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 Vielight Neuros are designed to deliver near-infrared (NIR) light to the default mode network (DMN) of the brain.
This article will address the importance of the DMN and the value of targeting this network using photobiomodulation (PBM).
What is 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. ,
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 
- 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 
- 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 
- 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,   multiple sclerosis (MS)  and post-traumatic stress disorder (PTSD).  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.
|Neurologic Condition||Relation to the DMN||Vielight Photobiomodulation Studies|
|Parkinson’s Disease (AD)|
|Traumatic Brain Injury|
|Autism Spectrum Disorder|
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.
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. 
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. 
The precuneus is a small section of the superior parietal lobe and it is thought to be the core hub of the DMN. 
It is involved in several vital cognitive and visuospatial roles as outlined below.
• Self-consciousness (such as self awareness) 
• Spatial memory (remembering different locations as well as spatial relations between objects) 
• Episodic memory (remembering everyday events) 
• Source memory (remembering the origin of a memory or of knowledge) 
• Motor imagery.  Motor imagery is used in sport training as mental practice of action, neurological rehabilitation.
• Motor coordination. 
Motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended actions, like running or throwing.
Inferior parietal lobule (IPL)
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:
- Pattern learning
- Mathematical operations 
- 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.
It is highly connected and communicates with various brain networks simultaneously and is involved in diverse functions. 
Cerebral blood flow and metabolic rate in the pCC are approximately 40% higher than average across the brain. , 
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. 
- Working memory performance (abnormalities of the ventral pCC is related to a decline) 
Intrinsic control networks
The pCC has also been strongly implicated as a key part of several intrinsic control networks. , 
- The dorsal attention network(control of visual attention and eye movement)
- The frontoparietal control network (involved in executive motor control). 
The pCC has been found to be activated during self-related thinking and deactivated during meditation and undistracted, effortless mind wandering.  These results track closely with findings about the role of the pCC in the DMN.
The temporal lobes (TL) sit behind the ears and are the second largest lobe.
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.
The hippocampus can be found within the temporal lobes.
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  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/
- 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.
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- Cavanna AE (2007). “The precuneus and consciousness”. CNS Spectrums. 12(7): 545–52. doi:1017/S1092852900021295. PMID 17603406
- 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
- 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
- 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
- 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
- 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.
- 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
- 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
- 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
- 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
- Smith; Kosslyn (2007). Cognitive Psychology: Mind and Brain. New Jersey: Prentice Hall. pp. 21, 194–199, 349.
- 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
- 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
- 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
- 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
- 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.
- 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.
- 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.
- 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.
- 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
- 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.
- 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
- 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
- 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.
- 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
- 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.
- 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.
- 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.
- 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.
- 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.
- 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
- 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
- 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]
- Buckner RL., Carroll DC. Self-projection and the brain. Trends Cogn Sci. 2007;11:49–57. [PubMed] [Google Scholar]
- 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]