Hanli Liu, professor of bioengineering at the University of Texas at Arlington (UTA), and Jacek Dmochowski, assistant professor of bioengineering at City University of New York, are working to use LED light to improve memory and cognitive function in astronauts during space missions. The two are co-investigators on an $800,000 NASA grant that will deliver a light-based technology to increase the energy available to brain cells and improve astronaut performance. Hanli Liu, professor of bioengineering at the University of Texas at Arlington, focuses her research on NIR light delivery to the brain. Courtesy of the University of Texas at Arlington. With the NASA grant, Liu will investigate whether LEDs can replace lasers as the delivery method for NIR light. Specifically, she will find the wavelength range and duration necessary to produce the desired effects. “An LED or a cluster of LEDs have a much lower power density than a laser,” Liu told Photonics Media. “Consequently, the energy to be deposited on the cortical region of the human brain will be much smaller, possibly leading to a less effective outcome. One potential solution is to lengthen the illumination time.” Liu’s recent work has focused on the neurophysiological principle of noninvasive delivery of NIR light to improve human cognition. This research has led to an understanding of how light can stimulate mitochondria, which are the powerhouses within cells, into creating more oxygen in the brain to increase cerebral metabolism and mitigate memory loss. “Researchers have evidence that memory can be improved right after shining light on specific areas of the human brain for eight to 10 minutes,” Liu said in a UTA press release. “We are trying to demonstrate that if we can increase power in LEDs within safe levels, we can make LED light reach the cortex, just like a laser, but safer, smaller, easier and more portable to use.” In general, lasers are heavy and bulky and would take too much space in the cramped quarters of a spacecraft or space station. LEDs are lighter and smaller and could be attached to a headband or similar device easily stowable. Light delivered by LED is also safer to human eyes than light from lasers. LED light in the red and NIR ranges is already in widespread use for relieving pain and treating acne, although few researchers have rigorously investigated its feasibility and limitation for boosting and stimulating brain metabolism. “The benefit of using near-infrared light is that this range of light can penetrate deeper into tissue because hemoglobin molecules absorb/attenuate light or optical energy much less in the NIR region than in the visible region,” Liu told Photonics Media. Work done on the grant could play an important role in long-duration space travel.