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Brain on Light: The Science of Photobiomodulation

Updated: Aug 12, 2025

By Shannon Kasun, Neuroscience Specialist


For centuries, light was regarded as a source of healing. Ancient Greek physicians prescribed heliotherapy—sun exposure—for a variety of ailments, while traditional Chinese medicine viewed light as a vital force in restoring balance and vitality. Today, modern neuroscience is uncovering a scientific basis for those early intuitions—particularly when it comes to red and near-infrared light.


Known as photobiomodulation (PBM), this therapy uses red to near-infrared light (typically 620–800 nm) to stimulate biological processes at the cellular level. Originally studied for its applications in wound healing, skin rejuvenation, and hair growth, PBM is now gaining traction for its potential in enhancing brain health and cognitive performance.


PBM works by targeting cytochrome c oxidase, a key enzyme in the mitochondria—the part of the cell responsible for generating ATP, the body’s main energy molecule. When red or infrared light penetrates tissue and is absorbed by cytochrome oxidase c, it boosts ATP production. Given that the brain consumes approximately 20% of the body’s energy, enhancing ATP availability supports mitochondrial efficiency and overall cellular function in the brain (Yellen, 2018). 


In transcranial applications, PBM is delivered through the skull to brain tissue. Research shows this can stimulate neural activity, increase cerebral blood flow, promote synaptic connectivity, trigger the release of neurotrophic factors, and reduce oxidative stress (Nairus et al., 2024). Together, these biological effects may help explain observed improvements in cognitive performance post PBM treatment.


One study found that participants receiving transcranial infrared laser stimulation performed significantly better on the Wisconsin Card Sorting Task—a widely used test of executive function (Blanco et al., 2016). In this task, individuals are asked to sort cards based on a rule (such as color, shape, or number), but the rule changes periodically without warning. To succeed, participants must detect the change and adjust their strategy—making the test a strong measure of cognitive flexibility and problem-solving. Compared to a placebo group, those who received PBM made fewer errors and adjusted more quickly when the rule changed, indicating enhanced executive functioning and mental adaptability.


Another study demonstrated that PBM improved attention and global cognition in women with mild cognitive impairment (Papi et al., 2022). This points to its potential not just for healthy aging, but for intervening early in the trajectory toward dementia.


As cognitive decline becomes a growing concern with age, photobiomodulation offers a noninvasive, low-risk tool to support long-term brain health. Early research highlights meaningful brain benefits—making it a practical and promising addition to any longevity toolkit. Accessible, affordable, and easy to integrate, this light-based therapy may be one of the simplest ways to support your brain for the long haul.


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