert S, Swinnen SP (2005). “The role of anterior cingulate cortex and precuneus in the coordination of motor behaviour”. Eur J Neurosci. 22(1): 235–46. doi:1111/j.1460-9568.2005.04176.x. PMID 16029213
12. Ole Numssen, Danilo Bzdok, Gesa Hartwigsen (2021) Functional specialization within the inferior parietal lobes across cognitive domains eLife 10:e63591 https://doi.org/10.7554/eLife.63591
13. R Leech; R Braga; DJ Sharp (2012). “Echoes of the brain within the posterior cingulate cortex”. The Journal of Neuroscience. 32(1): 215–222. doi:1523/JNEUROSCI.3689-11.2012. PMC 6621313. PMID 22219283
14. Leech R, Sharp DJ (July 2013). “The role of the posterior cingulate cortex in cognition and disease”. Brain. 137(Pt 1): 12–32. doi:1093/brain/awt162. PMC 3891440. PMID 23869106.
15. Pearson, John M.; Heilbronner, Sarah R.; Barack, David L.; Hayden, Benjamin Y.; Platt, Michael L. (April 2011). “Posterior cingulate cortex: adapting behavior to a changing world”. Trends in Cognitive Sciences. 15(4): 143–151. doi:1016/j.tics.2011.02.002. PMC 3070780. PMID 21420893
16. Maddock, R. J.; A. S. Garrett; M. H. Buonocore (2001). “Remembering Familiar People: The Posterior Cingulate Cortex and Autobiographical Memory Retrieval”. Neuroscience. 104(3): 667–676. CiteSeerX 1.1.397.7614. doi:10.1016/s0306-4522(01)00108-7. PMID 11440800. S2CID 15412482
17. Kozlovskiy SA, Vartanov AV, Nikonova EY, Pyasik MM, Velichkovsky BM (2012). “The Cingulate Cortex and Human Memory Processes”. Psychology in Russia: State of the Art. 5: 231–243. doi:11621/pir.2012.0014
18. Dubois B, Hampel H, Feldman HH, Scheltens P, Aisen P, Andrieu S, et al. (March 2016). “Preclinical Alzheimer’s disease: Definition, natural history, and diagnostic criteria”. Alzheimer’s & Dementia. 12(3): 292–323. doi:1016/j.jalz.2016.02.002. PMC 6417794. PMID 27012484
19. Smith; Kosslyn (2007). Cognitive Psychology: Mind and Brain. New Jersey: Prentice Hall. pp. 21, 194–199, 349.
20. Garrison KA, Santoyo JF, Davis JH, Thornhill TA, Kerr CE, Brewer JA (2013). “Effortless awareness: using real time neurofeedback to investigate correlates of posterior cingulate cortex activity in meditators’ self-report”. Front Hum Neurosci. 7: 440. doi:3389/fnhum.2013.00440. PMC3734786. PMID 23964222
21. Meguro, K. (1999). “Neocortical and hippocampal glucose hypometabolism following neurotoxic lesions of the entorhinal and perirhinal cortices in the non-human primate as shown by PET: Implications for Alzheimer’s disease”. Brain. 122(8): 1519–1531. doi:1093/brain/122.8.1519. ISSN 1460-2156
22. Andrews-Hanna, Jessica R. (1 June 2012). “The brain’s default network and its adaptive role in internal mentation”. The Neuroscientist. 18 (3): 251–270. doi:10.1177/1073858411403316. ISSN 1089-4098. PMC 3553600
23. Horn, Andreas; Ostwald, Dirk; Reisert, Marco; Blankenburg, Felix (2013). “The structural-functional connectome and the default mode network of the human brain”. NeuroImage. 102: 142–151. doi:10.1016/j.neuroimage.2013.09.069. PMID 24099851. S2CID 6455982
24. Buckner RL, Andrews-HannaJR, Schacter DL (2008). The Brain’s Default Network: Anatomy, Function, and Relevance to Diseas. Annals of the New York Academy of Sciences. 1124 (1): 1–38.
25. Van Eimeren T, Monchi O, Ballanger B, Strafella AP (2009). Dysfunction of the Default Mode Network in Parkinson Disease: A Functional Magnetic Resonance Imaging Study. Arch Neurol. 2009 July ; 66(7): 877–883.
26. Tessitore A, Esposito F, Vitale C, Santangelo G, Amboni M, Russo A, Corbo D, Cirillo G, Barone P, Tedeschi G (2012). Default-mode network connectivity in cognitively unimpaired patients with Parkinson disease. Neurology. 79(23):2226-32.
27. Rocca MA, Valsasina P, Absinta M, Riccitelli G, Rodegher ME, Misci P, Rossi P, Falini A, Comi G, Filippi M (2010). Default-mode network dysfunction and cognitive impairment in progressive MS. Neurology. 74(16):1252-9.
28. Judith K. Daniels, PhD, Paul Frewen, PhD, Margaret C. McKinnon, PhD, and Ruth A. Lanius (2011). Default mode alterations in posttraumatic stress disorder related to early-life trauma: a developmental perspective. J Psychiatry Neurosci. 2011 Jan; 36(1): 56–59
29. Mohan A, Roberto AJ, Mohan A, Lorenzo A, Jones K, Carney MJ, Liogier-Weyback L, Hwang S, Lapidus KA. The Significance of the Default Mode Network (DMN) in Neurological and Neuropsychiatric Disorders: A Review. Yale J Biol Med. 2016 Mar 24;89(1):49-57. PMID: 27505016; PMCID: PMC4797836.
30. Lancaster Katie, Venkatesan Umesh M., Lengenfelder Jean, Genova Helen M., Default Mode Network Connectivity Predicts Emotion Recognition and Social Integration After Traumatic Brain Injury, Frontiers in Neurology 10, 2019, https://www.frontiersin.org/articles/10.3389/fneur.2019.00825,DOI=10.3389/fneur.2019.00825, ISSN:1664-2295
31. Hafkemeijer A, van der Grond J, Rombouts SA. Imaging the default mode network in aging and dementia. Biochim Biophys Acta. 2012;1822(3):431–441
32. Mormino EC, Smiljic A, Hayenga AO, Onami SH, Greicius MD, Rabinovici GD. et al. Relationships between beta-amyloid and functional connectivity in different components of the default mode network in aging. Cereb Cortex. 2011;21(10):2399–2407.
33. Kwak Y, Peltier S, Bohnen NI, Müller ML, Dayalu P, Seidler RD. Altered resting state cortico-striatal connectivity in mild to moderate stage Parkinson’s disease. Front Syst Neurosci. 2010;4:143
34. Putcha D, Ross RS, Cronin-Golomb A, Janes AC, Stern CE. Altered intrinsic functional coupling between core neurocognitive networks in Parkinson’s disease. Neuroimage Clin. 2015;7:449–455.
35. Padmanabhan A, Lynch CJ, Schaer M, Menon V. The Default Mode Network in Autism. Biol Psychiatry Cogn Neurosci Neuroimaging. 2017 Sep;2(6):476-486. doi: 10.1016/j.bpsc.2017.04.004. PMID: 29034353; PMCID: PMC5635856.
36. Chao LL. Effects of Home Photobiomodulation Treatments on Cognitive and Behavioral Function, Cerebral Perfusion, and Resting-State Functional Connectivity in Patients with Dementia: A Pilot Trial. Photobiomodul Photomed Laser Surg. 2019 Mar;37(3):133-141. doi: 10.1089/photob.2018.4555. Epub 2019 Feb 13. PMID: 31050950.
37. Saltmarche AE, Naeser MA, Ho KF, Hamblin MR, Lim L. Significant Improvement in Cognition in Mild to Moderately Severe Dementia Cases Treated with Transcranial Plus Intranasal Photobiomodulation: Case Series Report. Photomed Laser Surg. 2017 Aug;35(8):432-441. doi: 10.1089/pho.2016.4227. Epub 2017 Feb 10. PMID: 28186867; PMCID: PMC5568598.
38. Liebert A, Bicknell B, Laakso EL, Heller G, Jalilitabaei P, Tilley S, Mitrofanis J, Kiat H. Improvements in clinical signs of Parkinson’s disease using photobiomodulation: a prospective proof-of-concept study. BMC Neurol. 2021 Jul 2;21(1):256. doi: 10.1186/s12883-021-02248-y. PMID: 34215216; PMCID: PMC8249215.
39. Chao Linda, Barlow Cody, Karimpoor Mahta, Lim Lew, Changes in Brain Function and Structure After Self-Administered Home Photobiomodulation Treatment in a Concussion Case, Frontiers in Neurology, 11, 2020, https://www.frontiersin.org/articles/10.3389/fneur.2020.00952
40. Pallanti S, Di Ponzio M, Grassi E, Vannini G, Cauli G. Transcranial Photobiomodulation for the Treatment of Children with Autism Spectrum Disorder (ASD): A Retrospective Study. Children. 2022; 9(5):755. https://doi.org/10.3390/children9050755
41. Andreasen NC., O’Leary DS., Cizadlo T., Arndt S., Rezai K. Remembering the past: two facets of episodic memory explored with positron emission tomography. Am J Psychiatry. 1995;152:1576–1585. [PubMed] [Google Scholar]
42. Buckner RL., Carroll DC. Self-projection and the brain. Trends Cogn Sci. 2007;11:49–57. [PubMed] [Google Scholar]
43. Spreng RN., Mar RA., Kim AS. The common neural basis of autobiographical memory, prospection, navigation, theory of mind, and the default mode: a quantitative meta-analysis. J Cogn Neurosci. 2009;21:489–510. [PubMed] [Google Scholar]

The question, “When should I use an alpha frequency and when should I use a gamma frequency?” is not new. In the context of brain photobiomodulation and Vielight products, this question refers to the Vielight Neuro Alpha and Neuro Gamma devices. More specifically, answering this question requires an understanding of the differences between these two devices, their effects, and their applications.

There is a relatively simple way to think about when to use the Vielight Neuro Alpha vs the Neuro Gamma transcranial photobiomodulation (tPBM) devices. To be more precise, the name “pulsed transcranial photobiomodulation (PtPBM) devices” offers a more complete description of the function of these unique products. Furthermore, this name refers to the only difference between these two devices, which is the pulse rate of the near-infrared (NIR) light that they emit.

What is the benefit of the pulsed light tPBM? The answer can be simple, and it can be complex. Here is a simple answer: the pulsation of the light acts as an additional brain stimulation mechanism. Distinct pulse rates can stimulate the brain differently, producing differentiated effects. They can modulate and regulate corresponding brain waves, as well as the entire spectrum of neural oscillations. Distinct pulse rates can also affect and help to induce different brain states.

About Vielight Neuro Devices

To bring research to practice, Vielight has developed home-use transcranial photobiomodualtion devices. These tPBM devices can modulate cellular processes in the neurons and stimulate neural oscillations in the brain. The Vielight Neuro devices have been on the market since 2016. The current generation of these devices, the Neuro 3 lineup, was launched in late 2021. The redesigned models offer better user experience, comfort, and longevity, while delivering the same high-quality pulsed photobiomodulation to the brain.

The Vielight Neuro line of devices includes three models: the Neuro Alpha, the Neuro Gamma and the Neuro Duo. All three devices share the same headset and nasal applicator designs. The headset is designed to cover and stimulate the default mode network (DMN) of the brain. These devices also have the same LED light sources. Four LEDs are located on the headset, and one on the nasal applicator. All of them emit 810 nm near-infrared (NIR) light.

What are the differences between Vielight Neuro models?

You may recall that the difference between the Neuro models is in the pulse rate of the NIR light that they emit. We touched on this subject earlier in this article. Let’s dive deeper into this.

The Vielight Neuro Alpha

The Vielight Neuro Alpha device emits 810 nm NIR light pulsed at the frequency of 10 Hz. This is the frequency that falls within the range of brain’s alpha oscillations band. The Neuro Alpha device can stimulate and regulate brain’s alpha neural oscillations, while also affecting other frequency bands of neural oscillations (Zomorrody at al, 2021). The researchers in this study conclude: “Findings from this study provide novel evidence that tPBM modulates neural oscillations in a frequency and location dependent manner. This is also the first investigation to measure the significant effect of an intranasal NIR LED on brain oscillation with EEG.” This study revealed important aspects and effects of PtPBM using NIR light pulsed at 10 Hz. More research on this subject, including other pulse frequencies, is warranted.

This device has been used in research studies. It is currently used in a study for TBI, which has not yet been completed. It was also employed in a pilot study for symptoms for Gulf War Illness (GWI). In this exploratory study the researcher concluded that:

Results of these two case reports suggest that PBM therapy may be safely used to help alleviate many GWI symptoms. PBM was well tolerated by both veterans and there were no adverse effects. However, the treatments will likely need to be continued on a regular basis based on previous studies that suggest the effects of PBM are not maintained. This points to the importance of having PBM devices that are amenable to home use for treating GWI. These promising, preliminary results suggest that future, larger-scale, controlled trials of home PBM for GWI are warranted. (Chao, 2019).

Neuro Alpha and alpha wave brain stimulation effects

The Neuro Alpha delivers PtPBM using alpha wave stimulation. It is suitable for a brain that needs help with more flexibility and state shifting, or conscious redirection of attention capability. Furthermore, the 10 Hz alpha PtPBM usually has a generally calming effect on the brain. Reportedly, the effects of this pulse frequency correlate with increases in internal focus, body awareness, and state of peacefulness.In a study by Saltmarche et al (2017), with individuals with mild to moderately severe cognitive impairments, participants showed significant cognitive improvement, increased function, better sleep, fewer angry outbursts, reduced anxiety, and less wandering.

Neurofeedback practitioners noticed, that if the brain tends to ruminate and loop, and has difficulty shifting between tasks and states, alpha stimulation can be very helpful. In such cases, alpha wave stimulation can provide support for much-needed cognitive flexibility. Anecdotally, a number of individuals who experienced the benefits of alpha wave stimulation reported feeling generally relaxed and calm.

On the other hand, there are individuals who can take only a little of alpha stimulation at a time. This can happen because alpha wave stimulation can introduce more variability to the brain. For example, this could be a case when it is hard for a brain to handle too much flexibility. Therefore, despite receiving beneficial effects from tPBM on cellular level, such individuals could find being exposed to prolonged alpha brain stimulation somewhat cognitively discomforting. However, the same individuals may benefit from shortening their alpha tPBM session duration to a more appropriate for them level. Thus, just 10 or even 5 minutes of alpha wave PtPBM could be sufficient to feel its benefits if you have a higher sensitivity to alpha stimulation.

The Vielight Neuro Gamma 

The Vielight Neuro Gamma device emits 810 nm NIR light pulsed at the frequency of 40 Hz. This is the frequency that falls within the range of brain’s gamma oscillations band. Just like the Neuro Alpha, the Neuro Gamma can also affect other frequency bands of neural oscillations (Zomorrodi et al, Scientific Reports, Nature 2019).

Authors’ note:

Active tPBM caused significant changes in network global efficacy in the alpha band for 50–60%, 75%, 85–90% of sparsity levels, in the gamma band for 15%, 50–60%, 70–75% and 90% of sparsity levels. Sham tPBM did not cause any significant change in the global efficacy. Additionally, by analyzing brain network properties using wPLI and the graph theory measures, we observed significant effects of active tPBM. The connectivity measures, which assessed the integration and segregation properties of the network, showed a significance increase in clustering coefficient, characteristic path length (CPL) and local efficiency measures for each oscillation frequency band. The pulse frequency employed likely plays an important role in the effects of tPBM on brain activity. Pulsing NIR light not only minimizes the heating effect and increases the possible penetration depth, but may effectively interact with cellular activity via two proposed mechanisms by: (a) impacting the ionic channels kinetic such as potassium and calcium in the mitochondria (b) increasing the dissociation rate of nitric oxide from cyctochrome c oxidase. (Zomorrodi et al, 2019).

The Neuro Gamma devices have been employed in a number of studies and clinical trials, including those for Alzheimer’s disease, Parkinson’s disease, TBI, concussion, and autism spectrum disorder.

Neuro Gamma and gamma wave brain stimulation effects 

In general, gamma wave stimulation is better suited for brains that tend to be more easily distracted and less focused. Furthermore, in some cases, combining tPBM with other activities to optimize brain’s performance can be an important factor in attaining best results. One such activity can be meditation, and current studies are exploring this amalgamation and its effects on the brain.

When it comes to the Neuro Gamma’s capabilities, they can be summarized as a non-invasive brain stimulation within the gamma band range. The 40 Hz pulse frequency range is associated with the natural gamma brain oscillations. This type of oscillations is usually present in the brain during high levels of activity in solving complex tasks. PtPBM stimulation in the 40 Hz gamma range can be beneficial for a brain that needs help to maintain engaged and complex processing states (Zhang et al, 2021).

Furthermore, studies (Chao, 2019) have shown that near-infrared light pulsed at 40 Hz can facilitate improvements in cognition. This includes improvements in speed and the ceiling of learning abilities. Other effects noticed in the studies were stimulation of brain’s immune cells, improved perfusion, and clearing out of toxic proteins.

The Vielight Neuro Duo 

Last, but not least, in the lineup is the Vielight Neuro Duo PtPBM device. The Neuro Duo can pulse the light either in the alpha or the gamma frequency band. Thus, the Neuro Duo combines the 40 Hz pulse frequency of the Neuro Gamma and 10 Hz pulse frequency of the Neuro alpha in one device, offering all the benefits of alpha and gamma PtPBM. You, as the user, can select one of the two frequencies for your tPBM session. For example, a recent study involving children with autism (Pallanti et al, 2022) employed both the Neuro Alpha and the Neuro Gamma devices. It demonstrated a reduction in the severity of autism spectrum disorder, as well as a reduction in cognitive and behavioral rigidity. The study also demonstrated an increase in sleep quality, and improvement in attention in the study participants.

The Vielight Neuro Pro — the flagship

The most recent addition to the Neuro family of Vielight devices has been the Vielight Neuro Pro. One-of-a-kind, the Neuro Pro offers customization options that no other photobiomodulation device can offer.

Unlike other Neuro devices, the Neuro Pro is not a one-button-push device. It comes with an app that drives the functionality of the device, giving the user full control over photobiomodulation parameters. This ability to customize numerous parameters of a tPBM session is what sets the Neuro Pro apart.

For example, with regards to the stimulation at the level of neural oscillations, the Neuro Pro covers all frequency bands. It has a pulse range of up to 10,000 Hz. This capacity allows users to set the pulse rate at any frequency corresponding to any of the known brain’s neural oscillations.

Whether you are interested in stimulating and regulating delta, theta, alpha, beta, or gamma oscillations, the Neuro Pro can help you do that.

If you are researcher, a neuroscientist, or a health and wellness practitioner with a focus on the brain, you may appreciate the unique customization features that the Neuro Pro offers. Furthermore, if you are a serious biohacker, an advanced meditator seeking to deepen your meditative experience, or a neurotech aficionado, you will surely be interested in the Neuro Pro.

Is dose important for alpha and gamma brain stimulation? 

How can I regulate the amount and level of brain photobiomodulation? How can I attain the optimal outcomes from pulsed tPBM? These are very important questions. Answering them would require consideration of the capabilities of the device used, as well as user’s individual sensitivities.

When it comes to the Vielight Neuro Alpha and Gamma devices, some users find it helpful trying different session duration options to create a tPBM experience that is optimal for them. Some people do well with only 5 or 10-minute sessions at first, and then work their way up over time. Others may find that they can tolerate only shorter session durations and stay with those with which they are comfortable. However, most users report a good tolerance of a full 20-min-session, which is the Neuro device’s pre-set default duration.

Selecting the right time of day for your tPBM session could make a difference as well. Some people are benefitting from using the gamma in the mornings, or as a midday or an afternoon “pick-me-up.” The same people can also find that, if they use it in the evenings, they have trouble sleeping. Some people benefit from a few minutes of gamma stimulation to jumpstart early in the day, and then a session of alpha stimulation in the evening, to wind down.

Finding a balanced dose of pulsed tPBM stimulation

Despite overwhelming biological similarities, we have many differences that can make us feel and react differently to various stimuli. For example, some people can run full gamma stimulation sessions and feel very energized and focused, whereas more than a brief exposure to the alpha may leave them feeling muddled and a little disconnected.

On the other hand, some may feel and enjoy the calming effect of the alpha stimulation sessions, but cannot tolerate more than only a few minutes of gamma stimulation. It is important to consider these sensitivities and use the devices accordingly. There are numerous ways that you can optimize and maximize your brain photobiomodulation experience. It only takes a little bit of effort and some trial time. Understanding that, Vielight offers a 6-month-80%-back return policy on all Vielight devices, and a two-year product warranty.

Furthermore, those who use the Neuro Pro devices have many more options available to them to fine-tune their tPBM experience. If you are a lucky Neuro Pro owner, in addition to the customizing the duration, you can consider turning off some of the LED modules, decreasing the power of the LEDs, or a combination of all three variables. This personalized customization can help you to optimize your tPBM session to fit your personal needs, tolerance, and comfort. ­

How to avoid brain overstimulation during pulsed tPBM?

20-min-sessions suggested for general Vielight Neuro use are usually suitable for most. However, there is a small number of individuals who may require a little bit of self-testing to establish the tPBM session duration that both tolerable and beneficial for them.

Brain overstimulation can happen as a result of excessive dosage of tPBM. Whether you are doing alpha or gamma brain stimulation, it is always best to avoid overstimulating your brain.

Overstimulation usually manifests itself in a form of a transient headache. Practice shows that there can be too much of a good thing, and more does not always mean better. Notably, an important factor in avoiding overstimulation is understanding your individual response to tPBM. It is important to establish the appropriate dose of stimulation that works for your brain specifically.

A simple way to do this is to start tPBM stimulation with lower duration and increase it over time. For example, a starting time can be 5 minutes per session, every second day, to establish your tolerance level. The users with good tolerance can gradually increase the time to 10 minutes, then to 15 minutes, and finally to full 20 minutes per session. This tolerance testing could be done over a period of 3-4 weeks. In addition to the tPBM session duration, it is important to consider the frequency of the sessions. The general suggested frequency of use for the Vielight Neuro devices is 3 times a week or every second day. However, in some cases the use can be extended to up to 6 days a week with one day off.

Some neurofeedback practitioners suggest that there are ways to mediate overstimulation with one pulse rate by using another. If a person prone to overstimulation undergoes gamma stimulation, for example, they could potentially mediate that overstimulated feeling by using alpha wave stimulation immediately after. This option could help to bring that higher frequency state in the brain’s gamma oscillations to a more agreeable level.

How to avoid brain under-stimulation during pulsed tPBM?

On the other hand, under-stimulation, or delivering insufficient levels of light energy to the brain, is also not a good practice. It would defeat the purpose of tPBM. Appropriate dosing of tPBM levels is an important factor in attaining best outcomes.

How long does it take to feel the effects of pulsed tPBM

In conclusion, it is important to note the timeline of when the effects of pulsed tPBM sessions may occur. Usually, users notice some effects of pulsed tPBM within a period of 2 weeks to 3 months after their first tPBM session. This period is reported anecdotally by the users, and seen in a number of studies, many of which have been mentioned above.

Everyone’s brain is “wired” somewhat differently, and sensitivities to brain stimulation differ. Depending on where you are on the sensitivity spectrum, you may feel the effects somewhat earlier or somewhat later.

Numerous studies conducted over the last two decades have shown the beneficial effects of photobiomodulation (PBM) on the body. Furthermore, a lot of research has been done over the last decade to better understand PBM’s effects on the brain. Today, there is a sufficient body of research-based evidence to conclude that PBM has beneficial effects on the brain. Various published, peer-reviewed studies provide solid support for such a conclusion.

This research has helped to uncover the cellular mechanisms of PBM. The majority of PBM studies have been done using constant light (no pulsation). However, more recently, studies have been conducted to scrutinize the effects of PBM using pulsed light. The effects of this type of PBM are of particular relevance to brain stimulation and modulation. Thus, research into brain-focused PBM, or transcranial photobiomodulation (tPBM), as a non-invasive brain stimulation modality is gaining interest.

As we noted, during a tPBM session, light can be pulsed to deliver pulsed transcranial photobiomodulation (PtPBM). The pulse rate usually corresponds to a particular neural oscillation frequency that is occurring in the brain naturally. The expectation from this is to attain additional benefits for the brain. These benefits can range, and they depend on the specific frequency at which the light is pulsing. As various neural oscillations are attributable to specific brain states, the pulsation of the light can help to induce a corresponding state. PtPBM is able to recruit brain’s attention. It can also help to induce various forms of learning, teaching the brain to react better to external stimuli. Most of tPBM-focused studies employed pulsed tPBM using either the alpha frequency of 10 Hz or the gamma frequency of 40 Hz.

Considering that different pulse frequencies affect brain differently, further research is needed to understand the scope of these effects better. There is a number of ongoing studies focused on benefits of tPBM for various applications. The range and scope of such studies are growing.

What cellular mechanism underlies photobiomodulation?

The benefits of cellular effects include those related to mitochondrial respiratory chain, as you will see below. Furthermore, studies also posit that tPBM helps to improve oxygenation and perfusion in the brain.

The fundamental mechanism that is thought to underly photobiomodulation (PBM) is based on its effect on Cytochrome C Oxidase (CCO), the fourth unit of the mitochondrial respiratory chain. The absorption of photons by CCO causes nitric oxide photodissociation (Lane, 2006). This event leads to an increase in electron transport activity and an increase in adenosine triphosphate (ATP), the energy source of cells.

Coincidently, there is an increase in production of reactive oxygen species (ROS) by the mitochondria. ROS play an important role in facilitating communication among the cells, as well as support of immune response. Furthermore, the release of Ca2+, as versatile second messengers, also takes place. In turn, these processes lead to the activation of transcription factors and signaling mediators (ie. NF-κB), producing long-lasting cellular effects (de Freitas & Hamblin, 2016).

A study by Wang et al. revealed a new cellular mechanism using a longer wavelength near-infrared light. They reported activation of heat or light-sensitive calcium ion channels (Wang et al., 2017). This is important because, as crucial components of the nervous system, ion channels are necessary for the normal activity of neurons and glia.

How does photobiomodulation affect inflammation, pain, and tissue healing?

As we noted above, reactive oxygen species play a central role in the progression of inflammation. During inflammatory conditions, ROS production causes an increase in the migration of inflammatory cells to the damaged tissue. Furthermore, polymorphonuclear neutrophils (PMNs) increase ROS production at the location of inflammation. In turn, this causes dysfunction within endothelial cells and additional tissue injury.

The migration of inflammatory cells results in more injury in inflamed tissue, as well as pain, delaying the healing process (Mittal et al., 2014). PBM (with light using wavelengths greater than 500 nm) increases the production of ROS in normal cells (Chen et al.). Thus, it reduces markers of oxidative stress in stressed and damaged cells (de Freitas & Hamblin, 2016), demonstrating that photobiomodulation promotes faster healing.

Furthermore, PBM can suppress inflammation by reduction in PGE2- levels and inhibition of cyclooxygenase-2 (COX-2) in cells (Bjordal et al., 2003). Cyclooxygenase-2 is an enzyme responsible for inflammation and pain. Therefore, the appropriate dose of PBM directed to the injured tissue could positively control pain, reduce inflammation, and expedite healing.

Although the pain control mechanisms of PBM are not yet clearly understood, several theories have been proposed. The regulation of pain (Melzack & Wall, 1965), modulation of inflammation, upregulation of β-endorphin production (Laakso et al., 1994), direct inhibition of neural activity (Snyder-Mackler & Bork, 1988), and acceleration of healing are all mechanisms by which PBM is thought to control pain.

How to maximize the benefits of photobiomodulation for the brain?

Hypothetically, to maximize the benefits of photobiomodulation for the brain, you would need a sophisticated delivery method. This delivery method would account for a number of parameters like power, light power density, duration, proximity, placement and more. An example of one such delivery method would be a PBM device that can combine and deliver the benefits related to cellular processes, and those related to stimulation of neural oscillations. These are two different pathways or mechanisms that can affect neural activity and the brain overall. However, these pathways can also be combined for a more holistic effect from tPBM.

A number of published studies provide support for tPBM’s positive effects on neural activity.  Animal and human studies show the benefits of both pulsed and continuous light during photobiomodulation. However, when it comes to brain-focused PBM, studies show that pulsed light can deliver more pronounced benefits.

It is possible that the added benefits of the pulsed light tPBM come from stimulation related to neural oscillations. For example, as studies show, pulsed light tPBM can upregulate or downregulate brain oscillations. Furthermore, the effect can happen on the entire frequency spectrum of neural oscillations, even if stimulation employs a single frequency.

Additional research will provide further evidence about the effects of different pulse frequencies. To advance such research, Vielight has developed the Neuro Pro, a fully customizable tPBM device with a pulse frequency range between 0 and 10,000 Hz. The Neuro Pro offers the inquisitive minds the opportunity to study how pulsed light tPBM affects the brain.  The Neuro Pro allows users to do that in a large range of pulse frequencies.

Effect of pulsing light

It would be beneficial to discuss the importance of pulsing the light at a certain frequency during PBM.

A study, published by Dr. Hamblin’s Laboratory, compared the effects of the same-dose of near-infrared (NIR) light transcranial PBM (tPBM) delivered with different pulse rates. The researchers compared three tPBM parameters. One was done with continuous wave light (no pulse), one with light pulsed at 10 Hz, and one with light pulsed at 100 Hz. All three tPBM options were delivered to mice with traumatic brain injuries (TBI) (Ando et al., 2011). The study found that beneficial effects on cognitive function were statistically better with 10 Hz tPBM than they were with either a continuous wave or 100 Hz.

Another interesting animal study came from MIT, under the leadership of Li-Huei Tsai (Iaccarino et al., 2016). The study demonstrated that genetically engineered Alzheimer’s mice ended up with reduced amyloid beta after tPBM with NIR light pulsing at 40 Hz (gamma frequency). Amyloid beta is the main component of the amyloid plaques found in the brains of subjects with Alzheimer’s disease. Notably, the researchers did not see the same effect with other pulse frequencies.

Using the data from this study, we can hypothesize that amyloid beta is attenuated in the brain regions that process pulsed light at 40 Hz. Furthermore, if we could deliver 40 Hz tPBM to certain areas of the brain, such as the default mode network (DMN), it could, theoretically, be an impactful treatment for Alzheimer’s disease.

In line with this hypothesis, Vielight Inc. is currently running a clinical trial to investigate the Vielight Neuro RX Gamma device as a treatment for mild-to-moderate Alzheimer’s Disease. Importantly, this pivotal clinical trial is double-blind, randomized, includes a placebo-controlled group, and involves 228 participants.

Default mode network (DMN) and brain’s resting state

Overlapping with the construct of neural oscillations is the brain’s resting state. The simplest way to define the brain’s resting state could be its readiness to act, while being in a state of rest or inaction, and consciousness.

The default mode network of the brain is associated with the state of consciousness. Referenced by the brain’s readiness to express action or will, the DMN is responsible for the brain’s resting state. The DMN consists of the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), precuneus (PCu), inferior parietal lobe, lateral temporal cortex and hippocampal formation. Furthermore, studies indicated that the DMN is generally divided into two subsystems: an anterior part (aDMN) and a posterior part (pDMN).

Considering the importance of the DMN, the placement of the light-emitting LEDs in the Vielight Neuro tPBM devices covers all areas of DMN. Furthermore, the Neuro Alpha tPBM device exposes the DMN to stimulation with 810 nm near-infrared light pulsed at 10 Hz. The Neuro Gamma tPBM device exposes the DMN to stimulation with 810 nm NIR light pulsed at 40 Hz.

Research has shown that factors like posture and eye movement can influence the brain’s resting state. Thus, meditation and meditative states, where internal focus and a state of calm are prevalent factors, can be linked to the DMN. Furthermore, EEG readings can help to capture prevalent brain oscillations during meditative practices.

The Default Mode Network and dementia

The DMN network is of particular relevance for Alzheimer’s Disease. The mesial prefrontal cortex, the medial temporal lobe, and, particularly, the hippocampus (the nodes of DMN) are involved in mediating episodic memory. In Alzheimer’s Disease, impairment in episodic memory is one of the first symptoms observed (Greicius et al., 2004). Given the significant role that the DMN plays in the pathophysiology of Alzheimer’s Disease, it represents an important neuroanatomical target for treatment. Targeting it with transcranial photobiomodulation is a non-invasive option that is being studied.

At this point, you may be interested in looking at study examples that used NIR tPBM on DMN locations. A tPBM study on Alzheimer patients by Dr. Linda Chao demonstrated some of the benefits of tPBM. The study presented post-treatment improvements in Alzheimer’s disease scores, increased cerebral perfusion, and increased connectivity (Chao, 2019). Dr. Chao performed tPBM using Vielight Neuro Gamma devices with LEDs placed on the head, over the DMN location (Fig. 1).

Figure 1: Placement of the Vielight Neuro pulsed tPBM device over the default mode network.

Another study, by Salmatche et al., tested the Vielight Neuro Alpha devices on subjects with mild to moderately severe dementia cases. They found that the subjects exhibited better sleep, fewer angry outbursts, less anxiety, and less wandering after the treatment (Saltmarche et al., 2017).

The Vielight Neuro Pro, meditation, and photobiomodulation

Practitioners who employ neurofeedback in combination with tPBM observed interesting effects of brain stimulation with pulsed tPBM. For example, with higher wave frequencies PtPBM, energy levels, focus, and arousal increase, while bodily awareness decreases. These observations point to a possibility that higher frequency PtPBM could be useful in attaining deeper and higher meditative states.

Studies suggest that long-term meditators have higher power in all wavelength ranges of brain oscillations. However, it is the higher gamma frequency range increase that is of particular interest, because it helps to attain higher level meditative states.

To better understand the effects of tPBM on meditative states, Vielight is working on a meditation study. This study will employ the Vielight Neuro Pro device. The Neuro Pro can be set to pulse the NIR light at a variety of frequencies, while a number of important tPBM variables can be customized. This customization flexibility is expected to help to investigate what effects various PtPBM protocols can produce on meditative states.

Conclusion

It is important to note that research into the effects of transcranial photobiomodulation on the brain has progressed significantly. Nevertheless, there are still many questions that need to be answered. Meanwhile, tPBM is garnering attention of more and more researchers and reputable research institutions worldwide. The depth and breadth of knowledge about its effects on the brain is expending. Thus, the understanding of tPBM pathways is growing, and it is very possible that new ones will be discovered.

The enhancement of human cognitive processes has long been a focus of scientific discovery. Progress in technology and research, has lead to non-invasive brain stimulation therapies playing increasingly important roles in improving neuroplasticity, brain performance, and neuromodulation.

What is non-invasive brain stimulation?

Non-invasive brain stimulation is defined as the delivery of energy through the cranium to the brain, to stimulate or improve its activity.

Over the past decade, new discoveries in neuroscience have led to a better understanding of the brain’s mechanisms and how different forms of energy can influence changes within the brain.

In this blogpost, the different energy sources used for brain stimulation will be examined along with their applications.

What are the different types of brain stimulation technologies?

Brain stimulation technologies involve activating or inhibiting the brain directly with:

• Electricity (transcranial direct stimulation, tDCS)
• Magnetic fields (transcranial magnetic stimulation, tMS)
• Electromagnetic radiation within the 600-1100nm range (photobiomodulation, PBM)

These different types of energy sources produce different outcomes.

Transcranial direct current stimulation (tDCS)

Transcranial direct stimulation involves the use of weak currents of electricity delivered via electrodes on the head. It was originally developed to help patients with brain injuries or neuropsychiatric conditions such as major depressive disorder.

tDCS works by applying a positive (anodal) or negative (cathodal) current via electrodes to an area. During stimulation, current flows between the electrodes, passing through the brain to complete the circuit. The position of the anode and cathode electrodes on the head is used to set how current flows to specific brain regions.^[1]

Mechanisms

It is hypothesized that anodal stimulation increases neuronal excitability, while cathodal stimulation produces the opposite effect. ^[2] However, the relationship between the stimulation and neural response is not dependent on just the electrode type but also the length and strength of the stimulation applied through it.^[3] Neurons throughout the cortex are not modulated in a homogenous manner. Neurons in deep cortical layers are often deactivated by anodal stimulation and activated by cathodal stimulation.^[4] Given the complexity of the brain’s electrical signaling, inconsistent outcomes of transcranial direct current stimulation (tDCS) may originate from the anatomical differences among individuals.^[5]

Technology

tDCS devices delivers low electric current to the scalp through electrodes placed on the head. A fixed current between 1 and 2 mA is typically applied. There is usually a control panel that allows you to program the device (to set the duration and intensity of stimulation).

Figure 1. This figure denotes transcranial direct current stimulation technology delivering continuous low current stimulation by applying a positive (anodal) or negative (cathodal) current via paired electrodes over the scalp.

Set-up

A standard tDCS set-up uses a target and a reference electrode. First, the desired locations of where the electrodes will be positioned are determined. Saline solution, conductive paste or EEG gel are used to affix the electrodes to the scalp and distribute the current. The participant’s hair should be parted to ensure good contact between scalp and electrode. Electrodes are then attached to the stimulator using wires connected to corresponding anodal/cathodal ports.

Outcomes

Research shows increasing evidence for tDCS as a treatment for depression.^{[6, 7, 8]} There is mixed evidence about whether tDCS is useful for cognitive enhancement in healthy people. There is no strong evidence that tDCS is useful for memory deficits in Parkinson’s disease and Alzheimer’s disease.

Transcranial magnetic stimulation (TMS)

Transcranial magnetic stimulation (TMS) is a non-invasive procedure that uses magnetic fields generated through electrical currents passing through an electromagnetic coil. The magnetic field then delivers electrical current into the brain through induction stimulate nerve cells in the brain.

Mechanisms

At present, the mechanisms of TMS is not well understood. What is known is the current produced is above the threshold needed to make a neuron activate. When the coil is placed on the motor cortex, TMS makes the cells in the motor cortex active, enough to make a finger twitch.

Some studies have proposed the activation of neurotransmitter systems as a working mechanistic model.^[9]

Technology

TMS equipment usually consists of a small electromagnetic coil and a computer which controls the frequency and power output.

Figure 2: TMS machines deliver electrical currents into the brain through induction from an electromagnetic coil.

Transcranial Photobiomodulation (tPBM)

Transcranial photobiomodulation or brain photobiomodulation is a newer field of brain stimulation that uses LEDs or lasers to deliver light energy in the near-infrared to far-infrared (800 – 1000+ nm) wavelengths to the brain.

Mechanisms

Brain photobiomodulation (PBM) utilizes red to near-infrared (NIR) photons to stimulate the cytochrome c oxidase enzyme of the mitochondrial respiratory chain. Cytochrome c oxidase is receptive to light energy. This results in an increase in ATP synthesis, leading to the generation of more cellular energy. Additionally, photon absorption by ion channels results in release of Ca²⁺ which leads to the activation of transcription factors and gene expression.

• Published study (May 2022) using the Vielight Neuro Alpha on how neurons and cellular components such as microtubules and tubulin respond to near-infrared PBM.
• Published study (April 2019) using the Vielight Neuro Gamma on how near-infrared PBM could positively cognition, memory consolidation and mental energy.

Figure 3 Mechanisms of photobiomodulation

Therapeutic Outcomes of Brain Photobiomodulation: CCO upregulation

The absorption of red to NIR photons by mitochondria CCO triggers a series of cellular and physiological effects occur in the brain, also known as CCO upregulation.

CCO upregulation leads to:

• A small increase in reactive oxygen species (ROS), which activate mitochondrial signaling pathways linked to neuroprotection.^[13]
• An increase in nitric oxide (NO) which stimulate vasodilation and cerebral blood flow.^[14]
• An increase in ATP production^[15]
• Combined, these effects trigger and improve the activation of signaling pathways and transcription factors that modulate the long-term expression of various proteins and metabolic pathways in the brain.[6] Additionally, electrophysiological effects on the human brain have also been demonstrated by PBM in older people.^{[16, 17]}

Metabolic effects and brain oxygenation

The metabolic effects of PBM in the elderly have been shown to increase cerebral blood flow (CBF) due to the increase in CCO activity, leading to an increase in brain oxygenation. Photobiomodulation of the prefrontal cortex was able to increase the resting-state EEG alpha, beta and gamma power, and more efficient prefrontal fMRI response, facilitating cognitive processing in the elderly. ^[18] Additionally, photobiomodulation of the Default Mode Network (DMN) has also been shown to increase cerebral perfusion due to an increase in mitochondrial activity. ^[19]

Brain PBM and anti-inflammatory effects

In addition to the above findings, PBM may be a promising strategy for improving aging brains because of its anti-inflammatory effects. ^{[20, 21]}

Brain PBM leads to a reduction in neuronal excitotoxicity

In 2022, researchers from the University of Alberta published a multi-layered study investigating the way that living cells, cellular structures, and components such as microtubules and tubulin respond to near-infrared photobiomodulation (NIR PBM) using the Vielight Neuro Alpha.

Their study showed that PBM balances excitatory stimulation with inhibition, indicating that PBM may reduce excitotoxicity which is relevant to the maintenance of a healthy brain. This study also showed that low-intensity PBM upregulates mitochondrial potential and improves physiological brain functions impaired due to trauma or neurodegeneration. ^[22]

Brain PBM increases cerebral vascularity and oxygenation

Aging is accompanied by changes in tissue structure, often resulting in functional decline. The blood vessels within the brain are no exception. As one ages, a decrease in blood flow to the brain is caused by a loss of cerebral vascularity, leading to cognitive decline when neurons cannot obtain sufficient oxygen.^[23] Brain photobiomodulation has also been shown to increase cerebral blood flow due to the vasodilation that occurs after the release of nitric oxide.^[24]

Figure 4 Therapeutic outcomes of photobiomodulation

Technology

Brain photobiomodulation devices consist of either headsets or helmets that position LEDs or laser diodes over the cranium.

The diodes need to generate enough power with proper wavelengths to penetrate the skull. There’s little utility in generating a lot of total power if none of it reaches the brain.

There are several aspects of brain photobiomodulation devices that users need to be aware of.

Penetration

Figure 5 Penetration of Neuro LEDs through the cranium and nasal area.

Brain photobiomodulation devices should be designed for maximum transmission of light energy safely without generating heat.

That can be accomplished through maximizing contact with the scalp. For example, the Vielight Neuro’s headset’s LED modules were designed to maximize contact with the scalp. Additionally, the headset design ensures that heat isn’t trapped.

Wavelength

The accepted wavelength range for brain photobiomodulation is within the NIR to far infrared range.

The near infrared (NIR) range in the electromagnetic spectrum has a theoretical maximum depth of penetration in tissue.

Figure 6 The optical window
Image source: Wang, Erica & Kaur, Ramanjot & Fierro, Manuel & Austin, Evan & Jones, Linda & Jagdeo, Jared. (2019).
Safety and penetration of light into the brain. 10.1016/B978-0-12-815305-5.00005-1.

Visible light (wavelength 400 to 700 nm) is substantially absorbed by hemoglobin and other organic matter. On the other hand, absorption by water increases at wavelengths longer than near infrared light (1000+nm). This implies that wavelengths outside of the near-infrared window cannot easily penetrate deeply through tissue.

References

1. Thair H, Holloway AL, Newport R, Smith AD. Transcranial Direct Current Stimulation (tDCS): A Beginner’s Guide for Design and Implementation. Front Neurosci. 2017;11:641. Published 2017 Nov 22. doi:10.3389/fnins.2017.00641
2. Cambiaghi M, Velikova S, Gonzalez-Rosa JJ, Cursi M, Comi G, Leocani L. (2010). Brain transcranial direct current stimulation modulates motor excitability in mice. Eur J Neurosci 31:704–709.
3. Roche, M. Geiger, B. Bussel, Mechanisms underlying transcranial direct current stimulation in rehabilitation, Annals of Physical and Rehabilitation Medicine, Volume 58, Issue 4, https://doi.org/10.1016/j.rehab.2015.04.009
4. P. Purpura, J.G. McMurtry, Intracellular activities and evoked potential changes during polarization of motor cortex, J Neurophysiol, 28 (1965), pp. 166-185
5. Kim JH, Kim DW, Chang WH, Kim YH, Im CH. Inconsistent outcomes of transcranial direct current stimulation (tDCS) may be originated from the anatomical differences among individuals: a simulation study using individual MRI data. Annu Int Conf IEEE Eng Med Biol Soc. 2013;2013:823-5. doi: 10.1109/EMBC.2013.6609627. PMID: 24109814.
6. Brunoni AR, Moffa AH, Fregni F, Palm U, Padberg F, Blumberger DM, Daskalakis ZJ, Bennabi D, Haffen E, Alonzo A, Loo CK (2016). “Transcranial direct current stimulation for acute major depressive episodes: meta-analysis of individual patient data”.  doi:1192/bjp.bp.115.164715.

1. Julian Mutz, Vijeinika Vipulananthan, Ben Carter, René Hurlemann, Cynthia H Y Fu, Allan H Young (2019). “Comparative efficacy and acceptability of non-surgical brain stimulation for the acute treatment of major depressive episodes in adults: systematic review and network meta-analysis”. BMJ. 364: l1079. doi:10.1136/bmj.l1079
2. “Transcranial direct current stimulation (tDCS) for depression”. NICE. August 2015. Retrieved 10 November 2015.

9. Peng Z, Zhou C, Xue S, Bai J, Yu S, Li X, Wang H, Tan Q. Mechanism of Repetitive Transcranial Magnetic Stimulation for Depression. Shanghai Arch Psychiatry. 2018 Apr 25;30(2):84-92. doi: 10.11919/j.issn.1002-0829.217047. PMID: 29736128; PMCID: PMC5936045.
10. Smith, Andrew M.; Mancini, Michael C.; Nie, Shuming (2009). “Bioimaging: Second window for in vivo imaging”. Nature Nanotechnology. 4(11): 710–711. doi:1038/nnano.2009.326. ISSN 1748-3387. PMC 2862008
11. Jang, J. Y., Blum, A., Liu, J., & Finkel, T. (2018). The role of mitochondria in aging. The Journal of clinical investigation, 128(9), 3662–3670. https://doi.org/10.1172/JCI120842
12. Dompe, C., Moncrieff, L., Matys, J., Grzech-Leśniak, K., Kocherova, I., Bryja, A., Bruska, M., Dominiak, M., Mozdziak, P., Skiba, T., Shibli, J. A., Angelova Volponi, A., Kempisty, B., & Dyszkiewicz-Konwińska, M. (2020). Photobiomodulation-Underlying Mechanism and Clinical Applications. Journal of clinical medicine, 9(6), 1724. https://doi.org/10.3390/jcm9061724
13. Suski, J. M., Lebiedzinska, M., Bonora, M., Pinton, P., Duszynski, J., & Wieckowski, M. R. (2012). Relation between mitochondrial membrane potential and ROS formation. In Mitochondrial bioenergetics (pp. 183-205). Humana Press.
14. Wang X., Tian F., Soni S.S., Gonzalez-Lima F., Liu H. Interplay between up-regulation of cytochrome-c-oxidase and hemoglobin oxygenation induced by near-infrared laser. Sci. Rep. 2016;6:30540. doi: 10.1038/srep30540.
15. Hamblin M.R. Photobiomodulation for traumatic brain injury and stroke. J. Neurosci. Res. 2018;96:731–743. doi: 10.1002/jnr.24190.
16. Cardoso FDS, Mansur FCB, Lopes-Martins RÁB, Gonzalez-Lima F, Gomes da Silva S. Transcranial Laser Photobiomodulation Improves Intracellular Signaling Linked to Cell Survival, Memory and Glucose Metabolism in the Aged Brain: A Preliminary Study. Front Cell Neurosci. 2021 Sep 3;15:683127. doi: 10.3389/fncel.2021.683127. PMID: 34539346; PMCID: PMC8446546.
17. Wang, X., Dmochowski, J. P., Zeng, L., Kallioniemi, E., Husain, M., GonzalezLima, F., & Liu, H. (2019). Transcranial photobiomodulation with 1064-nm laser modulates brain electroencephalogram rhythms. Neurophotonics, 6(2), 025013.
18. Vargas E, Barrett DW, Saucedo CL, et al. Beneficial neurocognitive effects of transcranial laser in older adults. Lasers in medical science. 2017;32(5):1153–1162. [PubMed: 28466195]
19. Chao LL. Effects of Home Photobiomodulation Treatments on Cognitive and Behavioral Function, Cerebral Perfusion, and Resting-State Functional Connectivity in Patients with Dementia: A Pilot Trial. Photobiomodul Photomed Laser Surg. 2019 Mar;37(3):133-141. doi: 10.1089/photob.2018.4555. Epub 2019 Feb 13. PMID: 31050950.
20. Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 2017;4(3):337-361. doi: 10.3934/biophy.2017.3.337. Epub 2017 May 19. PMID: 28748217; PMCID: PMC5523874.
21. dos Santos Cardoso, F., Mansur, F.C.B., Araújo, B.H.S. et al.Photobiomodulation Improves the Inflammatory Response and Intracellular Signaling Proteins Linked to Vascular Function and Cell Survival in the Brain of Aged Rats. Mol Neurobiol 59, 420–428 (2022). https://doi.org/10.1007/s12035-021-02606-4
22. Staelens Michael, Di Gregorio Elisabetta, Kalra Aarat P., Le Hoa T., Hosseinkhah Nazanin, Karimpoor Mahroo, Lim Lew, Tuszyński Jack A. Near-Infrared Photobiomodulation of Living Cells, Tubulin, and Microtubules In Vitro, Frontiers in Medical Technology 4. 2022 May 04, https://doi.org/10.3389/fmedt.2022.871196, ISBN:2673-3129
23. Salgado AS, Zângaro RA, Parreira RB, Kerppers II. The effects of transcranial LED therapy (TCLT) on cerebral blood flow in the elderly women. Lasers in medical science. 2015;30(1):339– 346. doi: 10.1007/s10103-014-1669-2 [PubMed: 25277249]
24. Yang T, Sun Y, Lu Z, Leak RK, Zhang F. The impact of cerebrovascular aging on vascular cognitive impairment and dementia. Ageing Res Rev. 2017 Mar;34:15-29. doi: 10.1016/j.arr.2016.09.007. Epub 2016 Sep 28. PMID: 27693240; PMCID: PMC5250548.

Vielight Neuro Gamma Shines in a Brain Injury Study

The sports medicine community recognizes that concussions from repetitive blows to the head are major public health concerns. To address this issue, Vielight is dedicating resources to seek for a solution using non-invasive transcranial photobiomodulation (tPBM) modality. We try to be a part of the solution by investing in quality research and development of tPBM devices as potential treatment options. We work with research labs such as Dr Margaret Naeser’s at the Boston University School of Medicine in association with the Boston VA. Several universities employ Vielight devices in their independent research.

One such research center, headed by Dr. David Tate at the University of Utah Department of Neurology, studied concussion using the Vielight RX Gamma as a treatment modality. They presented the results of their study at the recent 10th Annual Symposium of the Sports Neuropsychology Society in Dallas, Texas. Through this independent study, over a period of eight weeks, they studied 49 male and female former athletes with histories of concussion and/or repetitive subconcussive events. All participants had concussive symptoms caused by repeated blows to the head.

The university-led study used the Vielight Neuro RX Gamma to alleviate common symptoms of concussion.

The research team reported significant differences in their pre- and post-treatment experiences. When the RX-Gamma was used, there were improvements in symptoms of depression, post-traumatic stress, adjustment, sleep quality, reaction time, and bilateral grip strength. The RX Gamma is a clinical trial version of the Vielight Neuro Gamma tPBM device. Both are designed for home use. A summary of the findings can be accessed here: https://www.vielight. com/wp-content/uploads/2022/05/TPBMTreatment-Effects-in-Former-Athleteswith-Repetitive-Head-Hits-Liebel-04-22. pdf

Commenting on this study, Vielight’s CEO, Dr. Lew Lim, remarked, “The University of Utah’s study supports the positive effects that photobiomodulation (PBM) has on post-concussion symptoms. We are grateful that this university chose the Vielight Neuro RX Gamma to test our assumption that it could help with these circumstances. The encouraging results from this study give hope to people suffering from brain injury that healing is possible, when PBM is applied to the brain with the RX Gamma. Vielight’s only role in this independent study was to supply the devices.”

Watch the video here:

Vielight-Sponsored Study Discovers New Understanding in PBM Mechanisms

As part of the effort to develop more effective PBM devices, Vielight continues to invest in understanding fundamental cellular mechanisms related to PBM. In another study, Vielight collaborated with Dr. Jack Tuszynski’s lab at the University of Alberta. The aim of this study was to better understand how photons (light) delivered to the brain via PBM behave and participate in cellular mechanisms and how the cells receive, process, and transmit signals within themselves and their environment.

Although the efficacy of PBM has been reported over the years, its biochemical mechanisms are still poorly understood. For example, the effects of PBM on living cells and the role of microtubules in neuronal signaling are largely unknown.

Several important novel discoveries were made in our collaborative study with Dr. Jack Tuszynski’s lab. Firstly, living cells were exposed to light from a Vielight 810 Infrared LED in an in vitro experiment. The results showed that the cells responded with an increase in electrical current flow and resistance in the microtubules. This may suggest that PBM controls the toxic actions of excitatory neurotransmitters with inhibitory capabilities by keeping them in check.

In the second set of experiments, the research team studied how microtubules within a cell respond to low-intensity PBM. The microtubules were observed to disassemble widely when they were exposed to low-intensity near-infrared (NIR) light. This discovery suggests that low-intensity NIR PBM causes the mitochondria (the cells that create energy for all cells in a body) to be more active. It suggests that low-intensity NIR PBM causes mitochondrial activity to increase and demonstrates the efficacy of low-intensity PBM.

In the final set of experiments, the incubating solution for the tissues was changed slightly. It produced effects that were opposite to that observed in the earlier experiment when microtubules were observed to reassemble. This experiment shows that PBM produces different outcomes when the solutions are changed, reflecting dynamic tissue properties in living organisms.

In summary, the experimental results at the University of Alberta show that mechanisms of PBM are even more complex than expected. There is more work to be done to fully understand the mechanisms and how their systems can be controlled. Vielight has plans for more research in this area, which may lead to personalized PBM parameters in the future. Our work continues! This paper can be accessed at: https:// www.frontiersin.org/articles/10.3389/ fmedt.2022.871196/full.

Vielight Plans for More Online Public Education

PBM is increasingly recognized for its potential to improve health and well-being. This opens the field to future research in understanding the complex and intriguing processes which our bodies undergo to heal themselves when given help from PBM. We receive increasing requests for education, particularly in response to the introduction of our sophisticated Neuro Pro device. Attendees of our first webinar on the potential of the Neuro Pro on March 31, 2022 expressed their appreciation. The webinar can be viewed here: https://www.youtube.com/watch?v=xiaVM68PQj0&. We plan to organize more teaching webinars on PBM, particularly regarding how it can help one’s mental health. In the meantime, due to increasing demands on our staff resources, we are likely to scale back our presence in conferences. Please, continue to follow us for further updates.

We welcome Dr. Mahroo Karimpoor

The latest addition to our research team is Dr. Mahroo Karimpoor, PhD, as a Research Scientist in Photobiomodulation and Cell Therapy and Tissue Engineering. Mahroo is also an expert meditator and will be involved in the areas of meditation and mindfulness. Her last engagement was in tissue engineering and related disciplines at University College, London, UK.

Recent Educational Media

These educational videos and podcast would be of interest to those interested in Vielight and PBM technology:
• Penijean Gracefire and Sanjay Manchanda – Neuro Pro Photobiomodulation – Discovering the Possibilities Webinar. March 31, 2022: https://www.youtube.com/watch?v=xiaVM68PQj0
• Lew Lim. Cognitive Enhance with Light Therapy. NuroFlex Podcast. March 8, 2022: https://open.spotify.com/episode/3xYC0B41rU0mWj0W31kmAy
• Lew Lim. Photobiomodulation – The Energy-based Path to Higher Consciousness and Wellness. Immersive Wellness Summit 2021, Quantum University. October 9, 2021: https://www.youtube.com/ watch?v=IkuevUXLR8k
• Lew Lim. A Pivotal Clinical Trial Evaluating a Home-used Photobiomodulation Device in the Treatment of COVID-19 Respiratory Symptoms. PBM 2021, October 1-3, 2021: https://www.youtube.com/watch?v=2j-3h1NrKSs
• Lew Lim. Quantum Elements in Brain Photobiomodulation: new discoveries and new theories. PBM 2021, October 1-3, 2021: https://www.youtube.com/watch?v=u2l1aepfcMo

1. A growing problem facing the elderly – age-related cognitive decline
2. Several factors of brain aging and age-related cognitive decline
3. Brain photobiomodulation (PBM) and mitochondrial function
4. Brain PBM and metabolic effects
5. Brain PBM and anti-inflammatory effects
6. Brain PBM leads to a reduction in neuronal excitotoxicity
7. Brain PBM increases cerebral vascularity and oxygenation
8. Published research – Brain PBM within elderly demographics

A growing problem facing the elderly – age-related cognitive decline.

Due to advances in medical technology, the elderly demographic is the fastest growing segment of the global population. Consequently, the side effects of natural age-related cognitive decline – such as slowed thinking, memory recall and low mental energy is an increasingly prevalent problem because of the growth of the elderly population and the negative qualitative impacts on their quality of life.

Source: United Nations, Department of Economic and Social Affairs, Population Division (2019). World Population Prospects 2019.

On the other hand, advancements in brain stimulation research combined with technological innovation has made longevity (or anti-aging) neurotechnology a promising proposition for  in the 21st century.

The question arises: how can brain photobiomodulation be used as a longevity biohacking tool to partially mitigate the negative side effects from brain aging, by augmenting certain physiological processes?

In this article, we’ll reference published research studies to explore how brain photobiomodulation could be used for longevity and anti-aging by improving neuronal mitochondrial function and overall enhanced holistic brain performance.

Please note that nothing known can reverse genetic aging and its negative effects, but lifestyle and technological interventions have the potential to lessen or mitigate some of aging’s negative effects.

Several factors of brain aging and age-related cognitive decline

Brain aging is a natural biological process that results in a decline in brain physiological functions. Multiple factors contribute to this phenomenon.

One of the notable factors of brain aging is a gradual decline in mitochondrial function within neurons. This leads to a decline in cognitive function and suboptimal brain performance because neurons experience a reduction in mitochondrial energy metabolism.

Additionally, a decrease in cerebral blood flow and oxygenation due to a loss in brain vascularity leads to a decline in cognitive function.^[19]

The aging brain is also characterized by an increase neuroinflammation.^[17] Scientists have linked neuroinflammation with cognitive decline and higher risks for age-related cognitive impairment.^[18]

What are mitochondria and neurons?

• Mitochondria are the batteries of the cell. These membrane-bound cell organelles (mitochondrion, singular) generate most of the chemical energy needed to power the cell’s biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP).
• Neurons are information messengers. Neurons, sometimes called nerve cells, make up around 10 percent of the brain; the rest consists of glial cells and astrocytes that support and nourish neurons. They use electrical impulses and chemical signals to transmit information between different areas of the brain, and between the brain and the rest of the nervous system.

Focusing on neuronal mitochondria and the aging process

Neuronal mitochondria play key roles in regulating the brain aging process. When their function declines, the production of adenosine triphosphate (ATP) is reduced, leading to a reduction in neuronal metabolism. Additionally, a decline in mitochondrial function leads to reduced activation of signaling pathways and transcription factors that modulate the expression of various proteins.^[1]

Note: Transcription factors regulate the transcription of genes— the process of copying into RNA during protein synthesis (quick fact: at least 10,000 different proteins make you what you are and keep you that way). Proteins are the building blocks of who you are.

Brain photobiomodulation and mitochondrial function

Brain photobiomodulation holds the potential to enhance mitochondrial function, partially mitigating the negative effects of aging.

The mechanism of photobiomodulation (PBM) is due to the ability of cells to absorb photons of red-to-near infrared light (620–1100 nm) by the mitochondria photoacceptor, cytochrome c oxidase (CCO).^[2]

Note: CCO is the fourth enzymatic complex of the mitochondrial respiratory chain and it catalyzes the reaction reducing oxygen into water, which is coupled to the production of metabolic energy in cells.

Figure 1: Activation of mitochondria cytochrome c oxidase through photobiomodulation

The mitochondrial biomechanisms of photobiomodulation

CCO upregulation

The absorption of red to NIR photons by mitochondria CCO triggers a series of cellular and physiological effects occur in the brain, also known as CCO upregulation.

Figure 2: The cascade effects of photobiomodulation

CCO upregulation leads to:

• A small increase in reactive oxygen species (ROS), which activate mitochondrial signaling pathways linked to neuroprotection. ^[3]
• An increase in nitric oxide (NO) which stimulate vasodilation and cerebral blood flow.^[4]
• An increase in ATP production ^[5]

Combined, these effects trigger and improve the activation of signaling pathways and transcription factors that modulate the long-term expression of various proteins and metabolic pathways in the brain.^[6] Additionally, electrophysiological effects on the human brain have also been demonstrated by PBM in older people.^{[7, 8]}

Metabolic effects and brain oxygenation

The metabolic effects of PBM in the elderly have been shown to increase cerebral blood flow (CBF) due to the increase in CCO activity, leading to an increase in brain oxygenation. Photobiomodulation of the prefrontal cortex was able to increase the resting-state EEG alpha, beta and gamma power, and more efficient prefrontal fMRI response, facilitating cognitive processing in the elderly. ^[8] Additionally, photobiomodulation of the Default Mode Network (DMN) has also been shown to increase cerebral perfusion due to an increase in mitochondrial activity. ^[9]

Brain PBM and anti-inflammatory effects

In addition to the above findings, PBM may be a promising strategy for improving aging brains because of its anti-inflammatory effects. ^{[10, 11]}

Brain PBM leads to a reduction in neuronal excitotoxicity

In 2022, researchers from the University of Alberta published a multi-layered study investigating the way that living cells, cellular structures, and components such as microtubules and tubulin respond to near-infrared photobiomodulation (NIR PBM) using the Vielight Neuro Alpha.

Their study showed that PBM balances excitatory stimulation with inhibition, indicating that PBM may reduce excitotoxicity which is relevant to the maintenance of a healthy brain. This study also showed that low-intensity PBM upregulates mitochondrial potential and improves physiological brain functions impaired due to trauma or neurodegeneration. ^[14]

Brain PBM increases cerebral vascularity and oxygenation

Aging is accompanied by changes in tissue structure, often resulting in functional decline. The blood vessels within the brain are no exception. As one ages, a decrease in blood flow to the brain is caused by a loss of cerebral vascularity, leading to cognitive decline when neurons cannot obtain sufficient oxygen.^[21] Brain photobiomodulation has also been shown to increase cerebral blood flow due to the vasodilation that occurs after the release of nitric oxide.^[20]

Figure 3: The beneficial effects of photobiomodulation

Summary

These findings are promising because as one gets older, mitochondrial function decreases, cerebral perfusion and oxygenation decreases^[12] , inflammation increases and brain vascularity decreases.

However, brain photobiomodulation has the potential to partially improve mitochondrial function, cerebral blood flow, brain vascularity and potentially, reduce inflammation.

Published research – Brain PBM within elderly demographics

In 2017, researchers from the Department of Psychology and Institute for Neuroscience, University of Texas at Austin found that brain photobiomodulation increases resting-state EEG alpha, beta and gamma power, promotes more efficient fMRI activity, and facilitates behavioral cognitive processing in middle-aged and older adults at risk for cognitive decline. No adverse effects were reported.

These findings support the potential of brain photobiomodulation to augment neurocognitive function and to combat aging-related and vascular disease-induced cognitive decline ^[13]

In 2019, Dr. Chao from the Center for Imaging of Neurodegenerative Diseases, San Francisco VA Medical Center conducted a study on patients in their 80s diagnosed with dementia. The NIR PBM treatments were administered by a study partner at home three times per week with the Vielight Neuro Gamma device. After 12 weeks, there were improvements in the ADAS-cog and NPI scores, increased cerebral perfusion and increased connectivity between the posterior cingulate cortex and lateral parietal nodes within the default-mode network in the PBM group. ^[15]

In 2021, researchers from the School of Medical Sciences, University of Sydney, discovered that measures of mobility, cognition, dynamic balance and fine motor skill were significantly improved with PBM treatment for 12 weeks and up to one year in a pilot study with 12 participants. Many individual improvements were above the minimal clinically important difference, the threshold judged to be meaningful for participants. Individual improvements varied but many continued for up to one year with sustained home treatment using the Vielight Neuro Gamma. There was a demonstrable Hawthorne Effect that was below the treatment effect. No side effects of the treatment were observed.

References

1. Jang, J. Y., Blum, A., Liu, J., & Finkel, T. (2018). The role of mitochondria in aging. The Journal of clinical investigation, 128(9), 3662–3670. https://doi.org/10.1172/JCI120842
2. Dompe, C., Moncrieff, L., Matys, J., Grzech-Leśniak, K., Kocherova, I., Bryja, A., Bruska, M., Dominiak, M., Mozdziak, P., Skiba, T., Shibli, J. A., Angelova Volponi, A., Kempisty, B., & Dyszkiewicz-Konwińska, M. (2020). Photobiomodulation-Underlying Mechanism and Clinical Applications. Journal of clinical medicine, 9(6), 1724. https://doi.org/10.3390/jcm9061724
3. Suski, J. M., Lebiedzinska, M., Bonora, M., Pinton, P., Duszynski, J., & Wieckowski, M. R. (2012). Relation between mitochondrial membrane potential and ROS formation. In Mitochondrial bioenergetics (pp. 183-205). Humana Press.
4. Wang X., Tian F., Soni S.S., Gonzalez-Lima F., Liu H. Interplay between up-regulation of cytochrome-c-oxidase and hemoglobin oxygenation induced by near-infrared laser. Sci. Rep. 2016;6:30540. doi: 10.1038/srep30540.
5. Hamblin M.R. Photobiomodulation for traumatic brain injury and stroke. J. Neurosci. Res. 2018;96:731–743. doi: 10.1002/jnr.24190.
6. Cardoso FDS, Mansur FCB, Lopes-Martins RÁB, Gonzalez-Lima F, Gomes da Silva S. Transcranial Laser Photobiomodulation Improves Intracellular Signaling Linked to Cell Survival, Memory and Glucose Metabolism in the Aged Brain: A Preliminary Study. Front Cell Neurosci. 2021 Sep 3;15:683127. doi: 10.3389/fncel.2021.683127. PMID: 34539346; PMCID: PMC8446546.
7. Wang, X., Dmochowski, J. P., Zeng, L., Kallioniemi, E., Husain, M., GonzalezLima, F., & Liu, H. (2019). Transcranial photobiomodulation with 1064-nm laser modulates brain electroencephalogram rhythms. Neurophotonics, 6(2), 025013.
8. Vargas E, Barrett DW, Saucedo CL, et al. Beneficial neurocognitive effects of transcranial laser in older adults. Lasers in medical science. 2017;32(5):1153–1162. [PubMed: 28466195]
9. Chao LL. Effects of Home Photobiomodulation Treatments on Cognitive and Behavioral Function, Cerebral Perfusion, and Resting-State Functional Connectivity in Patients with Dementia: A Pilot Trial. Photobiomodul Photomed Laser Surg. 2019 Mar;37(3):133-141. doi: 10.1089/photob.2018.4555. Epub 2019 Feb 13. PMID: 31050950.
10. Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 2017;4(3):337-361. doi: 10.3934/biophy.2017.3.337. Epub 2017 May 19. PMID: 28748217; PMCID: PMC5523874.
11. dos Santos Cardoso, F., Mansur, F.C.B., Araújo, B.H.S. et al.Photobiomodulation Improves the Inflammatory Response and Intracellular Signaling Proteins Linked to Vascular Function and Cell Survival in the Brain of Aged Rats. Mol Neurobiol 59, 420–428 (2022). https://doi.org/10.1007/s12035-021-02606-4
12. Braz, I. D., & Fisher, J. P. (2016). The impact of age on cerebral perfusion, oxygenation and metabolism during exercise in humans. The Journal of physiology, 594(16), 4471–4483. https://doi.org/10.1113/JP271081
13. Vargas E, Barrett DW, Saucedo CL, Huang LD, Abraham JA, Tanaka H, Haley AP, Gonzalez-Lima F. Beneficial neurocognitive effects of transcranial laser in older adults. Lasers Med Sci. 2017 Jul;32(5):1153-1162. doi: 10.1007/s10103-017-2221-y. Epub 2017 May 2. PMID: 28466195; PMCID: PMC6802936.
14. Staelens Michael, Di Gregorio Elisabetta, Kalra Aarat P., Le Hoa T., Hosseinkhah Nazanin, Karimpoor Mahroo, Lim Lew, Tuszyński Jack A. Near-Infrared Photobiomodulation of Living Cells, Tubulin, and Microtubules In Vitro, Frontiers in Medical Technology 4. 2022 May 04, https://doi.org/10.3389/fmedt.2022.871196, ISBN:2673-3129
15. Chao LL. Effects of Home Photobiomodulation Treatments on Cognitive and Behavioral Function, Cerebral Perfusion, and Resting-State Functional Connectivity in Patients with Dementia: A Pilot Trial. Photobiomodul Photomed Laser Surg. 2019 Mar;37(3):133-141. doi: 10.1089/photob.2018.4555. Epub 2019 Feb 13. PMID: 31050950.
16. Liebert A, Bicknell B, Laakso EL, Heller G, Jalilitabaei P, Tilley S, Mitrofanis J, Kiat H. Improvements in clinical signs of Parkinson’s disease using photobiomodulation: a prospective proof-of-concept study. BMC Neurol. 2021 Jul 2;21(1):256. doi: 10.1186/s12883-021-02248-y. PMID: 34215216; PMCID: PMC8249215.
17. Sparkman NL, Johnson RW. Neuroinflammation associated with aging sensitizes the brain to the effects of infection or stress. Neuroimmunomodulation. 2008;15(4-6):323-30. doi: 10.1159/000156474. Epub 2008 Nov 26. PMID: 19047808; PMCID: PMC2704383.
18. Simen AA, Bordner KA, Martin MP, Moy LA, Barry LC. Cognitive dysfunction with aging and the role of inflammation. Ther Adv Chronic Dis. 2011 May;2(3):175-95. doi: 10.1177/2040622311399145. PMID: 23251749; PMCID: PMC3513880.
19. Yang T, Sun Y, Lu Z, Leak RK, Zhang F. The impact of cerebrovascular aging on vascular cognitive impairment and dementia. Ageing Res Rev. 2017 Mar;34:15-29. doi: 10.1016/j.arr.2016.09.007. Epub 2016 Sep 28. PMID: 27693240; PMCID: PMC5250548.
20. Salgado AS, Zângaro RA, Parreira RB, Kerppers II. The effects of transcranial LED therapy (TCLT) on cerebral blood flow in the elderly women. Lasers in medical science. 2015;30(1):339– 346. doi: 10.1007/s10103-014-1669-2 [PubMed: 25277249]
21. Yang T, Sun Y, Lu Z, Leak RK, Zhang F. The impact of cerebrovascular aging on vascular cognitive impairment and dementia. Ageing Res Rev. 2017 Mar;34:15-29. doi: 10.1016/j.arr.2016.09.007. Epub 2016 Sep 28. PMID: 27693240; PMCID: PMC5250548.

Introduction

At Vielight, we work tirelessly to offer products that are helpful to improve brain functions. A large part of this relates to the use of photobiomodulation (PBM) to modulate brain waveforms. Here we share why this understanding is useful, starting with the neurofeedback practitioners’ perspective.

Neurofeedback training and the brain 

Every brain is unique. Neurofeedback practitioners know that our brains respond to external stimuli in a variety of ways. These sensory stimuli can be helpful in modifying the brain’s responses when those responses are abnormal.

Neurofeedback training is based the principle that the brain uses sensory inputs to learn. Repeated information patterns indicate to your brain how to best prioritize received information. They also teach the brain response strategies to help it to interact most effectively with its immediate environment.

During a neurofeedback session your brain will receive cues based on changes in its attention and arousal. After some repetition, your brain learns which cortical behaviors have greater impacts on auditory or visual feedback patterns. As it learns, the brain begins to generate more of those desired responses and behaviors. Instead of traditional psychological “stick and carrot” techniques, neurofeedback targets the brain directly by employing various forms of stimulation.

Furthermore, neurofeedback training helps to train the brain to react differently to a stimulus or a set of stimuli in order to change an individual’s reaction. Brain wave frequencies, or neural oscillations, can play important roles in this process because they are present during specific brain states.

Brain oscillations, neurofeedback training, and photobiomodulation

Neural oscillations and brain states

Every brain state is associated with a particular band of brain frequencies, or rhythms. These rhythms are called “neural oscillations” because they are created by a multitude of neurons communicating with each other. These neural oscillations or brain waves can be registered and measured using an electroencephalogram, or EEG.

There is a correlation between a brain state and the type and frequency of neural oscillations produced during this state. It is possible that by stimulating a particular brain wave frequency, brain activity associated with this frequency can be modulated. Research shows that transcranial photobiomodulation (tPBM) can be effective in stimulating and modulating the brain.

Interventional and non-interventional ways to affect brain oscillations

EEG is an important part in neurofeedback training. It is a useful, non-interventional method of capturing brain state data and allowing for its analysis. In addition to non-interventional tools like EEG, the neurofeedback training also requires interventional tools. Brain photobiomodulation is one such interventional tool offering a non-invasive form of brain stimulation and modulation using light energy.

While brain PBM can start a restorative biochemical reaction in the neurons, it can also affect the brain’s natural oscillations. It can help to increase or decrease these oscillations, stimulating the brain to change its response. To achieve this goal, the light that is emitted during a tPBM session is pulsed at a specific frequency that is similar to natural brain oscillations. The choice of the pulse rate depends on the issue at hand and on the desired outcome.

A neurofeedback specialist uses equipment to map brain frequencies with qEEG, or quantitative electroencephalogram. Such frequency mapping can be helpful in assessing some deficiencies and abnormalities in the brain’s responses. Furthermore, the brain frequency mapping provides an image of brain oscillations and their respective frequency bands. These brain wave bands are defined differently by different contributors to the field. However, they are most commonly classified into the following five frequency band categories: delta, theta, alpha, beta, and gamma.

What are unique brain wave frequencies?

Brain’s delta wave frequency band — 0.1 Hz to 4 Hz 

Delta frequencies fall in the range of around 0.1 Hz to 4 Hz, and constitute the lowest range of brain frequencies. Brain activity in this frequency range correlates with the states of deep sleep, along with some anomalous processes.

In addition to being present in stages 3 and 4 of sleep, delta frequencies are also commonly predominant in infants under one year. The delta waves are the slowest and have the highest amplitude. They help the brain to focus inwardly, while decreasing awareness of the outside environment. These waves are helpful in attaining a state of connection with the unconscious mind.

High-performing individuals are able to decrease their delta waves to attain top levels of performance. On the other hand, individuals who are unable to decrease their delta wave activity in the brain can experience difficulty focusing. For example, individuals with attention deficit disorder (ADD) usually experience elevated delta wave activity when attempting to focus. Therefore, individuals with ADD have limited ability to stay focused and pay attention. This inability to focus can occur in anyone who has abnormal and unsuppressed delta wave reactions.

The inability to regulate delta wave activity impedes an individual’s ability to react fast to external stimuli. It can also be the cause of an inability to navigate the outside world with ease.

Brain’s theta wave frequency band — 4 Hz to 8 Hz 

Brain oscillations in the theta waves frequency band fall between approximately 4 Hz and 8 Hz. The brain activity in this frequency range often correlates with creativity, emotions, and sensations. Theta brain frequencies are present during inwardly focused brain activity, as well as the transitional state between alertness and sleep. Theta oscillations are often prominent during states of creative activities, meditation, and spiritual contemplation.

Furthermore, activity in the theta range correlates with states of learning and memory creation and integration. It can also be present during anxious episodes.

In comparison with delta waves, theta waves are faster. However, despite representing faster brain activity, they are also present during sleep. Theta wave activity commonly correlates with distracted or dreamy states and experiences.

Brain’s alpha wave frequency band — 8 Hz to 12 Hz 

Brain oscillations in the alpha wave frequency band fall between approximately 8 Hz and 12 Hz. Alpha wave activity correlates with states that combine relaxation, alertness, and awareness. For example, the brain’s alpha wave activity is present during some stages of meditation. Alpha band activity is also associated with mental resourcefulness, while enhancing a general sense of relaxation.

During alpha wave activity, individuals can accomplish a variety of tasks more efficiently. Alpha brain oscillations promote a sense of calm, allowing the brain to prioritize and focus better. They are also commonly present in normal adults and teenagers in relaxed states. Alpha wave activity also correlates with a state of alertness, but it is absent when the brain is performing specific tasks.

Furthermore, the brain’s alpha oscillations are present during relaxed learning and while applying knowledge. They occur in both classroom and work environments.

It is possible to increase your brain’s alpha activity by doing deep breathing exercises, or simply by closing your eyes. If you wish to lower your alpha state, you could try doing a complex task, like a mathematical calculation. Alpha wave activity promotes the ability to easily switch between tasks while increasing inner awareness, balance, and calmness. It correlates with faster brain activity than that of delta and theta brain waves. Faster brain wave activity refers to activities in the states of alertness and the execution of cognitive tasks. Slow brain wave activity is present during dream-like and meditative states.

Read a published abstract of a study with our Neuro Alpha device on neural oscillations:
https://www.brainstimjrnl.com/article/S1935-861X(21)00491-5/

Brain’s beta wave frequency band — 13 Hz to 35 Hz 

Beta frequencies produce faster brain activity than alpha frequencies. Beta frequencies begin at about 13 Hz. This faster frequency occurs during a state of alertness and consciousness. If you are performing an analytical task with your eyes open, your brain’s beta oscillations are at work. This happens because communication among the neurons is increasing.

In general, when you are processing information about the world, beta wave activity is evident in the brain. This activity is present during various tasks ranging from mathematical problem solving to decision making.

Furthermore, because of its significant range, the beta frequency band consists of three sub-ranges — low beta, mid beta, and high beta.

Low Beta Frequency Band — 13 Hz to 15 Hz
The low beta frequency range activity is associated with a more relaxed and focused state.

Mid Beta Frequency Band — 15 Hz to 18 Hz
The mid beta frequency range activity is associated with alertness, mental activity, and focus.

High Beta Frequency Band — 18 Hz to 35 Hz
The high beta frequency range activity is associated with higher levels of alertness and even agitation.

Brain’s gamma wave frequency band — 35 Hz to 100 Hz 

The fastest of the five frequency bands is the gamma frequency. It is prominent when the brain is processing complex information that requires input from different parts of the brain. Intense thinking and problem solving are states that correlate with gamma wave activity. The brain oscillations in the gamma wave frequency band fall between approximately 35 Hz and 100 Hz.

Brain activity associated with a frequency of 40 Hz is of particular importance. The 40 Hz gamma wave activity is, presumably, present and needed for consolidation and complex processing of information from different parts of the brain. Whereas activity in this frequency range correlates with good memory performance, its deficiency correlates with learning issues and even disabilities.

Read a published study with our Neuro Gamma device on neural oscillations: https://www.nature.com/articles/s41598-019-42693-x.epdf

Using photobiomodulation to modulate brain waves 

Considering the importance of brain oscillations, Vielight offers several products that have been found to modulate brain waves using photobiomodulation. The Vielight Neuro Alpha device trains the brain for mainly alpha brain waveforms and improves basic brain network functions. The Neuro Gamma elevates the faster brain waves of beta and gamma, and downregulates the slower delta and theta waves. The new Vielight Neuro Pro device offers the versatility of delivering PBM in the range from 0 to 10,000 Hz.

Understanding the effects of brain oscillations can be helpful in analyzing, supporting, and improving brain wellness. As studies suggest, brain PBM is a non-invasive form of neurostimulation that can help to affect and modulate brain oscillations. PBM with light pulsing at specific frequencies can help modulate and normalize brain oscillations. Considering that brain oscillations represent neural activity, this means that brain PBM can affect neural activity.