> Scalp application of red and NIR light is a new application for LED technology. More than 30 years ago, however, it was observed in human cadaver studies that

> Scalp application of red and NIR light is a new application for LED technology. More than 30 years ago, however, it was observed in human cadaver studies that red (600 nm) and NIR (800–900nm) wavelengths could penetrate through the scalp and skull (∼ 1 cm). Two physiological changes associated with exposure of cells to red and NIR wavelengths of light are: 1) Increased production of adenosine triphosphate (ATP) by the mitochondria, and 2) Increased vasodilation/regional cerebral blood flow (rCBF), explained subsequently. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4043367/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4043367/